Planta Med 2003; 69(6): 500-505
DOI: 10.1055/s-2003-40641
Original Paper
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

DPPH Radical Scavenging and Nitric Oxide Inhibitory Activities of the Constituents from the Wood of Taxus yunnanensis

Arjun H. Banskota1 , Yasuhiro Tezuka1 , Nhan Trung Nguyen1 , Suresh Awale1 , Takahiro Nobukawa2 , Shigetoshi Kadota1
  • 1Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan
  • 2Changchun College of Traditional Chinese Medicine, Changchun, P. R. China
Further Information

Publication History

Received: October 14, 2002

Accepted: February 15, 2003

Publication Date:
16 July 2003 (online)

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Abstract

The H2O, H2O/MeOH (1 : 1) and MeOH extracts of the wood of Taxus yunnanensis possessed significant DPPH radical scavenging and nitric oxide (NO) inhibitory activities. Chemical investigation of these extracts led us to isolation of nineteen compounds, i. e., five lignans, two simple phenolics, and twelve taxane-type diterpenes. Isotaxiresinol and seco-isolariciresinol, two major lignans of the wood, possessed potent DPPH radical scavenging activities with IC50 values of 21.7 and 28.9 μM, respectively. Similarly, coniferyl aldehyde, taxusin, 10-deacetyltaxuyunnanine C, hongdoushan A, and 2α,5α,10β-triacetoxy-14β-[(S)-2-methylbutyryloxy]-4(20),11-taxadiene showed potent NO inhibitory activity with IC50 values of 18.0, 22.1, 28.5, 15.0 and 26.4 μM, respectively, which were either equal or lower than the positive control N G-monomethyl-L-arginine (L -NMMA) with an IC50 value of 28.5 μM.