Abstract
Natural free fatty acids show inhibitory effects on α-glucosidase and can hence have potential applications in diabetes treatment. This study indicated that the inhibitory effect of fatty acids showed a significant negative correlation with affinity energy (- 0.87) and melting point (- 0.88). Guided by this relationship, two promotion strategies of hydration and esterification were put forward to increase the inhibitory effect of fatty acids on α-glucosidase. The hydration can import an extra hydroxy group into the C=C bond of fatty acids, that will enhance the interaction with α-glucosidase, while the esterification will lower the melting point of fatty acids, and promote the inhibitory effect. Hydroxy fatty acids and fatty acid isopropyl esters possessed higher inhibitory effects than the natural fatty acids. Then, rubber seed oil was modified into novel fatty acid derivatives with higher inhibitory effect on α-glucosidase. The inhibitory IC50 of hydroxy products and isopropanol esters was 0.42 ± 0.01 μM and 0.57 ± 0.01 μM, respectively. The result reveals a feasible route to construct fatty acid derivatives from natural oil with α-glucosidase inhibitory effect.