Synthesis of 13-(substituted benzyl) berberine and berberrubine derivatives as antifungal agents.

By introducing various aromatic groups in 13-C of berberine and berberrubine, a series of 13-(substituted benzyl) berberine and berberrubine derivatives were synthesized and examined for antifungal activities against various human pathogenic fungi. The synthesized compounds exhibited more potent antifungal activities than berberine and berberrubine. Among them, 13-(4-isopropyl benzyl) berberine (6e) exerted the most potent antifungal activities against Candida species (MIC=1-8 microg/ml) and a 4-fold stronger activity than 13-(4-isopropyl benzyl) berberrubine (7e) synthesized by pyrolysis of compound 6e.