Ministry of Education Key Laboratory of Green Pesticide and Ago-Bioengineering, Center for Research and Development of Fine Chemicals of Guizhou University , Guiyang 550025, People's Republic of China.
The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academy of Sciences , Guiyang 550002, People's Republic of China.
J Nat Prod. 2016 Apr 22;79(4):721-31. doi: 10.1021/acs.jnatprod.5b00641. Epub 2016 Feb 29.
The oleanane-type triterpene 18β-glycyrrhetinic acid (1) was modified chemically through the introduction of a trihydroxylated A ring and an ester moiety at C-20 to enhance its antibacterial activity. Compounds 22, 23, 25, 28, 29, 31, and 32 showed more potent inhibitory activity against Streptomyces scabies than the positive control, streptomycin. Additionally, the inhibitory activity of the most potent compound, 29, against Bacillus subtilis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus was greater than that of the positive controls. The antibacterial mode of action of the active derivatives involved the regulation of the expression of genes associated with peptidoglycans, the respiratory metabolism, and the inherent virulence factors found in bacteria, as determined through a quantitative real-time reverse transcriptase PCR assay.
齐墩果烷型三萜 18β-甘草次酸（1）通过在 C-20 位引入三羟基 A 环和酯基进行化学修饰，以增强其抗菌活性。化合物 22、23、25、28、29、31 和 32 对疮痂链霉菌的抑制活性强于阳性对照药链霉素。此外，最有效的化合物 29 对枯草芽孢杆菌、金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌的抑制活性强于阳性对照药。通过定量实时逆转录 PCR 检测，发现活性衍生物的抗菌作用模式涉及调节与肽聚糖、呼吸代谢和细菌固有毒力因子相关的基因表达。
