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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 3 (1991), S. 471-475 
    ISSN: 0899-0042
    Schlagwort(e): amino acids ; kinetics ; epimers ; OPA ; postcolumn reaction detection ; fluorescence detection ; amino acid racemization ; dating methods ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The kinetics of the reaction of the amino acid epimers L-isoleucine, D-alloisoleucine, L-threonine, and D-allo-threonine with o-phthaldialdehyde and mercaptoethanol were determined at 25°C. L-Isoleucine reacts faster than its D-epimer whereas L-threonine reacts slightly slower than its D-epimer. In the case of isoleucine, the consequence can be an allo/iso ratio which in the worst case is 25% too low if these amino acids are quantified by liquid chromatography and o-phthaldialdehyde fluorescence detection. The effect on dating of fossils by amino acid racemization is discussed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 102 (1921), S. 287-294 
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 2 (1990), S. 208-210 
    ISSN: 0899-0042
    Schlagwort(e): enantioselectivity ; three-point model ; didactic model ; chiral separations ; ligand-exchange chromatography ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: If diastereomeric complexes are adsorbed on a surface or if they include a molecule of solvent, two points of attractive interaction between the chiral species of the complex can be sufficient for mutual chiral recognition of these species. In special cases even one single point of interaction is sufficient. This extension of the three-point contact rule of Dalgliesh, first observed in chiral ligand-exchange chromatogrphy, can be demonstrated by using hands.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 7 (1995), S. 567-571 
    ISSN: 0899-0042
    Schlagwort(e): enantiomer separation ; chromatographic resolution ; peak integration ; peak size ratio ; calibration curve ; determination of optical purity ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The chromatographic quantitation of very low amounts of an enantiomer in the presence of its antipode can be an extraordinary challenge. If resolution of the peaks is not complete even at extreme mass ratios an integrator will yield inaccurate results due to geometric effects. A given resolution can be adequate for peaks of similar size but result in severe overlap if one of the signals is markedly smaller. If tailing occurs, which is more the rule than the exception, the problem is especially severe for last eluted small peaks. Additional obstacles are detector nonlinearity and other sources of unsatisfactory calibration curves, overloading phenomena, and the possible lack of standards of highest optical purity. These problems have been studied by computer simulations and the liquid chromatographic separation of (R,S)-phenylethyl naphthoic acid amide on a chiral stationary phase. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 2 (1990), S. 43-51 
    ISSN: 0899-0042
    Schlagwort(e): mexiletine ; flecainide ; tocainide ; propafenone ; chirality ; enantiomers ; HPLC ; homochiral derivatization ; isothiocyanates ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The search for new antiarrhythmic agents has been intense, because the established drugs for the treatment of cardiac arrhythmias are neither uniformly effective nor well-tolerated. Among the recently introduced new anti-arrhythmic agents are tocainide (TOC), mexiletine (MEX), flecainide (FLE), and propafenone (PRO). Each of these drugs is a chiral amine used clinically as the racemic mixture. We have examined the high-performance liquid chromatographic chiral resolution of the above four drugs via derivatization with homochiral derivatizing agents (HDAs). The amino functionality of the drugs was reacted with four homochiral isothiocyanates, 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (TAGIT), (R)-α-methylbenzyl isothiocyanate (RAMBI), (S)-1-(1-naphthyl)ethyl isothiocyanate (SNEIT), and (R)-1-(2-naphthyl)ethyl isothiocyanate (RBEIT). Complete separation of the two peaks (resolution factor R = 1.5) was achieved with all four HDAs for TOC, with TAGIT, RBEIT, and RAMBI for MEX, with TAGIT and SNEIT for PRO, and only with TAGIT for FLE. SNEIT was used to develop analytical procedures for the determination of the enantiomeric composition of TOC in human urine and blood serum. The four HDAs offer several advantages over many other HDAs and should be useful in studies of enantioselective drug action and disposition.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 6 (1994), S. 41-45 
    ISSN: 0899-0042
    Schlagwort(e): chiral HPLC ; Chiralpak AD ; amylose carbamate stationary phase ; antiestrogen ; breast cancer ; dichlorotriarylcyclopropane ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: (Z)-1,1-Dichloro-2-(4-benzyloxyphenyl)-2,3-bis(4-methoxyphenyl)cyclopropane (5), a potential antitumor agent designed to treat breast cancer, was prepared in three steps. A stereospecific palladium-catalyzed cross coupling reaction which provided the intermediate (Z)-triaryl alkene 4 was a crucial step in the synthesis. Makosza phase transfer reaction on 4 gave the enantiomeric (Z)-dichlorocyclopropane derivatives 5 which were resolved by semipreparative HPLC on a chiral stationary phase consisting of amylose tris-3,5-dimethylphenyl carbamate coated on silica gel. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 1 (1989), S. 167-169 
    ISSN: 0899-0042
    Schlagwort(e): enantioselectivity ; three-point model ; chiral receptors ; chiral separations ; didactic model ; elusion of the three-point model ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Hands can be used to demonstrate the three-point model of chiral recognition. The points of attachment are thumb, forefinger, and middle finger. This vivid model has the advantages of simplicity, perspicuity, and availability at any time, although two persons are necessary. It can be shown that two interactions are not sufficient for chiral recognition but that three attractive or two attractive and one repulsive attraction are needed. It can also be used to explain some possibilities of weakening or elusion of the three-point model.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Clinical and experimental medicine 146 (1968), S. 125-138 
    ISSN: 1591-9528
    Schlagwort(e): Thermoregulation ; Fever ; Chlorpromazine ; Thermoregulation ; Fieber ; Chlorpromazin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung In 160 Versuchen am Kaninchen wurde die Wirkung von Chlorpromazin, das besonders in den für die Wärmeregulation wichtigen zentralen Gebieten des Hypothalamus und der Formatio reticularis angereichert wird, auf die normale Körpertemperatur und die Fieberreaktion nach Gabe von Lipopolysacchariden gramnegativer Bakterien untersucht. Gemessen wurden die Rectal- und Ohrtemperatur, die Atem- und Herzfrequenz. Es ergab sich: 1. die Rectaltemperatur des unbeeinflußten Kaninchens wird bei einer Umgebungstemperatur von 22° C in Abhängigkeit von der Dosis gesenkt, 2. das Lipopolysaccharid-Fieber läßt sich durch Vorgabe von mehr als 1 mg/kg Chlorpromazin abschwächen oder unterdrücken, 3. die Reaktion in Empfängertieren durch Plasmaübertragung von fiebernden Spendertieren kann drei verschiedene Verlaufsformen ergeben: eingipflige, zweigipflige und afebrile. Eine Beziehung zur Größe des Spendertierfiebers bestand dabei nicht. Die Ergebnisse werden hauptsächlich durch die zentralen Angriffspunkte des Chlorpromazins erklärt.
    Notizen: Summary Chlorpromazine concentrates particularly in that central regions of the CNS important for the thermoregulation, in the hypothalamus and the formatio reticularis. Therefore in 160 experiments on rabbits the effect of chlorpromazine was tested at the normal body temperature and the fever reaction after medication of lipopolysaccharides (LPS) from gramnegative bacteria. Measured were the rectal- and ear-temperature, the heart- and respiration-frequency. It resulted that: 1. the rectal temperature of untreated rabbits at environmental temperature of 22°C ± 2°C is lowered, dependant on the dose, 2. the LPS-fever is diminished or suppressed after premedication of 〉 1 mg/kg chlorpromazine, 3. the reaction in the recipient animal may proceed in three different types of fever: mono- and biphasic curves and an afebrile one. A relation to the height of fever of the donor animal was not existant. Analogue to other experiments with central acting pharmaca and local cerebral temperature-stimulations in the area of the anterior hypothalamus as well as considering the distribution of chlorpromazine in the CNS these results are explained by specific effects of chlorpromazine in the hypothalamus and the formatio reticularis.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 91 (1864), S. 1-15 
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 1 (1834), S. 96-98 
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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