Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Chemistry  (21)
  • 1
    Electronic Resource
    Electronic Resource
    Study on drug metabolites by mass spectrometry. IVFor Part III, see Ref. 1. - metabolites of 2-(diethylamino) ethyltetrahydro-α-(1-naphthylmethyl)-2-furanpropionate oxalate in rats (1974)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1974), S. 66-72 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The determination of drug metabolites is very important in the biochemical field. However, the procedure for doing this has been very complicated in many cases. The major reason is because of the need for fairly large amounts of the samples. We have been studying procedures for the determination and identification by use of mass spectrometry, which usually gives a lot of information rapidly from very small amounts of the samples (below μg). In this paper, the metabolites excreted in urine and bile following oral administration of 2-(diethyamino)ethyl tetrahydro-α-(1-naphthylmethyl)-2-furanpropionate oxalate (1) in rats, were investigated by means of mass spectrometry and other techniques. The drug was not excreted unchanged in urine. Of the eight metabolites suspected to be present in urine and bile, the structures of three metabolites were elucidated to be tetrahydro-α-(1-naphthylmethyl)-2-furanpropionic acid (3) and α-(1-naphthylmethyl)-2-perhydro-5-oxofuranpropionic acid (4) in urine, and diethylaminoethanol (2) in bile. These metabolites might also be present as their structural isomers or conjugates.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200010114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Chemical ionization mass spectrometry of macrolide antibiotics. III - M-4365 and related compoundsPart II: Chemical ionization mass spectrometry of macrolide antibiotics: II - Platenomycin and related compounds, M. Suzuki, K.-I. Harada, N. Takeda and A. Tatematsu, Heterocycles 15, 1123 (1981). (1981)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 8 (1981), S. 332-336 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical ionization mass spectra of several 16-membered basic macrolide antibiotics containing an amino sugar are described. Depending on the reagent gas used (methane, isobutane or ammonia), a common pattern is exhibited by the chemical ionization mass spectra of all the compounds. That is, they show the protonated molecular ion as the base peak, which clearly indicates the molecular weight. Fragmentation involving carbon - carbon bond fission rarely occurs. As the major fragmentation pathway, the glycosidic bond is cleaved at both sides of the glycosidic oxygen atom to produce two aglycone-ions and three sugar-derived ions. These are shown to be useful in the structural characterization of new macrolide antibiotics.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200080803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Differentiation of 4α- and 4β-phorbol diesters by fast atom bombardment mass spectrometry (1993)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 22 (1993), S. 251-257 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) mass spectra of a series of stereoisomeric pairs of 4α- and 4β-phorbol diesters were determined in order to evaluate the possibility of differentiation between both isomers. A key feature in differentiating 4α- isomers (cis fusion of A/B ring in a tigliane nucleus) from 4β- isomers (trans A/B) is that the m/z 271 ion is only present in the FAB mass spectra of 4α- isomers, whereas this ion is virtually absent in the 4β-isomers. Analogously, the m/z 255 ion is only seen in the spectra of 4-deoxy-4α-phorbol diesters. The formation of m/z 271 (m/z 255) is characteristic with FAB ionization, but not with electron impact or chemical ionization. High-resolution, metastable decomposition and collision-activated dissociation experiments were carried out to elucidate the ion structure of m/z 271, and the mechanistic rationale for the formation was discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200220407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Desorption chemical ionization mass spectrometry of phorbol esters (1991)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 20 (1991), S. 31-39 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Desorption chemical ionization (DCI) mass spectra of a series of phorbol di- and monoesters have been determined by mainly using ammonia and isobutane as reagent gases. The applicability of this mass spectrometric method in structural characterization of this class of compounds is discussed. The DCI (NH3) mass spectra of phorbol diesters provided immediate confirmation of the molecular weight via an abundant adduction, [M + NH4]+. The DCI (iso-C4H10) mass spectra more clearly afforded useful structural information with regard to the constitutent fatty acid attached to C-12 or C-13 and deacyloxy moiety. Therefore, a combination of the mass spectra with both reagent gases allows characterization of phorbol esters. The intensities of peaks in the DCI (iso-C4H10) mass spectra can be used to distinguish the phorbol-12-monoesters from the 13-monoesters. It was found that hydrolysis of the phorbol 12,-13-diesters followed by DCI mass spectrometric analyses enabled the location of the longer-chain acyl moiety at either C-12 or C-13 in the parent alcohol.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200200108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Structural characterization of modified nucleosides in tRNA hydrolysates by frit-fast atom bombardment liquid chromatography/mass spectrometryPreliminary results were presented at the Kyoto '92 International Conference on Biological Mass Spectrometry, 20-24 September 1992, Kyoto, Japan. (1994)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 23 (1994), S. 465-474 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Feasibility for the structural characterization of modified nucleosides in transfer RNA at low microgram levels has been investigated by using continuous-flow frit-fast atom bombardment liquid chromatography/mass spectrometry (frit-FAB LC/MS). Sample of tRNAPhe from brewer's yeast (Saccharomyces cerevisiae) was used as a main model, and enzymatically hydrolysed by nuclease P1 and alkaline phosphatase. The resulting nucleoside mixture was separated by using a microbore reversed-phase LC column (150 mm × 0.5 mm i.d.) with an aqueous ammonium acetate-methanol gradient, and the mass spectra were acquired on both positive and negative ionization modes. The modified nucleosides were characterized by comparison of the relative LC elution times with authentic nucleosides, and further confirmed by the structural information from the frit-FAB mass spectra where both molecular and base ions were in general observed as intense peaks in both ionization modes. Tyically, 0.06-0.2 A260 units (3-10 μg) of isoaccepting tRNA was enough to obtain full-scan mass spectra of modified nucleosides, often occurring at a frequency of one per tRNA molecule using positive ion detection. The LC/MS system was used to screen modified nucleosides in tRNA of the extremely thermophilic microorganism Pyrodictium occultum.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200230803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Sequence determination of permethylated oligosaccharides by chemical ionization mass spectrometry (1983)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1983), S. 5-12 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chemical ionization mass spectra of several permethylated oligosaccharides were studied using isobutane and ammonia as reagent gases. In the molecular ion region, protonated molecule [MH]+ or ammonium adduct ion [M·NH4]+ were observed. Fragmentations were mainly restricted to the cleavages of the glycosidic bonds between the glycosidic oxygen and the anomeric carbon atoms. Resulting fragment ions were classified into oxonium type ions and their counterpart ions with hydrogen or methyl transfer, which were very useful for determining the sequence of the constituent saccharide units. These ions were confirmed by shift techniques with pertrideuteromethyl derivatives, deuterated reagent gases, i-C42H10 and N2H3, and 15NH3. Finally, these results were applied successfully to the structural characterization of the unknown trisaccharides, viridotriose A (6), B (7) and C (8).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200100103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Structural characterization of underivatized menthyl glycosides using chemical ionization mass spectrometry (1983)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1983), S. 608-613 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectra of a series of menthyl glycosides containing up to three sugar units produced by chemical ionization with isobutane and ammonia as reagent gases as well as (2H3) ammonia are reported. The applicability of this mass spectrometric method in structural characterization of the underivatized glycosides is discussed. All of the mass spectra are simple to interpret and afford useful diagnostic information about molecular weight and structural units in the molecules but little information for differentiation between the stereoisomers. The fragmentations producing the diagnostic ions have been confirmed with high resolution measurements and shift technique with (2H3)ammonia reagent gas.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200101106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The primary fragmentation step of isoxazole upon electron impact. A correlation with photochemistry (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 199-204 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three isomeric compounds, I, II and III, were prepared and their mass spectra recorded. Comparisons of the spectra showed that the fragmentation of I proceeds only by way of II, and that II itself is transformed in part to III upon electron impact. It is suggested that selective ionization of each one of the two isolated functional groups in II may afford two isomeric radical ions, IIa and IIb. A possible interrelation to the photochemistry of these compounds is also discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Mass spectrometry of tautomeric compounds - II: A mechanism of ketene elimination from enol acetates (1970)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 4 (1970), S. 211-214 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Comparisons of the mass spectral behaviour of the [M - 42] ions from enol acetates and that of the corresponding ketones indicate that the elimination of a ketene molecule from enol acetates proceeded through a four-membered cyclic transition state to afford fragment ions with an enolic structure.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210040123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Mass spectrometry of antibiotic kikumycin A, B and related compoundsPresented in part at the 7th Symposium of Mass Spectrometry on Organic Compounds, Kobe, Japan, October 1972. (1974)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 9 (1974), S. 635-648 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structures of kikumycin A and B, antiviral amidine antibiotics, have been elucidated by means of low and high resolution mass spectrometry. Amino acid composition and their sequences were also clearly demonstrated by this technique. The evidence for the fragmentation of terminal amidines or amides of kikumycin derivatives and related synthetic compounds was represented by the elimination of ammonia or water from the molecular ions to give stable nitrile ions. Additionally, the participation of the iminol structure in the pyrrole-2-carboxamide portion of kikumycin A and B was confirmed by the fragment ions derived from their iminol tautomers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210090703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...