ID 2.1.1.76 DE Quercetin 3-O-methyltransferase. AN Flavonol 3-O-methyltransferase. CA S-adenosyl-L-methionine + 3,5,7,3',4'-pentahydroxyflavone = S-adenosyl-L- CA homocysteine + 3-methoxy-5,7,3',4'-tetrahydroxyflavone. CC -!- Specific for quercetin. CC -!- Related enzymes bring about the 3-O-methylation of other flavonols, CC such as galangin and kaempferol. //