Search

Several samples of Colombian and a sample of Peruvian coca paste were subjected to chemical analysis to ascertain the complexity of these products. A neutral and acid fraction and a basic fraction were analyzed by gas chromatography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS). The basic fraction was also analyzed as its trimethylsilyl (TMS) derivative. Several gasoline residue components were identified in the neutral fraction. In addition to cocaine (greater than 60% in all cases), other alkaloids were identified. Lead and manganese analyses were carried out on these samples. While all the samples contained no lead (less than 45 ppm), most of the Colombian samples contained significant amounts of manganese (greater than 5%). Preliminary smoking experiments with a Colombian coca paste sample indicated that it behaves more like free cocaine than like a cocaine sulfate salt.

The cultivated Erythroxylum varieties E. coca var. coca, E. coca var. ipadu, E. novogranatense var. novogranatense and E. novogranatense var. truxillense contain 18 alkaloids, identified so far, belonging to the tropanes, pyrrolidines and pyridines, with cocaine as the main alkaloid. The biological activity of the following alkaloids has been reported in the literature: cocaine, cinnamoylcocaine, benzoylecgonine, methylecgonine, pseudotropine, benzoyltropine, tropacocaine, alpha- and beta-truxilline, hygrine, cuscohygrine and nicotine. The biological activity of cocaine and nicotine is not reviewed here, because it is discussed elsewhere in the literature. Hardly anything is known about the biological activity of the other alkaloids present in the four varieties mentioned. The biosynthesis of the coca alkaloids has been outlined.

In order to test the effects of commonly used preservation agents on the alkaloid content of herbarium specimens, fresh leaves of Erythroxylum coca, E. novogranantense, and E. novogranatense var. truxillense were air-or heat-dried or treated with six different liquid preservatives. The leaves were then extracted and analyzed quantitatively for cocaine content. Leaves which were soaked in preservatives showed appreciable pre-extraction of cocaine and probably of other alkaloids. The results compare well with a similar experiment conducted on flavonoid content of the leaves of a palm Jessenia bataua. If portions of herbarium specimens are to be useful for phytochemical screening using microtechniques, at least part of the collection must be air- or heat-dried to retain the chemical constituents.

South American Indians have used coca leaf as a remedy for thousands of years. Coca might be useful as a treatment for gastrointestinal ailments and motion sickness, as a fast-acting antidepressant medication, as a substitute stimulant for coffee in certain cases, and as an adjunct in programs of weight reduction and physical fitness. In leaf form, coca does not produce toxicity or dependence. Its effects are distinct from those of cocaine, which is but one of a number of active compounds in the leaf. Coca can be administered as a chewing gum containing a whole extract of the leaf, including alkaloids, natural flavors, and several nutrients. Legal mechanisms exist for importing, distributing, and dispensing coca, and experimentation with it by interested physicians would be valuable.

Male and female Wistar rats were trained to discriminate 5.0 mg/kg cocaine from 2.0 ml/kg saline using a two-bar food reinforcement (FR 30) drug discrimination paradigm. Once discrimination behavior had stabilized the subjects were tested (in extinction) with several doses of two different fractions of the coca leaf and four doses of cocaine HCl (1.0, 2.5, 7.5, 10 mg/kg). The fractions were prepared by extracting powdered coca leaves with 95% ethanol and then partitioning the residue between chloroform and water. Two doses of the water fractions (480, 960 mg/kg) and five doses of the chloroform fraction (7.5, 15, 30, 60 120 mg/kg) were tested. The water fractions was devoid of cocaine while the five doses of the chloroform fraction contained cocaine equivalent to 0.4, 0.83, 1.65, 3.3 and 6.6 mg/kg, respectively, as determined by gas chromatographic analysis. The 2.5, 7.5, and 10.0 mg/kg cocaine doses generalized to cocaine. The 1.0 mg/kg dose of cocaine generalized to saline. The water fraction at 480 mg/kg generalized to saline; however following pretreatment with the 960 mg/kg dose of this fraction, the animals failed to respond. The two largest doses of the chloroform fraction (60 and 120 mg/kg) generalized to cocaine while the other three doses did not. The 7.5 mg/kg generalized to saline; the 15 and 30 mg/kg doses engendered an intermediate level of responding on both the cocaine and saline lever.

The Laboratory of the Government Chemist examines most of the drugs that have been seized at the point of entry into the United Kingdom of Great Britain and Northern Ireland and has developed analytical methods for their rapid identification in the field and for more exact analysis and quantitation in the Laboratory. These methods are described for the major types of drugs encountered. Many seizures are examined in greater detail in order to compare samples and to correlate origin with physical and chemical appearance. Information on the procedures necessary to undertake this aspect of work is also presented.

A method for the determination of cocaine content in coca leaves (Erythroxylum coca) has been developed. The procedure involves refluxing the powdered leaves in 95% ethanol for 15 minutes, followed by acid-base partitioning with chloroform and a GLC assay. The recovery of cocaine was quantitative. This procedure was applied to determine cocaine content in three samples of Erythroxylum coca Lam. collected from different geographic locations in Peru. Using androst-4-ene-3,17-dione as the internal standard the calibration curve was linear over a factor of 0.5 to 10 fold cocaine concentration relative to internal standard. The slope (b) was 0.733, the coefficient of determination (r2) was 1.00 and the average precision was 3.9%.

Coca paste is an intermediary product in the chemical extraction of cocaine from coca leaves. Abusers smoke coca paste in a dried form, which contains from 40 to 91 per cent cocaine. Over the past 10 years, this pattern of drug abuse has attained epidemic proportions in some Latin American countries, particularly in Bolivia, Colombia and Peru. Addiction to coca paste develops in a few months and has serious health, social and economic consequences. The problem is particularly acute in Latin American countries because of the high doses of coca paste involved. The smoking of coca paste causes four distinct successive phases of mental disorder: euphoria, dysphoria, hallucinosis and paranoid psychosis. It can produce severe intoxication, prolonged or relapsing psychosis and, in some cases, death. Cocaine has been found in the blood of coca-leaf chewers, coca-paste smokers and users of cocaine hydrochloride. Excessive coca-paste smoking is often resistant to therapeutic interventions and there is a high rate of relapse after treatment and rehabilitation.

A method has been developed that allows for the detection of the eleven stereoisomers of diphenylcyclobutanedicarboxylic acid in illicit cocaine samples, including alpha-, gamma-, and epsilon-truxillic acids and beta- and delta-truxinic acids. These, and other carboxylic acids, were also detected as ester moieties of alkaloidal impurities in illicit cocaine as well as in alkaloids of the South American coca leaf, e.g., alpha- and beta-truxilline. After lithium aluminum hydride reduction of the acidic and basic extracts of a prepared sample, the reduced species were derivatized with heptafluorobutyric anhydride in the presence of pyridine. The heptafluorobutyryl derivatives of the reduced diphenylcyclobutanedicarboxylic compounds were easily detected on-column at low picogram levels using a moderately polar fused-silica capillary column in the splitless mode and interfaced with a 63Ni electron-capture detector.

The herbicide (2,4-dichlorophenoxy)-acetic acid (2,4-D) is considered to be the most cost-effective for eradicating illicit coca plants. Since coca leaves are chewed by the natives of coca producing areas, and, since coca paste and cocaine are widely abused, a study was undertaken to determine whether 2,4-D is translocated into the leaves and transferred to coca paste when coca plants are treated with this herbicide. The study concluded that basal treatment of coca plants with 2,4-D ester resulted in translocation of 2,4-D into the leaves, and this herbicide was detected in high concentrations one week after treatment. Coca paste prepared from leaves obtained from basally treated plants did not contain 2,4-D. Foliage spraying resulted in extremely high concentrations of 2,4-D in the leaves, with significantly high concentrations of the herbicide found one week after spraying. Trace amounts of 2,4-D were detected in coca paste prepared from plants sprayed by the foliage method.

The technique of mass-analyzed ion kinetic energy (MIKE) spectrometry is briefly reviewed. The direct analysis, without need of prior extraction or chromatographic purification, of cocaine and cinnamoylcocaine in coca plant tissues has been accomplished with this new technique. Detection limits of below 1 ng, with a quantitative accuracy of +/- 30% at the nanogram level, have been demonstrated.

The 24 hour lethal effects of cocaine were compared to those of a crude ethanol extract of the coca leaf (Erthroxylon coca) in male, Swiss mice. Various doses of cocaine HCl and coca leaf extracts suspended in a Tween 60, Arlacel 83, and distilled water vehicle were injected IP into groups of 10 mice. The LD50 for cocaine was 95.1 mg/kg. The LD50 for the coca extract was 3450 mg/kg. The LD50 of the extract based on its cocaine content was 31.4 mg/kg. The results clearly indicate that the coca leaf contains constituents other than cocaine that can contribute to a toxic effect of the plant.

Of the 4,196 samples of drugs seized and analysed at the Toxicology Laboratory of the National Bureau for the Control of Dangerous Substances during the period 1975-1982, 3,768 samples (89.8 per cent) contained coca paste, cocaine hydrochloride or related substances. Most of the samples analysed contained coca paste and came from La Paz, Santa Cruz and Cochabamba. With a slight exception in 1980, the number of samples increased steadily over an eight-year period. The increase in the number of seizures of cocaine-related substances was a result of the growth in the illicit production of these substances, which began to assume larger dimensions in 1976. In many areas, coca-paste and cocaine-related problems are growing out of all proportion. The smoking of cigarettes that contain a mixture of tobacco and coca paste, popularly known as pitillos, is the most common form of drug abuse.

The major pests of coca are listed and discussed along with methods used to control them in the past and present. Results of analyses for pesticide residues in samples of commercial Peruvian coca leaves are presented. Levels of pesticides found in these samples are too low to be considered a medical risk to coca chewers.

Recent research suggests that, in addition to the well-documented occurrence of significant quantities of cocaine and related alkaloids in a limited number of species, the genus Erythroxylon will prove to be a rich source of tropane alkaloids. These bases are esters of a range of acids with tropine, 3 alpha, 6 beta-dihydroxytropane and 3 alpha, 6 beta, 7 beta-trihydroxytropane; the numbers are further increased by nor-derivatives, and stereoisomerism involving the C-3 hydroxyl of the tropane skeleton. The diterpenes of the genus also appear worthy of further study.

Several solvents were tested for the extraction of the alkaloids in Erythroxylum coca. The resulting crude extracts were analyzed by gas chromatography--mass spectrometry. Ethanol extraction was found to be the only quantitative method presenting no artifacts. It was established that cocaine and cis- and trans-cinnamoylcocaine were the endogenous alkaloids in E. coca leaves. From the several breakdown compounds arising during long-term extraction with H2SO4 or CHCl3, ecgonine methyl ester was the only alkaloid fully identified; ecgonine methyl ester was tentatively identified on the basis of its mass spectrum fragmentation pattern. Quantification by mass fragmentography of the three endogenous compounds was performed using a stable-isotope dilution technique on individual leaves of single branches of E. coca, E. novogranatense and E. novogranatense var. truxillense. The relative amounts of these alkaloids changed with leaf age as well as between species and varieties. The variation in alkaloid levels between individual leaves was too great to allow the use of the ratio between cocaine and the cinnamoylcocaine levels as a taxonomic marker. The initial pH value of 17 different alkaline substances traditionally used during coca leaf chewing was measured after dissolution in H2O; values ranged between 10.1 and 12.8. Buffer capacity was determined by titration with HCl. Three types of curve shapes were obtained which could correspond to NaOH, Na2CO3 and NaHCO3 titration curves. One sample of alkaline material had no buffer capacity at all. The recovery and breakdown of the cocaine contained in E. coca leaf power was monitored for one hour at various pHs at 37 degrees C. The levels of cocaine and benzoylecgonine did not change by more than 17% at any of the pHs tested (6.0, 9.0 and 11.5). It was concluded that the alkaline substances are mainly responsible for the transformation of the alkaloids to free bases and not for a major hydrolysis of cocaine.

Literature concerning the taxonomy and alkaloid content of the coca plant is examined in this article. The process used to extract cocaine alkaloids from the plant is described and information relating to the constituents of illicitly processed cocaine reported. Investigations into the stereochemistry of cocaine resulting from United States laws controlling such drugs are reviewed. Advances in presumptive tests for cocaine are described and some comments are made relative to trends in chromatographic analysis.