Methyltransferase involved in the biosynthesis of the benzylisoquinoline alkaloid noscapine (By similarity). Catalyzes the conversion of (S)-scoulerine to (S)-tetrahydrocolumbamine (By similarity). (S)-scoulerine + S-adenosyl-L-methionine = (S)-tetrahydrocolumbamine + H(+) + S-adenosyl-L-homocysteine Alkaloid biosynthesis. Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family. COMT subfamily.