FREE-SOLUTION CAPILLARY ELECTROPHORETIC RESOLUTION OF CHIRAL AMINO-ACIDS VIA DERIVATIZATION WITH HOMOCHIRAL ISOTHIOCYANATES .1.
Articolo
Data di Pubblicazione:
1995
Citazione:
FREE-SOLUTION CAPILLARY ELECTROPHORETIC RESOLUTION OF CHIRAL AMINO-ACIDS
VIA DERIVATIZATION WITH HOMOCHIRAL ISOTHIOCYANATES .1. / R. Bonfichi, C. Dallanoce, S. Lociuro, A. Spada. - In: JOURNAL OF CHROMATOGRAPHY A. - ISSN 0021-9673. - 707:2(1995), pp. 355-365.
Abstract:
Within the framework of a more general study aimed at the enantiomeric
resolution of non-UV-absorbing chiral amino acids via derivatization
with chiral isothiocyanates, we have examined the applicability of two
such derivatizing agents, (S)-1-(1-naphthyl)ethyl isothiocyanate (SNEIT)
and (S)-1-phenylethyl isothiocyanate (SAMBI), to the resolution of the
enantiomers of alanine, phenylalanine, and valine in free-solution
capillary electrophoresis (FSCE). Isothiocyanates have distinct
advantages as chiral derivatizing agents in enantiospecific
chromatographic analysis, and the two reagents were readily synthesized
from commercially available reagents. SNEIT, previously not fully
described in the literature, was characterized by rigorous
physicochemical and spectroscopic means. The two diastereoisomeric
thiourea derivatives of each amino acid were separated by FSCE.
Heptakis-2,3,6-tri-O-methyl-beta-cyclodextrin was effective in assuring
the solubility of the derivatives in the working buffer and was more
efficient than beta-cyclodextrin in both dissolving the thioureas and
improving the electrophoretic resolution. Enantiomeric pairs migrated in
the order L before D. Under the conditions used SAMBI-derivatized amino
acids had longer elution times than the corresponding SNEIT derivatives.
The diastereomeric derivatives of valine and of phenylalanine had larger
separation factors alpha than the corresponding SAMBI derivatives, while
the derivatives of alanine had nearly identical alpha values with the
two derivatizing agents. The two reagents may be advantageous in the
enantiospecific analysis of amino acids, and it appears that further
exploration of these and other similar reagents is warranted.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
R. Bonfichi, C. Dallanoce, S. Lociuro, A. Spada
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