Polymeric macromolecules of well-designed structures and specific properties open promising directions in the capillary entangled polymer electrophoresis. Pluronic F-127, as a thermoassociating polymer, possesses some unique properties that can be utilized in capillary entangled polymer electrophoresis of amino acids, peptides and proteins. In this study, we studied properties of Pluronic F-127 polymer as an additive to BGE for the separation of peptides and proteins. The influence of the thermoassociation on separation selectivity was studied. The addition of Pluronic caused severe instabilities of the electrical current and the signal of the UV detector. This study reveals remarkable positive effect of a low pressure applied to the inlet buffer vial during the analysis, which apparently stabilizes the electrical current and the detector signal. The effect of hydrodynamic flow induced by the pressure applied on the separation efficiency was studied and the significance of this effect was discussed. Pluronic F-127, as a representative of synthetic macromolecules, was compared with dextran, as a representative of natural polymers, in terms of separation power, selectivity and repeatability of migration times.

• MeSH
• dextrany chemie   MeSH
• elektroforéza kapilární MeSH
• peptidy izolace a purifikace   MeSH
• poloxamer chemie   MeSH
• polymery chemie   MeSH
• proteiny izolace a purifikace   MeSH
• pufry MeSH
• teplota MeSH
• viskozita MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The chiral separation of racemic tamsulosin hydrochloride (TH) was carried out using cyclodextrin (CD)-mediated capillary electrophoresis (CE) with DAD at 200 nm. The best separation of enantiomers of the studied compound was achieved at 20 kV with 30 cm x 50 microm I.D. polyacrylamide (PAA)-coated fused-silica capillary (effective length 20 cm) and running buffer with sulfated-beta-CD (S-beta-CD) as chiral selector. Other selected native or derivatized CDs were also tested: beta-CD (5, 15 mmol l(-1)), carboxymethyl-beta-CD (5, 30 mmol l(-1)), dimethyl-beta-CD (15 mmol l(-1)) and hydroxypropyl-beta-CD (5, 30 mmol l(-1)). Several parameters such as capillary pretreatment, buffer type and concentration, pH of background electrolyte, methanol content, separation temperature and voltage, were optimized. The excellent baseline separation of chiral TH was successfully achieved within 12 min using 100 mmol l(-1) phosphate buffer with pH 2.5 containing 1.7 mmol l(-1) S-beta-CD. Rectilinear calibration range was 50.0-500.0 mumol l(-1) of each enantiomer (r = 0.9993-0.9996). The method was applied to the assay of R-TH in Omnic, capsules (nominal content 0.4 mg per capsule) with R.S.D. 2.75% (n = 6), recovery 99.3-101.7% and it was suitable for the chiral purity control of the active enantiomer in the pharmaceutical.

• MeSH
• akrylové pryskyřice chemie   MeSH
• alfa blokátory analýza   chemie   MeSH
• cyklodextriny chemie   MeSH
• elektroforéza kapilární MeSH
• financování organizované MeSH
• pufry MeSH
• reprodukovatelnost výsledků MeSH
• roztoky MeSH
• senzitivita a specificita MeSH
• stereoizomerie MeSH
• sulfonamidy analýza   chemie   MeSH

Functional gold nanoparticles (AuNPs) are commonly used to enhance the response of optical affinity biosensors. In this work, we investigated the effect of preparation conditions on functional properties of AuNPs functionalized with antibody (Ab-AuNPs), specifically AuNPs with antibody against carcinoembryonic antigen (CEA) covalently attached via carboxy-terminated oligo-ethylene thiolate linker layer. The following parameters of preparation of Ab-AuNP have been found to have a significant effect on Ab-AuNP performance in affinity biosensors: the time of reaction of activated AuNPs with antibody, concentrations of antibody and amino-coupling reagents, and composition of immobilization buffer (molarity and salt content). In contrast, pH of immobilization buffer has been demonstrated to have only a minor influence. Our experiments showed that the Ab-AuNPs prepared under optimum conditions offered a binding efficiency of Ab-AuNPs to CEA as high as 63%, which is more than 4 times better than the best efficiencies reported for similar functional AuNPs so far. We employed these Ab-AuNPs with a surface plasmon resonance (SPR) biosensor for the detection of CEA and showed that the Ab-AuNPs enhanced the sensor response to CEA by a factor of 1000. We also demonstrated that the Ab-AuNPs allow the biosensor to detect CEA at concentrations as low as 12 and 40 pg/mL in buffer and 50% blood plasma, respectively.

• MeSH
• imobilizační protilátky chemie   MeSH
• karcinoembryonální antigen analýza   krev   MeSH
• koncentrace vodíkových iontů MeSH
• kovové nanočástice chemie   MeSH
• lidé MeSH
• limita detekce MeSH
• povrchová plasmonová rezonance metody   MeSH
• pufry MeSH
• zlato chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH

• MeSH
• antigeny analýza   MeSH
• arboviry MeSH
• ascitická tekutina MeSH
• centrifugace - gradient hustoty MeSH
• cesium MeSH
• chloridy MeSH
• cytopatogenní efekt virový MeSH
• druhová specificita MeSH
• erytrocyty imunologie   MeSH
• ethylethery farmakologie   MeSH
• hemaglutinační testy MeSH
• hemaglutininy virové analýza   MeSH
• husy MeSH
• komplement fixační testy MeSH
• koncentrace vodíkových iontů MeSH
• kultivační techniky MeSH
• kuřecí embryo MeSH
• myši MeSH
• povrchově aktivní látky farmakologie   MeSH
• pufry MeSH
• testy inhibice hemaglutinace MeSH
• tromethamin MeSH
• virové proteiny analýza   MeSH
• virus Sindbis MeSH
• žlučové kyseliny a soli farmakologie   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• myši MeSH
• zvířata MeSH

• MeSH
• arboviry MeSH
• ascitická tekutina MeSH
• centrifugace - gradient hustoty MeSH
• cesium MeSH
• chloridy MeSH
• cytopatogenní efekt virový MeSH
• druhová specificita MeSH
• erytrocyty imunologie   MeSH
• ethylethery farmakologie   MeSH
• hemaglutinační testy MeSH
• hemaglutininy virové analýza   MeSH
• husy MeSH
• komplement fixační testy MeSH
• koncentrace vodíkových iontů MeSH
• kultivační techniky MeSH
• kuřecí embryo MeSH
• myši MeSH
• povrchově aktivní látky farmakologie   MeSH
• protilátky analýza   MeSH
• pufry MeSH
• testy inhibice hemaglutinace MeSH
• tromethamin MeSH
• virové proteiny analýza   MeSH
• virus Sindbis imunologie   patogenita   účinky léků   MeSH
• žlučové kyseliny a soli farmakologie   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• myši MeSH
• zvířata MeSH

The present study describes a rapid and effective capillary electrophoresis (CE) method for the enantioseparation of pindolol using single-isomer octa(6-O-sulfo)-γ-cyclodextrin. The complexation parameters were determined under neutral and high pH conditions to identify optimal separation conditions using a theoretical model. Baseline separation of pindolol enantiomers was achieved within 6 min in a sodium/MOPS buffer, pH 7.2, with a selector concentration of 6 mM. The method was validated according to the ICH guidelines using imidazole as an internal standard. Low limits of detection and quantification were found, specifically 1.2 μg/mL and 4 μg/mL (0.6 μg/mL and 2 μg/mL per enantiomer), respectively. The calibration curves showed good linearity, with a coefficient of determination R2 ≥ 0.999 over a 5 - 55 μg/mL concentration range and over a 50 - 300 μg/mL concentration range of the racemic mixture. The relative standard deviations (%RSD) of intra-day and inter-day precision were lower than 8% at LOQ level, lower than 3% at 50 μg/mL level and lower than 1.5% at 300 μg/mL level. Accuracy ranged from 95 to 103% (106% at LOQ level). The proposed method was successfully tested on a medical formulation of Visken® Sandoz intravenous solution and Visken® Teofarma pills for oral use.

• MeSH
• časové faktory MeSH
• elektroforéza kapilární metody   MeSH
• gama-cyklodextriny chemie   MeSH
• kalibrace MeSH
• koncentrace vodíkových iontů MeSH
• limita detekce MeSH
• pindolol izolace a purifikace   MeSH
• pufry MeSH
• reprodukovatelnost výsledků MeSH
• software * MeSH
• stereoizomerie MeSH
• Publikační typ
• časopisecké články MeSH
• validační studie MeSH

Garlic is a well-known example of natural self-defence system consisting of an inactive substrate (alliin) and enzyme (alliinase) which, when combined, produce highly antimicrobial allicin. Increase of alliinase stability and its activity are of paramount importance in various applications relying on its use for in-situ synthesis of allicin or its analogues, e.g., pulmonary drug delivery, treatment of superficial injuries, or urease inhibitors in fertilizers. Here, we discuss the effect of temperature, pH, buffers, salts, and additives, i.e. antioxidants, chelating agents, reducing agents and cosolvents, on the stability and the activity of alliinase extracted from garlic. The effects of the storage temperature and relative humidity on the stability of lyophilized alliinase was demonstrated. A combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin's mode of action and develop effective defence mechanism, which could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant (MDR) bacterial strains.

• MeSH
• antibakteriální látky farmakologie   MeSH
• Bacteria účinky léků   ultrastruktura   MeSH
• biokatalýza účinky léků   MeSH
• časové faktory MeSH
• česnek enzymologie   MeSH
• chemické jevy * MeSH
• disulfidy chemie   metabolismus   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kyseliny sulfinové chemie   metabolismus   MeSH
• lyasy štěpící vazby C-S metabolismus   MeSH
• lyofilizace MeSH
• mikrobiální testy citlivosti MeSH
• mikrobiální viabilita účinky léků   MeSH
• pufry MeSH
• stabilita enzymů účinky léků   MeSH
• stereoizomerie MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A method for the separation of six selected antihyperglycemic (antidiabetic) drugs (tolbutamide, gliclazide, glimepiride, glibenclamide, repaglinide, and glipizide) was developed with use of micellar electrokinetic chromatography. Two non-ionic poly(ethylene glycol)-based surfactants Genapol X-080 and Triton X-114 (reduced) were studied as neutral pseudostationary phases. High alkaline pH 10.0 was used to obtain negative charges of separated antidiabetic drugs and non-ionic surfactants were employed for selectivity alteration. Both non-ionic surfactants provided good selectivity at concentration 0.2% (v/v) in sodium borate buffer and the separation of six drugs was obtained within 5min. An on-line preconcentration method based on reversed electrode polarity switching was employed for the determination of antihyperglycemic drugs in blood serum after acetonitrile protein precipitation. The limits of detection ranged from 20.8nmolL(-1) for tolbutamide to 6.5nmolL(-1) for glibenclamide, respectively.

• MeSH
• chromatografie MeSH
• hypoglykemika analýza   krev   MeSH
• lidé MeSH
• polyethylenglykoly chemie   MeSH
• povrchově aktivní látky chemie   MeSH
• senzitivita a specificita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• hodnotící studie MeSH
• práce podpořená grantem MeSH

The unique capability of proton buffering is the rationale for using histidine (HIS) as a component of solutions for induction of cardiac arrest and myocardial protection in cardiac surgery. In humans, infusion of cardioplegic solution may increase blood plasma HIS from ~ 70 to ~ 21,000 µM. We examined the effects of a large intravenous dose of HIS on ammonia and amino acid concentrations and energy status of the body. Rats received 198 mM HIS intravenously (20 ml/kg) or vehicle. Samples of blood plasma, urine, liver, and soleus (SOL) and extensor digitorum longus (EDL) muscles were analysed at 2 or 24 h after treatment. At 2 h after HIS load, we found higher HIS concentration in all examined tissues, higher urea and ammonia concentrations in blood and urine, lower ATP content and higher AMP/ATP ratio in the liver and muscles, higher concentrations of almost all examined amino acids in urine, and lower glycine concentration in blood plasma, liver, and muscles when compared with controls. Changes in other amino acids were tissue dependent, markedly increased alanine and glutamate in the blood and the liver. At 24 h, the main findings were lower ATP concentrations in muscles, lower concentrations of branched-chain amino acids (BCAA; valine, leucine, and isoleucine) in blood plasma and muscles, and higher carnosine content in SOL when compared with controls. It is concluded that a load of large HIS dose results in increased ammonia levels and marked alterations in amino acid and energy metabolism. Pathogenesis is discussed in the article.

• MeSH
• adeninnukleotidy metabolismus   MeSH
• aminokyseliny chemie   metabolismus   MeSH
• amoniak metabolismus   MeSH
• energetický metabolismus MeSH
• histidin aplikace a dávkování   analýza   metabolismus   MeSH
• intravenózní podání MeSH
• kardioplegické roztoky chemie   MeSH
• karnosin metabolismus   MeSH
• krysa rodu rattus MeSH
• kyseliny ketoglutarové metabolismus   MeSH
• močovina metabolismus   MeSH
• orgánová specificita MeSH
• potkani Wistar MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

A large number of studies have estimated phenylalanine ammonia-lyase (PAL) activity because it strongly reacts to various stimuli. Activity of this enzyme has been assayed mainly by means of spectrophotometry, but the precision of this method is poorly known. We compared assays of PAL activity using spectrophotometry and high performance liquid chromatography (HPLC) in two species (Matricaria chamomilla and Arabidopsis thaliana). Additionally, copper-exposed M. chamomilla plants and buffer with additive were also tested. Our data indicate that spectrophotometry both overestimates (leaves of M. chamomilla) and underestimates (leaves and roots of A. thaliana) PAL activity in comparison with HPLC, suggesting interference of UV-absorbing metabolites. HPLC also showed more accurate detection of cinnamic acid in Cu-exposed chamomile roots. Addition of dithiothreitol to the extraction buffer enhanced PAL activity but reduced proteins, indicating an artificial negative effect. A comparison of PAL activity in selected species is also provided.

• MeSH
• Arabidopsis enzymologie   MeSH
• fenoly metabolismus   MeSH
• fenylalaninamoniaklyasa metabolismus   MeSH
• kořeny rostlin enzymologie   MeSH
• listy rostlin enzymologie   MeSH
• Matricaria enzymologie   MeSH
• měď metabolismus   MeSH
• spektrofotometrie * MeSH
• substrátová specifita MeSH
• vysokoúčinná kapalinová chromatografie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH