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Determination of enantiopurity of new types of acyclic nucleoside phosphonates by capillary electrophoresis with cyclodextrins-based chiral selectors
Šolínová, Veronika ; Kaiser, Martin Maxmilian ; Lukáč, Miloš ; Janeba, Zlatko ; Kašička, Václav
Capillary electrophoresis with neutral and cationic cyclodextrins as chiral selectors was applied for determination of enantiopurity analysis of new types of six acyclic nucleoside phosphonates, nucleotide analogues bearing ((3-hydroxypropan-2-yl)-1H-1,2,3-triazol-4-yl)phosphonic acid, 2-((diisopropoxyphosphonyl)methoxy)propanoic acid or 2 (phosphonomethoxy)propanoic acid moieties attached to adenine, guanine, 2,6-diaminopurine, uracil and 5-bromouracil nucleobases. All these compounds were found to be synthesized in pure enantiomeric forms. Employing the UV-absorption detection at 206 nm, their detection limits were in the low micromolar level.
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Chiral analysis of alfa-diimine Ru(II) and Fe(II) complexes by capillary electrophoresis using sulfated cyclodextrins as stereoselectors
Sázelová, Petra ; Koval, Dušan ; Severa, Lukáš ; Teplý, Filip ; Kašička, Václav
A fast and efficient capillary electrophoretic method was developed for enantioseparation of Ru(II) and Fe(II) polypyridyl complexes using anionic randomly sulfated alfa-, beta-, and gamma-cyclodextrins (S-alfa-CD, S-beta-CD, and S-gamma-CD) and their heptakis-(2,3-diacetyl-6-sulfato)-derivatives (Ac-S-alfa-CD, Ac-S-beta-CD, and Ac-S-gamma-CD) as chiral selectors. S-alfa-CD and S-gamma-CD were found to be the best chiral selectors providing high resolutions and short analysis times. The method was applied for the assessment of chiral purity of some batches of [Ru(bpy)3]2+ catalyst.
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Study of DNA oligonucleotides interactions with ethidium bromide by partial-filling affinity capillary electrophoresis
Růžička, Martin ; Koval, Dušan ; Kašička, Václav
A partial filling affinity capillary electrophoresis was developed and applied to investigation of non-covalent molecular interactions between double stranded DNA oligonucleotide (Dickerson dodecamer) and classical DNA intercalator ligand –ethidium bromide (EtBr). Binding constants of DNA EtBr complexes were determined from the dependence of migration time changes of DNA oligomer (applied as analyte) on the length of ligand zones introduced beforehand as plugs of various lengths in hydroxypropylcellulose coated fused silica capillary. Binding constants of DNA-EtBr complex were found to be in the range 4.2 x 103 – 1.5 104 L/mol.
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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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ANALYSIS OF NON-ENZYMATIC POSTTRANSLATIONAL MODIFICATED (GLYCATED) ALBUMIN BY NANO-LC/MS/MS
Šťastná, Zdeňka ; Pataridis, Statis ; Sedláková, Pavla ; Mikšík, Ivan
Posttranslational modifications of proteins are important reactions, which significantly affect the function of proteins in the organism. In principle, they can be divided into enzymatic and non-enzymatic modifications. Non-enzymatic reactions include glycation (earlier called nonezymatic glycosylation), which plays an important role in the development of chronic complications of diabetes mellitus, uremia, in the process of aging and degeneration of the brain.This work deals with the study of glycated albumins (human serum albumin and bovine serum albumin). Methodologically we used nano-liquid chromatography coupled to Q-TOF mass spectrometer. In vitro modified proteins were cleavaged by trypsin and arising peptides were separated on C18 nano column with trap-column. Peptides and their modifications were analysed by high-resolution Q-TOF mass spectrometer MaXis with precision determination of mass below 2 ppm. We found some modifications of proteins. Besides well known carboxymethyllysine new ones were determined - create mass shift 78, 132 and 218. Origin of these modifications is discussed and possible structure is presented. All found modifications were allocated to the structure of proteins and reactivity to various oxo-compounds was also examined
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Open-tubular capillary electrochromatography with bare gold nanoparticles-based stationary phase applied to separation of trypsin digested proteins
Mikšík, Ivan ; Lacinová, Kateřina ; Zmatlíková, Zdeňka ; Sedláková, Pavla ; Král, V. ; Sýkora, D. ; Řezanka, P. ; Kašička, Václav
Open-tubular capillary electrochromatography (OT-CEC) using bare gold nanoparticles-based stationary phase has been applied to separation of tryptic peptide fragments of native and glycated proteins, bovine serum albumin and human transferrin. OT-CEC with bare gold nanoparticles stationary phase was found to be a suitable technique for separation of complex peptide mixtures originating from enzymatic (tryptic) digestion of native and glycated bovine serum albumin and human transferrin, and for glycation studies of these proteins.
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