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Capillary electrophoresis applied to chiral analysis of helquats and characterization of their intermediates and interconversion barriers using randomly and single isomer sulfated cyclodextrins as stereoselectors
Kašička, Václav ; Koval, Dušan ; Sázelová, Petra ; Severa, Lukáš ; Vávra, Jan ; Adriaenssens, Louis ; Sonawane, Manoj R. ; Teplý, Filip
Capillary electrophoresis in acidic sodium phosphate background electrolyte, pH 2.4, with randomly sulfated alfa-, beta- and gamma-cyclodextrins as chiral selectors was applied to fast, high-resolution separation of enantiomers of a series of 35 helquats, a new class of N-heteroaromatic dicationic helicene-like species. The developed methodology was employed for evaluation of preparative enantioresolution procedures of helquats, for monitoring their racemization and for determination of interconversion barrier of helquat enantiomers.
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Chiral analysis of beta-alanyl-D,L-tyrosine and its derivatives by capillary electrophoresis with 2-hydroxypropyl-beta-cyclodextrin stereoselector
Sázelová, Petra ; Šolínová, Veronika ; Schimperková, Tereza ; Mášová, Alice ; Jiráček, Jiří ; Kašička, Václav
A new capillary electrophoretic method was developed for separation of enantiomers of antimicrobial dipeptide betha-Ala-D,L-Tyr and its derivatives using 50 mM Tris-phosphate, pH 2.50, as background electrolyte and 2-hydroxypropyl-betha-cyclodextrin at concentrations 20 – 60 mg/mL as chiral selector. In addition, association constants of complexes of the enatiomers of dipeptide betha-Ala-D,L-Tyr and its derivatives with 2-hydroxypropyl-betha-cyclodextrin chiral selector were determined.
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Capillary electrophoretic chiral analysis and estimation of helix inversion barrier of helquats using randomly sulfated cyclodextrins as chiral selectors
Kašička, Václav ; Koval, Dušan ; Sázelová, Petra ; Severa, Lukáš ; Adriaenssens, Louis ; Vávra, Jan ; Teplý, Filip
Capillary electrophoresis in acidic sodium phosphate background electrolyte, pH 2.4, with randomly sulfated alpha-, beta- and gamma-cyclodextrins as chiral selectors was employed for fast, high-resolution separation of enantiomers of a series of 24 helquats, a new class of N-heteroaromatic dicationic helicene-like species. The developed CE methodology will be utilized in the further investigation of helquats, e.g., in evaluation of their preparative enantioresolution procedures, in monitoring of their racemization and determination of interconversion barrier of helquat enantiomers.
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Enantiomer separation and determination of helix inversion barrier of helical dications by capillary electrophoresis
Koval, Dušan ; Adriaenssens, Louis ; Severa, Lukáš ; Teplý, Filip ; Sázelová, Petra ; Kašička, Václav
Enantiomeric helical forms of dicationic helquats, a novel family of charged helicene-like molecules, have been separated by capillary electrophoresis (CE) using sodium-phosphate buffer, pH 2.5, as background electrolyte and sulfated beta- and gamma-cyclodextrins as chiral selectors. Additionally, CE was used to determine barrier to helix inversion of helquats.
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Capillary electrophoresis employed for quantitative characterization of peptide interactions with small ions and cyclodextrins
Kašička, Václav ; Ehala, Sille ; Šolínová, Veronika ; Schimperková, Tereza ; Sázelová, Petra ; Koval, Dušan ; Makrlík, E.
Capillary affinity electrophoresis has been applied to investigate quantitatively two types of non-covalent peptide interactions: i) complexes of pseudopeptide valinomycin with ammonium ion and alkali metal ions, Li+, Na+, K+, Rb+ and Cs+, in methanol, and ii) complexes of enantiomers of dipeptide beta alanyl-D,L-tyrosine and its derivatives with chiral selector, 2-hydroxypropyl-beta-cyclodextrin, in water.
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Investigation of peptide complexes with small cations and cyclodextrins by capillary affinity electrophoresis
Kašička, Václav ; Ehala, Sille ; Šolínová, Veronika ; Schimperková, Tereza ; Sázelová, Petra ; Koval, Dušan
Capillary affinity electrophoresis was applied to quantitative evaluation of the strength of the complexes of i) valinomycin, macrocyclic dodecadepsipeptide ionophore, with small cations (ammonium and alkali metal ions, Li+, Na+, K+, Rb+ and Cs+) in methanol, and ii) enantiomers of dipeptide beta-alanyl-D,L-tyrosine and its derivatives with a chiral selector, 2 hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD), in water.
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