Synthesis and biological activity of 1,4-pentadien-3-one derivatives containing triazine scaffolds

Background Literatures revealed that 1,4-pentadien-3-one and triazine derivatives exhibited a wide variety of biological activities. In order to develop highly bioactive molecules, in this study, a series of novel 1,4-pentadien-3-one derivatives containing triazine moieties were synthesized and their antibacterial and antiviral activities were investigated. Methods A series of novel 1,4-pentadien-3-one derivatives containing triazine moieties were synthesized and characterized in detail via 1H NMR, 13C NMR and HRMS spectra. The antibacterial activities against Xanthomonas axonopodispv. citri (Xac), Xanthomonas oryzaepv. oryzae (Xoo) and Ralstonia solanacearum (R.s) were evaluated at 100 and 50 µg/mL using a turbidimeter and N. tabacun L. leaves under the same age as that of test subjects. The curative, protective and inactivation activities against tobacco mosaic virus (TMV) at a concentration of 500 µg/mL were evaluated via the half-leaf blight spot method. Results The bioassay results showed that some of the target compounds exhibited fine antibacterial activities against Xac and R.s. Particularly, half maximal effective concentration (EC50) values of some target compounds against R.s are visibly better than that of the positive control bismerthiazol (BT). Notably, compound 4a showed excellent inactivation activity against TMV with a EC50 value of 12.5 µg/mL, which was superior to that ofningnanmycin (NNM,13.5 µg/mL). Besides, molecular docking studies for 4awith tobacco mosaic virus coat protein (TMV-CP) showed that the compound was embedded well in the pocket between the two subunits of TMV-CP. These findings indicate that 1,4-pentadien-3-one derivatives containing triazine moieties may be potential antiviral and antibacterial agents.