Reversible Inhibitors of the Gastric (H+/K+)-ATPase. 5. Substituted 2,4-Diaminoquinazolines and Thienopyrimidines
作者:Robert J. Ife、Thomas H. Brown、Peter Blurton、David J. Keeling、Colin A. Leach、Malcolm L. Meeson、Michael E. Parsons、Colin J. Theobald
DOI:10.1021/jm00014a027
日期:1995.7
Quinazolines bearing a secondary 4-(arylamino) substituent demonstrate an SAR for inhibition of the gastric (H+/K+)-ATPase different from the previously described 3-acylquinolines, suggesting that, although these compounds are also K+-competitive, they probably bind to the enzyme in a different orientation. Compounds bearing a tertiary 4-(arylamino) substituent, however, in particular 4-(N-methylarylamino), appear to possess an SAR quite similar to the 3-acylquinolines. We show that this arises from the effect of the N-methylation, which is to orientate the 4-(arylamino) substituent syn to C-5, analogous to the 3-acylquinolines. Compounds possessing both a 4-(N-methylarylamino) substituent and a 2-(arylamino) substituent proved to be very potent, K+-competitive inhibitors of K+-stimulated ATPase activity with K-i values down to 12 nM. Some compounds also proved to be effective inhibitors of stimulated acid secretion in both the rat and dog when dosed intravenously. However, although a number of these demonstrated activity after oral administration in the dog, the level and variability precluded further evaluation.