A new cytochalasin from endophytic Phomopsis sp. IFB-E060

AIM:To study the chemical constituents of the solid culture of the endophyte Phomopsis sp.IFB-E060 in Vatica mangachapoi.METHOD:Isolation and purification were performed through silica gel column chromatography,gel filtration over Sephadex LH-20,ODS column chromatography,and HPLC.Structures of the isolated compounds were elucidated by a combination of spectroscopic analyses(UV,CD,IR,MS,1D,and 2D NMR).The cytotoxicity of the isolates was evaluated in vitro by the MTT method against the human hepatocarcinoma cell line SMMC-7721.RESULTS:Five compounds were isolated from the solid culture of the endophyte Phomopsis sp.IFB-E060 and their structures were identified as 18-methoxy cytochalasin J(1),cytochalasin H(2),(22E,24S)-cerevisterol(3),ergosterol(4),and nicotinic acid(5).Compound 1 had an inhibition rate of 24.4% at 10 gmL-1 and 2 had an IC50 value of 15.0 gmL-1,while a positive control 5-fluorouracil had an inhibition rate of 28.7% at 10 gmL-1.CONCLUSION:18-Methoxy cytochalasin J(1),produced by endophytic Phomopsis sp.IFB-E060,is a new cytochalasin with weak cytotoxicity to the human hepatocarcinoma cell line SMMC-7721.