a 4'-hydroxyflavanone + S-adenosyl-L-methionine = a 4'-methoxyflavanone + S-adenosyl-L-homocysteine + H(+)
a 4'-hydroxyflavanone + s-adenosyl-l-methionine = a 4'-methoxyflavanone + s-adenosyl-l-homocysteine + h(+)
"isoflavone O-methyltransferase"
"isoflavone o-methyltransferase"