Reaction catalyzed by 8-hydroxyquercetin 8-O-methyltransferase (2.1.1.88)
+
=
+
S-adenosyl-L-methionine
+
3,5,7,8,3',4'-hexahydroxyflavone
=
S-adenosyl-L-homocysteine
+
3,5,7,3',4'-pentahydroxy-8-methoxyflavone