N-Acetyl-D-mannosamine 6-phosphate is an intermediate in amino sugar metabolism and is a substrate for UDP-N-acetylglucosamine--peptide N-acetylglucosaminyltransferase, Bifunctional UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase, Alpha-N-acetylglucosaminidase and Exostosin-2. It can be generated from N-acetyl-neuraminate-9-phosphate or N-acetyl-D-mannosamine.


N-acetylneuraminic acid 9-phosphate

N-Acetylneuraminate 9-phosphate is an intermediate in Aminosugars metabolism. N-Acetylneuraminate 9-phosphate is the 4th to last step in the synthesis of colominate and is converted from N-Acetyl-D-mannosamine-6-phosphate via the enzyme N-Acylneuraminate-9-phosphate synthase (EC 2.5.1.57). It is then converted to N-Acetylneuraminate via the enzyme N-acylneuraminate-9-phosphatase(EC 3.1.3.29).


CTP

Cytidine 5'-(tetrahydrogen triphosphate) or CTP is a cytosine nucleotide containing three phosphate groups esterified to a ribose moiety at the 5' position. CTP is integral to the synthesis or mRNA, rRNA and tRNA through RNA polymerases. Cytidine triphosphate (CTP) is also critical to the synthesis of phosphatidylcholine via the enzyme CTP: phosphocholine cytidyltransferase. This reaction is the rate-limiting step in the synthesis of phosphatidylcholine.

Cytidine mono(tetrahydrogen triphosphate) (ester)


CMP-sialic acid

Cytidine monophosphate N-acetylneuraminic acid, also known as CMP acetylneuraminic acid or CMP-nana, belongs to the class of organic compounds known as pyrimidine nucleotide sugars. These are pyrimidine nucleotides bound to a saccharide derivative through the terminal phosphate group. Cytidine monophosphate N-acetylneuraminic acid is soluble (in water) and a moderately acidic compound (based on its pKa). Within the cell, cytidine monophosphate N-acetylneuraminic acid is primarily located in the cytoplasm, nucleus and golgi. Cytidine monophosphate N-acetylneuraminic acid exists in all living organisms, ranging from bacteria to humans. In humans, cytidine monophosphate N-acetylneuraminic acid is involved in the amino sugar metabolism pathway. Cytidine monophosphate N-acetylneuraminic acid is also involved in several metabolic disorders, some of which include the g(m2)-gangliosidosis: variant b, tay-sachs disease pathway, the sialuria or french type sialuria pathway, the salla disease/infantile sialic Acid storage disease pathway, and the tay-sachs disease pathway. Cytidine monophosphate N-acetylneuraminic acid is a nucleoside monophosphate sugar which donates N-acetylneuraminic acid to the terminal sugar of a ganglioside or glycoprotein.

Cytidine 5'-monophosphate n-acetylneuraminic acid

Cytidine monophosphate n-acetylneuraminic acid


lysosomal membrane

biolink:CellularComponent biolink:AnatomicalEntity biolink:PhysicalEssence biolink:OrganismalEntity biolink:SubjectOfInvestigation biolink:BiologicalEntity biolink:ThingWithTaxon biolink:NamedThing biolink:PhysicalEssenceOrOccurrent


Histidine

Histidine is an alpha-amino acid with an imidazole functional group. It is one of the 22 proteinogenic amino acids. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans and other mammals. It was initially thought that it was only essential for infants, but longer-term studies established that it is also essential for adults. Infants four to six months old require 33 mg/kg of histidine. It is not clear how adults make small amounts of histidine, and dietary sources probably account for most of the histidine in the body. Histidine is a precursor for histamine and carnosine biosynthesis. Inborn errors of histidine metabolism exist and are marked by increased histidine levels in the blood. Elevated blood histidine is accompanied by a wide range of symptoms, from mental and physical retardation to poor intellectual functioning, emotional instability, tremor, ataxia and psychosis. Histidine and other imidazole compounds have anti-oxidant, anti-inflammatory and anti-secretory properties (PMID: 9605177). The efficacy of L-histidine in protecting inflamed tissue is attributed to the capacity of the imidazole ring to scavenge reactive oxygen species (ROS) generated by cells during acute inflammatory response (PMID: 9605177). Histidine, when administered in therapeutic quantities is able to inhibit cytokines and growth factors involved in cell and tissue damage (US patent 6150392). Histidine in medical therapies has its most promising trials in rheumatoid arthritis where up to 4.5 g daily have been used effectively in severely affected patients. Arthritis patients have been found to have low serum histidine levels, apparently because of very rapid removal of histidine from their blood (PMID: 1079527). Other patients besides arthritis patients that have been found to be low in serum histidine are those with chronic renal failure. Urinary levels of histidine are reduced in pediatric patients with pneumonia. (PMID: 2084459). Asthma patients exhibit increased serum levels of histidine over normal controls (PMID: 23517038).  Serum histidine levels are lower and are negatively associated with inflammation and oxidative stress in obese women (PMID: 23361591).  Histidine supplementation has been shown to reduce insulin resistance, reduce BMI and fat mass and suppress inflammation and oxidative stress in obese women with metabolic syndrome.  Histidine appears to suppress pro-inflammatory cytokine expression, possibly via the NF-?B pathway, in adipocytes (PMID: 23361591). Low plasma concentrations of histidine are associated with protein-energy wasting, inflammation, oxidative stress, and greater mortality in chronic kidney disease patients (PMID: 18541578). Histidine may have many other possible functions because it is the precursor of the ubiquitous neurohormone-neurotransmitter histamine. Histidine increases histamine in the blood and probably in the brain. Low blood histamine with low serum histidine occurs in rheumatoid arthritis patients. Low blood histamine also occurs in some manic, schizophrenic, high copper and hyperactive groups of psychiatric patients. Histidine is a useful therapy in all patients with low histamine levels. (http://www.dcnutrition.com ).


Urocanic Acid

Urocanic acid is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e.g., pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. Researchers have found that c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity.


Tetrahydrofolic acid

Tetrahydrofolate is a soluble coenzyme (vitamin B9) that is synthesized de novo by plants and microorganisms, and absorbed from the diet by animals. It is composed of three distinct parts: a pterin ring, a p-ABA (p-aminobenzoic acid) and a polyglutamate chain with a number of residues varying between 1 and 8. Only the tetra-reduced form of the molecule serves as a coenzyme for C1 transfer reactions. In biological systems, the C1-units exist under various oxidation states and the different tetrahydrofolate derivatives constitute a family of related molecules named indistinctly under the generic term folate. (PMID 16042593). Folate is important for cells and tissues that rapidly divide. Cancer cells divide rapidly, and drugs that interfere with folate metabolism are used to treat cancer. Methotrexate is a drug often used to treat cancer because it inhibits the production of the active form, tetrahydrofolate. Unfortunately, methotrexate can be toxic, producing side effects such as inflammation in the digestive tract that make it difficult to eat normally. -- Wikipedia; Signs of folic acid deficiency are often subtle. Diarrhea, loss of appetite, and weight loss can occur. Additional signs are weakness, sore tongue, headaches, heart palpitations, irritability, and behavioral disorders. Women with folate deficiency who become pregnant are more likely to give birth to low birth weight and premature infants, and infants with neural tube defects. In adults, anemia is a sign of advanced folate deficiency. In infants and children, folate deficiency can slow growth rate. Some of these symptoms can also result from a variety of medical conditions other than folate deficiency. It is important to have a physician evaluate these symptoms so that appropriate medical care can be given. -- Wikipedia; Folinic acid is a form of folate that can help 'rescue' or reverse the toxic effects of methotrexate. Folinic acid is not the same as folic acid. Folic acid supplements have little established role in cancer chemotherapy. There have been cases of severe adverse effects of accidental substitution of folic acid for folinic acid in patients receiving methotrexate cancer chemotherapy. It is important for anyone receiving methotrexate to follow medical advice on the use of folic or folinic acid supplements. -- Wikipedia. Low concentrations of folate, vitamin B12, or vitamin B6 may increase the level of homocysteine, an amino acid normally found in blood. There is evidence that an elevated homocysteine level is an independent risk factor for heart disease and stroke. The evidence suggests that high levels of homocysteine may damage coronary arteries or make it easier for blood clotting cells called platelets to clump together and form a clot. However, there is currently no evidence available to suggest that lowering homocysteine with vitamins will reduce your risk of heart disease. Clinical intervention trials are needed to determine whether supplementation with folic acid, vitamin B12 or vitamin B6 can lower your risk of developing coronary heart disease. -- Wikipedia.

(6s)-tetrahydrofolate
(6s)-tetrahydrofolic acid
5,6,7,8-tetrahydrofolate
5,6,7,8-tetrahydrofolic acid
Tetra-h-folate
Tetrahydrafolate
Tetrahydrofolate
Tetrahydrofolic acid
Tetrahydropteroyl mono-l-glutamate
Tetrahydropteroylglutamate


Dihydrolipoate

Dihydrolipoic acid is an organic compound that is the reduced form of lipoic acid. This carboxylic acid features a pair of thiol groups. It is optically active but only the R-enantiomer is biochemically significant. The lipoic acid/dihydrolipoic acid pair participate in a variety of biochemical transformations.( from Wiki). Inside the cell, alpha lipoic acid is readily reduced or broken down to dihydrolipoic acid. Dihydrolipoic acid is even more potent than alpha lipoic acid, neutralizing free radicals, preventing them from causing harm. It directly destroys damaging superoxide radicals, hydroperoxy radicals and hydroxyl radicals. It has been shown in vitro that dihydrolipoate (DL-6,8-dithioloctanoic acid) has antioxidant activity against microsomal lipid peroxidation.Dihydrolipoate is tested for its neuroprotective activity using models of hypoxic and excitotoxic neuronal damage in vitro and rodent models of cerebral ischemia in vivo. Dihydrolipoate, similarly to dimethylthiourea, is able to protect neurons against ischemic damage by diminishing the accumulation of reactive oxygen species within the cerebral tissue.(PMID: 1345759).

6,8-bis-sulfanyloctanoate
6,8-bis-sulfanyloctanoic acid
6,8-dihydrothioctic acid
6,8-dimercapto-octanoate
6,8-dimercapto-octanoic acid
6,8-dimercaptooctanoate
6,8-dimercaptooctanoic acid
6,8-disulfanyloctanoate
6,8-disulfanyloctanoic acid
D,l-dihydrolipoate
D,l-dihydrolipoic acid
Dhla
Dihydro-dl-alpha-lipoate
Dihydro-dl-alpha-lipoic acid
Dihydro-lipoate
Dihydro-lipoic acid
Dihydro-thioctic acid
Dihydro-thiocytic acid
Dihydro-a-lipoate
Dihydro-a-lipoic acid
Dihydro-alpha-lipoate
Dihydro-alpha-lipoic acid
Dihydrolipoate
Dihydrolipoic acid
Dihydrothioctic acid
Dl-dihydro-a-6-thioctic acid
Dl-dihydro-alpha-6-thioctic acid
Reduced dl-6,8-thioctic acid
Reduced lipoate
Reduced lipoic acid
Reduced thioctic acid
6,8-bis-sulphanyloctanoate
6,8-bis-sulphanyloctanoic acid
6,8-dihydrothioctate
Dihydro-α-lipoate
Dihydro-α-lipoic acid
Dihydrothioctate


5,10-Methylene-THF is an intermediate in glycine, serine and threonine metabolism and one carbon metabolism. 5,10-CH2-THF can also be used as a coenzyme in the biosynthesis of thymidine. More specifically it is the C1-donor in the reactions catalyzed by thymidylate synthase and thymidylate synthase (FAD). It also acts as a coenzyme in the synthesis of serine from glycine via the enzyme serine hydroxymethyl transferase. 5,10-Methylene-THF is a substrate for Methylenetetrahydrofolate reductase. This enzyme converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. This reaction is required for the multistep process that converts the amino acid homocysteine to methionine. The body uses methionine to make proteins and other important compounds. 5,10-CH2-THF is a substrate for many enzymes including Bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase (mitochondrial), Aminomethyltransferase (mitochondrial), Serine hydroxymethyltransferase (mitochondrial), Methylenetetrahydrofolate reductase, C-1-tetrahydrofolate synthase (cytoplasmic), Serine hydroxymethyltransferase (cytosolic) and Thymidylate synthase.


Lipoic acid

Lipoic acid is a vitamin-like antioxidant that acts as a free-radical scavenger. Alpha-lipoic acid is also known as thioctic acid. It is a naturally occurring compound that is synthesized by both plants and animals. Lipoic acid contains two thiol groups which may be either oxidized or reduced. The reduced form is known as dihydrolipoic acid (DHLA). Lipoic acid (Delta E= -0.288) is therefore capable of thiol-disulfide exchange, giving it antioxidant activity. Lipoate is a critical cofactor for aerobic metabolism, participating in the transfer of acyl or methylamine groups via the 2-Oxoacid dehydrogenase (2-OADH) or alpha-ketoglutarate dehydrogenase complex. This enzyme catalyzes the conversion of alpha-ketoglutarate to succinyl CoA. This activity results in the catabolism of the branched chain amino acids (leucine, isoleucine and valine). Lipoic acid also participates in the glycine cleavage system(GCV). The glycine cleavage system is a multi-enzyme complex that catalyzes the oxidation of glycine to form 5,10 methylene tetrahydrofolate, an important cofactor in nucleic acid synthesis. Since Lipoic acid is an essential cofactor for many enzyme complexes, it is essential for aerobic life as we know it. This system is used by many organisms and plays a crucial role in the photosynthetic carbon cycle. Lipoic acid was first postulated to be an effective antioxidant when it was found it prevented vitamin C and vitamin E deficiency. It is able to scavenge reactive oxygen species and reduce other metabolites, such as glutathione or vitamins, maintaining a healthy cellular redox state. Lipoic acid has been shown in cell culture experiments to increase cellular uptake of glucose by recruiting the glucose transporter GLUT4 to the cell membrane, suggesting its use in diabetes. Studies of rat aging have suggested that the use of L-carnitine and lipoic acid results in improved memory performance and delayed structural mitochondrial decay. As a result, it may be helpful for people with Alzheimer's disease or Parkinson's disease. -- Wikipedia.

(+)-alpha-lipoic acid
(r)-(+)-lipoic acid
(r)-1,2-dithiolane-3-pentanoic acid
(r)-1,2-dithiolane-3-valeric acid
(r)-6,8-thioctic acid
Alpha-lipoic acid
Lipoic acid
R-la
Rla
Thioctic acid
Thioctic acid d-form
(r)-(+)-lipoate
R-(+)-lipoic acid


Ornithine

Ornithine is an amino acid produced in the urea cycle by the splitting off of urea from arginine. It is a central part of the urea cycle, which allows for the disposal of excess nitrogen. L-Ornithine is also a precursor of citrulline and arginine. In order for ornithine produced in the cytosol to be converted to citrulline, it must first cross the inner mitochondrial membrane into the mitochondrial matrix where it is carbamylated by ornithine transcarbamylase. This transfer is mediated by the mitochondrial ornithine transporter (SLC25A15; AF112968; ORNT1). Mutations in the mitochondrial ornithine transporter result in hyperammonemia, hyperornithinemia, homocitrullinuria (HHH) syndrome, a disorder of the urea cycle. (PMID 16256388) The pathophysiology of the disease may involve diminished ornithine transport into mitochondria, resulting in ornithine accumulation in the cytoplasm and reduced ability to clear carbamoyl phosphate and ammonia loads. (OMIM 838970).

(+)-s-ornithine
(s)-2,5-diaminopentanoate
(s)-2,5-diaminopentanoic acid
(s)-ornithine
(s)-a,d-diaminovalerate
(s)-a,d-diaminovaleric acid
5-amino-l-norvaline
L-(-)-ornithine
L-ornithine
(s)-2,5-diaminovaleric acid
(s)-alpha,delta-diaminovaleric acid
(s)-2,5-diaminovalerate
(s)-a,delta-diaminovalerate
(s)-a,delta-diaminovaleric acid
(s)-alpha,delta-diaminovalerate
(s)-α,δ-diaminovalerate
(s)-α,δ-diaminovaleric acid
(s)-a,δ-diaminovalerate
(s)-a,δ-diaminovaleric acid


Glutamic gamma-semialdehyde is the metabolic precursor for proline biosynthesis. The conversion from L-Glutamate, an ATP- and NADPH-dependent reaction, is catalyzed by the enzyme Delta-1-pyrroline-5-carboxylate synthetase (P5CS) (OMIM 138250). L-Glutamic-gamma-semialdehyde can also be converted to or be formed from the amino acids L-ornithine (EC 2.6.1.13) and L-proline (EC 1.5.99.8 and EC 1.5.1.2). It is also one of the few metabolites that can be a precursor to other metabolites of both the urea cycle and the citric acid cycle (BioCyc).

Glutamate-semialdehyde
Glutamic gamma-semialdehyde
L-glutamate 5-semialdehyde
L-glutamate-gamma-semialdehyde
L-glutamate-5-semialdehyde
L-glutamic-gamma-semialdehyde
5-oxo-l-norvaline
L-glutamate gamma-semialdehyde
L-glutamic acid 5-semialdehyde
L-glutamate g-semialdehyde
L-glutamate γ-semialdehyde
L-glutamic acid g-semialdehyde
L-glutamic acid gamma-semialdehyde
L-glutamic acid γ-semialdehyde


Proline

L-proline is one of the twenty amino acids used in living organisms as the building blocks of proteins. Proline is sometimes called an imino acid, although the IUPAC definition of an imine requires a carbon-nitrogen double bond. Proline is a non-essential amino acid that is synthesized from glutamic acid. It is an essential component of collagen and is important for proper functioning of joints and tendons. Proline is derived from the amino acid L-glutamate in which glutamate-5-semialdehyde is first formed by glutamate 5-kinase and glutamate-5-semialdehyde dehydrogenase (which requires NADH or NADPH). This semialdehyde can then either spontaneously cyclize to form 1-pyrroline-5-carboxylic acid, which is reduced to proline by pyrroline-5-carboxylate reductase, or turned into ornithine by ornithine aminotransferase, followed by cyclization by ornithine cyclodeaminase to form proline. L-Proline has been found to act as a weak agonist of the glycine receptor and of both NMDA and non-NMDA ionotropic glutamate receptors. It has been proposed to be a potential endogenous excitotoxin/neurotoxin. Studies in rats have shown that when injected into the brain, proline non-selectively destroys pyramidal and granule cells (PMID: 3409032). Therefore, under certain conditions proline can act as a neurotoxin and a metabotoxin. A neurotoxin causes damage to nerve cells and nerve tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of proline are associated with at least five inborn errors of metabolism, including hyperprolinemia type I, hyperprolinemia type II, iminoglycinuria, prolinemia type II, and pyruvate carboxylase deficiency. People with hyperprolinemia type I often do not show any symptoms even though they have proline levels in their blood between 3 and 10 times the normal level. Some individuals with hyperprolinemia type I exhibit seizures, intellectual disability, or other neurological or psychiatric problems. Hyperprolinemia type II results in proline levels in the blood between 10 and 15 times higher than normal, and high levels of a related compound called pyrroline-5-carboxylate. Hyperprolinemia type II has signs and symptoms that vary in severity, and is more likely than type I to involve seizures or intellectual disability.

(-)-(s)-proline
(-)-2-pyrrolidinecarboxylate
(-)-2-pyrrolidinecarboxylic acid
(-)-proline
(s)-(-)-proline
(s)-(-)-pyrrolidine-2-carboxylate
(s)-(-)-pyrrolidine-2-carboxylic acid
(s)-2-carboxypyrrolidine
(s)-2-pyrralidinecarboxylate
(s)-2-pyrralidinecarboxylic acid
(s)-2-pyrrolidinecarboxylate
(s)-2-pyrrolidinecarboxylic acid
(s)-proline
2-pyrrolidinecarboxylate
2-pyrrolidinecarboxylic acid
Proline
(2s)-pyrrolidine-2-carboxylic acid
(s)-pyrrolidine-2-carboxylic acid
L-(-)-proline
L-alpha-pyrrolidinecarboxylic acid
L-prolin
L-pyrrolidine-2-carboxylic acid
P
Prolina
Prolinum
(2s)-pyrrolidine-2-carboxylate
(s)-pyrrolidine-2-carboxylate
L-a-pyrrolidinecarboxylate
L-a-pyrrolidinecarboxylic acid
L-alpha-pyrrolidinecarboxylate
L-α-pyrrolidinecarboxylate
L-α-pyrrolidinecarboxylic acid
L-pyrrolidine-2-carboxylate


Hydroxyproline

4-Hydroxyproline (hydroxyproline or Hyp) is a major component of the protein collagen. Hydroxyproline is produced by hydroxylation of the amino acid proline and is, therefore, a post-translationally modified amino acid. Hydroxyproline and proline play key roles for collagen stability. In particular, they permit the sharp twisting of the collagen helix. Hydroxyproline is found in few proteins other than collagen. The only other mammalian protein which includes hydroxyproline is elastin. For this reason, hydroxyproline content has been used as an indicator to determine collagen and/or gelatin amount in tissue or biological samples. Increased serum and urine levels of hydroxyproline have been found in Paget's disease (PMID: 436278). Hydroxyproline (Hyp) content in biological fluids is used as a parameter of collagen catabolism, especially bone resorption or tissue degradation. Bedridden and elderly individuals show significantly elevated serum levels of hydroxyproline in comparison to normal, active individuals (PMID: 10706420). Elevated levels of urinary hydroxyproline are also indicative of muscle damage (PMID: 21988268). Increased reactive oxygen species (ROS) are also known to accelerate collagen degradation. Hydroxyproline levels increase in cases of depression and stress (PMID: 21483218). 4-Hydroxyproline is found to be associated with Alzheimer's disease, and also hydroxyprolinemia and iminoglycinuria which are both inborn errors of metabolism. 4-Hydroxyproline is also involved in metabolic disorders such as hyperprolinemia type I, hyperornithinemia with gyrate atrophy (HOGA), L-arginine:glycine amidinotransferase deficiency, creatine deficiency, and guanidinoacetate methyltransferase deficiency. A deficiency in ascorbic acid can result in impaired hydroxyproline formation (PubChem). trans-4-Hydroxy-L-proline is a biomarker for the consumption of processed meat.


1-pyrroline-3-hydroxy-5-carboxylic acid

Pyrroline hydroxycarboxylic acid is a metabolite identified in the urine of patients with type II hyperprolinemia. (OMIM 239510). The urinary excretion of Pyrroline hydroxycarboxylic acid increased in hyperprolinemic patients but not in healthy controls during oral loading of hydroxyproline and hydroxyproline-ornithine. (PMID: 533224). Hyperprolinemia type II (HP II) is a rare inherited metabolic disease due to the deficiency of pyroline-5-carboxylate dehydrogenase. It is generally believed to be a benign condition although some patients have neurological problems such as refractory convulsions. (PMID: 15214748). The oxidation of pyrroline-carboxylate generates glutamate and pyrroline-hydroxycarboxylate, a reaction catalyzed by hydroxyproline oxidase (PMID: 500817).


Glycocyamine

Guanidoacetic acid is a metabolite in the Urea cycle and metabolism of amino groups, and in the metabolic pathways of several amino acids. This includes glycine, serine, threonine, arginine and proline metabolism. Guanidinoacetic acid is also a precursor of creatine, an essential substrate for muscle energy metabolism.


Adomet

S-Adenosylmethionine (CAS: 29908-03-0), also known as SAM or AdoMet, is a physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in the treatment of chronic liver disease (From Merck, 11th ed). S-Adenosylmethionine is a natural substance present in the cells of the body. It plays a crucial biochemical role by donating a one-carbon methyl group in a process called transmethylation. S-Adenosylmethionine, formed from the reaction of L-methionine and adenosine triphosphate catalyzed by the enzyme S-adenosylmethionine synthetase, is the methyl-group donor in the biosynthesis of both DNA and RNA nucleic acids, phospholipids, proteins, epinephrine, melatonin, creatine, and other molecules.


S-adenosyl-L-homocysteine

S-Adenosyl-L-homocysteine (SAH) is formed by the demethylation of S-adenosyl-L-methionine. S-Adenosylhomocysteine (AdoHcy or SAH) is also the immediate precursor of all of the homocysteine produced in the body. The reaction is catalyzed by S-adenosylhomocysteine hydrolase and is reversible with the equilibrium favoring formation of SAH. In vivo, the reaction is driven in the direction of homocysteine formation by the action of the enzyme adenosine deaminase which converts the second product of the S-adenosylhomocysteine hydrolase reaction, adenosine, to inosine. Except for methyl transfer from betaine and from methylcobalamin in the methionine synthase reaction, SAH is the product of all methylation reactions that involve S-adenosylmethionine (SAM) as the methyl donor. Methylation is significant in epigenetic regulation of protein expression via DNA and histone methylation. The inhibition of these SAM-mediated processes by SAH is a proven mechanism for metabolic alteration. Because the conversion of SAH to homocysteine is reversible, with the equilibrium favoring the formation of SAH, increases in plasma homocysteine are accompanied by an elevation of SAH in most cases. Disturbances in the transmethylation pathway indicated by abnormal SAH, SAM, or their ratio have been reported in many neurodegenerative diseases, such as dementia, depression, and Parkinson's disease (PMID: 18065573, 17892439). Therefore, when present in sufficiently high levels, S-adenosylhomocysteine can act as an immunotoxin and a metabotoxin. An immunotoxin disrupts, limits the function, or destroys immune cells. A metabotoxin is an endogenous metabolite that causes adverse health effects at chronically high levels. Chronically high levels of S-adenosylhomocysteine are associated with S-adenosylhomocysteine (SAH) hydrolase deficiency and adenosine deaminase deficiency. S-Adenosylhomocysteine forms when there are elevated levels of homocysteine and adenosine. S-Adenosyl-L-homocysteine is a potent inhibitor of S-adenosyl-L-methionine-dependent methylation reactions. It is toxic to immature lymphocytes and can lead to immunosuppression (PMID: 221926).


Creatine

Creatine is an amino acid that occurs in vertebrate tissues and in urine. In muscle tissue, creatine generally occurs as phosphocreatine. Creatine is excreted as creatinine in the urine. Creatine functions as part of the cell's energy shuttle. The high energy phosphate group of ATP is transferred to creatine to form phosphocreatine in the following reaction: Cr + ATP <-> PCr + ADP. This reaction is reversibly catalyzed by creatine kinase. In the human body, creatine is synthesized mainly in the liver by the use of parts from three different amino acids: arginine, glycine, and methionine. 95% of it is later stored in the skeletal muscles and the rest is stored in the brain, heart, and testes.


Phosphocreatine

Phosphocreatine undergoes irreversible cyclization and dehydration to form creatinine at a fractional rate of 0.026 per day, thus forming approximately 2 g creatinine/day in an adult male. This is the amount of creatine that must be provided either from dietary sources or by endogenous synthesis to maintain the body pool of (creatine and) phosphocreatine. Creatine is an amino acid that plays a vital role as phosphocreatine in regenerating adenosine triphosphate in skeletal muscle to energize muscle contraction. Creatine is phosphorylated to phosphocreatine in muscle in a reaction that is catalyzed by the enzyme creatine kinase. This enzyme is in highest concentration in muscle and nerve. Oral administration increases muscle stores. During the past decade, creatine has assumed prominence as an ergogenic (and legal) aid for professional and elite athletes. Most (~ 95%) of the total body creatine-phosphocreatine pool is in muscle (more in skeletal muscle than in smooth muscle) and amounts to 120 g (or 925 mmol) in a 70 kg adult male. Approximately 60-67% of the content in resting muscle is in the phosphorylated form. This generates enough ATP at the myofibrillar apparatus to power about 4 seconds of muscle contraction in exercise. Phosphocreatine reacts with ADP to yield ATP and creatine; the reversible reaction is catalyzed by creatine kinase. phosphocreatine is the chief store of high-energy phosphates in muscle. Thus, this reaction, which permits the rephosphorylation of ADP to ATP, is the immediate source of energy in muscle contraction. During rest, metabolic processes regenerate phosphocreatine stores. In normal muscle, ATP that is broken down to ADP is immediately rephosphorylated to ATP. Thus, phosphocreatine serves as a reservoir of ATP-synthesizing potential. phosphocreatine is the only fuel available to precipitously regenerate ATP during episodes of rapid fluctuations in demand. The availability of phosphocreatine likely limits muscle performance during brief, high-power exercise, i.e., maximal exercise of short duration. With near maximal isometric contraction, the rate of utilization of phosphocreatine declines after 1-2 seconds of contraction, prior to the glycolysis peak at approximately 3 seconds. (PMID: 10079702, Nutr Rev. 1999 Feb;57(2):45-50.).


Urea

Urea is a highly soluble organic compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids. Urea is formed in a cyclic pathway known simply as the urea cycle. In this cycle, amino groups donated by ammonia and L-aspartate are converted to urea. Urea is essentially a waste product; it has no physiological function. It is dissolved in blood (in humans in a concentration of 2.5 - 7.5 mmol/liter) and excreted by the kidney in the urine. In addition, a small amount of urea is excreted (along with sodium chloride and water) in human sweat.

Arf
Alphadrate
B-i-k
Bromisovalum
Bubber shet
Calmurid
Calmurid hc
Carbaderm
Carbamide
Carbamide resin
Carbonyl diamide
Carbonyl diamine
Carbonyldiamide
Carbonyldiamine
Carmol
Helicosol
Hyanit
Isourea
Keratinamin
Keratinamin kowa
Mocovina
Onychomal
Panafil
Ure
Urea
Ureaphil
Ureophil
Beta-i-k
E927b
H2nc(o)nh2
Harnstoff
Karbamid
Ur
Uree


D-Proline

D-proline is an isomer of the naturally occurring amino acid, L-Proline. D-amino acids have been found in relatively high abundance in human plasma and saliva (PMID: 16480744). These amino acids may be of bacterial origin, but there is also evidence that they are endogenously produced through amino acid racemase activity (PMID: 1426150).


1-Pyrroline-2-carboxylic acid, also known as delta1-pyrroline 2-carboxylate, belongs to the class of organic compounds known as pyrrolines. Pyrrolines are compounds containing a pyrroline ring, which is a five-member unsaturated aliphatic ring with one nitrogen atom and four carbon atoms. 1-Pyrroline-2-carboxylic acid is slightly soluble (in water) and a weakly acidic compound (based on its pKa). In humans, 1-pyrroline-2-carboxylic acid is involved in the D-arginine and D-ornithine metabolism pathway and the arginine and proline metabolism pathway. 1-Pyrroline-2-carboxylic acid is also involved in several metabolic disorders, some of which include the hyperprolinemia type II pathway, the hyperornithinemia with gyrate atrophy (hoga) pathway, the prolinemia type II pathway, and the hyperprolinemia type I pathway. 1-Pyrroline-2-carboxylic acid is a terminal product of D-proline metabolism. Specifically D-proline is converted to 1-Pyrroline-2-carboxylic acid via D-amino acid oxidase. This spontaneously breaks down to 2-oxo-5-amino-valerate.


4-hydroxy-1-pyrroline-2-carboxylic acid

Much or all of the pyrrole-2-carboxylate (PCA) in human urine may be formed in urine from a labile precursor, presumably delta(1)-pyrroline-4-hydroxy-2-carboxylate. Normal human values for endogenous urinary PCA in 16 individuals averaged 0.51 mumol/day, with a range of 0.20-1.3 mumol and a SD of 0.31 mumol. The probable source of human PCA is free hydroxy-L-proline, as inferred from the high value for PCA in the urine of a subject with hereditary hydroxyprolinemia, and from the threeto eightfold elevation in PCA excretion by two normal subjects after a large oral load of hydroxyl-L-proline. (PMID: 4430715).


4-Hydroxy-L-glutamic acid is an intermediate in the metabolism of gamma-hydroxyglutamic acid. Specifically 4-Hydroxy-L-glutamic acid combines with 2-oxoglutarate to produce 4-hydroxy-2-oxoglutarate and glutamate. The reaction can be described as: 4-Hydroxy-L-glutamate + 2-Oxoglutarate <=> 4-Hydroxy-2-oxoglutarate + L-Glutamate. This reaction is catalyzed by 4-hydroxyglutamate aminotransferase (PMID 13948827).


L-4-hydroxyglutamic semialdehyde

L-4-Hydroxyglutamate semialdehyde is an intermediate in Arginine and proline metabolism. L-4-Hydroxyglutamate semialdehyde is the 4th to last step in the synthesis of Glyoxylate and is converted from L-erythro-4-Hydroxyglutamate via the enzyme 1-pyrroline-5-carboxylate dehydrogenase (EC 1.5.1.12). It is then converted to L-1-Pyrroline-3-hydroxy-5-carboxylate via enzymtic reaction.


4-hydroxy-2-oxoglutaric acid

4-Hydroxy-2-oxoglutaric acid, also known as 2-keto-4-hydroxyglutarate or 4-hydroxy-2-ketoglutarate, belongs to the class of organic compounds known as gamma-keto acids and derivatives. These are organic compounds containing an aldehyde substituted with a keto group on the C4 carbon atom. 4-Hydroxy-2-oxoglutaric acid is soluble (in water) and a moderately acidic compound (based on its pKa). Within the cell, 4-hydroxy-2-oxoglutaric acid is primarily located in the mitochondria. 4-Hydroxy-2-oxoglutaric acid exists in all living organisms, ranging from bacteria to humans. In humans, 4-hydroxy-2-oxoglutaric acid is involved in the arginine and proline metabolism pathway. 4-Hydroxy-2-oxoglutaric acid is also involved in several metabolic disorders, some of which include guanidinoacetate methyltransferase deficiency (gamt deficiency), ornithine aminotransferase deficiency (oat deficiency), the hyperprolinemia type I pathway, and the hyperornithinemia-hyperammonemia-homocitrullinuria [HHH-syndrome] pathway. 4-Hydroxy-2-ketoglutaric acid is a substrate for Fructose-bisphosphate aldolase A.


N(omega)-Hydroxyarginine is a product of the arginine-nitric oxide pathway, and is the first intermediate in the process catalyzed by nitric oxide synthase (NOS) (EC 1.14.13.99). NOS is a heme protein that catalyzes the oxygenation of L-arginine in the presence of NADPH to form nitric oxide and citrulline. N(omega)-Hydroxyarginine appears to interfere with cell proliferation/cell growth by inhibiting arginase, a binuclear Mn(2+) metalloenzyme that catalyzes the hydrolysis of L-arginine to L-ornithine and urea (EC 3.5.3.1). Arginase has 6R-tetrahydrobiopterin (H4B) as an enzyme-bound cofactor (PMID: 11259671, 11258880, 14504282, 9735327).


Nitric Oxide

The biologically active molecule nitric oxide (NO) is a simple, membrane-permeable gas with unique chemistry. It is formed by the conversion of L-arginine to L-citrulline, with the release of NO. The enzymatic oxidation of L-arginine to L-citrulline takes place in the presence of oxygen and NADPH using flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), heme, thiol, and tetrahydrobiopterin as cofactors. The enzyme responsible for the generation of NO is nitric oxide synthase (E.C. 1.7.99.7; NOS). Three NOS isoforms have been described and shown to be encoded on three distinct genes: neuronal NOS (nNOS, NOS type I), inducible NOS (NOS type II), and endothelial NOS (eNOS, NOS type III). Two of them are constitutively expressed and dependent on the presence of calcium ions and calmodulin to function (nNOS and eNOS), while iNOS is considered non-constitutive and calcium-independent. However, experience has shown that constitutive expression of nNOS and eNOS is not as rigid as previously thought (i.e. either present or absent), but can be dynamically controlled during development and in response to injury. Functionally, NO may act as a hormone, neurotransmitter, paracrine messenger, mediator, cytoprotective molecule, and cytotoxic molecule. NO has multiple cellular molecular targets. It influences the activity of transcription factors, modulates upstream signaling cascades, mRNA stability and translation, and processes the primary gene products. In the brain, many processes are linked to NO. NO activates its receptor, soluble guanylate cyclase by binding to it. The stimulation of this enzyme leads to increased synthesis of the second messenger, cGMP, which in turn activates cGMP-dependent kinases in target cells. NO exerts a strong influence on glutamatergic neurotransmission by directly interacting with the N-methyl-D-aspartate (NMDA) receptor. Neuronal NOS is connected to NMDA receptors (see below) and sharply increases NO production following activation of this receptor. Thus, the level of endogenously produced NO around NMDA synapses reflects the activity of glutamate-mediated neurotransmission. However, there is recent evidence showing that non-NMDA glutamate receptors (i.e. AMPA and type I metabotropic receptors) also contribute to NO generation. Besides its influence on glutamate, NO is known to have effects on the storage, uptake and/or release of most other neurotransmitters in the CNS (acetylcholine, dopamine, noradrenaline, GABA, taurine, and glycine) as well as of certain neuropeptides. Finally, since NO is a highly diffusible molecule, it may reach extrasynaptic receptors at target cell membranes that are some distance away from the place of NO synthesis. NO is thus capable of mediating both synaptic and nonsynaptic communication processes. NO is a potent vasodilator (a major endogenous regulator of vascular tone), and an important endothelium-dependent relaxing factor. NO is synthesized by NO synthases (NOS) and NOS are inhibited by asymmetrical dimethylarginine (ADMA). ADMA is metabolized by dimethylarginine dimethylaminohydrolase (DDAH) and excreted in the kidneys. Lower ADMA levels in pregnant women compared to non-pregnant controls suggest that ADMA has a role in vascular dilatation and blood pressure changes. Several studies show an increase in ADMA levels in pregnancies complicated with preeclampsia. Elevated ADMA levels in preeclampsia are seen before clinical symptoms have developed; these findings suggest that ADMA has a role in the pathogenesis of preeclampsia. In some pulmonary hypertensive states such as ARDS, the production of endogenous NO may be impaired. Nitric oxide inhalation selectively dilates the pulmonary circulation. Significant systemic vasodilation does not occur because NO is inactivated by rapidly binding to hemoglobin. In an injured lung with pulmonary hypertension, inhaled NO produces local vasodilation of well-ventilated lung units and may "steal" blood flow away from unventilated regions. This reduces intrapulmonary shunting and may improve systemic arterial oxygenation. Nitric oxide is a chemical mediator fundamental in the maintenance of adequate tissue perfusion and effective cardiovascular function. The use of nitrates is well established as pharmacological agents but it is only recently that it has been recognized that they act as a source of nitric oxide (PMID: 16966108, 8752507, 17181668, 16005189). Nitric oxide is used as a food additive (EAFUS: Everything Added to Food in the United States).

Mononitrogen monoxide
Nitric oxide
Nitrogen monoxide
Nitrogen oxide
Nitrogen protoxide
Nitrosyl hydride
Nitrosyl radical
Nitroxide radical
Nitroxyl
(no)(.)
[no]
Edrf
Endothelium-derived relaxing factor
Monoxido de nitrogeno
Monoxyde d'azote
Nitrogen monooxide
Nitrosyl
No
(.)no
No(.)
Oxido de nitrogeno(ii)
Oxido nitrico
Oxyde azotique
Oxyde nitrique
Stickstoff(ii)-oxid
Stickstoffmonoxid


Ferroheme

Heme is the color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins. A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. Not all porphyrins contain iron, but a substantial fraction of porphyrin-containing metalloproteins have heme as their prosthetic subunit; these are known as hemoproteins.

(protoporphyrinato)iron
Ferroheme
Ferroheme b
Ferroprotoheme
Ferroprotoporphyrin
Ferroprotoporphyrin ix
Ferrous protoheme
Ferrous protoheme ix
Haem
Hem
Heme
Iron protoporphyrin
Iron protoporphyrin ix
Iron(ii) protoporphyrin ix
Protoferroheme
Protohaem
Protoheme
Protoheme ix
Reduced hematin


FMN

Flavin mononucleotide (FMN), or riboflavin-5?-phosphate, is a biomolecule produced from riboflavin (vitamin B2) by the enzyme riboflavin kinase and functions as prosthetic group of various oxidoreductases including NADH dehydrogenase as well as cofactor in biological blue-light photo receptors. During the catalytic cycle, the reversible interconversion of oxidized (FMN), semiquinone (FMNH) and reduced (FMNH2) forms occurs in the various oxidoreductases. FMN is a stronger oxidizing agent than NAD and is particularly useful because it can take part in both one- and two-electron transfers. Flavin mononucleotide is also used as an orange-red food colour additive. It is the principal form in which riboflavin is found in cells and tissues.

Fmn
Flanin
Flavine mononucleotide
Flavol
Riboflavin
Riboflavin 5'-monophosphate
Riboflavin 5'-phosphate
Riboflavin mononucleotide
Riboflavin monophosphate
Riboflavin phosphate
Riboflavin-5'-phosphate na
Riboflavin-5-phosphate
Riboflavine 5'-monophosphate
Riboflavine 5'-phosphate
Riboflavine dihydrogen phosphate
Riboflavine monophosphate
Riboflavine phosphate
Riboflavine-5'-phosphate
Vitamin b2 phosphate
Flavin mononucleotide
Riboflavin 5'-(dihydrogen phosphate)


Tetrahydrobiopterin or BH4 is a cofactor in the synthesis of nitric oxide. In fact it is used by all three human nitric-oxide synthases (NOS) eNOS, nNOS, and iNOS as well as the enzyme glyceryl-ether monooxygenase. It is also essential in the conversion of phenylalanine to tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine to L-dopa by the enzyme tyrosine hydroxylase; and conversion of tryptophan to 5-hydroxytryptophan via tryptophan hydroxylase. Specifically, tetrahydrobiopterin is a cofactor for tryptophan 5-hydroxylase 1, tyrosine 3-monooxygenase, and phenylalanine hydroxylase all of which are essential for the formation of the neurotransmitters dopamine, noradrenaline and adrenaline. Tetrahydrobiopterin has been proposed to be involved in promotion of neurotransmitter release in the brain and the regulation of human melanogenesis. A defect in BH4 production and/or a defect in the enzyme dihydropteridine reductase (DHPR) causes phenylketonuria type IV, as well as dopa-responsive dystonias. BH4 is also implicated in Parkinson's disease, Alzheimer's disease and depression. Tetrahydrobiopterin is present in probably every cell or tissue of higher animals. On the other hand, most bacteria, fungi and plants do not synthesize tetrahydrobiopterin. -- Wikipedia.


anserine

This dipeptide is normally absent from human tissues and body fluids, and its appearance there is an artifact of diet (Proc Soc Pediatr Res 134, 1967.) and serum carnosinase deficiency. (OMIM 212200) Anserine is present in the skeletal muscle of birds and certain species of mammals, notably the rabbit, rat, and whale, contains anserine. (Proc Soc Pediatr Res 134, 1967) The methyl group of anserine is added to carnosine by the enzyme S-adenosylmethionine: carnosine N-methyltransferase. (J Biol Chem 237:1207, 1962.).


N(pros)-methyl-L-histidine zwitterion

3-Methylhistidine is a product of peptide bond synthesis and methylation of actin and myosin. The measurement of 3-methylhistidine provides an index of the rate of muscle protein breakdown. 3-Methylhistidine is a biomarker for meat consumption, especially chicken. It is also a biomarker for the consumption of soy products.


Carnosine

Carnosine (beta-alanyl-L-histidine) is found exclusively in animal tissues. It is a dipeptide of the amino acids beta-alanine and histidine. Carnosine has the potential to suppress many of the biochemical changes that accompany ageing (e.g. protein oxidation, glycation, AGE formation, and cross-linking) and associated pathologies (PMID: 16804013). It is highly concentrated in muscle and brain tissues. Some autistic patients take it as a dietary supplement and attribute an improvement in their condition to it. Supplemental carnosine may increase corticosterone levels. This may explain the "hyperactivity" seen in autistic subjects at higher doses. Carnosine also exhibits some antioxidant effects. The antioxidant mechanism of carnosine is attributed to its chelating effect against metal ions, superoxide dismutase (SOD)-like activity, and ROS and free radicals scavenging ability (PMID: 16406688). Carnosine is a biomarker for the consumption of meat. Carnosine is found to be associated with carnosinuria, which is an inborn error of metabolism.


N-carbamoyl-beta-alanine

Ureidopropionic acid is an intermediate in the metabolism of uracil. More specifically it is a breakdown product of dihydrouracil and is produced by the enzyme dihydropyrimidase. It is further decomposed to beta-alanine via the enzyme beta-ureidopropionase. Ureidopropionic acid is essentially a urea derivative of beta-alanine. High levels of Ureidopropionic acid are found in individuals with beta-ureidopropionase (UP) deficiency [PMID: 11675655]. Enzyme deficiencies in pyrimidine metabolism are associated with a risk for severe toxicity against the antineoplastic agent 5-fluorouracil.

3-(carbamoylamino)propanoate
3-(carbamoylamino)propanoic acid
3-ureido-propionate
3-ureidopropanoate
3-ureidopropanoic acid
3-ureidopropionate
3-ureidopropionic acid
Carbamoyl-b-ala-oh
Carbamoyl-beta-ala-oh
N-(aminocarbonyl)-'b-alanine
N-(aminocarbonyl)-b-alanine
N-(aminocarbonyl)-beta-alanine
N-carbamoyl-b-alanine
N-carbamoyl-beta-alanine
N-carbamyl-b-alanine
N-carbamyl-beta-alanine
Ureidopropionate
Ureidopropionic acid
Beta-ureidopropionate
Beta-ureidopropionic acid
3-[(aminocarbonyl)amino]propanoic acid
Ureidopropanoic acid
3-[(aminocarbonyl)amino]propanoate
N-carbamoyl-β-alanine
B-ureidopropionate
B-ureidopropionic acid
β-ureidopropionate
β-ureidopropionic acid
N-(aminocarbonyl)-β-alanine
Ureidopropanoate


Dihydrouracil

Dihydrouracil is an intermediate breakdown product of uracil. Dihydropyrimidine dehydrogenase (DHP) catalyzes the reduction of uracil into 5,6-dihydrouracil then dihydropyrimidinase hydrolyzes 5,6-dihydrouracil into N-carbamyl-beta-alanine. Finally, beta-ureidopropionase catalyzes the conversion of N-carbamyl-beta-alanine into beta-alanine. When present at abnormally high levels, dihydrouracil can be toxic although the mechanism of toxicity is not clear. In particular, patients with dihydropyrimidinase deficiency exhibit highly increased concentrations of 5,6-dihydrouracil and 5,6-dihydrothymine, and moderately increased concentrations of uracil and thymine can be detected in urine. Dihydropyrimidinase deficiency is a disorder that can cause neurological and gastrointestinal problems in some affected individuals (OMIM: 222748).  The neurological abnormalities that occur most often in people with dihydropyrimidinase deficiency are intellectual disability, seizures, weak muscle tone (hypotonia), an abnormally small head size (microcephaly), and autistic behaviours that affect communication and social interaction. Gastrointestinal problems that occur in dihydropyrimidinase deficiency include backflow of acidic stomach contents into the esophagus (gastroesophageal reflux) and recurrent episodes of vomiting. The direct measurement of the activity of DHP in patients has been hampered by the fact that the enzyme is expressed almost exclusively in liver tissue.


Uracil

Uracil is a common naturally occurring pyrimidine found in RNA, it base pairs with adenine and is replaced by thymine in DNA. Methylation of uracil produces thymine. Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates. Uracil serves as allosteric regulator and coenzyme for many important biochemical reactions. UDP and UTP regulate CPSase II activity in animals. UDP-glucose regulates the conversion of glucose to galactose in the liver and other tissues in the process of carbohydrate metabolism. Uracil is also involved in the biosynthesis of polysaccharides and the transportation of sugars containing aldehydes.


3-Aminopropanal is a reactive aldehyde that mediates progressive neuronal necrosis and glial apoptosis. (PMID 11943872). Increased activity of polyamine oxidase catabolizes polyamines (such as spermine, spermidine and putrescine) to produce 3-aminopropanal. (PMID 15246852).


trimethylenediamine

1,3-Diaminopropane is a stable, flammable and highly hydroscopic fluid. It is a polyamine that is normally quite toxic if swallowed, inhaled or absorbed through the skin. It is a catabolic byproduct of spermidine. It is also a precursor in the enzymatic synthesis of beta-alanine. 1, 3-Diaminopropane is involved in the arginine/proline metabolic pathways and the beta-alanine metabolic pathway.


Cupric cation

Copper is an essential nutrient to all higher plants and animals. Physiologically, it exists as an ion in the body. In animals, it is found primarily in the bloodstream, as a cofactor in various enzymes, and in copper-based pigments. In the body, copper shifts between the cuprous (Cu1+) and cupric (Cu2+) forms, though the majority of the body's copper is in the Cu2+ form. The ability of copper to easily accept and donate electrons explains its important role in oxidation-reduction (redox) reactions and in scavenging free radicals. Copper is a critical functional component of a number of essential enzymes known as cuproenzymes. For instance, the copper-dependent enzyme, cytochrome c oxidase, plays a critical role in cellular energy production. By catalyzing the reduction of molecular oxygen (O2) to water (H2O), cytochrome c oxidase generates an electrical gradient used by the mitochondria to create the vital energy-storing molecule, ATP. Another cuproenzyme, lysyl oxidase, is required for the cross-linking of collagen and elastin, which are essential for the formation of strong and flexible connective tissue. Another cuproeznyme, Monoamine oxidase (MAO), plays a role in the metabolism of the neurotransmitters norepinephrine, epinephrine, and dopamine. MAO also functions in the degradation of the neurotransmitter serotonin, which is the basis for the use of MAO inhibitors as antidepressants. One of the most important cuproenzymes is Superoxide dismutase (SOD). SOD functions as an antioxidant by catalyzing the conversion of superoxide radicals (free radicals or ROS) to hydrogen peroxide, which can subsequently be reduced to water by other antioxidant enzymes. Two forms of SOD contain copper: 1) copper/zinc SOD is found within most cells of the body, including red blood cells, and 2) extracellular SOD is a copper-containing enzyme found at high levels in the lungs and low levels in blood plasma. In sufficient amounts, copper can be poisonous or even fatal to organisms. Copper is normally bound to cuproenzymes (such as SOD, MOA) and is thus only toxic when unsequestered and unmediated. It is believed that zinc and copper compete for absorption in the digestive tract so that a diet that is excessive in one of these minerals may result in a deficiency in the other. An imbalance of zinc and copper status might be involved in human hypertension.

Copper
Cu
Copper (ii) ion
Copper(ii) cation
Copper, ion (cu2+)
Cu(ii)
Cu2+
Cu(2+)
Cupric ion


L-topaquinone

Topaquinone (TPQ), is the quinone of 2,4,5-trihydroxyphenylalanine. TPQ is the cofactor in most copper-containing amine oxidases. It is produced by post-translational modification of a strictly conserved active-site tyrosine residue with the participation of the copper ion at the active site. Once formed, TPQ acts as a switch between the heterolytic transformation of amine substrates to aldehydes, via a pyridoxal phosphate-like Schiff base complex, and one electron chemistry involving reduction of molecular oxygen (PMID: 12686122).


pantothenic acid

Pantothenic acid, also called vitamin B5, is a water-soluble vitamin required to sustain life. Pantothenic acid is needed to form coenzyme-A (CoA), and is thus critical in the metabolism and synthesis of carbohydrates, proteins, and fats. Its name is derived from the Greek pantothen meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole grain cereals, legumes, eggs, meat, and royal jelly.


Betaine

Betaine (or N,N,N-trimethylglycine) was named after its discovery in sugar beet (Beta vulgaris) in the 19th century. It is a small N-trimethylated amino acid, existing in zwitterionic form at neutral pH. It is now often called glycine betaine to distinguish it from other betaines that are widely distributed in microorganisms, plants, and animals. Many naturally occurring betaines serve as organic osmolytes, substances synthesized or taken up from the environment by cells for protection against osmotic stress, drought, high salinity, or high temperature. Intracellular accumulation of betaines permits water retention in cells, thus protecting from the effects of dehydration (Wikipedia). Betaine functions as a methyl donor in that it carries and donates methyl functional groups to facilitate necessary chemical processes. In particular, it methylates homocysteine to methionine, also producing N,N-dimethylglycine. The donation of methyl groups is important to proper liver function, cellular replication, and detoxification reactions. Betaine also plays a role in the manufacture of carnitine and serves to protect the kidneys from damage. Betaine comes from either the diet or by the oxidation of choline. Betaine insufficiency is associated with metabolic syndrome, lipid disorders, and diabetes, and may have a role in vascular and other diseases (PMID: 20346934). Betaine is important in development, from the pre-implantation embryo to infancy. Betaine is also widely regarded as an anti-oxidant. Betaine has been shown to have an inhibitory effect on NO release in activated microglial cells and may be an effective therapeutic component to control neurological disorders (PMID: 22801281). As a drug, betaine hydrochloride has been used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also been used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and for gastrointestinal disturbances (Martindale, The Extra Pharmacopoeia, 30th Ed, p1341).

(carboxymethyl)trimethylammonium hydroxide inner salt


Betaine aldehyde

Betaine aldehyde is an intermediate in the metabolism of glycine, serine and threonine. The human aldehyde dehydrogenase (EC 1.2.1.3) facilitates the conversion of betaine aldehyde to glycine betaine. Betaine aldehyde is a substrate for Choline dehydrogenase (mitochondrial). (PMID: 12467448, 7646513).

(formylmethyl)trimethylammonium
(formylmethyl)trimethyl-ammonium
Btl
Betaine aldehyde
Glycine betaine aldehyde
N,n,n-trimethyl-2-oxo ethanaminium
N,n,n-trimethyl-2-oxo-ethanaminium
Trimethyl(formylmethyl)ammonium


Choline

Choline is a basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism. Choline is now considered to be an essential vitamin. While humans can synthesize small amounts (by converting phosphatidylethanolamine to phosphatidylcholine), it must be consumed in the diet to maintain health. Required levels are between 425 mg/day (female) and 550 mg/day (male). Milk, eggs, liver, and peanuts are especially rich in choline. Most choline is found in phospholipids, namely phosphatidylcholine or lecithin. Choline can be oxidized to form betaine, which is a methyl source for many reactions (i.e. conversion of homocysteine into methionine). Lack of sufficient amounts of choline in the diet can lead to a fatty liver condition and general liver damage. This arises from the lack of VLDL, which is necessary to transport fats away from the liver. Choline deficiency also leads to elevated serum levels of alanine amino transferase and is associated with increased incidence of liver cancer.

(2-hydroxyethyl)trimethyl ammonium
(2-hydroxyethyl)trimethylammonium
(beta-hydroxyethyl)trimethylammonium
2-hydroxy-n,n,n-trimethyl-ethanaminium
2-hydroxy-n,n,n-trimethylethanaminium
Bilineurine
Biocolina
Biocoline
Choline
Choline cation
Choline ion
Cholinum
Hepacholine
Hormocline
Lipotril
N,n,n-trimethylethanol-ammonium
N,n,n-trimethylethanolammonium
Neocolina
Paresan
N-trimethylethanolamine
Trimethylethanolamine


homocysteine

Homocysteine is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with increased incidence of cardiovascular disease and Alzheimer's disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. Pyridoxal, folic acid, riboflavin, and Vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 %, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocysteinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD. (PMID 17136938, 15630149).

(+-)-homocysteine
(s)-2-amino-4-mercapto-butanoate
(s)-2-amino-4-mercapto-butanoic acid
2-amino-4-mercapto-butanoate
2-amino-4-mercapto-butanoic acid
2-amino-4-mercapto-butyric acid
2-amino-4-mercapto-dl-butyrate
2-amino-4-mercapto-dl-butyric acid
2-amino-4-mercaptobutyric acid
2-amino-4-sulfanylbutanoate
2-amino-4-sulfanylbutanoic acid
D,l-homocysteine
Dl-2-amino-4-mercaptobutyric acid
Dl-2-amino-4-mercapto-butyric acid
Dl-homocysteine
Dl-homocysteine (free base)
Hcy
Homo-cys
Homocysteine
L-2-amino-4-mercapto-butyric acid
L-homocysteine
Usaf b-12
2-amino-4-mercaptobutyrate


dimethylglycine

Dimethylglycine (DMG) is an amino acid derivative found in the cells of all plants and animals and can be obtained in the diet in small amounts from grains and meat. The human body produces DMG when metabolizing choline into Glycine. Dimethylglycine that is not metabolized in the liver is transported by the circulatory system to body tissue. Dimethylglycine was popular with Russian athletes and cosmonauts owing to its reputed ability to increase endurance and reduce fatigue. DMG is also a byproduct of homocysteine metabolism. Homocysteine and betaine are converted to methionine and N, N-dimethylglycine by betaine-homocysteine methyltransferase.

(dimethylamino)acetate
(dimethylamino)acetic acid
2-(dimethylamino)acetate
2-(dimethylamino)acetic acid
Dimethylglycine
N,n-dimethylaminoacetate
N,n-dimethylaminoacetic acid
N,n-dimethylglycine
N-methylsarcosine n,n-dimethyl-glycine


Racemethionine

Methionine is an essential amino acid (there are 9 essential amino acids) required for normal growth and development of humans, other mammals, and avian species. In addition to being a substrate for protein synthesis, it is an intermediate in transmethylation reactions, serving as the major methyl group donor in vivo, including the methyl groups for DNA and RNA intermediates. Methionine is a methyl acceptor for 5-methyltetrahydrofolate-homocysteine methyltransferase (methionine synthase), the only reaction that allows for the recycling of this form of folate, and is also a methyl acceptor for the catabolism of betaine. Methionine is the metabolic precursor for cysteine. Only the sulfur atom from methionine is transferred to cysteine; the carbon skeleton of cysteine is donated by serine (PMID: 16702340). There is a general consensus concerning normal sulfur amino acid (SAA) requirements. WHO recommendations amount to 13 mg/kg per 24 h in healthy adults. This amount is roughly doubled in artificial nutrition regimens. In disease or after trauma, requirements may be altered for methionine, cysteine, and taurine. Although in specific cases of congenital enzyme deficiency, prematurity, or diminished liver function, hypermethioninemia or hyperhomocysteinemia may occur, SAA supplementation can be considered safe in amounts exceeding 2-3 times the minimum recommended daily intake. Apart from some very specific indications (e.g. acetaminophen poisoning) the usefulness of SAA supplementation is not yet established (PMID: 16702341). Methionine is known to exacerbate psychopathological symptoms in schizophrenic patients, but there is no evidence of similar effects in healthy subjects. The role of methionine as a precursor of homocysteine is the most notable cause for concern. Acute doses of methionine can lead to acute increases in plasma homocysteine, which can be used as an index of the susceptibility to cardiovascular disease. Sufficiently high doses of methionine can actually result in death. Longer-term studies in adults have indicated no adverse consequences of moderate fluctuations in dietary methionine intake, but intakes higher than 5 times the normal amount resulted in elevated homocysteine levels. These effects of methionine on homocysteine and vascular function are moderated by supplements of vitamins B-6, B-12, C, and folic acid (PMID: 16702346). When present in sufficiently high levels, methionine can act as an atherogen and a metabotoxin. An atherogen is a compound that when present at chronically high levels causes atherosclerosis and cardiovascular disease. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of methionine are associated with at least ten inborn errors of metabolism, including cystathionine beta-synthase deficiency, glycine N-methyltransferase deficiency, homocystinuria, tyrosinemia, galactosemia, homocystinuria-megaloblastic anemia due to defects in cobalamin metabolism, methionine adenosyltransferase deficiency, methylenetetrahydrofolate reductase deficiency, and S-adenosylhomocysteine (SAH) hydrolase deficiency. Chronically elevated levels of methionine in infants can lead to intellectual disability and other neurological problems, delays in motor skills, sluggishness, muscle weakness, and liver problems. Many individuals with these metabolic disorders tend to develop cardiovascular disease later in life. Studies on feeding rodents high levels of methionine have shown that methionine promotes atherosclerotic plaques independently of homocysteine levels (PMID: 26647293). A similar study in Finnish men showed the same effect (PMID: 16487911).


5-methyltetrahydrofolic acid

5 methyltetrahydrofolic acid (5-MTHF) is the most biologically active form of the B-vitamin known as folic acid, also known generically as folate. 5-MTHF functions, in concert with vitamin B12, as a methyl-group donor involved in the conversion of the amino acid homocysteine to methionine. Methyl (CH3) group donation is vital to many bodily processes, including serotonin, melatonin, and DNA synthesis. Therapeutically, 5-MTHF is instrumental in reducing homocysteine levels, preventing neural tube defects, and improving vascular endothelial function. Research on folate supplementation suggests it plays a key role in preventing cervical dysplasia and protecting against neoplasia in ulcerative colitis. Folic acid also shows promise as part of a nutritional protocol to treat vitiligo, and may reduce inflammation of the gingiva. Furthermore, certain neurological, cognitive, and psychiatric presentations may be secondary to folate deficiency. Such presentations include depression, peripheral neuropathy, myelopathy, restless legs syndrome, insomnia, dementia, forgetfulness, irritability, endogenous depression, organic psychosis, and schizophrenia-like syndromes. After ingestion, the process of conversion of folic acid to the metabolically active coenzyme forms is relatively complex. Synthesis of the active forms of folic acid requires several enzymes, adequate liver and intestinal function, and adequate supplies of riboflavin (B2), niacin (B3), pyridoxine (B6), zinc, vitamin C, and serine. After formation of the coenzyme forms of the vitamin in the liver, these metabolically active compounds are secreted into the small intestine with bile (the folate enterohepatic cycle), where they are reabsorbed and distributed to tissues throughout the body. Human pharmacokinetic studies indicate folic acid has high bioavailability, with large oral doses of folic acid substantially raising plasma levels in healthy subjects in a time and dose dependent manner. Red blood cells (RBCs) appear to be the storage depot for folic acid, as RBC levels remain elevated for periods in excess of 40 days following discontinuation of supplementation. Folic acid is poorly transported to the brain and rapidly cleared from the central nervous system. The primary methods of elimination of absorbed folic acid are fecal (through bile) and urinary. Despite the biochemical complexity of this process, evidence suggests oral supplementation with folic acid increases the body's pool of 5-MTHF in healthy individuals. However, enzyme defects, mal-absorption, digestive system pathology, and liver disease can result in impaired ability to activate folic acid. In fact, some individuals have a severe congenital deficiency of the enzyme Methyl tetrahydrofolate reductase (5-MTHFR), which is needed to convert folic acid to 5-MTHF. Milder forms of this enzyme defect likely interact with dietary folate status to determine risk for some disease conditions. In individuals with a genetic defect of this enzyme (whether mild or severe), supplementation with 5- MTHF might be preferable to folic acid supplementation. (PMID: 17176169).


phosphatidyl-N-methylethanolamine

{2-[({2,3-bis[(9Z)-tetradec-9-enoyloxy]propoxy}(hydroxy)phosphoryl)oxy]ethyl}trimethylaminyl belongs to the class of organic compounds known as glycerophospholipids. These are derivatives of glycerophosphoric acid that contains at least one O-acyl, or O-alkyl, or O-(1-alkenyl) group attached to the glycerol residue.


5'-biotinyl-AMP (B-AMP) is the active form of biotin in mammals. In human cells, biotin is essential to maintain metabolic homeostasis and as regulator of gene expression. The vitamin biotin plays an essential role in gluconeogenesis, fatty acid synthesis, and carbohydrate metabolism because of its role as cofactor of five carboxylases; pyruvate carboxylase (PC), propionyl-CoA carboxylase (PCC), methylcrotonyl-CoA carboxylase, and two forms of acetyl-CoA carboxylase (ACC-1 and ACC-2). Carboxylase biotinylation is catalyzed by the enzyme holocarboxylase synthetase (HCS) through a reaction that involves the transformation of biotin into B-AMP and its subsequent attachment to a specific lysine residue in the carboxylases. B-AMP is also required to activate a signal transduction cascade that includes a soluble guanylate cyclase (sGC) and cGMP-dependent protein kinase (PKG). The regulatory role of biotin in the biotin cycle seems to be limited to the expression of proteins involved in the transport and utilization of exogenous vitamin while having no effect on biotinidase mRNA levels, enzyme responsible for biotin recycling during carboxylase turnover. Multiple carboxylase deficiency (MCD) is a life-threatening disease characterized by the lack of carboxylase activities because of deficiency of HCS activity. (PMID: 15905112, 11959985).

5'-adenylic acid monoanhydride with biotin

[3as-(3aa,4b,6aa)]-5'-adenylic acid monoanhydride with hexahydro-2-oxo-1h-thieno[3,4-d]imidazole-4-pentanoate

[3as-(3aa,4b,6aa)]-5'-adenylic acid monoanhydride with hexahydro-2-oxo-1h-thieno[3,4-d]imidazole-4-pentanoic acid


biocytin

Biocytin is a naturally occurring low molecular weight analog of biotin, and a primary source of this essential metabolite for mammals. Biotinidase acts as a hydrolase by cleaving biocytin and biotinyl-peptides, thereby liberating biotin for reutilization. Mammals cannot synthesize biotin and, therefore, derive the vitamin from dietary sources or from the endogenous turnover of the carboxylases. Free biotin can readily enter the biotin pool, whereas holocarboxylases or other biotin-containing proteins must first be degraded proteolytically to biocytin (biotinyl-e-lysine) or biotinyl-peptides. Biocytin is also an especially versatile marker for neuroanatomical investigations, shown that may have multiple applications, especially for labeling neurons. (PMID: 8930409, 1384763, 2479450).


Lysine

L-lysine is an essential amino acid. Normal requirements for lysine have been found to be about 8 g per day or 12 mg/kg in adults. Children and infants need more- 44 mg/kg per day for an eleven to-twelve-year old, and 97 mg/kg per day for three-to six-month old. Lysine is highly concentrated in muscle compared to most other amino acids. Lysine is high in foods such as wheat germ, cottage cheese and chicken. Of meat products, wild game and pork have the highest concentration of lysine. Fruits and vegetables contain little lysine, except avocados. Normal lysine metabolism is dependent upon many nutrients including niacin, vitamin B6, riboflavin, vitamin C, glutamic acid and iron. Excess arginine antagonizes lysine. Several inborn errors of lysine metabolism are known. Most are marked by mental retardation with occasional diverse symptoms such as absence of secondary sex characteristics, undescended testes, abnormal facial structure, anemia, obesity, enlarged liver and spleen, and eye muscle imbalance. Lysine also may be a useful adjunct in the treatment of osteoporosis. Although high protein diets result in loss of large amounts of calcium in urine, so does lysine deficiency. Lysine may be an adjunct therapy because it reduces calcium losses in urine. Lysine deficiency also may result in immunodeficiency. Requirements for this amino acid are probably increased by stress. Lysine toxicity has not occurred with oral doses in humans. Lysine dosages are presently too small and may fail to reach the concentrations necessary to prove potential therapeutic applications. Lysine metabolites, amino caproic acid and carnitine have already shown their therapeutic potential. Thirty grams daily of amino caproic acid has been used as an initial daily dose in treating blood clotting disorders, indicating that the proper doses of lysine, its precursor, have yet to be used in medicine. Low lysine levels have been found in patients with Parkinson's, hypothyroidism, kidney disease, asthma and depression. The exact significance of these levels is unclear, yet lysine therapy can normalize the level and has been associated with improvement of some patients with these conditions. Abnormally elevated hydroxylysines have been found in virtually all chronic degenerative diseases and coumadin therapy. The levels of this stress marker may be improved by high doses of vitamin C. Lysine is particularly useful in therapy for marasmus (wasting) and herpes simplex. It stops the growth of herpes simplex in culture, and has helped to reduce the number and occurrence of cold sores in clinical studies. Dosing has not been adequately studied, but beneficial clinical effects occur in doses ranging from 100 mg to 4 g a day. Higher doses may also be useful, and toxicity has not been reported in doses as high as 8 g per day. Diets high in lysine and low in arginine can be useful in the prevention and treatment of herpes. Some researchers think herpes simplex virus is involved in many other diseases related to cranial nerves such as migraines, Bell's palsy and Meniere's disease. Herpes blister fluid will produce fatal encephalitis in the rabbit. (http://www.dcnutrition.com).

(+)-s-lysine
(s)-2,6-diaminohexanoate
(s)-2,6-diaminohexanoic acid
(s)-2,6-diamino-hexanoate
(s)-2,6-diamino-hexanoic acid
(s)-lysine
(s)-a,e-diaminocaproate
(s)-a,e-diaminocaproic acid
2,6-diaminohexanoate
2,6-diaminohexanoic acid
6-amino-aminutrin
6-amino-l-norleucine
Aminutrin
L-(+)-lysine
L-2,6-diainohexanoate
L-2,6-diainohexanoic acid
L-2,6-diaminocaproate
L-2,6-diaminocaproic acid
L-lys
Lys
Lysine
Lysine acid
A-lysine
Alpha-lysine
H-lys-oh
(s)-alpha,epsilon-diaminocaproic acid
6-ammonio-l-norleucine
K
L-lysin
(s)-a,epsilon-diaminocaproate
(s)-a,epsilon-diaminocaproic acid
(s)-alpha,epsilon-diaminocaproate
(s)-α,epsilon-diaminocaproate
(s)-α,epsilon-diaminocaproic acid


Butyryl-CoA is an intermediate in the metabolism of Butanoate. It is a substrate for Acyl-coenzyme A oxidase 3 (peroxisomal), 3-ketoacyl-CoA thiolase (mitochondrial), 3-ketoacyl-CoA thiolase (peroxisomal), Acyl-coenzyme A oxidase 1 (peroxisomal), Acyl-CoA dehydrogenase (medium-chain specific, mitochondrial), Acyl-CoA dehydrogenase (long-chain specific, mitochondrial), Acyl-coenzyme A oxidase 2 (peroxisomal), Acetyl-CoA acetyltransferase (mitochondrial), Acetyl-CoA acetyltransferase (cytosolic), Acyl-CoA dehydrogenase (short-chain specific, mitochondrial) and Trifunctional enzyme beta subunit (mitochondrial).

Butanoyl-coa
Butanoyl-coenzyme a
Butyryl-coa
Butyryl-coenzyme a
CoA(4:0)


crotonoyl-CoA

Crotonoyl-CoA is an important component in several metabolic pathways, notably fatty acid and amino acid metabolism. It is the substrate of a group of enzymes acyl-Coenzyme A oxidases 1, 2, 3 (E.C.: 1.3.3.6) corresponding to palmitoyl, branched chain, and pristanoyl, respectively, in the peroxisomal fatty acid beta-oxidation, producing hydrogen peroxide. Abnormality of this group of enzymes is linked to coma, dehydration, diabetes, fatty liver, hyperinsulinemia, hyperlipidemia, and leukodystrophy. It is also a substrate of a group of enzymes called acyl-Coenzyme A dehydrogenase (E.C.:1.3.99-, including 1.3.99.2, 1.3.99.3) in the metabolism of fatty acids or branched chain amino acids in the mitochondria (Rozen et al., 1994). Acyl-Coenzyme A dehydrogenase (1.3.99.3) has shown to contribute to kidney-associated diseases, such as adrenogential syndrome, kidney failure, kidney tubular necrosis, homocystinuria, as well as other diseases including cretinism, encephalopathy, hypoglycemia, medium chain acyl-CoA dehydrogenase deficiency. The gene (ACADS) also plays a role in theta oscillation during sleep. In addition, crotonoyl-CoA is the substrate of enoyl coenzyme A hydratase (E.C.4.2.1.17) in the mitochondria during lysine degradation and tryptophan metabolism, benzoate degradation via CoA ligation; in contrast it is the product of this enzyme in the butanoate metabolism. Moreover, it is produced from multiple enzymes in the butanoate metabolism pathway, including 3-Hydroxybutyryl-CoA dehydratase (E.C.:4.2.1.55), glutaconyl-CoA decarboxylase (E.C.: 4.1.1.70), vinylacetyl-CoA Δ-isomerase (E.C.: 5.3.3.3), and trans-2-enoyl-CoA reductase (NAD+) (E.C.: 1.3.1.44). In lysine degradation and tryptophan metabolism, crotonoyl CoA is produced by glutaryl-Coenzyme A dehydrogenase (E.C.:1.3.99.7) lysine and tryptophan metabolic pathway. This enzyme is linked to type-1glutaric aciduria, metabolic diseases, movement disorders, myelinopathy, and nervous system diseases.


3-Hydroxybutyryl-CoA, also known as 3-hydroxybutanoyl-CoA or 3-OH-butyryl-CoA, belongs to the class of organic compounds known as (r)-3-hydroxyacyl coas. These are organic compounds containing a (R)-3-hydroxyl acylated coenzyme A derivative. 3-Hydroxybutyryl-CoA is slightly soluble (in water) and an extremely strong acidic compound (based on its pKa). 3-Hydroxybutyryl-CoA has been primarily detected in urine. Within the cell, 3-hydroxybutyryl-CoA is primarily located in the mitochondria, peroxisome and cytoplasm. In humans, 3-hydroxybutyryl-CoA is involved in the lysine degradation pathway, the pyridoxine dependency with seizures pathway, the fatty acid metabolism pathway, and the butyrate metabolism pathway. 3-Hydroxybutyryl-CoA is also involved in several metabolic disorders, some of which include medium chain acyl-CoA dehydrogenase deficiency (mcad), the ethylmalonic encephalopathy pathway, the hyperlysinemia II or saccharopinuria pathway, and very-long-chain acyl CoA dehydrogenase deficiency (vlcad). 3-Hydroxybutyryl-CoA is a substrate for Enoyl-CoA hydratase (mitochondrial), Trifunctional enzyme alpha subunit (mitochondrial) and Peroxisomal bifunctional enzyme.

(3r)-3-hydroxybutanoyl-coa
(3r)-3-hydroxybutanoyl-coenzyme a
(r)-3-hydroxybutanoyl-coa
(r)-3-hydroxybutanoyl-coenzyme a
(s)-3-hydroxybutanoyl-coa
(s)-3-hydroxybutanoyl-coenzyme a
3-hydroxybutanoyl-coa
3-hydroxybutanoyl-coenzyme a
3-hydroxybutyryl-coa
3-hydroxybutyryl-coenzyme a
3-oh-butyryl-coa
3-oh-butyryl-coenzyme a
Hydroxy-butyryl-coa
Hydroxy-butyryl-coenzyme a
Beta-hydroxybutyryl-coa
Beta-hydroxybutyryl-coenzyme a
Beta-hydroxybutyryl-s-coa
Beta-hydroxybutyryl-s-coenzyme a


Acetoacetyl-CoA

Acetoacetyl-CoA is an intermediate in the metabolism of Butanoate. It is a substrate for Succinyl-CoA:3-ketoacid-coenzyme A transferase 1 (mitochondrial), Hydroxymethylglutaryl-CoA synthase (mitochondrial), Short chain 3-hydroxyacyl-CoA dehydrogenase (mitochondrial), Trifunctional enzyme beta subunit (mitochondrial), Hydroxymethylglutaryl-CoA synthase (cytoplasmic), Peroxisomal bifunctional enzyme, Acetyl-CoA acetyltransferase (cytosolic), Acetyl-CoA acetyltransferase (mitochondrial), 3-hydroxyacyl-CoA dehydrogenase type II, Succinyl-CoA:3-ketoacid-coenzyme A transferase 2 (mitochondrial), 3-ketoacyl-CoA thiolase (mitochondrial), 3-ketoacyl-CoA thiolase (peroxisomal) and Trifunctional enzyme alpha subunit (mitochondrial).

3-acetoacetyl-coa
3-acetoacetyl-coenzyme a
3-oxobutyryl-coa
3-oxobutyryl-coenzyme a
Acetoacetyl coa
Acetoacetyl coenzyme a
Acetoacetyl-coa
Acetoacetyl-coenzyme a
S-acetoacetylcoenzyme a


HMG-CoA

3-hydroxy-3-methylglutaryl CoA (HMG-CoA) is formed when Acetyl-CoA condenses with acetoacetyl-CoA in a reaction that is catalyzed by the enzyme HMG-CoA synthase in the mevalonate pathway or mevalonate-dependent (MAD) route, an important cellular metabolic pathway present in virtually all organisms. HMG-CoA reductase (EC 1.1.1.34) inhibitors, more commonly known as statins, are cholesterol-lowering drugs that have been widely used for many years to reduce the incidence of adverse cardiovascular events. HMG-CoA reductase catalyzes the rate-limiting step in the mevalonate pathway and these agents lower cholesterol by inhibiting its synthesis in the liver and in peripheral tissues. Androgen also stimulates lipogenesis in human prostate cancer cells directly by increasing transcription of the fatty acid synthase and HMG-CoA-reductase genes. (PMID: 14689582).

S-(hydrogen 3-hydroxy-3-methylpentanedioate) coenzyme a


Acetoacetate

Acetoacetic acid (AcAc) is a weak organic acid that can be produced in the human liver under certain conditions of poor metabolism leading to excessive fatty acid breakdown (diabetes mellitus leading to diabetic ketoacidosis). It is then partially converted into acetone by decarboxylation and excreted either in urine or through respiration. Persistent mild hyperketonemia is a common finding in newborns. Ketone bodies serve as an indispensable source of energy for extrahepatic tissues, especially the brain and lung of developing rats. Another important function of ketone bodies is to provide acetoacetyl-CoA and acetyl-CoA for synthesis of cholesterol, fatty acids, and complex lipids. During the early postnatal period, acetoacetate and beta-hydroxybutyrate are preferred over glucose as substrates for synthesis of phospholipids and sphingolipids in accord with requirements for brain growth and myelination. Thus, during the first two weeks of postnatal development, when the accumulation of cholesterol and phospholipids accelerates, the proportion of ketone bodies incorporated into these lipids increases. On the other hand, an increased proportion of ketone bodies are utilized for cerebroside synthesis during the period of active myelination. In the lung, AcAc serves better than glucose as a precursor for the synthesis of lung phospholipids. The synthesized lipids, particularly dipalmityl phosphatidylcholine, are incorporated into surfactant, and thus have a potential role in supplying adequate surfactant lipids to maintain lung function during the early days of life (PMID: 3884391). The acid is also present in the metabolism of those undergoing starvation or prolonged physical exertion as part of gluconeogenesis. When ketone bodies are measured by way of urine concentration, acetoacetic acid, along with beta-hydroxybutyric acid or acetone, is what is detected.

3-ketobutyrate
3-ketobutyric acid
3-oxo-butanoate
3-oxo-butanoic acid
3-oxobutyrate
3-oxobutyric acid
Acetoacetate
Diacetate
Diacetic acid
3-oxobutanoic acid
Beta-ketobutyric acid
3-oxobutanoate
B-ketobutyrate
B-ketobutyric acid
Beta-ketobutyrate
β-ketobutyrate
β-ketobutyric acid


Butyric Acid

Butyric acid, a four-carbon fatty acid, is formed in the human colon by bacterial fermentation of carbohydrates (including dietary fiber), and putatively suppresses colorectal cancer (CRC). Butyrate has diverse and apparently paradoxical effects on cellular proliferation, apoptosis and differentiation that may be either pro-neoplastic or anti-neoplastic, depending upon factors such as the level of exposure, availability of other metabolic substrate and the intracellular milieu. In humans, the relationship between luminal butyrate exposure and CRC has been examined only indirectly in case-control studies, by measuring fecal butyrate concentrations, although this may not accurately reflect effective butyrate exposure during carcinogenesis. Perhaps not surprisingly, results of these investigations have been mutually contradictory. The direct effect of butyrate on tumorigenesis has been assessed in a no. of in vivo animal models, which have also yielded conflicting results. In part, this may be explained by methodology: differences in the amount and route of butyrate administration, which are likely to significantly influence delivery of butyrate to the distal colon. (PMID: 16460475) Butyric acid is a carboxylic acid found in rancid butter, parmesan cheese, and vomit, and has an unpleasant odor and acrid taste, with a sweetish aftertaste (similar to ether). Butyric acid is a fatty acid occurring in the form of esters in animal fats and plant oils. Interestingly, low-molecular-weight esters of butyric acid, such as methyl butyrate, have mostly pleasant aromas or tastes. As a consequence, they find use as food and perfume additives. Butyrate is produced as end-product of a fermentation process solely performed by obligate anaerobic bacteria.

1-butanoate
1-butanoic acid
1-butyrate
1-butyric acid
1-propanecarboxylate
1-propanecarboxylic acid
Butanate
Butanic acid
Butanoate
Butanoic acid
Buttersaeure
Butyrate
Butyric acid
Ethylacetate
Ethylacetic acid
Honey robber
Kyselina maselna
N-butanoate
N-butanoic acid
N-butyrate
N-butyric acid
Propanecarboxylate
Propanecarboxylic acid
Propylformate
Propylformic acid
4:0
Acide butanoique
Acide butyrique
Butoic acid
C4:0
Ch3-[ch2]2-cooh
Butoate


Caffeine

Caffeine is the most widely consumed psychostimulant drug in the world and is mostly consumed in the form of coffee. Whether caffeine and/or coffee consumption contributes to the development of cardiovascular disease (CVD), the single leading cause of death in the US, is unclear. The literature indicates a strong relationship between boiled, unfiltered coffee consumption and elevated cholesterol levels; however, there is a critical gap in the literature regarding the effects of coffee or caffeine consumption on fibrinogen or CRP, which is an independent predictor of CVD risk. Available studies are limited by small samples sizes, the inclusion of only men (or few women), and unrepresented age or ethnic groups. There is a critical need for controlled laboratory and epidemiological studies that include fibrinogen and CRP markers of CVD risk before conclusions can be drawn regarding the health effects of caffeine and/or coffee in a normal, healthy population of men and women (PMID: 16856769 ). The relationship between caffeine consumption and various illnesses such as cardiovascular disease and cancer remains equivocal. Prudence might dictate that pregnant women and chronically ill individuals exercise restraint in their use of caffeine, although research suggests relatively low or nonexistent levels of risk associated with moderate caffeine consumption (PMID: 7844249). There is extensive evidence that caffeine at dietary doses increases blood pressure (BP). However, concern that the drug may contribute to cardiovascular disease appears to have been dampened by (1) the belief that habitual use leads to the development of tolerance, and (2) confusion regarding relevant epidemiologic findings. When considered comprehensively, findings from experimental and epidemiologic studies converge to show that BP remains reactive to the pressor effects of caffeine in the diet. Overall, the impact of dietary caffeine on population BP levels is likely to be modest, probably in the region of 4/2 mm Hg. At these levels, however, population studies of BP indicate that caffeine use could account for premature deaths in the region of 14% for coronary heart disease and 20% for stroke (PMID: 14747639). Caffeine is a purine alkaloid that occurs naturally in coffee beans. At intake levels associated with coffee consumption, caffeine appears to exert most of its biological effects through the antagonism of the A1 and A2A subtypes of the adenosine receptor. Adenosine is an endogenous neuromodulator with mostly inhibitory effects, and adenosine antagonism by caffeine results in effects that are generally stimulatory. Some physiological effects associated with caffeine administration include central nervous system stimulation, acute elevation of blood pressure, increased metabolic rate, and diuresis. Caffeine is rapidly and almost completely absorbed in the stomach and small intestine and distributed to all tissues, including the brain. Caffeine metabolism occurs primarily in the liver, where the activity of the cytochrome P450 isoform CYP1A2 accounts for almost 95% of the primary metabolism of caffeine. CYP1A2-catalyzed 3-demethylation of caffeine results in the formation of 1,7-dimethylxanthine (paraxanthine). Paraxanthine may be demethylated by CYP1A2 to form 1-methylxanthine, which may be oxidized to 1-methyluric acid by xanthine oxidase. Paraxanthine may also be hydroxylated by CYP2A6 to form 1,7-dimethyluric acid, or acetylated by N-acetyltransferase 2 (NAT2) to form 5-acetylamino-6-formylamino-3-methyluracil, an unstable compound that may be deformylated nonenzymatically to form 5-acetylamino-6-amino-3-methyluracil. Caffeine concentrations in coffee beverages can be quite variable. A standard cup of coffee is often assumed to provide 100 mg of caffeine, but a recent analysis of 14 different specialty coffees purchased at coffee shops in the US found that the amount of caffeine in 8 oz (=240 ml) of brewed coffee ranged from 72 to 130 mg. Caffeine in espresso coffees ranged from 58 to 76 mg in a single shot (PMID: 16507475). Caffeine is a member of the methylxanthine family of drugs, and is the most widely consumed behaviourally active substance in the western world. A number of in vitro and in vivo studies have demonstrated that caffeine modulates both innate and adaptive immune responses. For instance, studies indicate that caffeine and its major metabolite paraxanthine suppress neutrophil and monocyte chemotaxis, and also suppress production of the pro-inflammatory cytokine tumour necrosis factor (TNF) alpha from human blood. Caffeine has also been reported to suppress human lymphocyte function as indicated by reduced T-cell proliferation and impaired production of Th1 (interleukin [IL]-2 and interferon [IFN]-gamma), Th2 (IL-4, IL-5), and Th3 (IL-10) cytokines. Studies also indicate that caffeine suppresses antibody production. The evidence suggests that at least some of the immunomodulatory actions of caffeine are mediated via inhibition of cyclic adenosine monophosphate (cAMP)-phosphodiesterase (PDE) and consequential increase in intracellular cAMP concentrations. Overall, these studies indicate that caffeine, like other members of the methylxanthine family, is largely anti-inflammatory in nature, and based on the pharmacokinetics of caffeine, many of its immunomodulatory effects occur at concentrations that are relevant to normal human consumption (PMID: 16540173).


Theobromine

Theobromine, or 3,7-Dimethylxanthine, is the principle alkaloid in Theobroma cacao (the cacao bean) and other plants. A xanthine alkaloid that is used as a bronchodilator and as a vasodilator. It has a weaker diuretic activity than theophylline and is also a less powerful stimulant of smooth muscle. It has practically no stimulant effect on the central nervous system. It was formerly used as a diuretic and in the treatment of angina pectoris and hypertension. (From Martindale, The Extra Pharmacopoeia, 30th ed, pp1318-9, as cited on Pubchem). Theobromine is a bitter alkaloid of the methylxanthine family, which also includes the similar compounds theophylline and caffeine. Despite its name, the compound contains no bromine. Theobromine is derived from Theobroma, the genus of the cacao tree, which is composed of the Greek roots theo ("God") and broma ("food"), meaning "food of the gods". It is the primary alkaloid found in cocoa and chocolate, and is one of the causes for chocolate's mood-elevating effects. The amount found in chocolate is small enough that chocolate can be safely consumed by humans in large quantities, but animals that metabolize theobromine more slowly, such as cats and dogs, can easily consume enough chocolate to cause chocolate poisoning. Theobromine is a stimulant frequently confused with caffeine. Theobromine has very different effects on the human body from caffeine; it is a mild, lasting stimulant with a mood improving effect, whereas caffeine has a strong, immediate effect and increases stress. In medicine, it is used as a diuretic, vasodilator, and myocardial stimulant. There is a possible association between prostate cancer and theobromine. Theobromine is a contributing factor in acid reflux because it relaxes the esophageal sphincter muscle, allowing stomach acid access to the esophagus (Wikipedia).


Theophylline

Theophylline is a methylxanthine drug used in therapy for respiratory diseases such as Chronic obstructive pulmonary disease (COPD) or asthma under a variety of brand names. As a member of the xanthine family, it bears structural and pharmacological similarity to caffeine. It is naturally found in black tea and green tea. A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-Cyclic nucleotide phosphodiesterase that degrades cyclic AMP (cAMP) thus potentiates the actions of agents that act through Adenylate cyclase and cAMP.

1,3-dimethylxanthine
Accurbron
Acet-theocin
Aerolate
Aerolate iii
Aerolate sr
Aminophylline
Aquaphyllin
Armophylline
Asbron
Asmax
Austyn
Bronkodyl
Bronkodyl sr
Choledyl sa
Constant-t
Diphyllin
Doraphyllin
Duraphyl
Dyspne-inhal
Elixex
Elixicon
Elixomin
Elixophyllin
Elixophyllin sr
Elixophylline
Euphylline
Euphylong
Labid
Lanophyllin
Liquophylline
Liquorice
Maphylline
Medaphyllin
Nuelin
Optiphyllin
Parkophyllin
Pseudotheophylline
Quibron t/sr
Quibron-t
Quibron-t/sr
Respbid
Slo-bid
Slo-phyllin
Solosin
Somophyllin-crt
Somophyllin-df
Somophyllin-t
Spophyllin retard
Sustaire
Synophylate
Synophylate-l.a. cenules
T-phyl
Tefamin
Teofilina
Teofyllamin
Teolair
Theacitin
Theal tabl.
Theal tablets
Theo-dur
Theo-dur-sprinkle
Theobid
Theobid jr.
Theochron
Theocin
Theoclair-sr
Theoclear 80
Theoclear l.a.-130
Theoclear la
Theoclear-200
Theoclear-80
Theocontin
Theodel
Theofol
Theograd
Theolair
Theolair-sr
Theolix
Theolixir
Theona p
Theophyl
Theophyl-225
Theophyl-sr
Theophyline
Theophyllin
Theophylline anhydrous
Theophylline-sr
Theostat 80
Theovent
Uni-dur
Unifyl
Uniphyl
Uniphyllin
Xanthium
Xantivent
1,3-dimethyl-7h-purine-2,6-dione


PARAXANTHINE

1,7-dimethylxanthine (paraxanthine) is the preferential path of caffeine metabolism in humans. Paraxanthine is a dimethylxanthine compound structurally related to caffeine. Like caffeine, paraxanthine is a psychoactive central nervous system (CNS) stimulant. It possesses a potency roughly equal to that of caffeine and is likely involved in the mediation of the effects of caffeine itself.


1-methylxanthine is the major metabolites of caffeine in the human. The oxidation of 1-methylxanthine to 1-methyluric acid occurred so rapidly that the parent compound could not be detected in plasma, and only low concentrations could be detected in brain. (PMID: 28863020.


7-Methylxanthine is a methyl derivative of xanthine, found occasionally in human urine. 7-Methylxanthine is one of the purine components in urinary calculi. Methylated purines originate from the metabolism of methylxanthines (caffeine, theophylline and theobromine). Caffeine is metabolized via successive pathways mainly catalyzed by CYP1A2, xanthine oxidase or N-acetyltransferase-2 to give 14 different metabolites, including 7-methylxanthine. CYP1A2 activity shows an inter-individual variability among the population. CYP1A2, an isoform of the CYP1A cytochrome P450 super-family, is involved in the metabolism of many drugs and plays a potentially important role in the induction of chemical carcinogenesis. Purine derivatives in urinary calculi could be considered markers of abnormal purine metabolism. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. This suggests that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. (PMID: 11712316, 15833286, 3506820, 15013152).


5-Acetylamino-6-formylamino-3-methyluracil, also known as afmu, belongs to the class of organic compounds known as hydroxypyrimidines. These are organic compounds containing a hydroxyl group attached to a pyrimidine ring. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. 5-Acetylamino-6-formylamino-3-methyluracil is considered to be a practically insoluble (in water) and relatively neutral molecule. 5-Acetylamino-6-formylamino-3-methyluracil has been found in human liver and kidney tissues, and has also been detected in multiple biofluids, such as urine and blood. Within the cell, 5-acetylamino-6-formylamino-3-methyluracil is primarily located in the cytoplasm. In humans, 5-acetylamino-6-formylamino-3-methyluracil is involved in the caffeine metabolism pathway. 5-Acetylamino-6-formylamino-3-methyluracil participates in Caffeine metabolism. 5-Acetylamino-6-formylamino-3-methyluracil is converted from paraxanthine via arylamine N-acetyltransferase [EC:2.3.1.5].


5-Acetylamino-6-amino-3-methyluracil (AAMU) is one of caffeine major metabolites. Analysis of caffeine and its metabolites is of interest with respect to caffeine exposure, for kinetic and metabolism studies and for opportunistic in vivo estimation of drug metabolizing enzyme activity in humans and animals. Urinary caffeine metabolite ratios are used in humans to assess the activity of cytochrome P450 1A2 (CYP1A2), xanthine oxidase and N-acetyltransferase 2 (NAT2), which are involved in the activation or detoxification of various xenobiotic compounds, including carcinogens. Investigating the activity of these enzymes is of clinical relevance for assessing intra- and inter-individual differences in NAT2- and CYP1A2-mediated drug metabolism, and for evaluating the risk of developing specific exposure-related diseases. (PMID: 3506820, 15685651, 12534641).