| Popis: |
To identify the predominant antioxidant compound in Polygonum cuspidatum leaves, the methanol extract of fresh samples were separated by liquid–liquid partitioning, octadecylsilyl Sep-pak®cartridge and high-performance liquid chromatography. The main active compound was identified as (1R,3R,4S,5R)-3-{[(2E)-3-(3,4-dihydroxyphenyl)-2-propenoyl]oxy}-1,4,5-trihydroxycyclohexanecarboxylic acid (neochlorogenic acid) by nuclear magnetic resonance and liquid chromatographymassspectroscopic analysis. Its content was found to be 2.31 mg/g of fresh leaves. As shown by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide anion scavenging assays, the contributionsof neochlorogenic acid as an antioxidant were 16.5% and 36.5%, respectively, suggesting that neochlorogenic acid is the predominant antioxidant in P. cuspidatum leaves. |
