Novel 1,2,4-triazole-based n-mannich derivatives: Synthesis, spectroscopic characterization, cytotoxic, antimicrobial, and enzyme inhibitory activities, and in silico studies

A series of novel 1,2,4-triazole-based Mannich bases was designed, synthesized, and evaluated for biological and theoretical properties. Schiff base intermediates (C1–6) were prepared by condensing 4-benzoxy-3-methoxybenzaldehyde with various 3-substituted-4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones. Mannich reactions with formaldehyde and 2,6-dimethylmorpholine produced six target compounds (D1–6). Structures were confirmed using spectroscopic techniques. Following structural confirmation, the compounds showed significant cytotoxicity against HT-29 and MCF-7 cancer cell lines in MTT assays. Enzyme inhibition studies demonstrated activity against glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH), indicating potential relevance to cancer metabolism. Moderate acetylcholinesterase inhibition was observed, with IC50 values from 56.81 to 182.40 µM. Antimicrobial testing showed that D1, D3, D4, and D5 were active against selected microbial strains, while D2 and D6 were inactive. Density functional theory (DFT) calculations, molecular docking, ADME/T predictions, and molecular mechanics simulations were conducted to complement the experimental findings. These computational analyses indicated favorable binding interactions and pharmacological profiles.In summary, the newly synthesized triazole-based Mannich derivatives represent promising candidates for further pharmacological investigation.