Synthesis and biological evaluation of 1,4-pentadien-3-one derivatives containing 1,2,4-triazole

A series of new 1,4-pentadien-3-one derivatives containing 1,2,4-triazole moiety were synthesized. The structures of the synthesized compounds were charactered via H-1 NMR, C-13 NMR and HRMS. Antibacterial bioassays indicated that some of compounds showed potential antibacterial activities against Ralstonia solanacearum (Rs), Xanthomonas oryzae pv. Oryzae (Xoo) and Xanthomonas axonopodis pv. Citri (Xac). Compounds F-8 and F-17 showed good in vitro antibacterial activities against Rs, with the EC50 values of 18.6 and 18.6 mu g/mL, respectively, which were better than commercial agent bismerthiazol (55.2 mu g/mL). Furthermore, compounds F-12 and F-15 showed good in vitro antibacterial activities against Xoo, with the EC50 values of 10.9 and 17.5 mu g/mL, which were better than commercial agent bismerthiazol (69.3 mu g/mL). Moreover, compounds F-2, F-9, F-16 and F-17 showed good in vitro antibacterial activities against Xac, with the EC50 values of 6.6, 5.4, 7.5 and 7.8 mu g/mL, respectively, which were better than commercial agent bismerthiazol (54.9 mu g/mL). The effect of compound F-9 on Xac bacterial cell membrane rupture was observed by scanning electron microscopy (SEM). In addition, antiviral bioassays indicated that some of compounds showed excellent protection activities against tobacco mosaic virus (TMV). Compounds F-5 and F-15 showed good protecting activity against TMV, with the EC50 values of 108.3 and 105.4 mu g/mL, respectively, which were better than commercial agent ningnanmycin (214.7 mu g/mL). Microscale thermophoresis (MST) also showed that the binding of compound F-2 to TMV coat protein (TMV-CP) yielded a Kd value of 1.260 +/- 0.654 mu mol/L, which was very close to ningnanmycin (1.058 +/- 0.286 mu mol/L). Similarly, the molecular docking studies for F-2 and F-5 with TMV-CP (PDB code: 1E17, ID: 4QGH) indicated that compounds F-2 and F-5 had partially interacted with TMV-CP. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.