Inhibitory mechanism of phenolic compounds in rapeseed oil on α-amylase and α-glucosidase: Spectroscopy, molecular docking, and molecular dynamic simulation

Developing naturally active components to control a-amylase/a-glucosidase activity is highly desired for preventing and managing type 2 diabetes. Rapeseed oil is rich in active phenolic compounds and seed oil is a major source of liposoluble inhibitors to these enzymes. However, it remains unclear about the interaction of phenolic compounds in rapeseed oil with a-amylase/a-glucosidase. This study found that the important phenolic compounds from rapeseed oil (Sinapic acid, SA; canolol, CAO; canolol dimer, CAO dimer) possessed effective inhibition performance against a-amylase and a-glucosidase. CAO showed the lowest and highest inhibitory effect, respectively. In the kinetics studies, the inhibition mechanism of SA/CAO/CAO dimer against a-glucosidase was non-competitive, exhibiting a different way from a-amylase. Fluorescence quenching spectra implied that the static processes were responsible for the spontaneous binding between the compounds and enzymes. Fouriertransform infrared spectroscopy (FT-IR) displayed these compounds-induced conformation alterations of a-amylase/a-glucosidase. Molecular docking revealed that SA/CAO/CAO dimer decreased the catalytic efficiency of a-amylase/a-glucosidase through hydrogen bonds, hydrophobic force, or 7L-7L interaction. Molecular dynamics matched well with the experimental and docking results regarding the inhibitory behaviors and interactions

Automated summary

The important phenolic compounds from rapeseed oil were found to effectively inhibit a-amylase and a-glucosidase. The inhibition mechanism was non-competitive and involved hydrogen bonds, hydrophobic force, or 7L-7L interaction. These compounds-induced conformation alterations of the enzymes were confirmed by FT-IR and molecular dynamics.