Reaction catalyzed by flavone 3'-O-methyltransferase (2.1.1.42)

		+			=			+
	S-adenosyl-L-methionine	+		3,3',4',5,5',7-hexahydroxyflavone	=		S-adenosyl-L-homocysteine	+		3,4',5,5',7-pentahydroxy-3'-methoxyflavone