International Journal of Molecular Sciences (May 2012)

Evaluation of Antioxidant and Free Radical Scavenging Capacities of Polyphenolics from Pods of <em>Caesalpinia pulcherrima</em>

  • Mei-Hsiang Lin,
  • Mei-Hsien Lee,
  • Lih-Chi Chen,
  • Wen-Chi Hou,
  • Hsiao-Jen Lu,
  • Tzu-Hua Wu,
  • Feng-Lin Hsu,
  • Wei-Jan Huang

DOI
https://doi.org/10.3390/ijms13056073
Journal volume & issue
Vol. 13, no. 5
pp. 6073 – 6088

Abstract

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Thirteen polyphenolics were isolated from fresh pods of <em>Caesalpinia pulcherrima </em>using various methods of column chromatography. The structures of these polyphenolics were elucidated as gallic acid (<strong>1</strong>), methyl gallate (<strong>2</strong>), 6-<em>O</em>-galloyl-D-glucoside (<strong>3</strong>), methyl 6-<em>O</em>-galloyl-β-D-glucoside (<strong>4</strong>), methyl 3,6-di-<em>O</em>-galloyl-α-D-glucopyranoside (<strong>5</strong>), gentisic acid 5-<em>O</em>-α-D-(6'-<em>O</em>-galloyl)glucopyranoside (<strong>6</strong>), guaiacylglycerol 4-<em>O</em>-β-D-(6'-<em>O</em>-galloyl)glucopyranoside (<strong>7</strong>), 3-methoxy-4-hydroxyphenol 1-<em>O</em>-β-D-(6'-<em>O</em>-galloyl)glucopyranoside (<strong>8</strong>), (+)-gallocatechin (<strong>9</strong>), (+)-catechin (<strong>1</strong><strong>0</strong>), (+)-gallocatechin 3-<em>O</em>-gallate (<strong>1</strong><strong>1</strong>), myricetin 3-rhamnoside (<strong>1</strong><strong>2</strong>), and ampelopsin (<strong>1</strong><strong>3</strong>). All isolated compounds were tested for their antioxidant activities in the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and peroxynitrite radicals scavenging assays. Among those compounds, <strong>11</strong>, <strong>12</strong>, and <strong>2</strong> exhibited the best DPPH-, hydroxyl-, and peroxynitrite radical-scavenging activities, respectively. Compound <strong>7</strong> is a new compound, and possesses better scavenging activities towards DPPH but has equivalent hydroxyl radical scavenging activity when compared to BHT. The paper is the first report on free radical scavenging properties of components of the fresh pods of <em>Caesalpinia pulcherrima</em>. The results obtained from the current study indicate that the free radical scavenging property of fresh pods of <em>Caesalpinia pulcherrima</em> may be one of the mechanisms by which this herbal medicine is effective in several free radical mediated diseases.

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