目的:研究一株分离自条斑紫菜丝状体上的真菌代谢产物的活性成分。方法:利用电镜观察真菌形态特征,利用MEA培养基进行大规模发酵,经硅胶层析、葡聚糖凝胶层析等各种层析手段分离化合物,通过波谱技术鉴定化合物结构,并利用MTT法测定化合物抗肿瘤活性。结果:该菌属于曲霉属,分离得到了两个化合物1和2,分别为cyclo(L-Trp-L-Phe)(1)和WIN64821(2)。MTT法测试结果表明,cyclo(L-Trp-L-Phe)和WIN64821对37株人体肿瘤细胞株具有中等细胞毒活性,其平均IC50分别为3.3和5.8μg·mL-1。结论:第一次报道这两种化合物的抗肿瘤活性。 OBJECTIVE: To study the active components of a fungal metabolite isolated from mycelia of Porphyra yezoensis. Methods: The morphological characteristics of fungi were observed by electron microscopy. Large-scale fermentation was performed using MEA medium. The compounds were separated by silica gel chromatography and Sephadex chromatography, and the structures of the compounds were identified by spectral analysis. The MTT method was used. Compound antitumor activity was measured. Results: The bacterium belonged to the genus Aspergillus. Two compounds 1 and 2 were isolated, which were cyclo(L-Trp-L-Phe)(1) and WIN64821(2). MTT assay results showed that cyclo (L-Trp-L-Phe) and WIN64821 had moderate cytotoxic activity against 37 human tumor cell lines with average IC50 of 3.3 and 5.8 μg·mL-1, respectively. Conclusion: The antitumor activity of these two compounds was first reported.