Impurities and Artifacts of Illicit Cocaine

Lukaszewski, Theodore; Jeffery, Wayne K.

doi:10.1520/jfs11250j

Cited by 52 publications

(12 citation statements)

References 6 publications

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“…The purity of the product was established by thin-layer chromatography (TLC), gas chromatography (GC), and HPLC analyses. Ecgonine methyl ester hydrochloride was prepared from ecgonine hydrochloride (0.3 g) by stirring with dry methanol (2.5 ml) and thionyl chloride (0.5 g) at 50°C for 48 h. Melting points and 1H nuclear magnetic resonance spectra of ecgonine and ecgonine methyl ester were in agreement with those previously reported (11,22). …”

supporting

confidence: 86%

Identification of a cocaine esterase in a strain of Pseudomonas maltophilia

1992

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A strain of Pseudomonas maltophilia (termed MB11L) which was capable of using cocaine as its sole carbon and energy source was isolated by selective enrichment. An inducible esterase catalyzing the hydrolysis of cocaine to ecgonine methyl ester and benzoic acid was identified and purified 22-fold. In the presence of the solubilizing agent cholate, cocaine esterase had a native Mr of 110,000 and was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be a monomer. In the absence of cholate, cocaine esterase had a native Mr of 410,000 and probably existed as a tetramer. The pH optimum of the enzyme was 8.0, and the Km values for cocaine, ethyl benzoate, and ethyl 2-hydroxybenzoate were 0.36, 1.89, and 1.75 mM, respectively.Inhibition studies indicated that the enzyme was a serine esterase, possibly possessing a cation-binding site similar to those of mammalian acetylcholinesterase and the atropine esterase of Pseudomonas putida PMBL-1.The cocaine esterase ofP. maltophilia MBl1L showed no activity with atropine, despite the structural similarity of cocaine and atropine.Microbial enzyme activities against alkaloids have been investigated as models of mammalian metabolism and as potential sources of new therapeutic compounds (16,17,38). Of the tropane alkaloids, the microbial metabolism of atropine has received the most significant attention. Corynebacterium belladonae catabolizes atropine via esterolytic hydrolysis of the tropic acid moiety followed by dehydrogenation, ring opening, and deamination of the tropane ring (27,28). A wide range of pseudomonads were also found to utilize atropine as their sole source of carbon and nitrogen (34). Further studies with nine of these strains identified two distinct classes of atropine esterase which possessed different physical and chemical properties (31). The atropine esterase from Pseudomonas putida PMBL-1 has been purified and extensively characterized (15,40,(43)(44)(45). Probing of the active site of the enzyme indicated an active serine residue and a classical charge relay system (43,44), although sequence analysis (15) and structure prediction (42) implied little homology to the serine protease families. Atropine esterase showed stereospecificity toward the (-)-isomer of atropine, (-)-hyoscyamine, and appeared to favor esters of tropic acid over those of acetic acid (34). Interestingly, the enzyme displayed no activity with the structurally related tropane alkaloid cocaine (34). In this paper, we describe the isolation of a strain of Pseudomonas maltophilia capable of using cocaine as its sole carbon and energy source and the partial purification and characterization of a cocaine esterase from this organism. Solutions and buffers were prepared by using water purified by a Milli-RO-60 system (Millipore Waters UK Ltd., Watford, United Kingdom). Ecgonine hydrochloride was prepared from cocaine by using the method of Findlay (11). The purity of the product was established by thin-layer chromatography (TLC), gas chromatography (GC), and HPLC analyses. Ecg...

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supporting

confidence: 86%

Identification of a cocaine esterase in a strain of Pseudomonas maltophilia

1992

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“…[24][25][26][27][28][29][30][31][32][33][34][35] Cocaine and truxillines were detected as the protonated molecules [M + H] + at m/z 304 and 659, respectively, in all three items using DESI-MS (Figure 3). [24][25][26][27][28][29][30][31][32][33][34][35] Cocaine and truxillines were detected as the protonated molecules [M + H] + at m/z 304 and 659, respectively, in all three items using DESI-MS (Figure 3).…”

Section: Natural Alkaloids and Impurities In Cocaine Samplesmentioning

confidence: 99%

“…Natural alkaloids and other impurities that have been found in significant levels in illicit natural cocaine include N-acetylnorcocaine, 2,3-didehydroecgonine, 2,3-didehydroecgonine methyl ester, benzoic acid, benzoyl ecgonine, N-benzoyl norecgonine methyl ester, trans-cinnamic acid, cis-and trans-cinnamoylcocaine, cisand trans-cinnamoylecgonine, ecgonine, ecgonine methyl ester, N-formylcocaine, N-norcocaine, N-norecgonine, tropacocaine, all five diastereomeric truxillic acids, all eleven diastereomeric truxillines, and all six diastereomeric truxinic acids. [24][25][26][27][28][29][30][31][32][33][34][35] Cocaine and truxillines were detected as the protonated molecules [M + H] + at m/z 304 and 659, respectively, in all three items using DESI-MS (Figure 3). The truxillines detected in DESI-MS analysis may represent a mixture of diastereoisomers, i.e., epsilon-, delta-, beta-, peri-, neo-, epi-, alpha-, omega-, gamma-, mu-, and zetatruxilline due to lack of chromatographic separation.…”

Section: Natural Alkaloids and Impurities In Cocaine Samplesmentioning

confidence: 99%

Qualitative analysis of seized cocaine samples using desorption electrospray ionization‐ mass spectrometry (DESI‐MS)

Stojanovska

Tahtouh

Kelly

et al. 2014

Drug Testing and Analysis

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Desorption electrospray ionization - mass spectrometry (DESI-MS) is a useful technique for the qualitative analysis of compounds found in seized drug material. In this study, DESI-MS was utilized in the screening analysis of illicit cocaine samples. The technique was also applied to the geographical origin determination of these samples. The limit of detection was determined to be 24.3 µg (or 3.47 µg/mm(2) ) and the analysis time was less than 1 minute per sample. The intra-day and inter-day precision for the detection of cocaine was 11 % and 42 %, respectively; therefore the quantitative data provided by DESI-MS was limited in its use for accurate determination of cocaine concentration in a sample. Using the quadrupole time-of-flight (QTOF) mass spectrometer, the presence of cocaine and impurities detected were confirmed by accurate tandem MS data. The qualitative chemical profiles obtained using DESI-MS were compared to two popular analysis techniques, GC-MS and LC-MS. The effects of a range of adulterants including caffeine, procaine, levamisole, lignocaine, paracetamol, and atropine on the detectability of cocaine were also investigated. It was found that the addition of these adulterants in a cocaine sample did not prevent the detection of the analyte itself (there was slight enhancement in some samples), which was useful in drug detection. The detection of truxillines in the seized samples by DESI-MS aided in the preliminary determination of geographical origin, i.e., Bolivian, Peruvian or Colombian leaf origin. The application of DESI-MS to the qualitative analysis and screening of seized cocaine samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples.

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“…Capillary gas chromatography coupled to flame ionisation detection (GC-FID) is one of the most frequently used technique for coca leaf analysis, but this method can easily generate artefacts in the heated injection port. Indeed, it is now well accepted that methylecgonidine is an artefact resulting from benzoic acid elimination from cocaine [35]. However, this compound is always considered as negligible as it represents less than 1% of the injected cocaine [36,37].…”

Section: Introductionmentioning

confidence: 99%

Optimisation of accelerated solvent extraction of cocaine and benzoylecgonine from coca leaves

et al. 2001

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Accelerated solvent extraction (ASE) was developed for the rapid extraction of cocaine and benzoylecgonine from coca leaves. Several parameters such as the nature of the extracting solvent, the pressure, temperature, extraction time, addition of alkaline substances, and sample granulometry were investigated to find the best extraction conditions. A central composite design was used to optimise critical parameters (pressure, temperature, and extraction time) and to assess the robustness of the extraction method. It was demonstrated that the extraction method was perfectly robust around optimal conditions (20 MPa, 80°C, and 10 min). Determination of both cocaine and benzoylecgonine in coca leaves was carried out by means of gas chromatography with flame ionisation detection (GC‐FID) or capillary electrophoresis with UV detection (CE‐UV). With the latter, separation of both compounds was achieved in less than 4 min with the use of a short‐end injection procedure.

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Impurities and Artifacts of Illicit Cocaine

Abstract: Mass spectra of impurities and artifacts of illicit cocaine are illustrated and discussed. The methods used in the synthesis of the compounds are described and nuclear magnetic resonance data are presented as proof of structure.

Cited by 52 publications

References 6 publications

Identification of a cocaine esterase in a strain of Pseudomonas maltophilia

Identification of a cocaine esterase in a strain of Pseudomonas maltophilia

Qualitative analysis of seized cocaine samples using desorption electrospray ionization‐ mass spectrometry (DESI‐MS)

Optimisation of accelerated solvent extraction of cocaine and benzoylecgonine from coca leaves

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