Chemical constituents from Tribulus terrestris and screening of their antioxidant activity

Phytochemistry. 2013 Aug;92:153-9. doi: 10.1016/j.phytochem.2013.04.005. Epub 2013 May 2.

Abstract

Two oligosaccharides (1,2) and a stereoisomer of di-p-coumaroylquinic acid (3) were isolated from the aerial parts of Tribulus terrestris along with five known compounds (4-8). The structures of the compounds were established as O-β-D-fructofuranosyl-(2→6)-α-D-glucopyranosyl-(1→6)-β-D-fructofuranosyl-(2→6)-β-D-fructofuranosyl-(2→1)-α-D-glucopyranosyl-(6→2)-β-D-fructofuranoside (1), O-α-D-glucopyranosyl-(1→4)-α-D-glucopyranosyl-(1→4)-α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside (2), 4,5-di-p-cis-coumaroylquinic acid (3) by different spectroscopic methods including 1D NMR ((1)H, (13)C and DEPT) and 2D NMR (COSY, TOCSY, HMQC and HMBC) experiments as well as ESI-MS analysis. This is the first report for the complete NMR spectral data of the known 4,5-di-p-trans-coumaroylquinic acid (4). The antioxidant activity represented as DPPH free radical scavenging activity was investigated revealing that the di-p-coumaroylquinic acid derivatives possess potent antioxidant activity so considered the major constituents contributing to the antioxidant effect of the plant.

MeSH terms

  • Antioxidants / chemistry*
  • Antioxidants / isolation & purification
  • Molecular Structure
  • Oligosaccharides / chemistry*
  • Oligosaccharides / isolation & purification
  • Quinic Acid / chemistry*
  • Quinic Acid / isolation & purification
  • Tribulus / chemistry*

Substances

  • Antioxidants
  • Oligosaccharides
  • Quinic Acid