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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
2012 - English
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.
Keywords:
helquat chiral analysis; capillary electrophoresis; sulfated cyclodextrins
Available at various institutes of the ASCR
Capillary electrophoretic chiral analysis and estimation of helix inversion barrier of helquats using randomly sulfated cyclodextrins as chiral selectors
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, ...
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
2012 - English
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.
Keywords:
capillary zone electrophoresis; antimicrobial peptides; chiral analysis
Available at various institutes of the ASCR
Chiral analysis of beta-alanyl-D,L-tyrosine and its derivatives by capillary electrophoresis with 2-hydroxypropyl-beta-cyclodextrin stereoselector
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 ...
Does oxidation make the organic aerosol coatings more hydrophilic? Insight from molecular dynamics study of oxidized surfactant monolayers
Roeselová, Martina; Khabiri, Morteza; Cwiklik, Lukasz
2012 - English
Organic compounds are ubiquitous in atmospheric aerosols. The morphology and structure of the organic phase affect the optical properties of the aerosols, their heterogeneous reactivity as well as their ability to nucleate cloud droplets and ice particles. It is commonly assumed that atmospheric oxidative ageing of the organic material, leading to the formation of polar groups such as carbonyl (=O), hydroxyl (-OH) and carboxylic acid (-COOH), will render the aerosol particle surfaces increasingly more hydrophilic, hence, able to take up more water. Field measurements have shown that a large fraction of the organic material found in aerosols are surface active compounds, such as fatty acids and lipids(Tervahattu, 2002 and 2005). An inverted micelle structure, with an aqueous core surrounded by an organic surfactant layer, has thus been proposed for aqueous aerosols, both marine and continental (Donaldson, 2006). While recent experiments suggest the existence of more complex structures, such as organic inclusions and surfactant lenses (Dennis-Smither, 2012), a monolayer (ML) of surface active organics on an aqueous subphase (the so called Langmuir monolayers) represents the basic model system used in laboratory studies aimed at elucidating the effect of oxidative processes on structural properties of organic coatings on aerosol particles. In our previous work, we used molecular dynamics computer simulations to study the structure and stability of oxidized phospholipid MLs (Khabiri, 2012). In this contribution, we employed the molecular dynamics simulation technique to investigate – with atomistic resolution – structural changes occuring in a fatty acid ML upon moderate degree of oxidation.
Keywords:
atmospheric aerosols; organic coatings; hydrophilic; hydrophobic; oxidation
Available at various institutes of the ASCR
Does oxidation make the organic aerosol coatings more hydrophilic? Insight from molecular dynamics study of oxidized surfactant monolayers
Organic compounds are ubiquitous in atmospheric aerosols. The morphology and structure of the organic phase affect the optical properties of the aerosols, their heterogeneous reactivity as well as ...
Synthesis of conformationally locked carbocyclic nucleosides with norbornane as pseudosugar moiety
Dejmek, Milan; Hřebabecký, Hubert; Šála, Michal; Dračínský, Martin; Nencka, Radim
2011 - English
We describe the chemical synthesis of three novel structural types of conformationally locked carbocyclic nucleosides with norbornane as sugar surrogate. The presented structures bear hydroxymethyl, nucleobase or both in the bridgehead positions of the norbornane pseudosugar and thus adopt three different conformations of the cyclopentane ring – North, South, and East.
Keywords:
norbornane; conformationally locked cyrbocyclic nucleosides
Available at various institutes of the ASCR
Synthesis of conformationally locked carbocyclic nucleosides with norbornane as pseudosugar moiety
We describe the chemical synthesis of three novel structural types of conformationally locked carbocyclic nucleosides with norbornane as sugar surrogate. The presented structures bear hydroxymethyl, ...
3-Fluoro-2-(phosphonomethoxy)propyl hypoxanthine and guanine derivatives as inhibitors of plasmodial hypoxanthine-guanine-xanthine phosphoribosyltransferases
Baszczyňski, Ondřej; Jansa, Petr; Hocková, Dana; Janeba, Zlatko; Dračínský, Martin; Holý, Antonín; Keough, D. T.; de Jersey, J.; Guddat, L. W.
2011 - English
A new methodology for the synthesis of ANPs containing 9-[2-(phosphonoethoxy)ethyl] (PEE) moiety has been developed. FPEP compound containing guanine moiety exhibited inhibition activity against the enzyme in micromolar range without any signs of toxicity.
Keywords:
ANPs; acyclic nucleoside phosphonates; anti-malarial; plasmodium; HGXPRTase
Available at various institutes of the ASCR
3-Fluoro-2-(phosphonomethoxy)propyl hypoxanthine and guanine derivatives as inhibitors of plasmodial hypoxanthine-guanine-xanthine phosphoribosyltransferases
A new methodology for the synthesis of ANPs containing 9-[2-(phosphonoethoxy)ethyl] (PEE) moiety has been developed. FPEP compound containing guanine moiety exhibited inhibition activity against the ...
Enzymatic synthesis of ester prodrugs of DHPA and related compounds by lipases
Blažek, Jiří; Kaiser, M. M.; Zarevúcka, Marie; Králová, B.; Krečmerová, Marcela
2011 - English
An enzymatic method was used for esterification of DHPA and related compounds with vinyl esters and catalyzed by different lipases in non-aqueous media (DMF). Esters of DHPA and other compounds could be synthesized and purified in satisfactory yields.
Keywords:
ester prodrugs; DHPA; lipases; transesterification; vinyl esters
Available at various institutes of the ASCR
Enzymatic synthesis of ester prodrugs of DHPA and related compounds by lipases
An enzymatic method was used for esterification of DHPA and related compounds with vinyl esters and catalyzed by different lipases in non-aqueous media (DMF). Esters of DHPA and other compounds could ...
Piperidine nucleoside phosphonic acid derivatives
Kovačková, Soňa; Dračínský, Martin; Rejman, Dominik
2011 - English
A series of novel phosphonic acid derivatives of piperidine nucleosides was prepared, whereby synthesis of both enantiomeric and diastereomeric derivatives was discussed. Preparation of diphosphate analogs of phosphonic acids derivatives is also described. The prepared nucleotide analogs were tested for their potential biological properties.
Keywords:
piperidine nucleoside; nucleoside phosphonic acids; nucleoside diphosphate analogs; nucleotide analogs
Available at various institutes of the ASCR
Piperidine nucleoside phosphonic acid derivatives
A series of novel phosphonic acid derivatives of piperidine nucleosides was prepared, whereby synthesis of both enantiomeric and diastereomeric derivatives was discussed. Preparation of diphosphate ...
Cyclic and acyclic phosphonate tyrosine ester prodrugs of acyclic nucleoside phosphonates
Williams, M.; Krylov, I. S.; Zakharova, V. M.; Serpi, M.; Peterson, L. W.; Krečmerová, Marcela; Kashemirov, B. A.; McKenna, Ch. E.
2011 - English
A series of P-O ester derivatives of HPMPA, HPMPC, PMEA a (R)-PMPDAP was synthesized as potential anti-malarial prodrugs.
Keywords:
ester prodrugs; ANP; peptide prodrugs; tyrosine; HPMPA; HPMPC; PyBOP
Available at various institutes of the ASCR
Cyclic and acyclic phosphonate tyrosine ester prodrugs of acyclic nucleoside phosphonates
A series of P-O ester derivatives of HPMPA, HPMPC, PMEA a (R)-PMPDAP was synthesized as potential anti-malarial prodrugs.
Hetaryl derivatives of 7-deazapurine ribonucleosides: potent cytostatic agents
Perlíková, Pavla; Nauš, Petr; Bourderioux, Aurelie; Hocek, Michal
2011 - English
A series of novel 7-deazapurine ribonucleosides substituted with aryl and hetaryl groups has been prepared. Suzuki or Stille cross-coupling reactions with 6-chloro-7-deazapurine ribonucleosides substituted with H, F of Cl atom in position 7 were used in the key step of the synthesis. Either cross-coupling of protected ribonucleoside with appropriate (het)arylboronic acid or stannane followed by deprotection, or single-step aqueous-phase Suzuki cross-coupling reaction of unprotected 7-deazapurine ribonucleoside with boronic acid provided target (het)aryl-7-deazapurine ribonucleosides. 6-Furyl- and 6-thienyl-7-deazapurine ribonucleosides showed cytostatic effect in multiple cancer cell lines in nanomolar range. Application of cyclosaligenyl and alanyl-ester phosphoramidate prodrugs did not improved cytostatic activity of parent nucleosides.
Keywords:
nucleosides; 7-deazapurines; cytostatic
Available at various institutes of the ASCR
Hetaryl derivatives of 7-deazapurine ribonucleosides: potent cytostatic agents
A series of novel 7-deazapurine ribonucleosides substituted with aryl and hetaryl groups has been prepared. Suzuki or Stille cross-coupling reactions with 6-chloro-7-deazapurine ribonucleosides ...
Synthesis of biaryl-substituted fluorescent nucleosides and nucleoside triphosphates and their incorporation to DNA
Riedl, Jan; Hocek, Michal
2011 - English
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show divers fluorescence from 400 to 560 nm when excited at 340 nm in water depending on structural and substitution pattern. The corresponding biaryl-substituted nucleoside triphosphates (dNTPs) were prepared analogously and used for polymerase incorporation to DNA. Applications in hybridization probes were studied.
Keywords:
nucleotides; fluorescence; DNA
Available at various institutes of the ASCR
Synthesis of biaryl-substituted fluorescent nucleosides and nucleoside triphosphates and their incorporation to DNA
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show ...
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