Abstract: Endophytes had plentiful biological diversity,and become an potential microorganism resource.The research on endophytes could have some significance for the protection of wild and endangered medicinal plants,expanding medicinal resources and the research and development of new drugs.Chemical constituents of fermentation broth of endophytic fungus Nigrospora sp.BM-2 was isolated from the leaf of Saccharum arundinaceum Retz were studied using column chromatography,semi-preparative HPLC,ODS column chromatography and Sephadex LH-20 column chromatography,respectively.Ten compounds were obtained.Based on NMR and MS analyses,their structures were elucidated as Pestalotiopyrones G (1),Nigrosporapyrone D (2),Pestalotiopyrones A (3),Hydroxypestalopyrone (4),Mellein (5),6-hydroxymellein (6),4-hydroxymellein (7),5,8-dihydroxy-4-methyl-coumarin (8),1H-indole-3-carboxaldehyde (9) and Isosclerone (10).Preliminary in vitro cytotoxic screening showed that all the compounds has no significant inhibitory activity against HepG2 and Caski cell lines,IC₅₀>100 μM.In addition,compounds 2-4 and 6-10 were isolated from Nigrospora sp.for the first time.

Key words: endophytic fungus, Saccharum arundinaceum Retz., secondary metabolite, structural elucidation