Number of found documents: 516
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Hmotnostně-spektrometrické zobrazování metforminu v řezech vybraných tkání
Strnad, Štěpán; Sýkora, D.; Vrkoslav, Vladimír; Cvačka, Josef; Maletínská, Lenka; Pirník, Zdenko
2016 - Czech
Cílem této práce byla optimalizace postupu přípravy vzorku a následné hmotnostně spektrometrické zobrazení metforminu v tkáňových řezech ledvin. Byla nalezena vhodná matrice DHB, která poskytovala dostatečnou mez detekce, a zároveň nedocházelo k interferenci iontů analytu s matričními ionty. Tato matrice byla na řezy nanášena sublimací. Při MALDI MSI analýzách na reálných vzorcích myší, kterým byl perorálně podán metformin, bylo zjištěno, že v ledvinách byla nejvyšší relativní koncentrace metforminu ve vnitřní zóně dřeně 30 min po podání léčiva. Jednu hodinu po podání se již koncentrace metforminu začala snižovat. Pro potvrzení těchto výsledků bude tato studie dále rozšířena o kvantifikaci metforminu v ledvinách, která bude provedena analýzou homogenátů tkání ledvin pomocí LC-MS. Mass spectrometry imaging is a powerful technique suitable for visualization of the distribution of a wide variety of compounds within tissue sections. The main aim of the study was the development and optimization of a sample preparation procedure allowing determination of the distribution of orally dosed metformin in mice kidney sections. Metformin is the first-line medication for the treatment of type 2 diabetes. The optimization of the sample preparation step before imaging experiments included the selection of a suitable matrix and the optimization of various parameters of MALDI analysis. 2,5-dihydroxybenzoic acid was identified as the best matrix providing highest sensitivity. A sublimation method was successfully used for the matrix deposition. The highest relative concentration of metformin was found in the inner zone of kidney 30 minutes after the drug administration. Keywords: mass spectrometry imaging; metformin; MALDI; MALDI MSI Available at various institutes of the ASCR
Hmotnostně-spektrometrické zobrazování metforminu v řezech vybraných tkání

Cílem této práce byla optimalizace postupu přípravy vzorku a následné hmotnostně spektrometrické zobrazení metforminu v tkáňových řezech ledvin. Byla nalezena vhodná matrice DHB, která poskytovala ...

Strnad, Štěpán; Sýkora, D.; Vrkoslav, Vladimír; Cvačka, Josef; Maletínská, Lenka; Pirník, Zdenko
Ústav organické chemie a biochemie, 2016

Mimikování metabolismu thiramu pomocí elektrochemie spojené s hmotnostní spektrometrií
Jaklová Dytrtová, Jana; Jakl, M.
2016 - Czech
On-line zapojení elektrochemické cely vlastní výroby před hmotnostní spektrometr s ionizací elektrosprejem (EC-ESI-MS) bylo studováno pro možné využití při simulaci metabolismu thiramu (T). Instrumentační přístup EC-ESI-MS potvrzuje vytvoření prvního metabolického produktu T (Tm). Tm se tvoří rozpadem disulfidové vazby. Je diskutován katalytický účinek mědi pocházející z měděné pracovní elektrody na tuto reakci. On-line hyphenation of a home-made electrochemical cell with an electrospray ionization mass spectrometer (EC-ESI-MS) was investigated to be applicable in mimicking of thiram (T) metabolism. The EC-ESI-MS instrumental approach confirms the creation of the first metabolic product of T (Tm). Tm is created via the decay of the disulfide bond. The catalytic effect of copper originated from the copper working electrode to this reaction is discussed. Keywords: cytochrome P450; oxidation; reduction; lab-on-chip; ex situ Available at various institutes of the ASCR
Mimikování metabolismu thiramu pomocí elektrochemie spojené s hmotnostní spektrometrií

On-line zapojení elektrochemické cely vlastní výroby před hmotnostní spektrometr s ionizací elektrosprejem (EC-ESI-MS) bylo studováno pro možné využití při simulaci metabolismu thiramu (T). ...

Jaklová Dytrtová, Jana; Jakl, M.
Ústav organické chemie a biochemie, 2016

Mobilization of neutral compounds by inorganic and small organic ions in capillary electrophoresis
Křížek, T.; Martínková, E.; Kubíčková, A.; Hladílková, Jana; Coufal, P.; Heyda, J.; Jungwirth, Pavel
2016 - English
The present study shows that neutral low-molecular-mass compounds that are presumed to possess zero electrophoretic mobility and are thus used as markers of electroosmotic flow in capillary electrophoresis can acquire electrophoretic mobility due to ion-specific interactions with constituents of background electrolyte. Therefore, these neutral markers, such as thiourea or dimethyl sulfoxide, can be separated in electric field and their migration order can vary depending on background electrolyte composition. This observation has some important implications for analytical and physico-chemical measurements using capillary electrophoresis because the choice of the marker-background electrolyte combination can influence the results of the measurement. Keywords: capillary electrophoresis; EOF markers; ion-specific effects; mobilization Available at various institutes of the ASCR
Mobilization of neutral compounds by inorganic and small organic ions in capillary electrophoresis

The present study shows that neutral low-molecular-mass compounds that are presumed to possess zero electrophoretic mobility and are thus used as markers of electroosmotic flow in capillary ...

Křížek, T.; Martínková, E.; Kubíčková, A.; Hladílková, Jana; Coufal, P.; Heyda, J.; Jungwirth, Pavel
Ústav organické chemie a biochemie, 2016

Capillary isotachophoresis and zone electrophoresis applied to determination of effective charge of polyelectrolytes
Kašička, Václav; Koval, Dušan; Ibrahim, A.; Chamieh, J.; Cottet, H.
2016 - English
Capillary electromigration methods, isotachophoresis (CITP) and zone electrophoresis (CZE) were applied to determination of effective charge of poly-alpha-L-glutamic acid and poly-alpha-L-lysine using both CITP-dedicated device and common CZE apparatus. Combination of CITP and CZE methods in both these types of devices proved to be a suitable platform for determination of effective charge of a wide range of polyelectrolytes – weak and strong, polycations and polyanions. Keywords: capillary isotachophoresis; polyelectrolytes; effective charge Available at various institutes of the ASCR
Capillary isotachophoresis and zone electrophoresis applied to determination of effective charge of polyelectrolytes

Capillary electromigration methods, isotachophoresis (CITP) and zone electrophoresis (CZE) were applied to determination of effective charge of poly-alpha-L-glutamic acid and poly-alpha-L-lysine using ...

Kašička, Václav; Koval, Dušan; Ibrahim, A.; Chamieh, J.; Cottet, H.
Ústav organické chemie a biochemie, 2016

Determination of stability constants of [Gly6]-antamanide complexes with small cations by affinity capillary electrophoresis
Pangavhane, Sachinkumar; Makrlík, E.; Ruzza, P.; Kašička, Václav
2016 - English
Affinity capillary electrophoresis (ACE) was employed for the determination of apparent stability constants Kst of complexes of cyclic peptide [Gly6]-antamanide ([Gly6]-AA) with alkali and alkali-earth metal ions: Li+, Na+, K+, Rb+, Cs+, NH4+, and Ca2+. Kst was determined from the dependence of effective mobility of [Gly6]-AA on the concentration of these ions in the background electrolyte using the non-linear regression analysis. Kst were found to be in the range 13.3 – 26.3. Keywords: affinity capillary electrophoresis; [Gly6]-antamanide; stability constant Available at various institutes of the ASCR
Determination of stability constants of [Gly6]-antamanide complexes with small cations by affinity capillary electrophoresis

Affinity capillary electrophoresis (ACE) was employed for the determination of apparent stability constants Kst of complexes of cyclic peptide [Gly6]-antamanide ([Gly6]-AA) with alkali and ...

Pangavhane, Sachinkumar; Makrlík, E.; Ruzza, P.; Kašička, Václav
Ústav organické chemie a biochemie, 2016

Investigation of acid-based properties of mono- and diaza[5]helicenes by non-aqueous capillary electrophoresis and quantum chemical calculations
Šolínová, Veronika; Štěpánová, Sille; Jančařík, Andrej; Klívar, Jiří; Šámal, Michal; Stará, Irena G.; Vacek Chocholoušová, Jana; Vacek, Jaroslav; Starý, Ivo; Kašička, Václav
2016 - English
Non-aqueous capillary electrophoresis (NACE) using methanol (MeOH) as a solvent of the background electrolytes was used to determine the thermodynamic acidity (ionization) constants (pKa) of a series of monoaza[5]helicenes and diaza[5]helicenes protonated to the first degree in MeOH and water. Depending on the number and position of the nitrogen atoms in their molecules, the analyzed aza[5]helicenes were found to be weak to moderate bases with methanolic pKa,MeOH in the range 3.90-8.75 and with aqueous pKa,H2O in the range 3.53-8.28. Keywords: capillary electrophoresis; azahelicenes; acidity constant Available at various institutes of the ASCR
Investigation of acid-based properties of mono- and diaza[5]helicenes by non-aqueous capillary electrophoresis and quantum chemical calculations

Non-aqueous capillary electrophoresis (NACE) using methanol (MeOH) as a solvent of the background electrolytes was used to determine the thermodynamic acidity (ionization) constants (pKa) of a series ...

Šolínová, Veronika; Štěpánová, Sille; Jančařík, Andrej; Klívar, Jiří; Šámal, Michal; Stará, Irena G.; Vacek Chocholoušová, Jana; Vacek, Jaroslav; Starý, Ivo; Kašička, Václav
Ústav organické chemie a biochemie, 2016

Capillary electrophoretic separation and structure-mobility relationship study of cyclic antimicrobial peptides
Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav
2016 - English
Capillary electrophoresis (CE) has been employed for qualitative and quantitative analysis, separation and physicochemical characterization of antimicrobial peptides isolated from the venom of eusocial bee Lassioglossum laticeps. From the CE experiments at various pH, the important physico-chemical parameters of analyzed peptides, effective mobilities and acidity constants were determined and the structure-mobility relationships of peptides with variable intramolecular cyclization of their molecules were investigated. Keywords: antimicrobial peptides; capillary electrophoresis; structure-mobility relationships Available at various institutes of the ASCR
Capillary electrophoretic separation and structure-mobility relationship study of cyclic antimicrobial peptides

Capillary electrophoresis (CE) has been employed for qualitative and quantitative analysis, separation and physicochemical characterization of antimicrobial peptides isolated from the venom of ...

Tůmová, Tereza; Monincová, Lenka; Čeřovský, Václav; Kašička, Václav
Ústav organické chemie a biochemie, 2016

Analýza doby letu nejen v hmotnostní spektrometrii
Cvačka, Josef
2016 - Czech
Byl vysvětlen princip a použití analyzátorů doby letu v hmotnostní spektrometrii a jiných oborech. Principles and application examples of time of flight analyzers in mass spectrometry and other fields were explained. Keywords: TOF; mass spectrometry Available at various institutes of the ASCR
Analýza doby letu nejen v hmotnostní spektrometrii

Byl vysvětlen princip a použití analyzátorů doby letu v hmotnostní spektrometrii a jiných oborech....

Cvačka, Josef
Ústav organické chemie a biochemie, 2016

Využití hmotnostní spektrometrie pro analýzu nepolárních sloučenin
Vrkoslav, Vladimír
2016 - Czech
Bylo popsáno využití hmotnostně spektrometrických technik pro detekci nepolárních sloučenin. Using of mass spectrometry techniques for detection of nonpolar compounds was described. Keywords: non-polar compounds; mass spectrometry Available at various institutes of the ASCR
Využití hmotnostní spektrometrie pro analýzu nepolárních sloučenin

Bylo popsáno využití hmotnostně spektrometrických technik pro detekci nepolárních sloučenin.


Using of mass spectrometry techniques for detection of nonpolar compounds was described.

Vrkoslav, Vladimír
Ústav organické chemie a biochemie, 2016

Investigation of calix[4]arene-bis(t-octylbenzo-18-crown-6) complex with cesium cation by affinity capillary electrophoresis
Štěpánová, Sille; Moyer, B.; Makrlík, E.; Kašička, Václav
2016 - English
Affinity capillary electrophoresis (ACE) was employed for investigation of non-covalent interactions of calix[4]arene-bis(t-octylbenzo-18-crown-6) with Cs+ ion in methanol. The apparent binding constant of the calix[4]arene-bis(t-octylbenzo-18-crown-6)-Cs+ complex was determined from the dependence of the effective electrophoretic mobilities of the calix[4]arene-bis(t-octylbenzo-18-crown-6) on the concentration of cesium ion in the backround electrolyte using a non-linear regression analysis. The logarithmic form of the conditional apparent binding constant of calix[4]arene-bis(t-octylbenzo-18-crown-6)-Cs+ complex was found to be equal to 1.61. Keywords: affinity capillary electrophoresis; calix[4]arene-bis(t-octylbenzo-18-crown-6); binding constant Available at various institutes of the ASCR
Investigation of calix[4]arene-bis(t-octylbenzo-18-crown-6) complex with cesium cation by affinity capillary electrophoresis

Affinity capillary electrophoresis (ACE) was employed for investigation of non-covalent interactions of calix[4]arene-bis(t-octylbenzo-18-crown-6) with Cs+ ion in methanol. The apparent binding ...

Štěpánová, Sille; Moyer, B.; Makrlík, E.; Kašička, Václav
Ústav organické chemie a biochemie, 2016

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