Inhibitory Mechanism of Engeletin Against α-Glucosidase

The inhibitory mechanism of engeletin against α-glucosidase was investigated for the first time by fluorescence spectroscopy and molecular docking. The results showed that engeletin could inhibit α-glucosidase in a noncompetitive inhibition mode with a half-maximal inhibitory concentration value of 48.5 ± 6.0 µg/mL (0.11 ± 0.014 mmol/L). It was found that engeletin could cause static fluorescence quenching of α-glucosidase by forming a complex with α-glucosidase. The thermodynamic parameters indicated that the combination of engeletin and α-glucosidase was driven by hydrophobic force. The molecular docking results confirmed that some amino acid residues of α-glucosidase (Trp391, Arg428, Glu429, Gly566, Trp710, Glu771) could interact with engeletin by hydrogen bonding.