Planta Med 2005; 71(11): 1036-1039
DOI: 10.1055/s-2005-873123
Original Paper
Pharmacology
© Georg Thieme Verlag KG Stuttgart · New York

Diterpenes Isolated from Croton zambesicus Inhibit KCl-Induced Contraction

Chiara Baccelli1 , Sébastien Block1 , Benoit Van Holle1 , André Schanck2 , David Chapon2 , Bernard Tinant2 , Luc Van Meervelt3 , Nicole Morel4 , Joelle Quetin-Leclercq1
  • 1Laboratoire de Pharmacognosie, Unité d’Analyse Chimique et Physico-Chimique des Médicaments, Université Catholique de Louvain, Bruxelles, Belgium
  • 2Unité CSTR, Département de Chimie, Université Catholique de Louvain, UCL 28.15, Louvain-la-Neuve, Belgium
  • 3Biomolecular Architecture, Chemistry Department, K.U. Leuven, Leuven, Belgium
  • 4Laboratoire de Pharmacologie, Université Catholique de Louvain, UCL 54.10-FARL, Bruxelles, Belgium
Further Information

Publication History

Received: October 12, 2004

Accepted: May 30, 2005

Publication Date:
17 October 2005 (online)

Abstract

A mixture of two new diterpenes was isolated from a dichloromethane extract of Croton zambesicus: ent-18-hydroxytrachyloban-3β-ol (1) and ent-18-hydroxyisopimara-7,15-diene-3β-ol (2). The two compounds crystallised together and were separated after derivatisation of the pimarane derivative with osmium tetroxide. The structure of 1 was elucidated by 1D- and 2D-NMR analysis and by X-ray diffraction of a crystal containing both compounds while 2 was only identified by crystallographic data. As this plant is widely used in African folk medicine against hypertension, we have analysed the vasorelaxant activity of the isolated molecules. The mixture of the two compounds inhibited the KCl-induced contraction of male Wistar rat aorta (IC50 = 1 μg/mL), while the purified trachylobane (compound 1) and the hydroxylated pimarane showed a lower activity than the mixture.

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Chiara Baccelli

Laboratoire de Pharmacognosie

Unité d’Analyse Chimique et Physico-Chimique des Médicaments

Université Catholique de Louvain

UCL 72.30-CHAM

Av. E. Mounier 72

1200 Bruxelles

Belgium

Phone: +32-(0)276-47230

Fax: +32-(0)276-47253

Email: chiara.baccelli@cham.ucl.ac.be

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