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

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. (C) 2016 Elsevier Inc. All rights reserved.