目的 研究涠洲岛珊瑚共附生真菌Alternaria sp. GXIMD 02516的次级代谢产物及其抗菌活性。方法 采用硅胶柱色谱等技术对化合物进行分离纯化，利用核磁共振、质谱等谱学技术进行结构鉴定，采用滤纸片琼脂扩散法和改良肉汤稀释法测定其抑菌活性。结果 从菌株Alternaria sp. GXIMD 02516的次级代谢产物中分离鉴定了15个化合物，分别为钩端孢菌素N（1）、leptosphaerin L（2）、clearanol D（3）、3-(1-羟乙基)-7-甲氧基苯酞（4）、porriolide（5）、tenuissimasatin（6）、(R)-3,4-二氢-4,6,8-三羟基-4,5-二甲基-3-亚甲基异铬烯-1-酮（7）、1-脱氧红布内酯（8）、djalonensone（9）、百叶酚（10）、phaeosphaeride A（11）、对羟基苯甲醛（12）、chaxine B（13）、BB（14）、去甲基林西甾醇A₃（15）。化合物9～11和13～15对铜绿假单胞菌具有抑制作用，最小抑菌浓度（minimal inhibitory concentration，MIC）为0.78～25 μg/mL，化合物13～15还对表皮葡萄球菌和耐甲氧西林金黄色葡萄球菌具抑制作用，MIC为0.78～3.13 μg/mL。结论 化合物1为新化合物，4为新天然来源苯并呋喃酮类化合物，化合物11和13～15为首次从该属中分离得到，化合物9～11和13～15具有抑菌活性。

Objective To investigate secondary metabolites of the Weizhou Island coral-associated fungus Alternaria sp. GXIMD 02516 and their antibacterial activities. Methods The compounds were isolated and purified by chromatographic methods exemplified by silica gel column. The structures of the compounds were identified by extensive spectroscopic methods, including NMR, MS, etc. Their antibacterial activity was further evaluated by methods of the Kirby-Bauer test and the modified broth dilution. Results 15 compounds were isolated and identified from the fungus Alternaria sp. GXIMD 02516, which were identified as leptosphaerin N (1), leptosphaerin L (2), clearanol D (3), 3-(1-hydroxyethyl)-7-methoxyphthalide (4), porriolide (5), tenuissimasatin (6), (R)-3,4-dihydro-4,6,8-trihydroxy-4,5-dimethyl-3-methyleneisochromen-1-one (7), 1-deoxyrubralactone (8), djalonensone (9), stemphyperylenol (10), phaeosphaeride A (11), para-hydroxybenzaldehyde (12), chaxine B (13), BB (14), and demethylincisterol A₃ (15). Compounds 9—11 and 13—15 showed inhibitory activity against Pseudomonas aeruginosa, with minimal inhibitory concentration (MIC) values of 0.78—25 μg/mL. Moreover, compounds 13—15 showed inhibitory activity against Staphylococcus epidermidis albus and Methicillin resistant Staphylococcus aureus, with MIC values of 0.78—3.13 μg/mL. Conclusion Compound 1 was a new compound, and compound 4 was a new natural benzofuranone derivative. Besides, compounds 11 and 13—15 were obtained from the Alternaria genus for the first time. Compounds 9—11 and 13—15 showed antibacterial activities.

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广西杰出青年科学基金项目(2024GXNSFFA010004);广西重点研发计划项目(桂科AB24010109);国家自然科学基金项目(U20A20101);辽宁省博士科研启动基金计划(2022-BS-160);广西海洋药物重点实验室开放课题(LMD2023-5)