Chitosan-derived porous magnetic M-NPC/Arg/SO3H nanocatalyst for the green synthesis of 1,2-disubstituted benzimidazoles: docking study against CXCR4 and Anti-HIV therapeutics

This study presents the development of a novel, magnetically recoverable sulfonic acid-functionalized nitrogen-doped porous carbon nanocatalyst derived from well-characterized chitosan extracted from Persian Gulf shrimp shell waste. Chitosan, as the key renewable carbohydrate polymer, was first coated onto cobalt ferrite nanoparticles at optimized loadings, followed by controlled carbonization to form the magnetic nitrogen-doped porous carbon (M-NPC) support. Sequential functionalization with arginine and sulfonic acid groups afforded the highly active heterogeneous solid acid catalyst M-NPC/Arg/SO 3 H. Comprehensive characterization confirmed the crystalline structure, uniform morphology, high surface area, thermal stability, and superparamagnetic behavior of the catalyst, enabling facile magnetic recovery. The catalyst excelled in the green one-pot synthesis of 1,2-disubstituted benzimidazoles under mild conditions, delivering high yields. M-NPC/Arg/SO 3 H showed excellent turnover metrics, negligible metal leaching, and remarkable recyclability. Molecular docking against CXCR4 (PDB: 3ODU) revealed favorable binding to Arg188 and Trp102. Most compounds satisfied Lipinski’s Rule of Five, exhibited excellent predicted oral absorption, high Caco-2 permeability and moderate-to-high CNS activity, positioning them as promising CXCR4 antagonist leads for HIV-1 entry inhibition and cancer metastasis suppression. This integrated approach combines waste valorization of a renewable polysaccharide, sustainable catalysis, green synthesis and virtual screening, offering an eco-friendly platform for drug discovery.