Cathinone structure

Although the Catha edulis plant contains a number of chemicals, vitamins, and minerals, its main active ingredient is cathinone, an alkaloid with a chemical structure similar to ephedrine and d-amphetamine. Like amphetamine, it increases the levels of dopamine in the brain and acts as a mild stimulant. For this reason, khat is sometimes referred to as a natural amphetamine. 

The major effects of khat on the central nervous system can be attributed to cathinone (S-(-)-alpha-aminopro-priophenone) in fresh khat leaves and cathine (norpseu-doephedrine) in dried khat leaves and stems. Cathinone, a phenylalkylamine, is the major active component and is structurally similar to amfetamine. It degrades to norp-seudoephedrine and norephedrine within days of leaf picking. Cathinone increases dopamine release and reduces dopamine re-uptake (1). 

Having obtained and described a suitable sample, the next stage is to analyse the material for the presence of cathinone and cathine. In addition to these drugs, other structurally similar compounds found in the C. edulis plant include norephedrine (3). It is well accepted that cathinone is converted into this compound by the process of enzymatic reduction. Furthermore, the oxidation product, 1-phenyl-1,2-propanedione (4), and the cathinone dimer, 3,6-dimethyl-2,5-diphenylpyrazine (5), may also be identified. These, however, are reported to form as artefacts of the isolation and analytical processes [6]. 

Since the isolation of cathinone and the other khat phenylalkylamines from fresh material, and their structural and stereochemical characterization, there has been interest in producing these compounds synthetically in chiral form. Buckley and Rapoport (24) have shown that N-ethoxycarbonyl-L-alanine, as its acid chloride (10), can successfully acylate benzene in the presence of aluminum... 

Uptake blocker (Table 12) display a certain degree of structural relatedness to the endogenous neurotransmitter whose transport is inhibited dopamine uptake by the anonaine, cocaine, ibogaine, and salsolinol (see Scheme II) serotonin by 12-hydroxyibogaine, ibogaine, and norharman noradrenaline and adrenaline by cathinone, ephedrine, salsolinol GABA by arecaidine, and guvacine. Reserpine and deserpidine... 

Bupropion (amfebutamone) is a phenylisopropylaminoketone that is structurally related to the phenylisopropylamine CNS stimulant, methamphetamine, and the phenylisopropylaminoketone, cathinone (a constituent in khat), and the anorexiant, diethylpropion (Fig. 21.21). Although structurally similar to the CNS stimulants, bupropion exhibits distinctive different pharmacologic and therapeutic effects. The absence of the tricyclic ring system in bupropion results in a better adverse-effect profile than with the TCAs. The tertiary butyl group in bupropion prevents its N-dealkylation to metabolites that could possess sympathomimetic and/or anorexigenic properties. 

Amphetamines are synthetic compounds, structurally related to the natural product cathinone. The latter is an alkaloid extracted from the leaves of the plant, Khat (Catha eduUs). Chewing of fresh leaves of Khat produces effects similar to those of amphetamines. The structure of cathinone or a-aminopropiophenone is as follows ... 

Alkylation of the phenylethane skeleton, or oxidation of the alcohol function (as in (S)-cathinone) weakens the activity. Ofgreater importance for pharmacological efficacy is the absolute configuration of the alcohoL The (R)-enantiomers are clearly more potent than the (S)-enantiomers. If the number of phenolic hydroxy-groups is reduced, the oral availability is improved, and central effects exceed the peripheral ones. The benzene ring is itself not essential and can be replaced by various heterocydes. If an ether function is introduced between the aromatic moiety and the side-chain of a sympathomimetic, the typical structural pattern of first and second generation antagonists is obtained. 

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