Identification of the effective a-amylase inhibitors from Dalbergia odorifera: Virtual screening, spectroscopy, molecular docking, and molecular dynamic simulation

Inhibiting the activity of alpha-amylase has been considered as one efficient way to prevent and treat type 2 diabetes recently. Dalbergia odorifera, a kind of Leguminosae plant, has a positive therapeutic effect on type 2 diabetes, possibly contributing by some constituents that can inhibit the activity of alpha-amylase. In this study, we found that eriodictyol was one potential constituent through virtual screening. The interaction mode between eriodictyol and alpha-amylase was elucidated by molecular docking, multi-spectroscopic analysis, and molecular dynamic simulation. The results revealed that eriodictyol quenched the intrinsic fluorescence of alpha-amylase, and the quenching mode was static quenching. Eriodictyol could spontaneously interact with alpha-amylase, mostly stabilized and influenced by the hydrophobic interaction, while the binding sites (n) was 1.13 +/- 0.07 and binding constant (K-b) was (1.43 +/- 0.14) x 10(5) at 310 K, respectively. In addition, FT-IR and CD had been applied to identify that eriodictyol can trigger the conformational change of alpha-amylase. Taken together, the results provided some experimental data for developing new alpha-amylase inhibitors from Dalbergia odorifera, which may further prevent and treat diabetes and diabetes complications.