Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Electrophoresis 16 (1995), S. 1510-1518 
    ISSN: 0173-0835
    Keywords: Chiral separation ; Enantiomers ; Human serum transferrin Stereoselective interactions ; Capillary zone electrophoresis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Enantiomers can be separated by using human serum transferrin as a chiral phase. With the help of the native protein we were able to separate enantiomers with high efficiency, using a low ionic strength 2-(N-morpholino)ethanesulfonic acid (MES) buffer, pH 6, in capillary zone electrophoresis. Tryptophan methyl, ethyl and butyl ester enantiomers - moving towards the cathode at pH 6 - were resolved by passing through an iron-free transferrin zone in coated capillaries. Since the isoelectric point of the iron-free transferrin is a little higher than 6, the protein zone is either not moving in the experiment or is slowly moving towards the anode. Under the simplest experimental conditions the highest resolution was obtained for the butyl ester enantiomers and the lowest for the methyl ester ones. By changing the experimental conditions, however, this order could be reversed. The results indicate that the lengths of the alkyl chains in the enantiomers have a significant effect on the resolution, i.e., on the interaction between the protein and the separands.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0173-0835
    Keywords: Cyclodextrin modified - micellar electrokinetic chromatography ; Chiral separation ; Chrysene metabolism ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: A γ-cyclodextrin (γ-CD) modified electrokinetic micellar capillary chromatography (MEKC) method was used for the enantiomer separation of a racemic trans-1,2-dihydro-1,2-dihydroxy-chrysene (chry-trans-1,2-diOH) mixture. The chiral resolution was strongly influenced by several important parameters: surfactant concentration and addition of organic modifier to the background electrolyte (BGE). An optimized electrophoretic system was used, consisting of the following conditions: 25 mM phosphate buffer, pH 7.8, 50 mM sodium dodecyl sulfate, 20 mM γ-CD, 7.4% V/V 2-propanol as BGE; the applied voltage, 18 kV, corresponded to 37 μA at a constant temperature of 25°C. This electrophoretic method was applied for monitoring the chry-trans-1,2-diOH enantiomer formation in a real sample, obtained from in vitro metabolic activation of chrysene by phenobarbital-ß-naphthoflavone-induced rat microsomes. The (+) and (-) enantiomers were identified by the racemate and the single enantiomer standard addition method and by spectra comparison with the synthetic compound. Under the experimental conditions used for chrysene activation, the (+) optical isomer was the prevailing form. The CD-MEKC system showed high reproducibility and selectivity, allowing a fast and interference-free analysis even of the in vitro metabolic sample extract, without any pretreatment.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...