3-methylquercetin 3'-O-methyltransferase activity
Catalysis of the reaction: 3',4',5,7-tetrahydroxy-3-methoxyflavone + S-adenosyl-L-methionine = 3,3'-O-dimethylquercetin + H+ + S-adenosyl-L-homocysteine.
GO:0008168
methyltransferase activity
is_a