3,4-dihydroxy-5-methoxyphenethylamine + S-adenosyl-L-methionine = 4-hydroxy-3,5-dimethoxyphenethylamine + S-adenosyl-L-homocysteine + H(+)
3,4-dihydroxy-5-methoxyphenethylamine + s-adenosyl-l-methionine = 4-hydroxy-3,5-dimethoxyphenethylamine + s-adenosyl-l-homocysteine + h(+)