Study On The Secondary Metabolites And Their Bioactivities Of Two Actinomycetes

Hainan province is located in the tropical and subtropical monsoon climate zone, and surrounded by the sea. Wuzhishan is the largest National Nature Reserve of Hainan, and it’s one of the highest original tropical rainforest in the world. Another typical tropical rainforest in Hainan is Bawangling, which has a mild climate and abundanted rainfall, plant, and animal species. The ecosystem is integrated, and the ecological function is complete and the actinomycetes resource is rich. Many of actinomycetes strains possessed antimicrobial activities have been collected from the soil of the above two places, and preliminary identifactions have been made by the group of Professor Zeng Huicai. This study was designed to isolate the bioactive and novel compounds from two strains of the actinomyces.In this study, the fementation broth of two actinomycete strains were extracted with ethanol, and the compounds from the extract were isolated by column chromatography, then the structures of all the compounds were elucidated by physicochemical and spectral data (UV, IR, MS, 1D NMR and 2D NMR). Five new compunds together with seven known compounds and two not elucidated compounds were isolated from the extract of the fementation liquid of Stretomyces sp.15-4-2. Five new compounds were elucidated as 4a,10β-dimethyldecahydronaphthalene-1α,3β,5α,7α-tetraol (1),5αH-eudesmane-1α,6α,11-t--riol (2),2-methyl-2,5,6-bornantriol (3),7-(4-methoxybenzyl)-4,5,6,7-tetrahydro-1,3-oxazepi--ne-5,6-diol (4),4,4’-(3-hydroxypropane-1,1-diyl)diphenol (5). The known compounds were N-(2-hydroxy-1-(4-methoxyphenyl)ethyl)acetamide (6),2-(4-methoxyphenyl)-2-(propylamin--o)ethanol (7), cytoxazone (8), p-hydroxybenzoic acid (9), (2S,3R)-3-hydroxy-2-methylbuta--noic acid (10),p-methylphenol (11), and p-dimethoxy benzene (12). A known compound was extracted from Stretomyces costaricanus and elucidated as actinomycin D (15).The anti-microbial activities of all the compounds were tested by paper disco diffusion method. Compounds 1,6,8,9, and 10 showed anti-microbial activities against methicillin-resistant Staphylococcus aureus. (MRSA), compounds 13 and 14 showed anti-microbial activities against Fusarium oxysporum f.sp. cubense race 4, Fusarium oxysporum f.sp niveum and Fusarium oxysporum f.sp vasinfectum. Among them, the anti-MRSA effects of 6,8,9 and 10 were reported for the first time. Compound 15 exhibited activities towards chronic myelogenous leukemia (K562), human gastric carcinoma (SGC-7901), and human hepatoma (SMMC-7721) cell lines, and the anti-microbiol activities against Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), Fusarium oxysporum f.sp. cubense race 4, Fusarium oxysporum f.sp niveum, and Fusarium oxysporum f.sp vasinfectum were reported for the first time.