Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore.
Molecules. 2023 Aug 2;28(15):5832. doi: 10.3390/molecules28155832.
Natural products have long been used as a source of antimicrobial agents against various microorganisms. Actinobacteria are a group of bacteria best known to produce a wide variety of bioactive secondary metabolites, including many antimicrobial agents. In this study, four actinobacterial strains found in Singapore terrestrial soil were investigated as potential sources of new antimicrobial compounds. Large-scale cultivation, chemical, and biological investigation led to the isolation of a previously undescribed tetronomycin A () that demonstrated inhibitory activities against both Gram-positive bacteria (SA) and methicillin-resistant (MRSA) (i.e., MIC of 2-4 μM and MBC of 9-12 μM), and several known antimicrobial compounds, namely nonactin, monactin, dinactin, 4E-deacetylchromomycin A3, chromomycin A2, soyasaponin II, lysolipin I, tetronomycin, and naphthomevalin. Tetronomycin showed a two- to six-fold increase in antibacterial activity (i.e., MIC and MBC of 1-2 μM) as compared to tetronomycin A (), indicating the presence of an oxy-methyl group at the C-27 position is important for antibacterial activity.
天然产物一直被用作对抗各种微生物的抗菌剂的来源。放线菌是一类以产生各种生物活性次级代谢产物而闻名的细菌，包括许多抗菌剂。在这项研究中，从新加坡陆地土壤中发现的四种放线菌菌株被作为新的抗菌化合物的潜在来源进行了研究。大规模的培养、化学和生物学研究导致了一种以前未被描述的四烯霉素 A () 的分离，该化合物对革兰氏阳性菌 (SA) 和耐甲氧西林的 (MRSA) 都表现出抑制活性（即 MIC 为 2-4 μM，MBC 为 9-12 μM），以及几种已知的抗菌化合物，即非烯霉素、单烯霉素、二烯霉素、4E-去乙酰基克拉霉素 A3、克拉霉素 A2、大豆皂素 II、脂解素 I、四烯霉素和萘甲羟肟酸。与四烯霉素 A () 相比，四烯霉素的抗菌活性（即 MIC 和 MBC 为 1-2 μM）提高了两到六倍，这表明 C-27 位置上存在一个氧甲基基团对抗菌活性很重要。
