Conclusions and recommendations of the Expert Group on the Botany and Chemistry of Khat

Abstract

The Expert Group on the Botany and Chemistry of Khat was convened by the United Nations Narcotics Laboratory at Antananarivo, Madagascar, from 27 November to 1 December 1978 to discuss the research still needed on the botany and chemistry of khat and prepare guidelines for future investigations. The following text is quoted from the report of the Group (MNAR/3/1979, pp. 9-11):

Details

Pages: 65 to 70
Creation Date: 1980/01/01

Conclusions and recommendations of the Expert Group on the Botany and Chemistry of Khat

The Expert Group on the Botany and Chemistry of Khat was convened by the United Nations Narcotics Laboratory at Antananarivo, Madagascar, from 27 November to 1 December 1978 to discuss the research still needed on the botany and chemistry of khat and prepare guidelines for future investigations. The following text is quoted from the report of the Group (MNAR/3/1979, pp. 9-11):

"It was agreed that certain aspects required particular attention:

"(a) In the light of new and expanded pharmacological and medical studies on khat and its constituents, it is considered essential to provide researchers with materials of known chemical composition. There is, therefore, an urgent need for specific qualitative means of identification of khat material and quantitative analysis of the important plant constituents. Because of the variability in preferences, and presumably in potency, of different plant material, it is important for epidemiologists to have field methods available to aid in identifying the plant. It is felt that quantitative methods should be refined to assay material for cathine, cathinone, nor-ephedrine and the total polyester alkaloidal fraction. Initially, more sophisticated techniques, such as gas-liquid chromatography and high-pressure liquid chromatography should be employed, coupled with a standardized extraction procedure. Efforts should be made as well to develop simple methods suitable for analysis in the field.

"(b) It will be essential that the purified amine constituents, particularly the more abundant cathinone and cathine, and standardized freeze-dried plant and extracts be made available for pharmacological and medical studies.

"(c) Botanical studies on the variation in plant material, both cultivated and growing wild in countries concerned with the problem of khat, should proceed using the chemical constituents as markers. Investigations should be made to determine whether the presence of cathinone and cathine can be used for this purpose. In addition, the morphological methods of identification previously developed could be applied. This would allow the screening of many varieties by the same methods.

"(d) The need has been expressed for the development of suitable tests to aid the identification of khat by enforcement officers, and such tests will become increasingly important if wider control is extended over this plant material. Research should therefore be carried out to develop such identification tests.

"(e) Certain scientific issues, although of lesser concern in connection with the abuse of khat and the question of possible control, are of considerable academic interest. These issues include: the biosynthetic pathway of the amines and their possible inter-conversion; continuing characterization of the polyester alkaloids, with their eventual isolation or synthesis for pharmacological studies; and further identification of other constituents, such as the polyphenols and tannins, which may be known to have toxicological effects. Investigations on these aspects could well form the basis for post-graduate dissertations.

"It is recognized that such a comprehensive list of objectives requires careful planning and allocation of resources. The Group stressed the central role of the United Nations Narcotics Laboratory in the work on khat, particularly with regard to co-ordinating the research of collaborating national laboratories and institutions.

"To ensure that reliable material of known composition is being used in animal and human studies, there should be close co-operation between investigators in the chemical and pharmacological fields. Such co-operation would most effectively be developed and maintained through the Laboratory and the World Health Organization.

"It was agreed that it would seem rational that laboratories in countries affected by the problem of khat should be especially active in connection with research and with the provision and assay of material. In certain cases, some form of assistance may be required for these laboratories and ways and means should be found to provide such assistance."

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Catha edulis Forsk. (khat) belongs to the Celastraceae and is an evergreen tree or large shrub.

Top: A plantation in Kenya consisting mainly of tree-type plants. Bottom: A plantation of shrubs in Madagascar.

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A farmer and his family cultivating and selling khat.

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Khat is sold in markets (left)and also in local food shops (right).

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