红树林内生真菌 Aspergillus sp. H6a聚酮类次级代谢产物的分离、鉴定及抑菌活性评价

Isolation, identification and antibacterial activity of polyketone secondary metabolites of endophytic fungus Aspergillus sp. H6a in mangroves

摘要:

目的 探讨红树林内生真菌 Aspergillus sp. H6a中分离获取的聚酮类天然产物。方法 采用柱色谱 和高效液相色谱等分离技术对 Aspergillus sp. H6a的大米固体发酵物进行分离与纯化，借助 NMR 和 MS等波谱学 技术解析它们的结构，使用二倍稀释法评价分离所得化合物的抑菌活性（抑菌测试菌株为金黄色葡萄球菌、大肠 杆菌、藤黄微球菌、粪链球菌、白色念珠菌和黑曲霉）。结果 共分离得到 9 个吡喃酮类化合物，分别鉴定为 4- methyl-5，6-dihydropyren-2-one（1）、aspergyllone（2）、carbonarone A（3）、6-styryl-7，8-dihydroxy-4-methoxypyran-2-one （4）、aspergilluso（l 5）、pyrophen（6）、rubrofusarin B（7）、flavasperone（8）和 isoeugenin（9）。化合物 1、3、7、8 对金黄色 葡萄球和藤黄微球菌均表现出一定的抑菌活性；此外，化合物1对菌粪链球菌、化合物3对黑曲霉、化合物7对大肠 杆菌及粪链球菌亦表现出抑菌活性。结论 从红树林内生真菌Aspergillus sp. H6a中分离获取聚酮类天然产物，其 中化合物1、3、7、8有一定的抑菌制活性。

Abstract:

Objective Explore the polyketide natural products isolated from the endophytic fungus Aspergillus sp. H6a found in mangroves. Methods The solid fermentation products of Aspergillus sp. H6a derived from rice were separated and purified using column chromatography and preparative high-performance liquid chromatography. The structures of these compounds were analyzed by spectroscopic techniques such as nuclear magnetic resonance (NMR) and mass spectrometry (MS). The antibacterial activity of the isolated compounds was evaluated using the double dilution method. Results A total of nine pyranone compounds were isolated, and identified as follows: 4-methyl-5,6- dihydropyren-2-one (1), aspergyllone (2), carbonarone A (3), 6-styryl-7, 8-dihydroxy-4-methoxypyran-2-one (4), aspergillusol (5), pyrophen (6), rubrofusarin B (7), flavasperone (8), and isoeugenin (9). Compounds 1, 3, 7, and 8 all showed certain antibacterial activities against Staphylococcus aureus and Micrococcus luteus. In addition, compound 1 exhibited activity against Streptococcus faecalis, compound 3 against Aspergillus niger, compound 7 against both Escherichia coli and Streptococcus faecalis. Conclusion Polyketide natural products were successfully isolated from the endophytic fungus Aspergillus sp. H6a in mangroves.