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Pharmaceutical Biology
1998, Vol.36, No.3, pp. 173-179
© Swets & Zeitlinger
The Distribution of Mesembrine Alkaloids in Selected Taxa of Kanna
and their Modification in the Sceletium Derived `Kougoed'
Michael T. Smith , Courtney R. Field , Neil R. Crouch and Manton
Hirst
Univ. Natal, Botany Dept., Pietermaritzburg, South Africa
Natal Herbarium, Ethnobotany Programme, National Botanical Institute
Kaffrarian Museum, Kingwilliam's Town, South Africa
Twenty species from
nine genera of the Mesembryanthemaceae (Aptenia, Bergeranthus,
Delosperma, Drosanthemum, Glottiphyllum, Lampranthus, Oscularia,
Ruschia, and Sceletium) as well as the reportedly psychoactive
preparation `kougoed', prepared from `fermenting' Sceletium
tortuosum, were screened for the presence of the mesembrine
alkaloids. Using gas chromatography (GC) with a nitrogen-phosphorous
detector (NPD) three putative alkaloids were detected in Sceletium
tortuosum whose mass spectra corresponded to those of
4'-O-demethylmesembrenol, mesembrine and mesembrenone. All the
Mesembryanthemaceae plants investigated were shown to have
Dragendorff-positive compounds on thin layer chromatograms (TLC);
those containing mesembrine alkloids, as shown by later GC MS
analysis, exhibited similar Rf values to the Sceletium alkaloids.
Howev! er, using the technique employed in this study which
encompassed the use of column and gas chromatography, the only genus
containing mesembrine alkaloids to any significant extent was
Aptenia. Alkaloid levels were found to be extremely low in all other
taxa investigated. When a `modern' technique for the preparation of
a fermented Sceletium product, `kougoed', was carried out it was
found that levels, as well as the ratios, of the three alkaloids
changed markedly. Substantial increases in total alkaloid levels
were observed when the Sceletium material was crushed and bruised
prior to drying for alkaloid extraction whereas no such changes
occured when intact plants were oven dried at 80°C prior to alkaloid
extraction. It is speculated that of the many potentially usable
Mesembryanthemaceae plants available to the indigenous peoples,
Sceletium was selected because it is the only genus with alkaloid
levels high enough to! eli cit a psychoactive response. The
traditional preparation technique also appears to have evolved as a
method of producing a dry, stable, and relatively palatable
preparation of increased pharmacological activity.
Keywords: 4'-O-demethylmesembrenol , ethnopharmacology , `kougoed' ,
mesembrenone , mesembrine , Mesembryanthemaceae , pharmacological
activity , psychoactive , Sceletium
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