A series of novel chalcone derivatives containing the 1,2,4-triazine moiety were synthesized and their structures were confirmed by 1H NMR, 13C NMR and elemental analyses.

A series of myricetin derivatives containing amide, thioether, and 1,3,4-thiadiazole moieties were designed and synthesized, and their antiviral and antibacterial activities were assessed. The bioassays showed that all the title compounds exhibited potent in vitro antibacterial activities against Xanthomonas citri (Xac), Ralstonia solanacearum (Rs), and Xanthomonas oryzae pv. Oryzae (Xoo). In particular, the compounds 5a, 5f, 5g, 5h, 5i, and 5l, with EC50 values of 11.5–27.3 μg/mL, showed potent antibacterial activity against Xac that was better than the commercial bactericides Bismerthiazol (34.7 μg/mL) and Thiodiazole copper (41.1% μg/mL). Moreover, the in vivo antiviral activities against tobacco mosaic virus (TMV) of the target compounds were also tested. Among these compounds, the curative, protection, and inactivation activities of 5g were 49.9, 52.9, and 73.3%, respectively, which were better than that of the commercial antiviral Ribavirin (40.6, 51.1, and 71.1%, respectively). This study demonstrates that myricetin derivatives bearing amide, thioether, and 1,3,4-thiadiazole moieties can serve as potential alternative templates for the development of novel, highly efficient inhibitors against plant pathogenic bacteria and viruses.

A series of penta-1,4-dien-3-one oxime ether derivatives containing a quinoxaline moiety were synthesized, and their bioactivities and action mechanism were evaluated.

A series of novel chalcone derivatives containing a thiophene sulfonate group were designed and synthesized. The structures of all title compounds were determined by 1 H-NMR, 13 C-NMR and HRMS.Antibacterial bioassays indicated that, compound 2l demonstrated excellent antibacterial activities against Xanthomonas axonopodis pv. citri (Xac), with an EC 50 value of 11.4 mg mL À1 , which is significantly superior to those of bismerthiazol (BT) (51.6 mg mL À1 ) and thiodiazole-copper (TC) (94.7 mg mL À1 ).Meanwhile, the mechanism of action of compound 2l was confirmed by using scanning electron microscopy (SEM). In addition, compound 2e showed remarkable inactivation activity against Tobacco mosaic virus (TMV), with an EC 50 value of 44.3 mg mL À1 , which was superior to that of ningnanmycin (120.6 mg mL À1 ). Microscale thermophoresis (MST) also showed that the binding of compounds 2e and 2h to Tobacco mosaic virus coat protein (TMV-CP) yielded K d values of 0.270 and 0.301 mmol L À1 , which are better than that of ningnanmycin (0.596 mmol L À1 ). At the same time, molecular docking studies for 2e and 2h with TMV-CP (PDB code: 1EI7) showed that the compound was embedded well in the pocket between the two subunits of TMV-CP in each case. These results suggested that chalcone derivatives containing a thiophene sulfonate group may be considered as activators in the design of antibacterial and antiviral agents.Scheme 1 Synthetic route of title compounds 2a-2v.This journal is