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South African Journal of Chemistry

On-line version ISSN 1996-840X
Print version ISSN 0379-4350

S.Afr.j.chem. (Online) vol.61  Durban  2008




Characterization and cardiovascular effects of (13S)-9α,13α-epoxylabda-6β(19),15(14)diol dilactone, a diterpenoid isolated from Leonotis leonurus



Kene C. ObikezeI; Jean M. McKenzieII, *; Ivan R. GreenIII; Pierre MugaboI

IDepartment of Pharmacology, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
IICentral Analytical Facility, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
IIIDepartment of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa




A new diterpenoid, (13S)-9α,13α-epoxylabda-6β(19),15(14)diol dilactone (1), was isolated from Leonotis leonurus and the structure determined via NMR analysis. The compound causes significant changes in blood pressure of anaesthetized normotensive rats and exhibits a negative chronotropic effect.

Keywords: Leonotis leonurus, diterpenoid, NMR analysis, chronotropic effect



Full text available only in pdf format.



Financial support was provided by the South African National Research Foundation.



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Received 11 August 2008
Revised 10 September 2008
Accepted 15 September 2008



* To whom correspondence should be addressed. E-mail:

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