label: isorhamnetin 3-O-methyltransferase activity
label_lc: isorhamnetin 3-o-methyltransferase activity
description: "Catalysis of the reaction: isorhamnetin + S-adenosyl-L-methionine = 3,3'-O-dimethylquercetin + H+ + S-adenosyl-L-homocysteine."