Design, synthesis and biological evaluation of new 1,-Bis-(5-alkyl-3-tosyl-1,3,4,2-triazaphospholino)alkanes as in vitro -amylase and lipase inhibitors

A series of new 1,omega-bis-(5-alkyl-3-tosyl-1,3,4,2-triazaphospholino)alkanes 2 and 3 were obtained in excellent yields by the condensation of 1,omega-bis-(1-tosylamidrazone)alkanes 1 with two equivalent molars of Lawesson's Reagent (LR) and trisdimethylaminophosphine, respectively. All synthesized compounds were characterized by various spectroscopic techniques including IR, 1H NMR, 13C NMR and 31P NMR and elemental analysis. The newly synthesized compounds were evaluated against key enzymes related to diabetes and obesity such as alpha-amylase and lipase. This study showed that the compounds 3a and 2b are an excellent inhibitor of alpha-amylase (with IC50 = 18.8 mM) and lipase (with IC50 = 19 mM) respectively, as compared with standard, orlistat (IC50 = 22 mM). Among this series, compounds 3a and 2b with the CH3 or C2H5 group at position 6 were identified as the most potent inhibitors against alpha-amylase, and lipase enzymes. The remaining compounds were found to be moderately active. Further, molecular docking simulation studies were done to identify the interactions and binding mode of synthesized analogs at binding site of alpha-amylase and lipase enzymes.