Methyltransferase involved in the biosynthesis of the benzylisoquinoline alkaloid noscapine (PubMed:22535422, PubMed:22653730, PubMed:29610307). Catalyzes the conversion of (S)-scoulerine to (S)-tetrahydrocolumbamine (PubMed:22535422, PubMed:22653730). Can convert (S)-tetrahydrocolumbamine to tetrahydropalmatine (PubMed:22535422). Can convert (S)-norreticuline to (S)-norcodamine (PubMed:22535422). Can convert (S)-reticuline to (S)-codamine (PubMed:22535422). Substrate preference is (S)-scoulerine > (S)-tetrahydrocolumbamine > (S)-norreticuline > (S)-reticuline (PubMed:22535422). (S)-scoulerine + S-adenosyl-L-methionine = (S)-tetrahydrocolumbamine + H(+) + S-adenosyl-L-homocysteine (S)-tetrahydrocolumbamine + S-adenosyl-L-methionine = H(+) + S-adenosyl-L-homocysteine + tetrahydropalmatine (S)-norreticuline + S-adenosyl-L-methionine = (S)-norcodamine + H(+) + S-adenosyl-L-homocysteine (S)-reticuline + S-adenosyl-L-methionine = (S)-codamine + H(+) + S-adenosyl-L-homocysteine Alkaloid biosynthesis. Homodimer. Highly expressed in capsules (PubMed:22653730). Expressed is stems (PubMed:22653730, PubMed:22535422). Expressed at low levels in roots (PubMed:22535422). Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family. COMT subfamily.