Syntheses, antiviral activities and induced resistance mechanisms of novel quinazoline derivatives containing a dithioacetal moiety

[Display omitted] •Novel quinazoline derivatives containing dithioacetal moiety were designed and synthesized.•Compound 4b exhibited excellent activity against cucumber mosaic virus and potato virus Y.•Compound 4b can induce resistance of tobacco. A series of novel quinazoline derivatives containing a dithioacetal moiety were designed and synthesized, and their structures were characterized by 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, and high-resolution mass spectrometry. Bioassay results indicated that compound 4b exhibited remarkable protective activity against cucumber mosaic virus (CMV, EC50 = 248.6 μg/mL) and curative activity against potato virus Y (EC50 = 350.5 μg/mL), which were better than those of ningnanmycin (357.7 μg/mL and 493.7 μg/mL, respectively). Moreover, compound 4b could increase the chlorophyll content in plants, improve photosynthesis, and effectively induce tobacco anti-CMV activity.