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  • Artikel  (10)
  • Artikel: DFG Deutsche Nationallizenzen  (10)
  • Wiley-Blackwell  (10)
  • Springer Nature
  • 2010-2014
  • 1985-1989  (10)
  • 1
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 189 (1988), S. 287-292 
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Unsaturated spiroorthoesters, which undergo no shrinkage on polymerization, were synthesized in high yield by an elimination reaction of the corresponding halomethylated spiroorthoesters with potassium hydroxide (KOH) or potassium tert-butoxide (t-BuOK) using a phase transfer catalyst. It was found that tetrabutylammonium bromide exhibits a catalytic activity higher than that of the other quaternary ammonium salts, 18-crown-6 and poly(ethylene glycol) (M̄w = 300) under equal conditions. The elimination reaction of halomethylated spiroorthoesters proceeds easily in toluene or diglyme with t-BuOK and in tert-butyl alcohol with KOH leading to the corresponding unsaturated compounds in high yields. In addition, the bromomethylated spiroorthoesters showed higher reactivity than the chloromethylated spiroorthoesters under equal conditions.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 1353-1362 
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Polymerization of homologues of 1-(trimethylsilyl)-1-propyne [CH3C≡CSi(CH3)3] was studied. CH3C≡CSi(CH3)2(n-C6H13) (I) polymerized with 1 : 1 mixtures of TaCl5 and organometallic cocatalysts (e.g., Ph4Sn and Ph3Bi) to produce in good yields a polymer having a weight-average molecular weight (Mw) over 1 × 106. CH3C≡CSi(CH3)2 Ph (II) and CH3C≡CSi(C2H5)3 (III) formed polymers having Mw's of ∼ 5 × 105 in moderate yields in the presence of TaCl5-based catalysts. In contrast, none of CH3C≡CSi(CH3)2(i-C3H7), CH3C—CSi(CH3)2(t,-C4H9), C2H5C≡CSi(CH3)3, and n,-C4H9C≡CSi(CH3)3 polymerized, which is attributed to the steric effect of the monomers. Some other 1-silyl-1-propynes also failed to polymerize. The three new polymers formed from (I)-(III) had the structure \documentclass{article}\pagestyle{empty}\begin{document}$\rlap{--} [{\rm CCH}_{\rm 3} \hbox{=\hskip-2pt=} {\rm C(SiRR'R''}\rlap{--} ]_n$\end{document} according to IR and 13C-NMR spectra. They were white solids, soluble in low-polarity solvents (e.g., toluene and chloroform) and stable enough in air at room temperature.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 681-690 
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Polymers with both pendant spiro ortho ester and carboxylic acid moieties were synthesized by partial esterification of poly(methacrylic acid), poly(methacrylic acid-co-methyl methacrylate), or poly(methacrylic acid-co-styrene) with halomethylated spiro ortho esters in the presence of 1,8-diazabicyclo[5,4,0]undecene-7 in dimethyl sulfoxide. The extent of esterification increased with increasing reaction temperature. The reaction of polymeric carboxylic acids with chloromethylated spiro ortho esters proceeded to 80% of conversion at 100°C for 120 h. In contrast, the degree of esterification with bromomethylated spiro ortho ester reached 80% at 60°C within 24 h. Thermo-crosslinking of polymers having pendant spiro ortho ester moiety and carboxylic acid could be effected in films. The rate of spiro ortho ester ring-opening increased with increasing reaction temperature and with increasing content of carboxylic acid groups in the polymer. Further, the rates of gel production were also measured. The polymer containing an equimolar mixture of spiro ortho ester moieties and carboxylic acids exhibited the highest reactivity. In addition, it was found that thermal crosslinking reaction of the polymer occurred with minimum volume shrinkage.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    ISSN: 0887-624X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Polymerization of new 1-(trimethylsilyl)-1-propyne homologs containing two silicon atoms [CH3C≡CSi(CH3)2CH2Si(CH3)3 and CH3C≡CSi(CH3)2CH2CH2Si(CH3)3] was investigated by use of Ta and Nb catalysts. CH3C≡CSi(CH3)2CH2Si(CH3)3 was polymerized quantitatively by TaCl5 alone to provide a polymer having molecular weight over 106. CH3C≡CSi(CH3)2CH2CH2Si(CH3)3 was polymerized in good yield by an equimolar mixture of TaCl5 with an appropriate organometallic cocatalyst such as Ph4Sn to give a polymer with molecular weight of ca. 4 X 105. Nb catalysts were less active toward these monomers than the corresponding Ta catalysts. These two kinds of polymers had alternating double bonds along the main chain according to IR and 13C-NMR spectra. Both polymers were white solids completely soluble in low-polarity solvents like toluene, and solution casting afforded uniform, tough films. These polymers were thermally fairly stable, and their softening points were above 350°C. Films of these polymers showed smaller oxygen permeability coefficients [Po2 = 4 × 10-9 - 8 × 10-9 cm3(STP) · cm/(cm2·sec·cmHg)] but larger separation factors [(Po2/Po2) = 3.4 - 3.6] than a poly[1-(trimethylsilyl)-1-propyne] film.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 1 (1987), S. 181-188 
    ISSN: 0884-3996
    Schlagwort(e): Lampteromyces ; bioluminescence ; riboflavin ; light emitter ; mushroom ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: The bioluminescence of the luminous mushroom, Lampteromyces japonicus, was studied by using the mushroom gills and also the luminous mycelia, the latter being cultured from the isolated spores and grown in a potato sucrose medium. The luminescence intensity of the mushroom gills and the cultured mycelia was measured in an aqueous suspension under various conditions. The original intensity was enhanced by exposing the luminous cells to oxygen for several hours or to acids or bases for a short period. This enhancement enabled measurement of their bioluminescence spectra which were identical to the fluorescence spectrum of riboflavin, having a maximum at 524 nm. The green fluorescent substance was extracted with cold water from the mushroom and it was identified as riboflavin by spectroscopic and chromatographic analyses. Riboflavin was concluded to be the light emitter of this mushroom.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 2 (1988), S. 73-79 
    ISSN: 0884-3996
    Schlagwort(e): bioluminescence ; fluorescence ; Dyakia striata ; snail ; mollusc ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: The luminescent land snail Dyakia striata displayed a bioluminescence spectrum with a maximum wavelength of 515 nm. A green fluorescent substance extracted from the photogenic organ of an adult snail had a similar wavelength maximum but its fluorescence spectrum differed from that of flavin chromophore substances involved in light emission in some other luminescent organisms.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    ISSN: 1052-9306
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Evaluation of positive and negative ion fast atom bombardment (FAB) mass spectrometry for structural investigations have been studied on 30 cardiac glycosides in comparison with their field desorption (FD) mass spectra. FD mass spectra showed the prominent molecular cluster ions and the same protonation induced fragments as that established for steroid oligoglycosides. Even if the molecular cluster ions of some di- and triglycosides were hardly detected in the positive ion FAB mass spectra owing to their low intensities, a dramatic improvement was observed when sodium chloride or potassium iodide was added to the glycerol matrix. Furthermore, the prominent molecular ion species, [M - H]-, and the sequence of glycosidic linkage were easily detected in the negative mode. The combination of positive and negative ion FAB mass spectrometry of the cardenolide-type cardiac glycosides provides useful information concerning the molecular weight as well as the structures of both aglycone and sugar moieties.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 0170-2041
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Biologisch aktive Glycoside aus Asteroidea, XIII. - Glycosphingolipide aus dem Seestern Acanthaster planci, 22). - Isolierung und Struktur von sechs neuen CerebrosidenSechs neue Cerebroside (Ceramid-monohexoside), Acanthacerebrosid A (1), B (2), C (3), D (4), E (5) und F (6), wurden aus der wasserunlöslichen Lipid-Fraktion des Chloroform-Methanol-Extrakts des Seesterns Acanthaster planci isoliert. Auf Grund der chemischen und spektrometrischen Untersuchungen ließen sich die Strukturen als 1-O-(β-D-Glucopyranosyl)-substituiertes (2S,3S,4R)-2-[(2R)-2-Hydroxytetracosanoylamino]-1,3,4-hexadecanetriol (1), (2S,3S,4R)-2-[(2R)-2-Hydroxyhexadecanoylamino]-1,3,4-docosantriol (2), (2S,3S,4R,13E)-2-[(2R)-2-Hydroxyhexadecanoylamino]-13-docosen-1,3,4-triol (3), (2S,3R,4E,10E)-2-[(2R)-2-Hydroxydocosanoylamino]-4,10-octadecadien-1,3-diol (4), (2S,3R,4E,10E)-2-[(2R)-2-Hydroxytricosanoylamino]-4,10-octadecadien-1,3-diol (5) und (2S,3R,4E,10E)-2-[(2R)-2-Hydroxytetracosanoylamino]-4,10-octadecadien-1,3-diol (6) charakterisieren. Die Isolierung der strukturell sehr ähnlichen Cerebroside gelang durch Reversed-Phase-HPLC. Negativ-FABMS-Spektrometrie ließ sich erfolgreich zur Molmassen-Bestimmung der Cerebroside einsetzen.
    Notizen: Six new cerebrosides (ceramide monohexosides), acanthacerebroside A (1), B (2), C (3), D (4), E (5), and F (6) were isolated from the water-insoluble lipid fraction of the chloroform-methanol extract of the starfish Acanthaster planci. On the basis of chemical and spectral evidences, they were characterized as 1-O-(β-D-glucopyranosyl)-substituted (1S,3S,4R)-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-hexadecanetriol (1), (2S,3S,4R)-2-[(2R)-2-hydroxyhexadecanoylamino]-1,3,4-docosanetriol (2), (2S,3S,4R,13E)-2-[(2R)-2-hydroxyhexadecanoylamino]-13-docosene-1,3,4-triol (3), (2S,3R,4E,10E)-2-[(2R)-2-hydroxydocosanoylamino]-4,10-octadecadiene-1,3-diol (4), (2S,3R,4E,10E)-2-[(2R)-2-hydroxydocosanoylamino]-4,10-octadecadiene-1,3-diol (5), and (2S,3R,4E,10E)-2-[(2R)-2-hydroxytetracosanoylamino]-4,10-octadecadiene-1,3-diol (6). Reversed-phase HPLC was effective to isolate these cerebrosides revealing the very close resemblance in structure. Negative FABMS spectrometry was useful in providing information on the molecular mass of the cerebrosides.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    ISSN: 0170-2041
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Biologisch aktive Glycoside aus Asteroidea, XVII. - Glycosphingolipide aus dem Seestern Acanthaster planci, 3. - Isolierung und Struktur von zwei neuen Ceramid-LactosidenAus der wasserlöslichen Lipid-Fraktion des Chloroform/Methanol-Extraktes des Seesterns Acanthaster planci ließen sich zwei neue Acanthalactoside A (1) und B (2) isolieren. Aufgrund chemischer und spektroskopischer Befunde wurden die Strukturen von 1 und 2 als 1-O-[β-D-Galactopyranosyl-(1→4)-β-D-glucopyranosyl]-substituiertes (2S,3S,4R)-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-hexadecanetriol (1) und (2S,3S,4R,13E)-2-[(2R)-2-hydroxyhexadecanoylamino]-13-docosen-1,3,4-triol (2) ermittelt. Die Isolierung des Glycosphingolipid-Gemisches aus der wasserlöslichen Lipid-Fraktion, die auch anderes Material wie zum Beispiel Steroid-Saponine enthalten, gelang mit Hilfe der Reversed-phase-Säulenchromatographie. Reversed-phase-HPLC ließ sich effektiv zur Isolierung der strukturell sehr ähnlichen Ceramiddihexodside einsetzen. Negativ-FAB-Massenspektrometrie diente zur erfolgreichen Bestimmung und Absicherung der Struktur der Ceramid-dihexoside.
    Notizen: Two new ceramide lactosides, acanthalactoside A (1) and B (2) were isolated from the water-soluble lipid fraction of the chloroform/methanol extract of the starfish Acanthaster planci. On the basis of chemical and spectral evidence, the structures of 1 and 2 were characterized as 1-O-[β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-substituted (2S,3S,4R)-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-hexadecanetriol (1) and (2S,3S,4R,13E)-2-[(2R)-2- hydroxyhexadecanoylamino]-13-docosene-1,3,4-triol (2), respectively. Reversed-phase column chromatography was useful to obtain the glycosphingolipid mixture from the watersoluble lipid fraction containing also other material such as steroid saponins. Reversed-phase HPLC was also effectual to isolate these ceramide dihexosides reveling very close resemblance in structure. Negative FAB mass spectrometry was successfully used for the determination and confirmation of the ceramide dihexosides.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    BioEssays 4 (1986), S. 167-171 
    ISSN: 0265-9247
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Cytoskeletal organization in embryonic skeletal muscle cells has been examined by transmission electron microscopy; the technique involves preparation using the platinum replication method of freezedried samples, with and without cryofracture. The cytoskeletons in developing muscle cells appear to play a role in preserving cell shape as well as in anchoring myofibrils to cell membrane.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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