Preparation and investigation of LC packing made by microwave-assisted solid-phase synthesis.

The preparation of the so-called bonded phase liquid chromatographic packings is usually carried out by heating the silica, the silane, a catalyst, or a scavenger in an appropriate solvent (often toluene.) Due to the longtime of boiling, the procedure is time and energy consuming, and solvent intensive. The goal of this work is to present a simple, environment-friendly preparation method with reduced solvent consumption to synthetize RP liquid chromatographic stationary phases.

The effect of toxins on inorganic phosphate release during actin polymerization.

During the polymerization of actin, hydrolysis of bound ATP occurs in two consecutive steps: chemical cleavage of the high-energy nucleotide and slow release of the γ-phosphate. In this study the effect of phalloidin and jasplakinolide on the kinetics of P(i) release was monitored during the formation of actin filaments. An enzyme-linked assay based spectrophotometric technique was used to follow the liberation of inorganic phosphate.

Analysis of nonderivatized steroids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using C70 fullerene as matrix.

Neutral steroid hormones are currently analyzed by gas or liquid chromatography/mass spectrometry based methods. Most of the steroid compounds, however, lack volatility and do not contain polar groups, which results in inadequate chromatographic behavior and low ionization efficiency. Derivatization of the steroids to form more volatile, thermostable, and charged products solves this difficulty, but the derivatization of compounds with unknown chemical moieties is not an easy task.

Enrichment of Amadori products derived from the nonenzymatic glycation of proteins using microscale boronate affinity chromatography.

Amadori peptides were enriched using boronate affinity tips and measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). As demonstrated by electrochemical measurements, the tips show the highest binding efficiency for glucose at pH 8.2 employing ammonium chloride/ammonia buffer with ionic strength of 150 mM, exceeding taurine buffer at the same concentration.

Use of fullerene-, octadecyl-, and triaconthyl silica for solid phase extraction of tryptic peptides obtained from unmodified and in vitro glycated human serum albumin and fibrinogen.

SPE plays a crucial role in bioanalytical research. In the present work a novel fullerene(C60)-derivatised silica material is compared with octadecyl(C18) - and triaconthyl(C30)-silicas regarding recoveries of peptides and sequence coverage of HSA and fibrinogen digests. C30- and C60(30 nm)-SPE materials were found to be the two most prominent SPE materials.

Alcohol-free red wine inhibits isoproterenol-induced cardiac remodeling in rats by the regulation of Akt1 and protein kinase C alpha/beta II.

There is increasing evidence that moderate consumption of red wine containing high amount of polyphenols and anthocyanins is associated with decreased incidence of cardiovascular morbidity and mortality. Therefore, we hypothesized that cardiac hypertrophy and fibrosis as well as Akt (protein kinase B, PKB) and protein kinase C (PKC) cascades can be beneficially influenced by an alcohol-free red wine (AFRW) extract rich in 14 types of polyphenols and 4 types of anthocyanins during cardiac remodeling. To test this assumption, rats were treated with isoproterenol (ISO) to induce postinfarction remodeling and were given tap water or AFRW ad libitum for 8 weeks.

Analysis of nitrate ion in nettle (Urtica dioica L.) by ion-pair chromatographic method on a C30 stationary phase.

Nitrate ion is a frequent pollutant not only in soil and natural water resources but in vegetables and foods as well. In our study we focused on nettle due to its increased ability to accumulate nitrate ions. A new, simple method for the separation and determination of nitrate ion based on reversed-phase ion-pair chromatography has been elaborated.

A validated HPLC method for the quantitative analysis of trans-resveratrol and trans-piceid in Hungarian wines.

A new, simple procedure for the determination of phenolic components of wines, such as resveratrol and piceid isomers, has been elaborated and validated. A set of 70 red wines and 3 white wines from two wineries (Polgar Winery and Bock Winery, Villany, Hungary) are analyzed by reversed-phase high-performance liquid chromatography. The samples are injected without pretreatment and UV-vis and mass spectrometric (MS) detection has been applied.

Influence of the pore structure on the properties of silica based reversed phase packings for LC.

This paper describes the preparation and investigation of new, highly loaded, monomeric, silica based, reversed phase C18 and C30 packings. The influence of pore structure and endcapping on the properties of C18 and C30 packings is described. Using hydrothermal procedures, silicas with predictable pore size (9.

Cloning, sequencing, structural and molecular biological characterization of placental protein 20 (PP20)/human thiamin pyrophosphokinase (hTPK).

Full-length cDNAs of placental protein 20 (PP20) were cloned by screening a human placental cDNA library, which encode a 243 amino acid protein, identical to human thiamin pyrophosphokinase (hTPK) as confirmed by protein sequence analysis. Genomic alignment showed that the PP20/hTPK gene contains 9 exons. It is abundantly expressed in placenta, as numerous EST clones were identified.

Isolation of a new member of the ecdysteroid glycoside family: 2-deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside.

A new ecdysteroid glycoside, 2-deoxy-20-hydroxyecdysone 22-O-beta-D-glucopyranoside, is isolated from the herb Silene italica ssp. nemoralis (Waldst. and Kit.

Determination of serotonin released from coffee wax by liquid chromatography.

A simple hydrolysis and extraction method was developed for the release of serotonin (5-hydroxytryptamine) from a coffee wax sample obtained from decaffeination of coffee beans. The recoverable amount of serotonin was determined by reversed-phase high-performance liquid chromatography with gradient elution and UV detection, using the standard addition method. Different type of basic deactivated chromatographic columns were used for the separation.

Separation of serum carotenoids and vitamin A on chromsil-amino and -cyano phases by a bi-directional gradient elution technique.

Vitamin A, beta-carotene, lycopene, beta-cryptoxanthin, lutein and zeaxanthin can be simultaneously separated in human serum extracts by normal-phase liquid chromatography. Two stationary phases (containing amino and cyano groups, respectively) were investigated. With a bi-directional (up-down) gradient-elution technique both packings are useful for the determination of serum levels of carotenoids and retinol in serum extracts.

Infrared spectrometric analysis of urinary calculi.

The composition of urinary calculi was studied by means of infrared spectroscopy. Analysis of 150 calculi has shown that their infrared spectrum offers quick and reliable results and the method helps to plan the therapy. Organization of a central laboratory for calculus analysis is recommended.