Abstract：Abstract Objective To discover the secondary metabolites with antimicrobial and antitumor activities from the strain Streptomyces sp. Qhu-M197 derived from the alpine meadow in the Qinghai-Tibetan plateau. Methods Firstly, the phylogenetic analysis was performed with the 16S rRNA gene sequence of strain Qhu-M197 to identify its taxonomic status; secondly, the active secondary metabolites were isolated from the fermentation extracts of strain Qhu-M197 by the chromatography, and further identified by high-resolution mass spectrometry combined with data of nuclear magnetic resonance; finally, the antimicrobial and antitumor activities of the isolated compounds were evaluated by the microdilution method and CCK8 methods. Results The phylogenetic analysis revealed that the strain Qhu-M197 belonged to Streptomyces. Furthermore, the fermentation extracts from MS medium displayed significant antibacterial activities against Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis). Four compounds, namely mithramycin, aerugine, aeruginol, and 2,3,4,5-tetrahydro-3,5-dihydroxy-6H-1,5-benzoxazocin-6-one, were isolated and purified from the MS fermentation extracts, mithramycin showed inhibitory activities against S. aureus and B. subtilis with minimal inhibitory concentration (MIC) at 0.012 and 0.095 μg/mL, respectively, and against tumor cell lines HepG2 and MCF-7 with IC50 at 0.45 and 0.46 μmol/L, respectively. Conclusion The study revealed Streptomyces spp, originating from an alpine meadow on the Qinghai-Tibet Plateau, represented by strain Qhu-M197, are important source for discovery of secondary metabolites with antimicrobial and antitumor activities.
樊嘉凯 向信 邓佳文 邱庆辉 马艳 张得钧 张本印*. 高寒草甸链霉菌Qhu-M197活性次级代谢产物的研究[J]. 中国抗生素杂志, 2022, 47(07): 670-676.
Fan Jia-kai, Xiang Xin, Deng Jia-wen, Qiu Qing-hui, Ma Yan, Zhang De-jun, and Zhang Ben-yin. Study on the bioactive secondary metabolites produced by Streptomyces sp. Qhu-M197 derived from the alpine meadow. CJA, 2022, 47(07): 670-676.
