(S)-norprotosinomenine + S-adenosyl-L-methionine = (S)-6-O-methylnorprotosinomenine + S-adenosyl-L-homocysteine + H(+)
(s)-norprotosinomenine + s-adenosyl-l-methionine = (s)-6-o-methylnorprotosinomenine + s-adenosyl-l-homocysteine + h(+)
(S)-norprotosinomenine + S-adenosyl-L-methionine = (S)-6-O-methylnorprotosinomenine + S-adenosyl-L-homocysteine + H(+)
(s)-norprotosinomenine + s-adenosyl-l-methionine = (s)-6-o-methylnorprotosinomenine + s-adenosyl-l-homocysteine + h(+)