中文摘要：

在生物活性测定指导下,综合运用硅胶柱层析、凝胶柱层析以及半制备HPLC等方法,从南海海绵Xestospongiatestudinaria来源的一株共附生真菌Pleosporaceae sp.发酵液的乙酸乙酯提取物中分离鉴定出5个甾体类化物,通过NMR,MS等波谱技术鉴定其结构分别为：（22E,24R）-5α,8α-epidioxy-ergosta-6,22-dien-3β-ol（1）,（22E,24R）-5α,8α-epidioxy-ergosta-6,9,22-trien-3β-ol（2）,（22E）-ergosta-5,7,22-trien-3β-ol（3）,ergosta-6α-hydroxy-4,22-dien-3-one（4）,（22E）-5α-cholesta-7,22-diene-3β,5α,6β-triol（5）。这些化合物均为首次从Pleosporaceae属真菌中分离获得。化合物1,4和5具有较强的卤虫Ar-temia salina致死活性,化合物1还显示强的抗藤壶Balanus amphitrite附着活性,其EC50为0.85μg/mL。

英文摘要：

Under the guidance of bioassay,five steroids were isolated from the ethyl acetate extract of a sponge-derived fungus Pleosporaceae sp.by column chromatography on silica gel and Sephadex LH-20 and preparative-HPLC.Their structures were elucidated as（22E,24R）-5α,8α-epidioxy-ergosta-6,22-dien-3β-ol（1）,（22E,24R）-5α,8α-epidioxy-ergosta-6,9,22-trien-3β-ol（2）,（22E）-ergosta-5,7,22-trien-3β-ol（3）,ergosta-6α-hydroxy-4,22-dien-3-one（4） and（22E）-5α-cholesta-7,22-diene-3β,5α,6β-triol（5）,respectively,on the basis of their spectroscopic data including NMR and MS,combining with the data of literatures.All of the compounds were isolated from the genus of Pleosporaceae for the first time.Compounds 1 and 5 exhibited strong lethality to brine shrimp Artemia salina.And compound 1 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite with the EC50 of 0.85 μg/mL.