label: neuraminic acid
label_lc: neuraminic acid
description: "A 9-carbon sugar that is 5-amino-3,5-dideoxy-D-glycero-D-galacto-non-2-ulosonic acid in either its open-chain or cyclic hemiketal forms. Although it does not occur naturally, many of its derivatives are found widely distributed in animal tissues and in bacteria, particularly in glycoproteins and gangliosides. N- or O-substituted derivatives of neuraminic acid are known as sialic acids."