label: 3',5'-di-O-methyltricetin + S-adenosyl-L-methionine <=> 3',4',5'-O-trimethyltricetin + S-adenosyl-L-homocysteine + H(+)
label_lc: 3',5'-di-o-methyltricetin + s-adenosyl-l-methionine <=> 3',4',5'-o-trimethyltricetin + s-adenosyl-l-homocysteine + h(+)