Antifungal activity of magnolol and honokiol

Two neolignan compounds, magnolol (5,5'-diallyl-2,2'-dihydroxybiphenyl, 1) and honokiol (5,5'-diallyl-2,4'-dihydroxybiphenyl, 2), were isolated from the stem bark of Magnolia obovata and evaluated for antifungal activity against various human pathogenic fungi. Compound 1 and 2 showed significant inhibitory activities against Trichophyton mentagrophytes, Microsporium gypseum, Epidermophyton floccosum, Aspergillus niger, Cryptococcus neoformans, and Candida albicans with minimum inhibitory concentrations (MIC) in a range of 25-100 microg/ml. Therefore, compound 1 and 2 could be used as lead compounds for the development of novel antifungal agents.