https://www.selleckchem.com/products/GDC-0449.html baumannii clinical isolates had weaker biofilm formation capacity than A. baumannii ATCC19606. Colistin-heteroresistant A. baumannii isolates exhibited regrowth after 12 h at 0.5 × MIC, 1 × MIC, and 2 × MIC. The results of PCR and sequencing revealed mutations of lpxACD in some colistin heteroresistant A. baumannii isolates. qRT-PCR also showed that the expressions of efflux pump genes were upregulated in some of the heteroresistant isolates. Our study was the first report of colistin heteroresistant A. baumannii clinical isolates in China. The transition of colistin heteroresistance to resistance should be of concern in future clinical surveillance.InhA or enoyl-acyl carrier protein reductase of Mycobacterium tuberculosis (mtInhA), which controls mycobacterial cell wall construction, has been targeted in the development of antituberculosis drugs. Previously, our in silico structure-based drug screening study identified a novel class of compounds (designated KES4), which is capable of inhibiting the enzymatic activity of mtInhA, as well as mycobacterial growth. The compounds are composed of four ring structures (A-D), and the MD simulation predicted specific interactions with mtInhA of the D-ring and methylene group between the B-ring and C-ring; however, there is still room for improvement in the A-ring structure. In this study, a structure-activity relationship study of the A-ring was attempted with the assistance of in silico docking simulations. In brief, the virtual chemical library of A-ring-modified KES4 was constructed and subjected to in silico docking simulation against mtInhA using the GOLD program. Among the selected candidates, we achieved synthesis of seven compounds, and the bioactivities (effects on InhA activity and mycobacterial growth and cytotoxicity) of the synthesized molecules were evaluated. Among the compounds tested, two candidates (compounds 3d and 3f) exhibited superior properties as mtIn