Synthesis and three-dimensional quantitative structure-activity relationship study of quinazoline derivatives containing a 1,3,4-oxadiazole moiety as efficient inhibitors against Xanthomonas axonopodis pv. citri

A series of quinazoline derivatives containing a 1,3,4-oxadiazole moiety were synthesized and evaluated for their antibacterial activities against Xanthomonas axonopodis pv. citri (Xac) and Ralstonia solanacearum (Rs). Antibacterial bioassays indicated that most of target compounds exhibited significant antibacterial activities against Xac and Rs in vitro. Strikingly, compounds 6d–6i, 6m–6r and 6u–6x showed antibacterial activity against Xac, with \(\hbox {EC}_{50}\) values ranging from 14.42 to 38.91 \(\upmu \)g/mL, which are better than that of bismerthiazol (39.86 \(\upmu \)g/mL). Based on the antibacterial activity against Xac, comparative molecular filed analysis and comparative molecular similarity index analysis models were generated to investigate the structure-activity relationship of title compounds against Xac. The analytical results indicated that the above models exhibited good predictive accuracy and could be used as practical tools for guiding the design and synthesis of more potent quinazoline derivatives containing a 1,3,4-oxadiazole moiety.