Thiazolyl-pyrazoline derivatives: In vitro and in silico evaluation as potential acetylcholinesterase and carbonic anhydrase inhibitors

Abstract

Alzheimer's disease (AD) is a complex, predominant, and progressive form of dementia. The treatment of AD alters depending on the cognitive and behavioral symptoms. The utility of cholinergic replacement by acetylcholinesterase (AChE) inhibitors in AD treatment has been well-documented so far. Recent studies have also demonstrated that human carbonic anhydrases (hCAs) serve as important targets for AD treatment. In an attempt to identify potent AChE and hCA inhibitors, new thiazolyl-pyrazolines (3a-k) were designed based on the molecular hybridization of thiazole and pyrazoline scaffolds. A facile and versatile synthetic route consisting of three steps, namely Claisen-Schmidt reaction, the formation of the 2-pyrazoline ring system, and Hantzsch thiazole synthesis was used to prepare compounds 3a-k. The synthesized derivatives were experimentally validated for efficacy by in vitro and direct enzymatic assays. Furthermore, the compounds were subjected to in silico screening using Schrödinger Suite software to identify the binding affinities of potential compounds based on Glide XP scoring, MM-GBSA calculating, and validation. The results of in vitro and in silico studies revealed that compounds 3a, 3f, and 3d were the most promising derivatives in this series due to their significant effects on AChE, hCA I, and hCA II, respectively.

Keywords: Acetylcholinesterase; Alzheimer's disease; Carbonic anhydrase; Morpholine; Thiazolyl-pyrazoline.