Planta Med 2005; 71(4): 372-375
DOI: 10.1055/s-2005-864108
Letter
© Georg Thieme Verlag KG Stuttgart · New York

Xanthones from the Roots of Polygala caudata and their Antioxidation and Vasodilatation Activities in vitro

Li-Lin Lin1 , Feng Huang1 , Si-Bao Chen1 , 2 , Da-Jian Yang2 , Shi-Lin Chen1 , 2 , Jun-Shan Yang1 , Pei-Gen Xiao1
  • 1Institute of Medicinal Plant Development, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, P. R. China
  • 2Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
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Publikationsverlauf

Received: June 7, 2004

Accepted: November 15, 2004

Publikationsdatum:
27. April 2005 (online)

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Abstract

Three new xanthones, 2-hydroxy-1,6,7-trimethoxyxanthone (1), 1,4-dimethoxy-2,3-methylenedioxyxanthone (2), and 7-hydroxy-1,2-dimethoxyxanthone (3), together with five known compounds, 2,7-dihydroxy-1-methoxyxanthone (4), 1-methoxy-2,3-methylenedioxyxanthone (5), 7-hydroxy-1-methoxyxanthone (6), euxanthone (1,7-dihydroxyxanthone) (7), and gentitein (1,3,7-trihydroxyxanthone) (8), were isolated from the roots of Polygala caudata. Their structures were established on the basis of spectral evidence. In the antioxidation activity screening in vitro with luminol chemiluminescence methods, compounds 1 - 5 and 7 and 8 showed H2O2 scavenger activity, with a scavenging effect of 58.4 - 94.5 % at 10 μg/mL, and 26.0 - 84.7 % at 2 μg/mL. Compounds 4 and 8 also exhibited scavenging effects on the reactive oxygen free radicals produced by macrophage respiratory bursts, with a scavenging effect of 71.7 % and 63.4 % at 10 μg/mL, 41.2 % and 47.8 % at 2 μg/mL, respectively. In the vasodilatation assay, compounds 4 - 7 exhibited relaxing activity on the contractions evoked by KCl in Wistar rat thoracic aorta rings in a dose-dependent manner.

References

Dr. Shi-Lin Chen

Department of Applied Biology & Chemical Technology

The Hong Kong Polytechnic University

Hung Hom, Kowloon

Hong Kong

Fax: +852-2364-9932

eMail: bcslchen@inet.polyu.edu.hk