Bioactive Steroid from the Root Bark of Psorospermum corymbiferum

Aim: To isolate, characterize and investigate the antifungal activity of the root bark of Psorospermum corymbiferum (Clusiaceae). Methods: The finely ground root bark of Psorospermum corymbiferum was cold-extracted by percolation with 98% ethanol (5.0 L) for two weeks. The ethanol extract was macerated with n-hexane, chloroform, ethylacetate and methanol successively to give the respective solvent extracts. Fractionation of the extract was done using column chromatography on silica gel with cyclohexene: ethylacetate (1: 1) as eluents, and the subfractions were purified by TLC using cyclohexane: ethylacetate (7: 3). The structures were elucidated based on spectral analysis (IR, 1H NMR and 13C NMR) in comparison with the data with those reported in the literature. The minimum inhibitory concentration (MIC) was determined on Candida alblican and Candida stelloroides. Results: Three known compounds, acetylvismione F, prenylated bianthrone and 1, 8-dihydroxyanthraquinone and a steroid were isolated from the plant. MIC determined on Candida alblican and C. stelloroides were 20 and 15 μg·mL-1, respectively. The steroidal compound (diosgenin) was characterized for the first time from Psorospermum corymbiferum (Clusiaceae). Conclusion: The results suggested that the isolation has anticandidal properties, supporting the use of this plant in folk medicine. The current drug of choice for disseminated Candidiasis is amphotericin B with MIC of 0.39 μg·mL-1, which could be a promising lead for a new antifungal drug especially if subjected to SAR in antifungal drug design. © 2011 China Pharmaceutical University.