(S)-bulbocapnine + S-adenosyl-L-methionine = (S)-N-methylbulbocapnine + S-adenosyl-L-homocysteine + H(+)
(s)-bulbocapnine + s-adenosyl-l-methionine = (s)-n-methylbulbocapnine + s-adenosyl-l-homocysteine + h(+)