Green synthesis of tetrahydropyridine-3-carboxylate derivatives and evaluation of antimicrobial and antimalarial activities supported by molecular docking, POM studies, and drug-likeness analysis.

A series of novel haloarene-decorated tetrahydropyridine derivatives B(1a-1f) were synthesized via a simple, environmentally benign one-pot multicomponent reaction employing ethanol as a green solvent and [Et₃NH][HSO₄] as a Brønsted acid ionic liquid catalyst. The reaction utilized methyl acetoacetate (1 mmol), substituted aromatic aldehydes (2 mmol), and substituted anilines (2 mmol) at 60 °C to afford the desired compounds. All compounds were evaluated for their in vitro antimicrobial activity against three fungal strains (Candida albicans, Aspergillus niger, and Aspergillus clavatus), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and two Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes), using the serial broth dilution method. Additionally, their antimalarial potential was assessed against chloroquine- and quinine-sensitive 3D7 and multidrug-resistant Dd2 strains of Plasmodium falciparum. Among the synthesized derivatives, compounds B1a, B1b, and B1b exhibited the most potent antimicrobial and antimalarial activities. Molecular docking studies revealed that compound B1f showed the highest binding affinity toward S. aureus nucleoside diphosphate kinase, with a predicted free binding energy of - 913 kcal/mol. Pharmacological profiling suggested favorable drug-like properties and non-toxic behavior. These findings highlight haloarene-decorated tetrahydropyridine derivatives as promising dual-action candidates with potential to combat both bacterial and malarial infections.