Phenolic antioxidants from the whole plant of Phyllanthus urinaria

Chem Biodivers. 2007 Sep;4(9):2246-52. doi: 10.1002/cbdv.200790183.

Abstract

The 1,1-diphenyl-2-picrydydrazyl (DPPH) assay on the extract of Phyllanthus urinaria L. (Euphorbiaceae) displayed considerable radical-scavenging activity (SC50 = 14.3 microg/ml). Further bioassay-guided purification of the extract led to the isolation of a series of 15 phenolic compounds, including the ellagitannins 1-7, the flavonoids 8-10, and the simple hydroxylated (or glycosylated) aromatic acids 11-15. Their structures were identified by spectroscopic analyses and comparison with authentic samples or literature data. The structure of repandinin B (1) was for the first time fully assigned by 1D- and 2D-NMR experiments. The phenolic compounds 1, 3, 4, 6, 9, 11, and 15 have not been isolated before from the title plant. The antioxidant activities and mushroom-tyrosinase-inhibitory activities of all compounds were determined by DPPH-radical-scavenging and mushroom-tyrosinase-inhibitory assays (Table 2).

MeSH terms

  • Antioxidants / chemistry*
  • Antioxidants / isolation & purification
  • Antioxidants / pharmacology*
  • Biphenyl Compounds / chemistry
  • Flavonoids / chemistry
  • Flavonoids / isolation & purification
  • Flavonoids / pharmacology
  • Hydrazines / chemistry
  • Hydrolyzable Tannins / chemistry
  • Hydrolyzable Tannins / isolation & purification
  • Hydrolyzable Tannins / pharmacology
  • Monophenol Monooxygenase / antagonists & inhibitors
  • Phenols / chemistry*
  • Phenols / isolation & purification
  • Phenols / pharmacology*
  • Phyllanthus / chemistry*
  • Picrates
  • Plant Extracts / chemistry

Substances

  • Antioxidants
  • Biphenyl Compounds
  • Flavonoids
  • Hydrazines
  • Hydrolyzable Tannins
  • Phenols
  • Picrates
  • Plant Extracts
  • 1,1-diphenyl-2-picrylhydrazyl
  • Monophenol Monooxygenase