Synthesis, Antibacterial Activity, and Action Mechanism of Novel Sulfonamides Containing Oxyacetal and Pyrimidine.

Bacterial leaf blight (BLB) and bacterial leaf streak (BLS) are two serious bacterial diseases caused by pv. () and pv. (), respectively. However, the control of these diseases by conventional pesticides remains challenging due to development of resistances. We aimed to address this pending problem and developed a series of novel pyrimidine sulfonamide derivatives. Structurally, title compounds bear a unique oxyacetal group, which has a proven immune-activating effect. Compound designed based on the 3D-QSAR model was demonstrated as the optimal activity against and , with EC values of 26.7 and 30.8 mg/L, respectively, which were higher than the positive controls bismerthiazol (29.9 and 32.7 mg/L) and thiodiazole copper (30.5 and 36.4 mg/L). On the prevention level, the biological activity test showed compound had superior protective activity (43.7%) on BLS to thiodiazole copper (32.1%). The defense enzymes and proteomics results suggested that compound could be a versatile candidate as it improved plant's resistance to disease.