Biocatalyzed cross-coupling of sinomenine and 1,2-dihydroxybenzene by Coriolus unicolor

Sinomenine is a clinically available drug for the treatment of rheumatoid arthritis (RA). In a continuous research aiming at discovery of sinomenine derivates with better bioactivity, a cross-coupling reaction of sinomenine and 1,2-dihydroxybenzene catalyzed by a fungus Coriolus unicolor afforded an unique CC cross-coupled compound 2, together with (S)-disinomenine and (R)-disinomenine. The structure of 2 was elucidated by MS and NMR spectroscopy. Compound 2 was further assayed for the inhibitory activity on IL-6 overproduction in SW982 cells and exhibited a much more potent activity on IL-6 (96% inhibition) compared with those of (S)-disinomenine and sinomenine (17% and 12% inhibition, respectively).