Chromone-3-acrylic acid ester analogues: Design, synthesis and biological evaluation as potential pancreatic lipase inhibitors

A novel series of 21 chromone-3-acrylic acid ester analogues (5aa-5cm) were designed, synthesized and evaluated for PL inhibitory activity. The molecular docking study indicate that all the designed chromone analogues have the good binding ability (MolDock score: -115.86 to -160.07 kcal/mol) in the active site of PL enzyme (PDB ID: 1LPB), showing interactions with essential amino acid residues (Phe77, Tyr114, Ser152, Phe215, Arg256). Also, all the analogues were checked for in silico drug likeness property and all were found to have drug like properties, obeying Lipinski rule of 5, with no PAINS alerts. Analogue 5am, with the best docking score, was stable in molecular dynamics simulation for 100 ns (maximum RMSD of 6.4 & ANGS;), showing crucial amino acid interactions for more than 60% of the simulation time. The structure of the synthesized analogues were then confirmed by NMR, HRMS and IR spectroscopy. Among the synthesized analogues, 5am and 5ad exhibited potent PL inhibition with IC50 of 5.16 & PLUSMN; 0.287 & 5.82 & PLUSMN; 0.933 & mu;M, respectively, as compared with orlistat (IC50 = 0.86 & PLUSMN; 0.09 & mu;M). The inhibition kinetics and in silico studies confirmed competitive type of inhibition of analogue 5am. The current work highlights the importance of chromone analogues as potential PL inhibitors. Further, the lead optimization may lead to much more potential PL inhibitors.