Pyrrolidine-based hybrid compounds: design, synthesis, in vitro and in vivo pharmacological properties and molecular docking studies.

Aims: To design, synthesize, and evaluate pyrrolidine-based hybrids bearing indole, thiourea, and vinyl sulfone pharmacophores as dual inhibitors of human carbonic anhydrase I/II (hCAI/II) and acetylcholinesterase (AChE), with secondary profiling of complementary bioactivities.

Materials & methods: Three hybrids (6a, 6b, 8) were obtained via imine azomethine ylide 1,3-dipolar cycloaddition and derivatization. Structures were confirmed spectroscopically and assayed in vitro for hCAI/II and AChE inhibition. Additional evaluations included antioxidant (DPPH), antibacterial, antifungal, antituberculosis (M. tuberculosis H37Rv), cytotoxicity (HCT116, DPSCs), anti-inflammatory (COX-2, SOD1 ELISA, mouse xylene-induced), antidepressant (forced swim test), molecular docking, and in silico ADMET.

Results: Compound 6b was the most potent inhibitor (hCAII Ki 75.79 ± 2.83 nM, AChE Ki 43.17 ± 10.44 nM), outperforming acetazolamide (Ki 299.33 ± 45.44 nM) and tacrine (Ki 103.47 ± 11.54 nM). Compound 6a showed the strongest antioxidant effect (72.30% DPPH), antibacterial activity against A. baumannii (MIC 125 µg/ml, comparable to ampicillin), and superior anti-TB potency (MIC 31.25 µg/ml). Compound 6b exhibited stronger antibacterial activity (MIC 62.5 µg/ml). Both reduced COX-2 levels, and 6a increased SOD1. The hybrids were selectively cytotoxic to HCT116, sparing DPSCs. Docking studies confirmed key binding interactions, while ADMET predicted favorable profiles.     .

Conclusions: The hybrids validate a focused dual-target strategy. Compound 6b is the most potent hCAII and AChE inhibitor, while 6a emerges as a broader multi-target lead with antioxidant, antimicrobial, anti-inflammatory, and antidepressant potential.