Synthesis of 2-styryl-quinazoline and 3-styryl-quinoxaline based sulfonate esters via sp3 C–H activation and their evaluation for α-glucosidase inhibition†
Abstract
Synthesis of 2-styryl-quinazolines and 3-styryl-quinoxaline based sulfonates is reported via sp3 C–H functionalization in the presence of triethylamine (10 mol%). The resulting compounds were tested for α-glucosidase enzyme inhibition (in vitro) using acarbose as a standard drug (IC50 = 33 ± 2.65 μM) because α-glucosidases increase the carbohydrate digestion, and therefore the blood glucose levels. Inhibitors of this enzyme are known to reduce postprandial hyperglycemia. Among the compounds screened, 3o and 5n were found to be active with IC50 = 28 ± 1.99 μM and IC50 = 32 ± 2.11 μM, respectively, with a competitive mode of inhibition. The molecular docking analysis using the MAL12 homology model supported the in vitro results. The stability of 5g was studied using DFT calculation and it was found that the difference in total energy of the cis and trans (ΔE) isomers is −85.67 kcal mol−1.