Galangin inhibits α-glucosidase activity and formation of non-enzymatic glycation products

[Display omitted] •Galangin reversibly inhibits α-glucosidase in a mixed-type manner.•Galangin binds to the active site of α-glucosidase and induces its conformational change.•The binding is mainly driven by hydrophobic interaction and hydrogen bonds.•Galangin strongly inhibits the formation of advanced glycation end products. Inhibition of α-glucosidase and non-enzymatic glycation is considered as an effective approach to treat type 2 diabetes. Herein, multispectroscopic techniques and molecular docking analysis were used to investigate the inhibition of galangin on α-glucosidase and non-enzymatic glycation. Galangin showed a reversible inhibition on α-glucosidase activity in a mixed-type manner through a monophasic kinetic process, and induced the fluorescence quenching and conformational changes of α-glucosidase by forming α-glucosidase-galgangin complex. Molecular docking revealed that galangin primarily interacted with the amino acid residues within the active site of α-glucosidase, which may prevent the entrance of substrate resulting in a decrease in catalytic efficiency of α-glucosidase. Moreover, galangin moderately inhibited the formation of intermediates of non-enzymatic glycation, fructosamine and α-dicarbonyl compounds and strongly inhibited the formation of advanced glycation end products.