Enzymatically synthesized kaempferol fatty acid esters enhance glycolipid metabolism regulation and α-glucosidase inhibition.

Kaempferol (KAE) is a dietary flavonoid with recognized effects on glucolipid metabolism and oxidative stress, but its poor lipophilicity and low bioavailability limit its application. In this study, KAE derivatives with different fatty acid chain lengths (C2-C12) were synthesized using acylation catalyzed by lipozyme TL IM, and their biological activities were then systematically evaluated. In vivo assays in hyperglycemic zebrafish (Danio rerio) demonstrated that two medium-chain derivatives, 4'-O-octanoyl-kaempferol (C8-KAE) and 4'-O-decanoyl-kaempferol (C10-KAE), exerted superior effects on glucose regulation, lipid metabolism, and oxidative stress compared with KAE. RT-qPCR analysis showed that C8-KAE and C10-KAE more effectively coordinated the expression of key genes governing gluconeogenesis, glycogen synthesis, lipogenesis, and fatty acid oxidation, indicating multi-target regulation of glucolipid homeostasis. Subsequent in vitro tests confirmed their stronger α-glucosidase inhibitory activity than KAE, while molecular docking, molecular dynamics simulations, and MM/GBSA binding free energy analyses consistently indicated more stable and favorable binding interactions with the enzyme. These findings indicate that medium-chain acylation is an efficient strategy to upgrade KAE into more potent modulators of glucolipid metabolism and identify C8-KAE and C10-KAE as promising lead compounds.