Isolation, characterization, and in vitro inhibitory activity of a new alpha-glucosidase inhibitor from Schleichera oleosa (Lour.) Oken leaves

Context: The development of novel and potent alpha-glucosidase inhibitors from natural sources holds immense promise for treating diabetes. Aims: To identify the isolated compound, determine its inhibitory potency, explore its molecular interactions with the alpha-glucosidase receptor, and understand the role of specific structural features in its inhibitory activity. Methods: Research began with the isolation and identification of the new gallic acid derivative of the Schleichera oleosa leaf extract. The isolated compound (1) was characterized as 3,5-dihydroxy-4-methoxybenzoic acid using spectroscopic techniques. In vitro studies were carried out to compare the IC50 values of the ethanolic extract, isolate 1, and acarbose. Results: Isolate 1 exhibited significantly higher inhibitory potency against the -glucosidase enzyme compared to acarbose. Subsequently, molecular docking studies were performed to gain insight into the molecular interactions between the gallic acid derivatives and the active site of the -glucosidase receptor. The docking simulations revealed that the protection of the methyl group on the hydroxy group of the gallic acid derivatives played a crucial role in enhancing its binding affinity to the alpha-glucosidase receptor. This molecular interaction insight provides valuable information for the design of more potent and selective -glucosidase inhibitors based on this structural feature. Conclusions: These results collectively suggest that the newly isolated gallic acid derivative has promising potential as a natural -glucosidase inhibitor for diabetes management. Further research and optimization of this compound could lead to the development of novel and effective therapeutics for glycemic control in individuals with diabetes.