Reaction catalyzed by quercetin 3-O-methyltransferase (2.1.1.76), flavonoid 3',5'-methyltransferase (2.1.1.267)

4		+			=	4		+
	4 S-adenosyl-L-methionine	+		quercetin	=		4 S-adenosyl-L-homocysteine	+		3,3',5,7-tetramethoxyquercetin