Synthesis of New Glucose-containing 5-Arylisoxazoles and their Enzyme Inhibitory Activity

Carbohydrates are an important group of biomolecules that have received special attention due to their significant role in the design and synthesis of new bioactive compounds. In this study, a new class of 5-arylisoxazole-glucose hybrids was designed and synthesized for evaluation of their inhibitory effects on α-glucosidase, α-amylase, and tyrosinase. The target compounds depicted selective α-glucosidase inhibitory activity over α-amylase, which is an important factor in reducing probable gastrointestinal problems in the treatment of type 2 diabetes. In this respect, compound 9a, possessing the phenylisoxazole group, was found to be the most potent α-glucosidase inhibitor (IC50 = 292.2 ± 0.1 μM) compared to acarbose (IC50 = 750.2 ± 0.1 μM) as the positive control. All compounds were also evaluated for their anti-tyrosinase effect, and among them, compound 9j, containing a fluoroaryl moiety, showed potent activity (IC50 = 50.1 ± 6.3 μM) in comparison to kojic acid (IC50 = 23.6 ± 2.6 μM). Also, docking studies were performed to investigate the probable mode of action, which indicated the construction of important H-bonding interactions between the sugar moiety and the enzyme’s active sites. According to the results, hybrids containing heterocycles attached to glucose can be used to inhibit α-glucosidase.