Discovery of a novel chemotype of potent human ENaC blockers using a bioisostere approach. Part 1: Quaternary amines
摘要:
We report the identification of a novel series of human epithelial sodium channel (ENaC) blockers that are structurally distinct from the pyrazinoyl guanidine chemotype found in prototypical ENaC blockers such as amiloride. Following a rational design hypothesis a series of quaternary amines were prepared and evaluated for their ability to block ion transport via ENaC in human bronchial epithelial cells (HBECs). Compound 11 has an IC50 of 200 nM and is efficacious in the Guinea-pig tracheal potential difference (TPD) model of ENaC blockade with an ED50 of 44 mu g kg(-1) at 1 h. As such, pyrazinoyl quaternary amines represent the first examples of a promising new class of human ENaC blockers. (C) 2011 Elsevier Ltd. All rights reserved.
Fifteen novel amiloride analogues were synthesized and their diuretic properties compared to amiloride and triamterene in white wistar rats. Whereas none of the 6‐substituted derivatives exhibited significant natriuretic and antikaliuretic effects, five of the compounds modified in the 2‐position were found equal or better than standards. The results are discussed with respect to chemical structure