Novel Benzoxazin-3-one Derivatives: Design, Synthesis, Molecular Modeling, Anti-HIV-1 and Integrase Inhibitory Assay

Design, synthesis and antifungal activity of novel 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety

A series of 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety were designed, synthesized and evaluated for their in vitro antifungal activities against Gibberella zeae, Pellicularia sasakii, Phytophthora infestans, Capsicum wilt, and Phytophthora capsica. The structures of target compounds were characterized by 1H NMR, 13H NMR, 19F NMR and HRMS. The preliminary antifungal evaluation of all target compounds showed that some target compounds possessed moderate to good activities against G. zeae, P. sasakii, P. infestans and C. wilt. Among them, compounds 5L and 5o exhibited noticeable inhibition effects against G. zeae with the EC50 values (effective concentration for 50% activity) of 20.06 and 23.17 μg/ml, respectively, which were even nearly double effective than that of hymexazol (40.51 μg/ml). Meanwhile, compound 5q displayed a notable inhibitory effect toward P. sasakii, with the EC50 value of 26.66 μg/ml, which was better than that of hymexazol (32.77 μg/ml). In addition, compound 5r yielded the EC50 value of 15.37 μg/ml against P. infestans, which was less than those of hymexazol (18.35 μg/ml) and carbendazim (34.41 μg/ml). Eventually, compound 5p showed higher inhibitory effect against C. wilt, with EC50 value of 26.76 μg/ml, which was better than that of hymexazol (>50 μg/ml).

Design, Synthesis, Molecular Modeling and Anti-HIV Assay of Novel Quinazolinone Incorporated Coumarin Derivatives

BACKGROUND

The emergence of drug-resistant viral strains has created the need for the development of novel anti-HIV agents with a diverse structure that targets key enzymes in the HIV lifecycle.

OBJECTIVE

Considering the pharmacophore of integrase inhibitors, one of the validated targets for anti-HIV therapy, we designed a quinazolinone incorporated coumarin scaffold to affect HIV.

METHODS

Coumarin is a beta enol ester and also a well-known drug scaffold. Designed structures were prepared using a one-pot three-component reaction from 3-amino-4-hydroxycoumarin, isatoic anhydride and benzaldehyde derivatives.

RESULTS

In vitro anti-HIV and cytotoxicity assay indicated that more than half of the compounds had EC50 values lower than 50 µM. Unsubstituted phenyl derivative showed the highest activity and selectivity with an EC50 value of 5 µM and a therapeutic index of 7. Compounds were docked into the integrase active site to investigate the probable mechanism of action. Accordingly, the hydroxyl moiety of coumarin along with the carbonyl of the quinazolinone ring could function as the metal chelating group. Quinazolinone and phenyl groups interact with side chains of IN residues, as well.

CONCLUSION

Here, a novel anti-HIV scaffold is represented for further modification and in-vivo studies.