Synthesis and biological evaluation of indole derivatives as α-amylase inhibitor

Abstract A series of twenty indole hydrazone analogs ( 1 – 21 ) were synthesized, characterized by different spectroscopic techniques such as 1 H NMR and EI-MS, and screened for α -amylase inhibitory activity. All analogs showed a variable degree of α -amylase inhibition with IC 50 values ranging between 1.66 and 2.65 μM. Nine compounds that are 1 (2.23 ± 0.01 μM), 8 (2.44 ± 0.12 μM), 10 (1.92 ± 0.12 μM), 12 (2.49 ± 0.17 μM), 13 (1.66 ± 0.09 μM), 17 (2.25 ± 0.1 μM), 18 (1.87 ± 0.25 μM), 20 (1.83 ± 0.63 μM), and 19 (1.97 ± 0.02 μM) showed potent α -amylase inhibition when compared with the standard acarbose (1.05 ± 0.29 μM). Other analogs showed good to moderate α -amylase inhibition. The structure activity relationship is mainly focusing on difference of substituents on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.