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  • 1
    Electronic Resource
    Electronic Resource
    Analysis of effector cell-derived lyso platelet activating factor by electron capture negative ion mass spectrometry (1991)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 20 (1991), S. 545-552 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantification of 1-O-alkyl-2-lyso-sn-3-glycero-phosphocholine (lysoPAF) and determination of the different molecular species released by cells has been hampered by the molecules's lack of intrinsic bioactivity, unavailability of a suitable internal standard, and reliance on derivatives requiring electron impact techniques. We have synthesized trideuterated internal standards (labeled on the terminal carbon of the alkyl chain) for both C16:0 and C18:0 lysoPAF. Using these standards, we isolated and quantified lysoPAF released from A23187-stimulated human neutrophils and rat alveolar macrophages. Extracted lysoPAF was purified by solid-phase extraction and thin-layer chromatography. The polar phosphorylcholine group was removed with 29 M HF or phospholipase C. The two free hydroxyl groups were derivatized with pentafluorobenzoyl chloride. The resultant bis-pentafluorobenzoyl derivative, analyzed by gas chromatography/electron capture negative ion mass spectrometry, underwent substantial fragmentation. Lowering of the ion source temperature resulted in a dramatic increase in signal-to-noise ratio, with the vast majority of the ion current carried in the molecular anion. Stimulated neutrophils released 16.3 and 10.2 ng/106 cells of C16:0 lysoPAF and C18:0 lysoPAF, respectively. Rat macrophages synthesized 15.9 ng/106 cells of C16:0 lysoPAF, but C18:0 lysoPAF was variably detected at low levels. We conclude that use of the bispentafluorobenzoyl ester derivative of lysoPAF allows facile quantification of this autacoid metabolite in biological matrices.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200200907
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  • 2
    Electronic Resource
    Electronic Resource
    Enantiospecific quantification of hexobarbital and its metabolites in biological fluids by gas chromatography/electron capture negative ion chemical ionization mass spectrometry (1991)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 20 (1991), S. 559-564 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A highly sensitive and specific assay based on gas chromatography/electron capture negative ion chemical ionization mass spectrometry has been developed for the analysis of the enantiomers of hexobarbital and its major metabolites in human urine and plasma. S-(+)-(5-2H3)hexobarbital and R-(-)-(5-2H3)hexobarbital were synthesized for clinical studies along with (±)-(1,5-2H6)hexobarbital and the deuterated major metabolites for use as internal and reference standards. Hexobarbital enantiomers and their metabolites were analyzed after pentafluorobenzyl and trimethylsilyl derivatization, following solid-phase extraction from plasma and urine. Intense negative ion spectra were observed for all of the derivatives. The base peak in the spectra corresponded to the M - penta-fluorobenzyl anion [M — PFB]- except for 1,5-dimethylbarbituric acid, where M-· was the most abundant ion. The applicability of the method was demonstrated by following the plasma concentration-time profiles and urinary excretion in a male extensive metabolizer of mephenytoin who was given a pseudoracemic oral dose of hexobarbital containing equal 50 mg amounts of S-(+)-2(H0)hexobarbital and R-(-)-(2H3)hexobarbital. Marked stereoselective disposition was observed, with the R-(-)-enantiomer being more efficiently metabolized, primarily by alicyclic oxidation and ring cleavage.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200200909
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  • 3
    Electronic Resource
    Electronic Resource
    Mass spectra of some 2-(3′,5′-diphenylpyrazol-1′-yl)-6-substituted Benzothiazoles (1987)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 22 (1987), S. 49-51 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210220113
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  • 4
    Electronic Resource
    Electronic Resource
    Mass spectra of some 1-(6′-substituted-4′-methyl-2′-quinolyl)-3-methylpyrazol-5-ols and their 4-substituted analogues (1987)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 22 (1987), S. 212-215 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron impact induced fragmentation of some 1-(6′-substituted-4′-metbyI-2′-quinolyI)-3-methylpyrazoI-5-ols follows a route where the pyrazole moiety is preferentially cleaved with successive losses of two moieties of 41 u. High-resolution measurements have established that the first loss is due to the Ċ2HO moiety, which necessitates an intramolecular hydrogen transfer followed by ring fission. The resultant ion loses CH3CN in a subsequent step. The origin of many fragment ions was traced with the use of B/E linked-scan spectra.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210220407
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  • 5
    Electronic Resource
    Electronic Resource
    K-absorption edges of cobalt in its metallic soaps and their liquid crystalline solutions in benzene (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 14 (1985), S. 136-138 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: X-ray K-absorption edges of cobalt in some metallic soaps (myristate, palmitate, stearate and oleate) and their solutions in benzene have been recorded. The latter are liquid crystals. The bond length between the metal and the ligand was found to be greater in solutions than in the solids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300140307
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  • 6
    Electronic Resource
    Electronic Resource
    13C NMR studies of the friedelane series of triterpenoids and the conformation of the D and E rings in friedelan-7-oneDedicated to Proof. Ajay K. Bose on his sixtieth birthday. (1987)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 25 (1987), S. 39-41 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; Friedelanes ; Triterpenoids ; D/E ring conformation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 13C chemical shifts in the spectra of friedelan-7-one (1), methyl 3-oxofriedelan-25-oate (2), methyl friedelan-25-oate (3), 7-oxofriedelan-3-α-yl acetate (4), friedelan-3-one (5), 2-hydroxy-3, 4-seco-friedelan-3-oic acid (6), methyl 2-oxo-3,4-seco-friedelan-3-oate (7), methyl 2-hydroxy-3,4-seco-friedelan-3-oate (8) and 3,4-seco-friedelan-2,3-diol (9) have been fully assigned using two-dimensional heteronuclear correlation NMR spectroscopy, BB proton decoupled, DEPT and selective heteronuclear spin decoupling methods. These assignments and the observation of substantial NOEs between 26-methyl and 28-methyl and between 28-methyl and 30-methyl support the boat to boat conformations for the D and E rings in 1. Corrections and correlations are made of some earlier literature assignments of friedelanones.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260250110
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  • 7
    Electronic Resource
    Electronic Resource
    Improved 2D inverse proton detected C,H correlation NMR techniques for the total assignment of carbon resonances of a highly delta opioid receptor agonist peptide (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 231-237 
    Details
    ISSN: 0749-1581
    Keywords: Inverse experiments ; Long-range H,C correlations ; Delta opioid receptor agonist peptide ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Assignment of the 13C resonances of the highly delta opioid receptor selective cyclic peptide enkephalin (DPDPE) was accomplished by using single-quantum inverse proton detected 2D heteronuclear correlation spectroscopy. The pulse sequences described provided better sensitivity and resolution than the corresponding, commonly used, multiple-quantum evolution experiments, since during the SQ-evolution period there is no line broadening due to scalar and dipolar 1H-1H interactions. The proton detected C,H correlation spectrum, in combination with the H-TOCSY relay C,H correlation, gave the assignment of all protonated carbons. The C,H correlation optimized for long-range coupling gave the assignments of all non-protonated carbons, such as the carbonyl carbons of the peptide bonds. These spectra also allowed the sequential assignment of this molecule.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310304
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  • 8
    Electronic Resource
    Electronic Resource
    Carbon-13 NMR spectral assignments of some bicyclo[4.3.0]nonanone and bicyclo[4.4.0]decalone systems (1995)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 33 (1995), S. 987-988 
    Details
    ISSN: 0749-1581
    Keywords: NMR ; 13C NMR ; bicyclo[4.3.0]nonan-4-ones ; bicyclo[4.4.0]decal-4-ones ; hydrindanones ; decalones ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR signal assignments of some bicyclo[4.3.0]nonan-4-ones (hydrindanones) and bicyclo[4.4.0]decal-4-ones are reported.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260331210
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  • 9
    Electronic Resource
    Electronic Resource
    Carbon-13 and proton two-dimensional NMR study of diterpenoids of Coleus forskohliiCDRI Communication No. 4027. (1988)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 26 (1988), S. 117-119 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; 1H NMR ; 2D NMR ; Diterpenoids of Coleus forskohlii ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The stereochemical assignments of coleonol-B (1), coleonol-D (2) and coleosol (3) were accomplished by 2D 1H—1H (COSY), 1H—13C (hetero COSY), NOE difference NMR spectroscopic, stereospecific coupling constant and selective heteronuclear spin decoupling studies. The complete 13C chemical shift assignments of 2, 3 and coleol (4) were made for the first time. The earlier 1H chemical shift assignments were corrected and the stereostructure of coleonol-D was reassigned.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260260206
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  • 10
    Electronic Resource
    Electronic Resource
    Two-dimensional NMR analysis of himachalol and its correlation with other sesquiterpenoids of the himachalane seriesCDRI Communication No. 3829. (1988)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 26 (1988), S. 47-50 
    Details
    ISSN: 0749-1581
    Keywords: Himachalol ; isocentdarol ; centdarol ; centdarone ; stereochemistry ; 13C NMR chemical shifts ; 2D NMR ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-field 1H NMR studies of himachalol (1) have been carried out by two-dimensional NMR methods. The stereochemical aspects of this molecule were studied through the application of stereospecific coupling constants, the nuclear Overhauser effect and lanthanide-induced chemical shifts. Complete and unambiguous 13C chemical shift assignments of 1 have been made for the first time by using two-dimensional heteronuclear (1H—13C) correlation NMR spectroscopy, DEPT, broad-band proton decoupling and selective heteronuclear spin decoupling 13C NMR methods. Complete 13C chemical shift assignments of isocentdarol, centdarol and centdarone have also been made using some of the above techniques and their stereostructures have been corrected.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260260112
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