Quinazoline-2,4(1H,3H)-dione derivatives as new class of CB1 Agonists: A pharmacophore-based virtual screening workflow and drug discovery.

Background: The cannabinoid 1 (CB1) receptor is the primary target of Δ Methods: Here, we identified novel CB1 agonists using virtual screening approaches. First, we developed a pharmacophore model based on the known CB1 agonist AM11542 and screened a database of over three million compounds. Molecular docking using AutoDock Vina identified 61 hits with binding affinities of less than -9.00 Kcal/mol. Subsequent ADME-Tox (absorption, distribution, metabolism, excretion, and toxicity) analysis narrowed the selection to 18 promising candidates. Results: Among these, three agonists exhibited strong characteristics, including a favorable inhibition constant (Ki) and key hydrogen-bond interactions with critical residues in the CB1 binding pocket: PUBChem157251136 (Ki=2.09 nM), ZINC64438485 (Ki= 0.262 nM) and ZINC64438506 (Ki =0.244 nM). These agonists formed stable hydrogen bonds with CB1 binding pocket residues (Ser383, Ser173, His178 and Thr197). Molecular dynamics simulations (100 ns, GROMACS) demonstrated structural stability (RMSD < 1 nm) and low conformational flexibility (RMSF < 1 nm) for all complexes. MM-GBSA binding free energy calculations further confirmed the thermodynamic stability of all complexes, with interaction energies ranging from -30.59 to -49.98 kcal/mol. These comprehensive simulations confirm that all identified agonist complexes maintain stable binding conformations with optimal interaction profiles characteristic of CB1 receptor activation. Conclusion: These results could pave the way for researching and developing new quinazolinz-2, 4(1H, 3H)-Dione derivatives as a new class of CB1 receptor agonists.