
Design and Evaluation of Heterocyclic Analogues with Multi-Target Biological Potential: A Synthetic and Computational Approach
Mohammadreza Rahimi 1 ℗, Saghi Sepehri 2 ©, Mansour Miran 3, Parastou Saeedkhani 1, Fatemeh Mansouri 1, Daniyal Abbasi 1, Somayeh Ranjbari 4
Abstract
Introduction: tetrahydropyrimidines (THPMs), synthesized via the Biginelli reaction, are heterocyclic compounds with diverse pharmacological properties. Owing to their structural resemblance to nucleotides, they have gained attention for antioxidant, anticancer, and antimicrobial activities. The present study aimed to synthesize novel THPM analogues and evaluate their biological activities. Methods and Materials: a series of THPM derivatives (4a–4j) were synthesized through a one-pot Biginelli reaction using urea, β-ketoesters or α-ketoacids, and substituted aromatic aldehydes in the presence of Co(HSO₄)₂ as a catalyst. Antioxidant activity was evaluated using the DPPH assay. Cytotoxicity was assessed against HepG-2 and MCF-7 cell lines using the MTT assay. Antimicrobial activity was tested against S. aureus, B. subtilis, E. coli, P. aeruginosa, and C. albicans via the Alamar blue method. In silico analyses included pharmacokinetic prediction, cardiotoxicity assessment, and molecular docking and dynamics simulations at the Eg5 target site. Results: Among the synthesized compounds, 4e and 4a showed the highest antioxidant activity (IC₅₀: 0.07 and 0.83 mg/mL, respectively). Compound 4a exhibited potent cytotoxicity (IC₅₀: 15.81 µM on HepG-2; 16.28 µM on MCF-7), comparable to doxorubicin. Derivative 4d also showed significant anticancer effects (IC₅₀: 12.34 µM and 14.31 µM, respectively). In antimicrobial assays, compound 4b was the most active against S. aureus and B. subtilis (MIC: 7.31 and 10.81 µM), while 4j demonstrated superior activity against P. aeruginosa and E. coli (MIC: 8.12 and 11.45 µM). Docking studies showed stable binding of the most active compounds in the Eg5 active site, which was confirmed by molecular dynamics simulations. Conclusion and Discussion: Structure-activity relationships revealed that the presence of hydroxyl and ethoxy groups at specific positions on the phenyl ring enhanced antioxidant and cytotoxic properties. Lipophilicity and electron-donating characteristics significantly influenced antimicrobial potency. These results highlight THPMs as promising multifunctional agents for pharmaceutical applications. Further preclinical studies are warranted.
Keywords: Antioxidant, Dihydropyrimidine, Biginelli reaction, Neoplasm, Molecular dynamics simulations