Synthesis and SAR studies of potent H+/K+-ATPase inhibitors of quinazolinone-Schiff’s base analogues

Abstract

A series of quinazolinone derived Schiff base derivatives 7–36 were synthesized and characterized by analytical and spectroscopic techniques. The synthesized analogues were screened for their in vitro H+/K+-ATPase inhibition. Most of the compounds showed excellent activity, compared to that of omeprazole, a reference drug. In particular, hydroxy and methoxy derivatives 13–24 were the most active compounds possessing a significant increase for different substituents on the benzene ring thus, contributing positively to gastric H+/K+-ATPase inhibition. Preliminary structure-activity relationship revealed that the compounds 13–24 with electron donating moiety (OH, OCH3) were found to be excellent activity and compounds 9–12 and 25–36 with electron withdrawing moiety (Cl, F, NO2 and Br) were found to be least antiulcer agents.