12-hydroxydihydrochelirubine 12-O-methyltransferase activity

Catalysis of the reaction: 12-hydroxydihydrochelirubine + S-adenosyl-L-methionine(1+) = S-adenosyl-L-homocysteine + dihydromacarpine + H(+).

Source:http://purl.uniprot.org/go/0030780