ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Biochemistry and Biotechnology
  • Essential oil analysis
  • High resolution GC-MS
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
  • 1
    Digitale Medien
    Digitale Medien
    Catalytic transformation of anise (Pimpinella anisum L.) oil over zeolite Y (1995)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 18 (1995), S. 501-503 
    Details
    ISSN: 0935-6304
    Schlagwort(e): High resolution GC-MS ; Mass spectrometry ; Anise oil ; Catalytic transformation ; Zeolite Y ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240180810
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Stabilization of substilisin E in organic solvents by site-directed mutagenesis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 141-147 
    Details
    ISSN: 0006-3592
    Schlagwort(e): protein engineering ; enzymes in organic solvents ; protein stabilization ; subtilisin E ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Subtilisin E was rationally engineered to improve its stability in polar organic solvents such as dimethylformamide (DMF). A charged surface residue, Asp248, was substituted by three amino acids of increasing hydrophobicity, Asn, Ala, and Leu; all three variants were stabilized with respect to wild type in 80% DMF. This stabilization was only observed in the presence of high concentrations of the organic solvent: no stability enhancements were observed in 40% DMF. In contrast, the mutation Asn218 → Ser alters internal hydrogen bonding interactions and stabilizes subtilisin E in both 40% and 80% DMF. This study provides additional evidence that substitution of surface-charged residues is a generally useful mechanism for stabilizing enzymes in organic media and that the stabilizing effects of such substitutions are unique to highly altered solvent environments. The effects of the single amino acid substitutions on free energies of stabilization are additive in the Asp248 → Asn + Asn218 → Ser combination variant, yielding an enzyme that is 3.4 times more stable than wild type in 80% DMF.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260390204
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Organic acid production from CO2/H2 and CO/H2 by mixed-culture anaerobes (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 23 (1981), S. 2293-2306 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The gases CO, CO2, and H2 were used as substrates in anaerobic fermentations producing organic acids. Various mixed bacterial sources were used, including sewage sludge digester effluent, rabbit feces, and soil. Nonsterile microorganism selection was carried out using CO2/H2 and CO/H2 as the primary carbon and energy sources. Cultures were grown in specially designed, high-pressure (to 70 psig) flasks. Methanogenic bacteria were eliminated from the cultures. Liquid products of the fermentations were acetic through caproic acids, with the even-numbered acids predominating. Carbon balances showed conclusively that acetic acid was formed from carbon contained in the CO or CO2 feed gas. Measurements made included rates of acid product formation, cell density, and degree of gas utilization. Limited characterization of the microorganisms was also performed. Production of organic acids by mixed culture inocula from CO2/H2 or CO/H2 had not been reported previously. Application of this work is to the production of organic chemicals from synthesis gas (SNG), produced by the gasification of fossil fuels (peat, lignite, and various ranks of coals), biomass (agricultural and forest residues, and various biomass crops grown expressly for energy recovery), and municipal solid waste.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260231012
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Enhanced release of rosmarinic acid from Coleus blumei permeabilized by dimethyl sulfoxide (DMSO) while preserving cell viability and growth (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 459-464 
    Details
    ISSN: 0006-3592
    Schlagwort(e): permeabilization ; dimethyl sulfoxide ; Coleus blumei ; preconditioning ; cell viability ; rosmarinic acid ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Continuous permeabilization of preconditioned Coleus blumei cells with dimethyl sulfoxide (DMSO) is shown to be an effective strategy for the enhanced release of rosmarinic acid (RA) while preserving cell viability. When nonpreconditioned cells were permeabilized with DMSO, they lost their viability at DMSO concentrations higher than a critical value located between 0.1% and 0.5% DMSO. Product release was low [0.49 g RA/100 g dry cell weight (DCW)] at 0.1% DMSO. Preconditioning cells at 0.1% DMSO ensured high viability at DMSO concentrations of 0.5%, 1.0%, and 1.5%. Product release reached a maximum of 2.85 g RA/100 g DCW at 0.5% DMSO, which was 66.4% of the total rosmarinic acid produced. © 1992 John Wiley & Sons, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260400403
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    HRGC/FID/NPD and HRGGC/MSD study of Colombian ylang-ylang (Cananga odorata) oils obtained by different extraction techniques (1996)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 19 (1996), S. 353-358 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Capillary gas chromatography ; Gas chromatography-mass spectrometry ; Essential oil analysis ; Ylang-ylang oil ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Steam distillation (SD), simultaneous distillation-solvent extraction (SDE), and supercritical (CO2) extraction (SFE) were used to isolate volatile secondary metabolites from fresh, totally mature flowers of Colombian ylang-ylang (Cananga odorata). The various extracts were analyzed by capillary chromatography (DB-1, DBWAX, 60 m columns) using FID, NPD or MSD (EI, 70 eV). Kováts indexes, mass spectra, or standard substances were employed for compound identification. 51, 70, and 73 compounds at concentrations above 100 ppb were detected in the SD, SDE, and SFE extracts, respectively. The main constituents of these extracts were linalool (20.7, 28.0, and 16.5%), germacrene-D (10.1, 3.1, and 20.3%) benzyl benzoate (14.1, 2.9, and 3.9%), benzyl acetate (9.6, 17.0, and 6.2%), caryophyllene (3.1, 2.9, and 3.9%), and p-methylanisole (6.8, 6.1, and 2.7%). 85% of the composition of SDE extracts was represented by oxygenated compounds. Heavy hydrocarbons (Cn 〉20) and fatty acids were found only in the SFE extracts, which also had a higher content of nitrogenated compounds (phenylacetonitrile, 4-methylbenzaldoxime, indole, 2-phenyl-nitroethane, and methyl anthranilate) and sesquiterpenes (43% vs 19.5% in SD and 8.1% in SDE) and 1.5 - 2 times lower concentration of monoterpenes and light oxygenated compounds than the SD (49.7%) and SDE (64.5%) extracts.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240190609
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    HRGC and GC-MS analysis of essential oil from colombian ylang-ylang (Cananga odorata Hook fil. et Thomson, forma genuina) (1993)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 16 (1993), S. 441-444 
    Details
    ISSN: 0935-6304
    Schlagwort(e): High resolution capillary gas chromatography ; High resolution gas chromatography-mass spectrometry ; Essential oil analysis ; Ylang-ylang oil composition ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Samples of essential oil from Colombian ylang-ylang trees were analyzed by means of HRGC, HRGC-MS, IR and 1H- and 13C-NMR. 57 components were detected, 51 of which were positively identified. Camphene and anethol were identified in ylang-ylang essential oil for the first time. Among the composition-determining variables studied (extraction time, part of the flower, and flower freshness), the extraction time and the flower condition (fresh versus dry) were found to have the largest incidence in the quality of the essential oil.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240160713
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Stimulation of glucose catabolism through the pentose pathway by the absence of the two pyruvate kinase isoenzymes in Escherichia coli (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 58 (1998), S. 292-295 
    Details
    ISSN: 0006-3592
    Schlagwort(e): metabolic engineering ; carbon metabolism ; Escherichia coli mutants ; microbial growth ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Escherichia coli strains devoid of one or both of the two pyruvate kinase isoenzymes (PKA and PKF), were grown on minimal media in batch fermentations. The strain lacking both PKs showed a 28% decrease on its specific growth rate when compared to the wild type. However, protein and CO2 yields did not change. Using radioactive 1-C14 glucose and collecting the CO2 produced by the cultures, it was found that the mutant lacking both pyruvate kinases, metabolized glucose mainly through the pentose pathway (PP). The increased participation of the PP in glucose metabolism in this strain, was also reflected on the levels of the glucose-6-phosphate and 6-phosphogluconate dehydrogenases.© 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58:292-295, 1998.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 8
    Digitale Medien
    Digitale Medien
    Inhibition of the system luminol-H2O2-Fe(CN)63- chemiluminescence by the Mn(II) indirect determination of isoniazid in a pharmaceutical formulation (1998)
    New York : Wiley-Blackwell
    Journal of Bioluminescence and Chemiluminescence 13 (1998), S. 131-137 
    Details
    ISSN: 0884-3996
    Schlagwort(e): chemiluminescence ; flow injection ; isoniazid ; solid-phase reactors ; pharmaceutical analysis ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: A flow injection procedure for the indirect chemiluminescent determination of isoniazid is proposed. The method is performed in a flow-injection manifold provided with a solid-phase reactor. The reactor was made from manganese dioxide physically entrapped by polymerization; the redox reaction isoniazid-manganese dioxide released Mn(II) which was monitored through its inhibitory effect on the reaction between luminol and hydrogen peroxide in presence of potassium hexacyanoferrate(III). The procedure resulted in a linear calibration graph over the range 5-15 mg/L of isoniazid with a sample throughput of 43 samples/h. The influence of foreign compounds was studied and the method was applied to determination of the drug in a pharmaceutical formulation. © 1998 John Wiley & Sons, Ltd.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 9
    Digitale Medien
    Digitale Medien
    Determination of cells' water membrane permeability: Unexpected high osmotic permeability of Saccharomyces cerevisiae (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 56 (1997), S. 62-70 
    Details
    ISSN: 0006-3592
    Schlagwort(e): osmotic shock ; water permeability ; mixing time constant ; mathematical model ; yeast ; leukemia K562 cells ; Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Water permeability (Lp), calculated from the volume variations of cells subjected to an osmotic shock, is classically used to characterize cell membrane properties. In this work, we have shown the importance of the kind of mixing reactor used to measure the Lp parameter. A mathematical model including the mixing time constant has been proposed allowing an accurate Lp estimation even though the mixing time constant is higher than the cell time constant obtained in response to a perfect shock. The estimated Lp values of human leukemia K562 cells were found to be the same whatever the mixing time constant. The Lp value of Saccharomyces cerevisiae could not be exactly estimated. However, S. cerevisiae has unexpectedly high water permeability, implying that this yeast may contain water channels in the membrane. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 62-70, 1997.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 10
    Digitale Medien
    Digitale Medien
    Catalytic transformation of copaiba (Copaifera officinalis) oil over zeolite ZSM-5 (1995)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 18 (1995), S. 54-58 
    Details
    ISSN: 0935-6304
    Schlagwort(e): High resolution capillary GC ; High resolution GC-MS ; Zeolite ZSM-5 ; Copaiba tree (Copaifera officinalis) ; Copaiba oil ; Fuel oil ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The oil extracted from the trunk of the copaiba tree (Copaifera officinalis) is composed of sesquiterpenes, C15H24, and a small amount (〉7 %) of sesquiterpenols, C15H26O; these were identified from their Kováts indices and mass spectra. The use of zeolites in the catalytic transformation of this renewable source of hydrocarbons is of interest in the search for new chemicals and ecologically clean fuels. Oil samples from copaiba trees growing in Colombia's Oriental Plains were circulated over zeolite ZSM-5 in a continuous flow fixed-bed micro reactor at 225, 265, and 325°C, for 1 h and subsequently analyzed by HRGC and GC-MS. Whereas only thirty four sesquiterpenes were identified in the original oil, over two hundred compounds were found in the product of the treatment of copaiba oil with zeolite ZSM-5. This complex mixture of sesquiterpenes, light aromatic compounds, and indene and naphthalene derivatives resulted from reactions such as isomerization, hydrogenation, cracking, and dehydrogenation with and without cracking. The amount of cracking products and aromatic compounds increased with reactor temperature but decreased with catalyst aging.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240180112
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...