label: 4',7,8-trihydroxyflavone + S-adenosyl-L-methionine = 7,8-dihydroxy-4'-methoxyflavone + S-adenosyl-L-homocysteine + H(+)
label_lc: 4',7,8-trihydroxyflavone + s-adenosyl-l-methionine = 7,8-dihydroxy-4'-methoxyflavone + s-adenosyl-l-homocysteine + h(+)