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  • 1
    Electronic Resource
    Electronic Resource
    Identification of carpronium chloride and its metabolite in human urine by field desorption mass spectrometry using deuterium labelling (1979)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 6 (1979), S. 467-471 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The identification of carpronium chloride and a metabolite in human urine has been performed by means of field desorption mass spectrometry using deuterium labelling. Essential points in this study are the simultaneous administration of a deuterium labelled drug ([2H9]carpronium chloride), a purification procedure by ion pair extraction with an iodine reagent, and the use of paper electrophoresis to examine the degree of clean-up. The field desorption mass spectra of the purified extracts obtained from sample urine gave a characteristic pattern resulting from the carpronium cation (m/z 160, m/z 169) and a metabolite of the N-(3-carbohydroxypropyl)trimethyl ammonium cation (m/z 146, m/z 155).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200061102
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  • 2
    Electronic Resource
    Electronic Resource
    Field desorption mass spectrometry of betaine hydrohalides (1982)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 9 (1982), S. 438-442 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Field desorption mass spectra of betaine hydrohalides are generally characterized by field desorption ions such as [Betaines+H]+ and cluster ions [nBetaines+H]+. In compounds where the conformation between [N]+ and COOH in the molecule is unable to form a betaine structure, the field desorption mass spectra consist only of compiex field desorption ions due to thennal decomposition products. Quaternary ammonium cations [C]+ and cluster ions [nC+(n - 1)A]+, which arise from ordinary quaternary ammonium compounds, are hardly produced. The effect of counter-ions on the field desorption mass spectra and the mechanism of field desorption ion formation are also discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200091006
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  • 3
    Electronic Resource
    Electronic Resource
    Intermolecular methyl transfer on pyrolysis of carpronium chloridePresented in part at the 12th Annual Symposium of Organic and Biomedical Mass Spectrometry, Tokyo, Japan (1977). (1979)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 14 (1979), S. 61-65 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The methyl transfer occurring in the production of methyl N,N-dimethyl-γ-aminobutyrate by pyrolysis of carpronium chloride was examined by means of pyrolysis gas chromatography mass spectrometry with the aid of some deuterated compounds. The mass spectra of methyl N,N-dimethyl-γ-aminobutyrate, produced from deuterated derivatives of carpronium chloride, showed inter alia, characteristic molecular ion peaks which indicated that the methyl of the trimethylammonium group transfers and displaces the methyl of the carbomethoxy group of the tertiary amino compound. The results show that an intermolecular methyl transfer occurs in part on pyrolysis of carpronium chloride, to form methyl N,N-dimethyl-γ-aminobutyrate in which the methyl oxygen is replaced by a methyl from the nitrogen of the original compound. The mechanism presented involves the bimolecular reaction between zwitterionic intermediates formed by ionic O-demethylation of carpronium chloride.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210140202
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  • 4
    Electronic Resource
    Electronic Resource
    Pyrolysis reaction of carpronium chloride and its structurally related compounds. 1 - electronic and steric effects on the orientation of the pyrolysis reaction (1983)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1983), S. 27-33 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pyrolysis reaction of carpronium chloride and its structurally related compounds, which were trimethyl-aminoalkyl acid alkyl esters involving two, three or four skeletal methylene groups, have been investigated by pyrolysis gas chromatography mass spectrometry. The results indicated that the reaction modes of these ammonium compounds were essentially dependent on the number of skeletal methylene groups, and secondarily on the length of the carbon chain of the ester group. These phenomena have been interpreted in terms of electronic and steric contributions for the ionic elimination reaction. The electronic and steric effects on the orientation of the reaction are discussed on the basis of the atomic population calculated by the CNDO/2 method.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210180107
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  • 5
    Electronic Resource
    Electronic Resource
    Pyrolysis reaction of carpronium chloride and its structurally related compounds. 2 - a mass spectrometric study of the lactonization mechanism (1983)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1983), S. 139-146 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of the pyrolysis reaction of carpronium chloride [(CH3)3N+—(CH2)3—COOCH3CI-] leading to γ-butyrolactone and tetramethylammonium chloride was investigated by means of thermal analysis, pyrolysis gas chromatography mass spectrometry and field desorption mass spectrometry, using deuterium labelling. The results indicated that carpronium chloride pyrolysed to yield equimolar amounts of γ-butyrolactone and tetramethylammonium chloride, methyl transfer occurred between N and O during the pyrolysis process. The mechanism is discussed on the basis of the experimental results, and with the aid of the theoretical results calculated by the CNDO/2 method. The mechanism presented is as follows. γ-Butyrolactone is formed by the intramolecular migration of the π-orbital of C=O to the carbon adjacent to [(CH3)3N]+ via a 5-membered ring transition state, accompanied by a bimolecular reaction between [(CH3)3N]+ and the CH3 of O—CH3, resulting in the formation of tetramethylammonium chloride in an amount equimolar with γ-butyrolactone.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210180402
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  • 6
    Electronic Resource
    Electronic Resource
    Analysis of drugs by pyrolysis II - an improved method for the determination of carpronium chloride in plasma by selected ion monitoring (1980)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 7 (1980), S. 1-6 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A sensitive and specific method has been devised for the determination of carpronium chloride, a parasympathomimetic agent, in plasma. The method is based on selected ion monitoring combined with the pyrolysis reaction of (3-isopropoxycarbopropyl)trimethylammonium chloride derived by transesterification of the drug. Carpronium chloride-[2H9] is used as an internal standard. The drug and the internal standard are separated from deproteinized plasma by ion pair extraction, and converted into isopropyl ester derivatives. The derivatives are pyrolysed to produce the respective isopropyl N,N-dimethyl-γ-aminobutyrates available for selected ion monitoring. Measurement is carried out in the electron impact mode by monitoring the fragment ion [M—OC3H7]+ (m/z 114, 120). The method is applicable to 5 ng ml-1 plasma with about 10% coefficient of variation, and has been utilized successfully for the pharmacokinetics of carpronium chloride in man.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200070102
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  • 7
    Electronic Resource
    Electronic Resource
    Analysis of drugs by pyrolysis. IPresented in part at the 10th Annual Symposium of Organic and Biomedical Mass Spectrometry, Nagoya, Japan, 11-13 November 1975.-selected ion monitoring combined with a pyrolysis method for the determination of carpronium chloride in biological samplesAbbreviation: MTB = (3-methoxycarbopropyl)trimethyl-ammonium chloride, carpronium chloride. (1977)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 4 (1977), S. 241-247 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to establish an analytical method for carpronium chloride, a parasympathomimetic agent, the pyrolysis reaction of carpronium chloride was examined in a g.c.m.s. system, which revealed that γ-butyrolactone was produced directly from the drug as the main pyrolysis product. In the case of conversion of [2,2,3,3-2H4]carpronium chloride into the deuterated γ-butyrolactone, 2H/1H scrambling was observed and confirmed to occur during the pyrolysis process of the deuterated compound. The proportion of γ-[2H4]butyrolactone among the pyrolysis products was almost independent of the operating conditions, so [2,2,3,3-2H4]carpronium chloride was of practical use as an internal standard for selected ion monitoring. By incorporation of the pyrolysis reaction of carpronium chloride with selected ion monitoring and the use of [2,2,3,3-2H4]carpronium chloride as an internal standard, a rapid, sensitive and selective method was devised for the determination of the drug in biological samples. The method was utilized successfully for the biopharmaceutical studies of carpronium chloride in man.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200040410
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