Synthesis and antiviral bioactivities of 2-aryl- or 2-methyl-3-(substituted-benzalamino)-4(3H)-quinazolinone derivatives

A simple and general method has been developed for the synthesis of various 4(3H)-quinazolinone derivatives by the treatment of the appropriate 3-amino-2-aryl-4(3H)-quinazolinone with a substituted benzaldehyde in ethanol. The structures of the compounds were characterized by elemental analysis, IR, H-1-NMR and C-13-NMR spectra. The title 2aryl- or 2-methyl-3-(substituted-benzalamino)-4(3H)-quinazolinone compounds III-1 similar to III-31 were found to possess moderate to good antiviral activity. Semi-quantitative PCR and Real Time PCR assays were used to ascertain the target of action of compound III-31 against TMV. The studies suggest that III-31 possesses antiviral activity due to induction of up-regulation of PR-1a and PR-5, thereby inhibiting virus proliferation and movement by enhancement of the activity of some defensive enzyme.