Home Products Cited in Publications Worldwide Pharmacophore Establishment and Optimization of Saturated 1, 6-Naphthyridine-Fused Quinazolinones that Inhibit Meningoencephalitis-Causing Naegleria fowleri
Lish, Matthew S; McKeon, Jillian EM; Palmentiero, Caroline M; Pomeroy, Julia M; Roster, Colm P; Guzei, Ilia A; Morris, James C; Golden, Jennifer E
DOI:10.1021/acs.jmedchem.4c01630 PMID:39402986
Primary amoebic meningoencephalitis (PAM) is a human brain infection caused by Naegleria fowleri with a 97% mortality rate. Quinazolinones resulting from a Mannich-coupled domino rearrangement were recently identified as inhibitors of the amoeba. Herein, we resolved the effective concentrations for 25 pilot compounds and then, using the Mannich protocol and a key late-stage, N-demethylation/functionalization, we synthesized 53 additional analogs to improve potency, solubility and microsomal stability. We established an antiamoebic quinazolinone pharmacophore, culminating in (±)-trans-57b which featured the best combination of potency, selectivity index, solubility, and microsomal stability. Enantiomeric separation afforded (4aS,13bR)-57b (BDGR-20237) with a 41-fold potency advantage over its enantiomer. ADME and mouse pharmacokinetic profiling for BDGR-20237 revealed high brain penetrance but a limited half-life which did not statistically enhance the mouse survival in a pilot efficacy study. The pharmacophoric model, supported by 88 quinazolinones, several of which exhibit subnanomolar potency, will guide further scaffold optimization.