(S)-tetrahydropapaverine + S-adenosyl-L-methionine <=> (S)-N-methyltetrahydropapaverine + S-adenosyl-L-homocysteine + H(+)
(s)-tetrahydropapaverine + s-adenosyl-l-methionine <=> (s)-n-methyltetrahydropapaverine + s-adenosyl-l-homocysteine + h(+)
(S)-tetrahydropapaverine + S-adenosyl-L-methionine <=> (S)-N-methyltetrahydropapaverine + S-adenosyl-L-homocysteine + H(+)
(s)-tetrahydropapaverine + s-adenosyl-l-methionine <=> (s)-n-methyltetrahydropapaverine + s-adenosyl-l-homocysteine + h(+)