Erythroxylum, alkaloids

Ci-,H2,N04. Colourless prisms, m.p. 98°C. Obtained from coca, either by direct purification, or by acid hydrolysis of the mixed alkaloids to ecgonine, which is then methylated and benzoylated. Coca consists of the dried leaves of Eryihroxyluni coca and Erythroxylum iruxillense, shrubs growing in Bolivia and Peru. 

The amount of cuscohygrine is the main difference between the two commercial varieties of coca leaves Erythroxylum coca Lam. var. coca and var. spru-ceanum (Erythroxylaceae). Coca leaves collected in Bolivia and in Peru have cuscohygrine as the main alkaloid besides cocaine, whereas the opposite situation occurs with material collected in Java (35). 

When we look at another tropane alkaloid, cocaine, we get a different scenario. Cocaine is obtained from the coca plant Erythroxylum coca, and is a powerfnl local anaesthetic, bnt now known primarily as a dmg of abuse. There is no chiral centre in the acid portion, which is benzoic acid, but the optical activity of cocaine comes from the alcohol methylecgonine. Because of the ester function in methylecgonine, the tropane system is no longer symmetrical, and the four chiral centres all contribute towards optical activity. 

Johnson EL and Emcho SD (1994) Variation in alkaloid content in Erythroxylum coca leaves from leaf bud to leaf drop. Ann Bot 73, 645-650. 

Three new alkaloids have been isolated1 from the root-bark of Erythroxylum dekindtii besides the already known methylecgonidine, valeroidine, poroidine, isoporoidine, and tropine. A decoction of this bark is used in West Africa as a febrifuge.2... 

The stimulant narcotic cocaine (benzoylmethylecgonine) from Erythroxylum coca (coca) and other Erythroxylum species (Erythroxylaceae) inhibits serotonin (5HT) and dopamine reuptake. Related bioactive tropane alkaloids from Erythroxylum species include benzoylecgonine, benzoyltropeine (tropine benzoate), cinnamoylcocaine (cinnamoylmethylecgonine) and ecgonine. 

Gas chromatography of cocaine of plant origin has mainly involved the analysis of the coca plant [77-79]. Identification and quantitation GC methods of minor naturally occurring tropane alkaloids in illicit cocaine samples have also been reviewed [80]. Moore et al. presented an in-depth methodology for the analysis of the coca plant by GC-FID, GC-ECD, and GC-MS for the identification of alkaloids of unknown structure [81]. Recently, Casale et al. [82] have analyzed the seeds from Erythroxylum coca for their alkaloidal content. Several tropane alkaloids were detected and characterized and it appeared that methylecgonidine (MEG) was the primary constituent and not an analytical artifact. 

During a screening of tropane alkaloids in Erythroxylum species from Southern Brazil, Zuanazzi et al. [83] identified a new alkaloid as 3p,6p-ditigloyloxynortropane. The five investigated species were also screened for MEG, tropacocaine, and cocaine. Tropacocaine and MEG were present in two plants but no cocaine was detected in any species. 

Although an impressive number of alkaloids have been isolated from plant sources, only a few contain simple pyrrole rings. These include a series of tropane alkaloids from the bark of Erythroxylum vacciniifoUum, for example, 82, that share as common structural features a methylpyrrole moiety <2005JNP1153> methyl-(5-formyl-l//-pyrrole-2-yl) -hydroxybutyrate 83 from sweet chestnut seeds <2002MI22> and solsodomine A 84 and B 85 from the fresh berries of Solanum sodomaeum L. <1998JNP848>. The latter are the first pyrrole alkaloids from the genus Solanum. 

An alkaloid obtained from coca leaves, Erythroxylum coca (Erythroxylaceae) and its varieties. 

An alkaloid obtained from coca, the dried leaves of Erythroxylum coca and other species of Erythroxylum (Erythroxylaceae), or by synthesis from ecgonine. 

The dried leaves of Erythroxylum Coca Lamarck (Fam. Erythroxylacece), known commercially as Huanuco Coca, or of E. Truxillense Rushy, known commercially as Truxillo Coca, 3nelding when assayed by the process given below, not less than 0.5 per cent, of the ether-soluble alkaloids of Coca. U.S. VIII. The dried leaves of Erythroxylum coca, Lam., and its varieties. fir., 1898. 

CO-beneldopa benserazide levodopa. cocaine (ban, usan] (cocaine hydrochloride (jan, usan)) is an ester of benzoic acid and methylecgonine and the principal alkaloid of Erythroxylum coca and other Erythroxylum spp. (Erythroxylaceae). It is a LOCAL ANAESTHETIC (used topically because of toxicity), and has pronounced indirect-acting SYMPATHOMIMETIC actions by virtue of being an UPTAKE INHIBITOR (interferes with Uj active uptake of noradrenaline into noradrenergic nerve terminals). It is a VASOCONSTRICTOR and can be used as a topical mydriatic and ocular diagnostic agent. It is a powerful CNS stimulant (similar in action to amphetamine), with considerable abuse potential, cocaine hydrochloride cocaine. 

It was thus possible to compare and determine the relative proportions of these two alkaloids in Erythroxylum coca Lam. in different plant parts (Tingo Maria) (Table 27) [243]. 

Coca leaves (Erythroxylum coca) have been used in South America since the time of the Incas, if not longer. Although the habit of coca chewing is usually attributed to the extremes of altitude and climate, other causes, such as malnutrition and adverse social, educational, and economic factors, are probably of more importance (278). As with opium, use of the crude plant material does not produce so dramatic a syndrome as does the use of the pure alkaloid (279). Nevertheless, in spite of the often-repeated statement that the use of coca increases resistance to fatigue and is harmless and possibly beneficial in its natural environment, the fact remains that it undermines the physical and mental health of the population and thus leads to a deterioration of the very living conditions that caused it (280). 

Hygrine-type alkaloids are very often detected in members of the Solanaceae family which contain tropane alkaloids. In particular, cuscohygrine is present in nearly all cases. In a similar way but in a smaller number of genera, hygrine is distributed in plants which contain tropane alkaloids, as for example in the Erythroxylum species (Erythroxylaceae). 

Tropane alkaloids mainly occur in the Solanaceae family but are also found in other families such as Convolvulaceae, Erythroxylaceae, Proteaceae and Rhizophoraceae. Less frequently, tropane alkaloids have been mentioned in the Euphorbiaceae, Brassicaceae and Olacaceae families which show no taxonomic relationships with Solanaceae. In several species of Erythroxylum, the tropane alkaloids are characterized by a 3 3-hydroxy function and a carboxyl group at C-2 of the tropane nucleus. The most famous representant of this group is cocaine (Fig. 2). In Table 1 the distribution of tropane alkaloids in the plant kingdom is indicated. 

Novak, M. etal 1984. Biological activity of the alkaloids of Erythroxylum coca and Erythroxylum novogranatense Journal of Ethnopharmacology 10(3) 261—274. 

The first local anaesthetic to be used was cocaine as alkaloid isolated from the leaves of Erythroxylon coca (Erythroxylum coca). Carl Koller, an Australian ophthalmologist in 1884, made an epoch making observation that cocaine hydrochloride causes anaesthesia in the eye. A follow-up by Willstatter and Muller towards an elaborated elucidation of the structure of cocaine ultimately paved the way to the synthesis of a large number of compounds exhibiting local anaesthetic characteristics. 

Christen P, Roberts MF, Phillipson JD, Evans WC. Alkaloids of the genus Erythrox-ylum.ll. Alkaloids of Erythroxylum zambesiacum stem bark. Phytochemistry 1993 34(4) 1147-51. 

Ribeiro EMD, Lima LS, David JM, do Vale AE, Lopes LMX, David JP. A new tro-pane alkaloid and other constituens of Erythroxylum rimosum (Erythroxylaceae). 

Zanolari B, Guilet D, Marston A, Queiroz EF, de Queiroz Paulo M, Hostettmann K. Methylpyrrole tropane alkaloids from the bark of Erythroxylum vacciniifolium. J Nat Prod 2005 68 1153-8. 

Nicotine belongs to the Solanaceae (nightshade family) alkaloids. It is the principal alkaloid of tobacco, but occurs also as a trace component in Acacia, Sedum, Erythroxylum, Equisetum and Lycopodium species. The two economically most important tobacco species are Nicotiana tabacum (Virginia tobacco), which grows up to 3 metres in height, has reddish flowers and lancet-shaped, pointed leaves, and the 1.2-metre high Nicotiana rustica species (known in South America as Mapacho and in Vietnam as Thuoc Lao), with greenish-yellow flowers and egg-shaped leaves (Fig. 5.204). 

Cocaine is an alkaloid isolated from the leaves of Erythroxylum coca or Eryth-roxylum novogramtense (Erythroxylaceae). The former shrub grows wild in Bolivia, and the latter grows in Peru. The mean cocaine content of cocaine leaves is said to be 0.7-2.5%, and the cocaine content of the latter species is... 

These alkaloids are minor products in many important drug plants, especially those of the genus Erythroxylum (Erythroxylaceae) and of the Solanaceae. In general, the activity of pyrrolidine alkaloids is overshadowed by the more active tropane alkaloids with which they co-occur (Massiot and Delaude, 1986). 

Although all tropane alkaloids are derived from ornithine or arginine, some differences in intermediates and labeling patterns have been observed. On introduction of [5- " C]or-nithine into plants of Erythroxylum, the activity was divided... 

Probably the best known alkaloid of this group is cocaine (16), derived from the coca plant Erythroxylum coca, Eryth-roxylaceae) (White, 1989). This polymorphic species is a native of the Andes of northwestern South America. The leaves of the plant, which contain 0.5-2% cocaine, are chewed by many Andean Indians who are said to derive a feeling of well-being and alleviation of hunger pangs thereby. There is no concomitant hallucinogenic effect. Most commercially cultivated coca for the pharmaceutical industry comes from Peru and Bolivia (Boucher, 1991 Tyler et al., 1981 White, 1989). 

---