Analysis of Phenylpropanoid Components and Antioxidant and Uric Acid-Lowering Activities of Ginger

Abstract

In order to explore the biological functions of active ingredients in dried ginger, high performance liquid chromatography (HPLC) and mass spectrometry (MS) with selective reaction monitoring/multi-reaction monitoring (SRM/MRM) were used for qualitative and quantitative analysis of active ingredients in dried ginger. The antioxidant and uric acid-lowering activities of dried ginger extract and its active components were determined. The results showed that the most abundant phenylpropanoid components in dried ginger extract were phenylalanine, ferulic acid and p-coumaric acid. All these compounds had significant antioxidant capacity in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging capacity and ferric ion reducing power, and the decreasing order of the antioxidant capacity was ferulic acid > dried ginger extract > p-coumaric acid. In vitro xanthine oxidase inhibition assay showed that all the three drugs had strong uric acid lowering activity, the effect of p-coumaric acid being more pronounced than that of ferulic acid and dried ginger extract. Molecular docking revealed that ferulic acid and p-coumaric acid inhibited xanthine oxidase by the formation of hydrogen bonds, van der Waals force and π-π stacking with amino acid residues in the enzyme. In this study, ferulic acid, p-coumaric acid and ginger extract have good antioxidant capacity and xanthine oxidase inhibitory activity in vitro, and therefore have the potential to be developed into new uric acid-lowering products.

Keywords

• dried ginger; ferulic acid; p-coumaric acid; antioxidant activity; xanthine oxidase; molecular docking