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
  • General Chemistry  (39)
  • Cyclodextrin derivatives  (5)
  • Essential oils  (5)
  • cyclodextrin derivatives  (5)
  • Cyclodextrins  (2)
  • Dynamic gas chromatography  (2)
  • 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane
  • Wiley-Blackwell  (55)
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
  • 1
    Digitale Medien
    Digitale Medien
    A Molecular-Dynamics Simulation of the Complex Formation between Methyl (R)/(S)-2-Chloropropionate and Heptakis(3-O-acetyl-2,6-di-O-pentyl)-β-cyclodextrin (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 119-126 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Host-guest complexes ; Molecular-dynamics (MD) simulation ; Enantioselective gas chromatography ; Cyclodextrins ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The energies of complexation of methyl (R)/(S)-2-chloropropionate [(R)/(S)-2] with heptakis(3-O-acetyl-2,6-di-O-pentyl)-β-cyclodextrin (1) and the structures of the corresponding complexes were determined by molecular-dynamcis (MD) simulations at 300 and 333 K. The geometry of the complexes, the conformations of complexed and uncomplexed 1 and (R)/(S)-2 and the closest H-H distances between host and guest in the complexes were determined from the trajectories. The results correspond to the experimental findings from enantioselective gas chromatography.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19941270120
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Enantioselective capillary gas chromatography in the investigation of stereochemical correlations of terpenoids (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 10 (1998), S. 499-504 
    Details
    ISSN: 0899-0042
    Schlagwort(e): enantioselective capillary gas chromatography ; cyclodextrin derivatives ; stereochemistry of terpenes ; monoterpenes ; essential oils ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Capillary gas chromatography employing the unique selectivities of specifically substituted cyclodextrins is highly suited for stereochemical investigations of terpenoid compounds. The analysis of many essential oils have shown that monoterpene derivatives regularly occur as enantiomeric mixtures. In the case of sesquiterpene hydrocarbons, liverworts (Hepaticae) and other lower organisms usually biosynthesize compounds of opposite stereochemistry as compared to higher plants and enantiomeric mixtures occur only occasionally. The investigation of diterpene hydrocarbons has so far shown no indication of the presence of both enantiomers in the same plant. Chirality 10:499-504, 1998. © 1998 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 3
    Digitale Medien
    Digitale Medien
    New technique for the determination of interconversion processes based on capillary zone electrophoresis: Studies with axially chiral biphenyls (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 8 (1996), S. 441-445 
    Details
    ISSN: 0899-0042
    Schlagwort(e): capillary zone electrophoresis ; axially chiral biphenyls ; energy barrier ; cyclodextrin derivatives ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A new technique is presented for the investigation of the rotational energy barrier of axially chiral biphenyls, based on capillary zone electrophoresis using cyclodextrin derivatives as chiral selectors. Only minute amounts are required for the investigation of dynamic processes with energy barriers of 100-130 kJ/mol. The influence of the chiral selector on the conformational stability of atropisomers can be determined separately for each enantiomer. Additionally, segmentation of the capillary into different buffer zones allows us to exclude any influence of the chiral selector on the rotational energy barrier. © 1996 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
  • 4
    Digitale Medien
    Digitale Medien
    Enantiomeric composition of the chiral constituents of essential oils. Part 2: Sesquiterpene hydrocarbons (1994)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 17 (1994), S. 315-320 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective GC ; Sesquiterpene hydrocarbons ; Cyclodextrin derivatives ; Essential oils ; Liverworts ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A number of sesquiterpene hydrocarbons commonly occurring in essential oils has been prepared as racemic mixtures by chemical synthesis. Preparative gas chromatography with selectively per-O-alkylated cyclodextrins has been employed for the isolation of enantiomeric mixtures or pure enantiomers from the essential oils of higher plants and liverworts (Hepaticae). The enantiomers of α-curcumene, α- and β-bisabolene, β-elemene, δ-elemene, α-copaene, δ-cadinene, cis- and trans-calamenene, and bicyclogermacrene could be resolved by enantioselective gas chromatography on capillary columns coated with cyclodextrin derivatives. The enantiomeric composition of these sesquiterpene hydrocarbons in various essential oils was determined.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240170507
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Gas chromatographic enantiomer separation of agrochemicals and polychlorinated biphenyls (PCBs) using modified cyclodextrins (1994)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 17 (1994), S. 859-864 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective gas chromatography ; Cyclodextrin derivatives ; Polychlorinated pesticides ; Polychlorinated biphenyls (PCBs) ; Pyrethroid insecticides/Allethrin ; Organophosphorus pesticides/Acephate, Malaoxon ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The enantiomers of the polychlorinated polycyclic xenobiotics heptachlor, cis- and trans-chlordane, cis- and trans-heptachlorepoxide, oxychlordane, and bromocyclen have been resolved by gas chromatography with selectively substituted cyclodextrins. The order of elution of these compounds and of α-hexachlorocyclohexane (α-HCH) was determined by comparison with enantiomerically enriched reference compounds obtained by preparative enantioselective gas chromatography.A separation of the eight stereoisomers of the pyrethroid insecticide allethrin into seven peaks was achieved. Both trans-diastereomers were separated into their enantiomers and the order of elution could be determined by comparison with commercially available (S)-bioallethrin and trans-bioallethrin. Also one cis-diastereomer was separated, wheras the other cis-isomer could not be resolved. In addition 15 out of 19 stable atropisomeric polychlorinated biphenyls with 5, 6 and 7 chlorine substituents, some chiral organophosphorus pesticides, including acephate and malaoxon and the herbicide bromoacil were separated.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240171209
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Enantiomeric composition of the chiral constituents of essential oils - part 3: Diterpene hydrocarbons (1997)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 20 (1997), S. 257-260 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective GC ; Diterpene Hydrocarbons ; Cyclodextrin derivatives ; Essential oils ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Enantiomeric diterpene hydrocarbons were isolated from different plants and identified by mass spectrometric and NMR investigations. All enantiomeric pairs could be resolved by capillary gas chromatography using either heptakis(2,6-di-O-methyl-3-O-pen-tyl)-β-cyclodextrin or heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-β-cyclodextrin as chiral stationary phases.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240200503
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Influence of substituents on the rotational energy barrier of atropisomeric biphenyls  -  studies by polarimetry and dynamic gas chromatography (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 781-786 
    Details
    ISSN: 0947-3440
    Schlagwort(e): Atropisomers ; Biphenyls, axially chiral ; Enantiomerization ; Dynamic gas chromatography ; Polarimetry ; Energy barriers ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: We have synthesized a series of 2,2′-substituted biphenyls and particularly derivatives of 2,2′-bis(trifluoromethyl)biphenyl (4) with either one or two fluoro, chloro, bromo, amino, nitro or methoxy substituents in the para positions for investigating the influence of these substituents on the rotational energy barrier of the biphenyls by polarimetry and dynamic gas chromatography (DGC). Axially chiral biphenyls with at least two bulky substituents in the ortho positions were separated by gas chromatography on selectively modified cyclodextrins. Due to competition between resolution and enantiomerization in the gas chromatographic column 2-tert-butyl-2′-isopropyl- (2), 2-isopropyl-2′-(trifluoromethyl)biphenyl (5), and some para-substituted derivatives of 4 show temperature-dependent interconversion profiles and coalescence phenomena in analogy to dynamic NMR studies. The accelerating effect on the rate of enantiomerization of electron-donating groups in the para positions and the decelerating effect of electron-accepting groups has been determined. Dynamic gas chromatography is shown to be a useful supplement to studies of thermal enantiomerization kinetics of optically enriched or separated compounds by polarimetry for the investigation of energy barriers of atropisomeric biphenyls.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jlac.1995199505114
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Gas chromatographic separation of atropisomeric alkylated and polychlorinated biphenyls using modified cyclodextrins (1993)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 16 (1993), S. 376-378 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Resolution of atropisomers ; Alkylated biphenyls ; Polychlorinated biphenyls (PCBs) ; Dynamic gas chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Selectively alkylated cyclodextrins have been used to resolve the enantiomers of 2,2′ alkylated biphenyls. The configurational stability of 2,2′-dimethyl and 2,2′-diethyl biphenyls is insufficient for gas chromatographic separation even at ambient temperature. 2-Isopropyl-2′-t-butyl- and 2,2′-di-t-butylbiphenyl are configurationally stable under the conditions applied, whereas 2,2′-diisopropyl- and 2,2′-bis(trifluoromethyl)biphenyl show temperature-dependent interconversion of the enantiomers during chromatography. The gas chromatographic separation of the enantiomers of some ortho trichlorinated biphenyls carrying 4, 5, and 6 chlorine substituents has been demonstrated for the first time.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240160609
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Enantiomeric composition of the chiral constituents in essential oils. Part 1: Monoterpene hydrocarbons (1992)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 15 (1992), S. 184-189 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective gas chromatography ; Cyclodextrin derivatives ; Monoterpene hydrocarbons ; Essential oils ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using a dual column gas chromatograph equipped with two capillary columns coated with heptakis(6-O-methyl-2,3-di-O-pentyl)-β-cyclodextrin (6-me-2,3-pe-β-CD) and octakis(6-O-methyl-2,3-di-O-pentyl)-γ-cyclodextrin (6-me-2,3-pe-γ-CD), respectively, all important olefinic monoterpene hydrocarbons occurring in essential oils, including α-thujene, α- and β-pinene, camphene, sabinene, α- and β-phellandrene, Δ-3-carene and limonene can be resolved into enantiomers. With the chromatographic system described the characteristic enantiomeric composition of these monoterpene hydrocarbons in essential oils can be determined.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240150310
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Stereochemical analysis of constituents of essential oils and flavor compounds by enantioselective capillary gas chromatography (1990)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 13 (1990), S. 328-332 
    Details
    ISSN: 0935-6304
    Schlagwort(e): Enantioselective gas chromatography ; Cyclodextrin derivatives ; Terpenoid hydrocarbons ; Chiral carbonyl compounds ; Flavor alcohols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Modified cyclodextrins interact enantioselectively with a great variety of volatile chiral constituents of essential oils by forming diastereomeric inclusion complexes. Capillary gas chromatography is used for resolving the enantiomers of terpenoid hydrocarbons (camphene, α-pinene, limonene, α-phellandrene), carbonyl compounds (carvone, fenchone, menthone, isomenthone, piperitone, camphor, myrtenal), and alcohols (trifluoroacetylated β-citronellol, myrtenol, trans-pinocarveol, 1-octen-3-ol, and underivatized linalool). The enantiomeric composition of some of these compounds in a variety of essential oils is investigated.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jhrc.1240130507
    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...