Author Topic: Data on Khat (Catha Edulis) and cathine  (Read 25034 times)

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Data on Khat (Catha Edulis) and cathine
« on: October 18, 2004, 03:21:00 PM »
Found this on the web, and because I couldn't find data by UTFSE I decided to post for future reference.

Catha edulis

For centuries, khat, the fresh young leaves of the Catha edulis shrub, have been consumed where the plant is cultivated, primarily in East Africa and the Arabian peninsula. There, chewing khat predates the use of coffee and is used in a similar social context.
Catha edulis Forssk belongs to the Celastraceae family and, a neighbouring species of the Evonymus, it is the sole representative of the Genus Catha. The Swedish botanist Forsskal, the explorer of lower Egypt and Arabia, was the first to mention this plant, which he called gat or khat. His description of it was published posthumously in 1775 in his Flora aegyptico-arabica.

The plant has also been described under the following names: Celastrus edulis Vahl, Catha forsskalii Rich, and Trigonotheca serrata Hochst, Methyscophyllum glaucum Eckl. and Zeyher.

It is a shrub which grows to between 1-2 m in arid regions, and may reach 10 m or more in the equatorial zone; under cultivation, it may often grow to a height of 3-4 m. An evergreen in appearance, it is not unlike the spindle-tree. The leaves, which are bifarious- at least at the top of the branches- are whole, and lanceolate or ovate (8-10 cm long by 4-5 cm broad). The South African form (called Methyscophyllum glaucum Eckl. and Zeyher) is a variety with very narrow, bluey-green leaves (4.25 cm); they have a short petiole (0.5 cm) with two small caducous stipules.

The limb, which at the base is smooth, has over the remainder of the leaf some thirty mossy serrations. The median vein projects on the underside and the secondary veins, running at an angle of forty-five degrees, meet in a curve near the margin of the limb. The leaves are coriaceous, smooth, shiny on the upper side, dark green when fresh, but becoming brownish or reddish-brown if kept; they have not much odour, but an aromatic, astringent taste. The flowers of type 5, arranged in axillary cymes, are small, regular in shape and greenish-white: they have a short calyx, petals longer, upright, overlapping, spreading out at the top, five alternisepalous stamens and free ovary with three loculi. The fruit is a slightly trigonal, oblong capsule with three valves, containing one to three seeds with a triangular, membranous wing. The albumen is pulpy and the cotyleda are foliaceous.

Geographical distribution. According to A. Chevalier, the plant originated in tropical East Africa. From Abyssinia, where khat grows wild along the river banks above 1500m, it was introduced into the mountains in south Yemen and is also found in Kenya, Tanganyika, Uganda and South Africa (Transvaal, the Cape, Natal). It is cultivated in Abyssinia (in the Harar district) and in Arabia in irrigated terraces, and is often grown with the coffee plant at an altitude around 2,000m. It is very hardy and can be grown in the Mediterranean region and in the south of the United States.

It is grown by sowing or from seedlings, and the leafy twigs are picked after three or four years. The drug is sold in bundles of stalks in full leaf weighing about 500 g and measuring 40 cm long by 8-10 cm in diameter. There are several varieties, differing in quality, the yellow leaves being the most sought after.

Chemical composition: The chemical study of khat goes back to the end of the nineteenth century; in 1887 by Fl¨¹ckiger and Gerock who, in view of the stimulating properties of the drug, thought that it contained Caffeine, discovered the presence of an alkaloid called Cathine. Beitter, who wrote a thesis on it in 1900, isolated an amorphous base, Katine, the sulphate and hydrochlorate of which are obtained in crystalline form: the yield is low-0.2% for leaves from Harar, 0.5% for those from Aden.

In 1911, J. Chevalier obtained one per thousand total alkaloids from the leaves; the content of the stalks would have been less. A little later, in 1912, Stockmann separated three alkaloids which he called Cathine, Cathinine and Cathidine, the first two in a crystal form; unfortunately, he gave no constants. He pointed out that, unlike Cathinine, Cathine and Cathidine were fairly soluble in water. Cathine and Cathinine can also be distinguished by their different solubility in pure alcohol, Cathine sulphate being only soluble with difficulty in this solvent.

Khat has been brought into the United States and other countries for use by emigrants from the source countries. It contains a number of chemicals among which are two controlled substances, Cathinone (Schedule I) and Cathine (Schedule IV). As the leaves mature or dry, Cathinone is converted to Cathine, which significantly reduces its stimulatory properties.

In 1933, Wolfes undertook the extraction of khat alkaloid by benzine; after separation of Cathidine, owing to its insolubility in water, he succeeded in obtaining Cathine in a crystalline form (77¡ãF.). The corresponding hydrochlorate, which crystallizes in pure alcohol after the addition of ether, melts at 181¡ãF, its rotatory power being (¦Á) 20 = + 43.3¡ãF (water); its ultimate analysis gives the formula: (C9H13ON.HCl). Through these properties, the author showed that Cathine is identical with d-nor-iso-ephedrine (or d-nor-pseudo-ephedrine), a substance found in its natural state in certain Ephedras in China (Smith), and of which Nagai and Kanao made the Synthesis with that of many derivatives of Ephedrine.

Try to replicate the conditions of high altitude Ethiopia!. Great difficulty growing Khat from seed, however once you have a plant growing it is easy to take cuttings. Catha edulis is adapted to a wide range of soil conditions (near Harar, where most of the Khat is grown, the soil is said to be neutral to slightly acidic despite being high in Calcium and low in Nitrogen) - it is suggested that water supply is more important than soil type, particularly in the early growing period. Khat does not tolerate poor drainage and will not grow well in wet soils.

It will grow in full sun, partial sun, or even shade. In Ethiopia Khat is not grown from seed, but is vegetatively propagated from 12" suckers or branches near the ground level, and sometimes by cuttings taken from branches (although these do not root so readily). Plants are set out when the rainy season begins. The top parts will be cut back by frost but Khat plants will grow back from the roots - unless they are frozen too.

Catha edulis seeds are legal to posess in the United States, however cultivaton or alkaloid extraction of this species is prohibited by both state and federal law.

Active constituents: Cathinone: (C9H11NO); (S-alpha-aminopropiophenone) , Cathine: (C9H13NO); (d-noriso-ephedrine), Cathine: (C9H13NO); (norephedrine).

Cathinone: (C9H11NO), a Pharmacologically active alkaloid extracted from the leaves of khat, Catha edulis Forsk., Celastraceae.

Cathinone hydrochloride: (C9H11NO.HCl); (C9H12ClNO)

Cathine hydrochloride: (C9H13NO.HCl)

Cathinone: (C9H11NO), 1235.

Some trade or other names: 2-amino-1-phenyl-1-propanone, alpha-aminopropiophenone, 2-aminopropiophenone, and norephedrone.

Methcathinone: (C10H13NO), 1237.

(Some other names: 2-(methylamino)-propiophenone; alpha-(methylamino)propiophenone; 2-(methylamino)-1-phenylpropan-1-one; alpha-N-methylaminopropiophenone; monomethylpropion; ephedrone; N-methylcathinone; methylcathinone; AL-464; AL-422; AL-463 and UR1432), its salts, optical isomers and salts of optical isomers.

What SWIX finds interesting is that cathinone is converted to cathine in the drying leaves, which won't be as hard to reduce as the benzylic ketone maybe. SWIX knows where to find this tree here and will aim to do some work in the future when not so busy....  8)