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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