Tropane alkaloids chromatography

The absolute configuration of (-l-)-physoperuvine, and of its N-benzoyl derivative, was determined by the positive Cotton effect around 290 nm, in the region exactly as reported5 for (R)-(+)-3-methylcycloheptanone. The racemic form accompanies the optically active one in the plant they were separated by column chromatography. Since tropane alkaloids form in vivo from ornithine via A-pyrroline,6 the biogenetic role of secotropanes is likely to be that of products of degradation rather than of intermediates in the formation of the tropane bases. 

A new method for the rapid separation of alkaloids, inter alia atropine, has been elaborated, using chromatography on paper that is impregnated with zirconium oxide.57 Cation-exchange h.p.l.c. analysis of tropane alkaloids has been developed,58 followed by post-column derivatization using the fluorimetric ion-pair technique.58,59 Gas chromatography of tropanes has been reviewed.60... 

Liquid Chromatography-Mass Spectrometric Analysis of Tropane Alkaloids in Mammalian Samples Techniques and Applications... 

Auriola S, Martinsen A, Oksman-Caldentey KM, Naaranlahti T (1991) Analysis of tropane alkaloids with thermospray high-performance liquid chromatography-mass spectrometry. J Chromatogr 562 737-744... 

Current methods for tropane alkaloids analysis have been well covered in the literature. An excellent comprehensive review written by B. Drager [45] appeared in 2002, describing the analysis of tropane and related alkaloids in plant material. Sample preparation procedures were reviewed, as well as the analytical methods used for performing the separation and detection of tropane alkaloids, such as gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE). Therefore, this chapter will not describe in detail these well-known analytical methods but discuss some recently developed applications for the analysis of tropane alkaloids in plant material and biological matrices. 

The isolation of atropine, scopolamine, and cocaine occurred long before the development of modern analytical techniques. Gas chromatography was the first instrumental technique available in the field of separation science and thus it is not surprising that these alkaloids were firstly analyzed by GC despite their low volatility. With the advent of capillary columns and the proliferation of various sample introduction and detection methods, GC has evolved as the dominant analytical technique for screening, identification, and quantitation of tropane alkaloids of plant origin as well as in biological fluids. The state-of-the-art of GC analysis of tropane alkaloids has been the subject of two comprehensive reviews [45,58]. We shall therefore mainly focus on publications which have appeared since 2002. 

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. 

The analysis of tropane alkaloids by liquid chromatography has been performed for over 30 years. The first high-performance liquid chromatography (HPLC) analysis of tropane alkaloids was published in 1973 and concerned the separation of atropine and scopolamine as well as homatropine and apoatropine [102] the first analysis of these compounds in plant material appeared 12 years later [103]. 

Analysis of tropane alkaloids in biological fluids has been developed mostly for cocaine and metabolites. Indeed, it is well recognized that cocaine remains one of the most widely consumed drugs of abuse worldwide. Generally, reversed phase liquid chromatography coupled with UV-VIS detection is employed for these analyses. 

Paper chromatography has been used for quantitative determinations of the tropane alkaloids or for their separation from crude drugs prior to determination. ... 

Tropane alkaloids in crude drugs can be qualitatively identified, separated by paper chromatography and quantitatively assayed by colorimetric determination (106). Whatman No. 3 filter paper was used and the chromatograms were developed with the solvent water saturated n-butanol-glacial acetic acid (25 1) for 18 hours. Corresponding areas on the chromatograms were identified, cut off, eluted with ethanol and determined colorimetrically. 

Other stationary phases have also proved to be useful for gas chromatography o tropane alkaloids. For simultaneous quantitative determination of atropine and scopolamine, Solomon et al.1 applied an SE-30 column (2.5 ). During studies on the metabolism of tropane alkaloids, whereby quantitative determinations of minor alkaloids were carried out, Achari and Newcombe4 used columns with SE-30 (2 %), XE-60 (2 %), Versamid (5 %), QF-1 (2.5 %) and PEGS... 

A special application in the field of gas chromatography of tropane alkaloids is reaction... 

Fluorimetric ion-pair chromatography has been applied for ergotamine, ergotaminine and dihydroergotamine in connection with the analysis of pharmaceutical preparations containing tropane alkaloids 36,30,3 (Chapter 4). 

Mateus, L., Cherkaoui, S., Christen, R, and Veuthey, J.-L. (1998) Use of a Doehlert design in optimizing the analysis of selected tropane alkaloids by micellar electro-kinetic capillary chromatography. / Chromatogr A, 829, 317-325. 

Further recent contributions to the analytical chemistry of the tropane alkaloids include the selective determination by g.l.c. of atropine/hyoscyamine and scopolamine in admixture with other amines e.g. phenylpropanolamine and chlorpheniramine) often used in drug mixtures, the separation and identification of tropane alkaloids by g.l.c. of their trimethylsilyl ethers, and the separation of alkaloid mixtures by high-speed, high-pressure liquid chromatography. ... 

Carbon-13 n.m.r. and mass spectrometry have become essential methods in quantitative analysis of alkaloid mixtures extracted from plants, in addition to g.l.c. and photometry. Study of the mechanism of fragmentation of 3-substi-tuted tropanes is a useful tool for analysis of mixtures of tropane alkaloids. A comprehensive study on the n.m.r. spectroscopy of tropane alkaloids included most major representatives of this class. Other papers deal with the n.m.r. spectra of cocaine metabolites and derivatives. A radioimmunassay of atropine and benzoylecgonine in urine was published. Photometric determination of tropane derivatives in chloroform extracts was done via colorimetry of the bromocresol purple complex.Adsorption chromatography methods have been used with different resins. ... 

El Bazoui A, Bellimam MA, Lancar 1, Soulaymani A. Gas-liquid chromatography-mass spectrometry investigation of tropane alkaloids in Hyoscyamus albus L. from Morocco. Z Naturforsch C 2012 67(9 - 10) 461-5. 

Namera A, Yashdd M, Hirose Y, Yamaji S, Tani T, Kojima T (2002) Quantitative analysis of tropane alkaloids in biological materials by gas chromatography-mass spectrometry. Forensic Sci Int 130(l) 34- 3. doi 10.1016/s0379-0738(02)00302-x... 

Chromatography Hyphenation Sample preparation Separation and detection techniques Tropane alkaloids... 

Numerous methods for high-performance Uquid chromatography (HPLC) of tropane alkaloids have been developed. The chromatographic conditions depend on the variability of the analyzed matrices (extracts from different plant tissues, pharmaceutical preparations, clinical, and forensic probes) and analytes (pure compounds or alkaloid mixtures with different composition). Most often, columns packed with reverse-phase Cl 8 stationary phase are used for the separation of tropane alkaloids. Gradient or isocratic elution generally involves buffered mixtures at the acidic pH of water—acetonitrile or acetonitrile—methanol, such as acetonitrile-triethylammonium phosphate buffer (25 75) at pH 6.2 [65] acetonitrile-50 mM phosphate buffer at pH 2.95 (10 90 and 20 80) [66], methanol-0.05 M... 

The use of detectors other than UV for the analysis of tropane alkaloids has been reviewed previously [15, 24, 27]. In contrast to conventional detectors such as UV, RI, fluorescence, and ELSD coupled with LC, the MS detector provides information on the molecular structure of the separated compotmds (Fig. 31.3). Over the past decade, liquid chromatography coupled with mass spectrometry (LC-MS) has undergone tremendous technological improvement and is now one of the most powerful tools for the investigation of natural compotmds. 

The combination of gas chromatography and an isotope ratio measurement mass spectrometer (ir/n-GC-MS) was used to study the detoxification and degradation pathways of tropane alkaloids involving iV-demethylation to the respective nor-compounds. Molinie et al. developed protocols for sample preparation, including liquid-hquid and SPE extraction, and analysis of the kinetic isotope effects (KlEs) with irm-GC-MS and ir/M-elemental analysis (EA)-MS [100]. Degradation experiments were performed with a Pseudomonas strain that uses tropane alkaloids as sole source of carbon and nitrogen. The authors found that liquid-liquid extraction from the aqueous medium in combination with ir/n-GC-MS was the most convenient method for measurement of the ratio. Later, Kosieradzka... 

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