Characterization of volatile constituents from Origanum onites and their antifungal and antibacterial activity.

Essential oils obtained by hydrodistillation (HD) and microwave-assisted HD (MWHD) of Origanum onites aerial parts were analyzed by GC and GCIMS. Thirty-one constituents representing 98.6% of the water-distilled oil and 52 constituents representing 99.

BioArena system for knowing and understanding the biological world: a review with new experimental results.

A simple observation is the basis of the development of BioArena system: according to the first observations during the biological incubation after inoculation there is formaldehyde (HCHO) emission from the chromatographic spots; in this emission process, the level of HCHO molecules decreases time dependently. In fact, the antibiotic effect of an antibiotic-like compound decreases in parallel with the HCHO emission. The investigations demonstrated clearly a unique function and role of endogenous HCHO and its one main reaction product, ozone (O3), in the antiproliferative (e.

Separation and identification of antibacterial chamomile components using OPLC, bioautography and GC-MS.

Components of 50% aqueous ethanol chamomile (Matricaria recutica L.) flower extract, previously found antibacterial in a TLC-bioautographic study, were separated and isolated by the use of on-line overpressured layer chromatography (OPLC). This system consisted of an OPLC 50 BS system, an on-line coupled flow-through UV detector, and a manual fraction collector.

BioArena studies: unique function of endogenous formaldehyde and ozone in the antibiotic effect--a review.

The investigations demonstrated clearly a unique function and role of endogenous formaldehyde (HCHO) and ozone (O3) in the antibiotic effect of diverse molecules having different chemical structure. Elimination of HCHO and/or O3 from the layer chromatographic spots resulted in a decrease in the antimicrobial activity. On the basis of detection and measure of endogenous HCHO and O3 BioArena enables to both direct isolation and biological evaluation of new bioactive compounds.

Overpressured layer chromatography: from the pressurized ultramicro chamber to BioArena system.

The pressurized ultramicro (UM) chamber as a closed adsorbent layer chamber enables the use of a special chromatoplate and a pump to increase and optimize the mobile phase flow velocity through an optional development distance in an adsorbent layer. This chamber is the basic instrument of overpressured-layer chromatography (OPLC), which is a separation technique that combines the advantages of conventional TLC/HPTLC with those of HPLC. The versions of OPLC instrument, the character and achievement of off-line and on-line OPLC systems in analytical and preparative use are described.

Overpressured layer chromatography (OPLC)--a flexible tool of analysis and isolation.

This review briefly summarizes the overpressured layer chromatography (OPLC) technique and its progress from the beginning until today. Some theoretical aspects, important technical and methodological solutions, as well as analytical separations and isolations are demonstrated covering the last 30 years. The infusion and transfusion OPLC operations, as well as their combination, and their off-line and on-line processes, and off-line and on-line hyphenations for detection and structure elucidation are presented.

Investigation of the antibacterial mechanism of aflatoxins in the BioArena system.

The influence of monomethylated basic amino acids [NG-monomethyl-L-arginine (MMA) and Nepsilon-monomethyl-L-lysine (MML)] and ozone capturers (indigo carmine, d-limonene) on the antibacterial effect of the mycotoxins aflatoxins B1, B2, G1 and G2 was studied in BioArena, which is a complex bioautographic system especially suitable for investigating biochemical interactions. In the presence of the formaldehyde precursors MMA or MML, the antibacterial-toxic activity of all the aflatoxins against the phytopathogenic bacterium Pseudomonas savastanoi pv. phaseolicola was enhanced dose-dependently.

Multiple beneficial effects of resveratrol and their chemical-biochemical basis.

On the basis of in vitro and in vivo investigations trans-resveratrol (RV) is a natural, concentration-dependent formaldehyde (HCHO) mobilizer, scavenger, capture and carrier molecule. The capturing and mobilization of HCHO from a given biological unit (e.g.

Effect of ascorbigen and 1'-methylascorbigen on disease resistance of bean plants to Uromyces phaseoli.

The effect of ascorbigen and 1'-methylascorbigen on the disease resistance of bean (Phaseolus vulgaris L.,. cv.

Effect of formaldehyde on cell proliferation and death.

Formaldehyde (HCHO) may reach living organisms as an exogenous agent or produced within cells. The so-called formaldehydogenic compounds like S-adenosyl-L-methionine, N-hydroxymethyl-L-arginine, 1'-methyl ascorbigen, methanol, E-N-trimethyl lysine and methylamine are special exogenous sources of HCHO. Endogenous HCHO can be formed from hydroxymethyl groups during enzymatic methylation and demethylation processes.

Potential role of formaldehyde in the mechanism of action of ascorbigens on the basis of BioArena studies.

The effect of ascorbigen and 1'-methylascorbigen as a model compound pair was studied on the phytopathogenic bacterium Pseudomonas savastanoi pv. phaseolicola in the BioArena experimental system after overpressured layer chromatography. Results showed a characteristic, strong antibacterial effect of 1'-methylascorbigen and weak effect of ascorbigen present on the adsorbent layer as chromatographic spot.

The influence of L-ascorbic acid on the antibacterial-toxic activity of aflatoxins on adsorbent layer.

Aims: To substantiate the role of formaldehyde (HCHO) and its reaction products in the mechanism of the antibacterial-toxic effect of aflatoxins B1 (AFB1), B2, G1 and G2.

Materials And Results: Toxins were separated by overpressured layer chromatography, which was followed by biological evaluation directly on the adsorbent layer (BioArena system with Pseudomonas savastanoi pv. phaseolicola indicator bacteria).

Opposite effect of Cu(II) and Se(IV) ions on the antibacterial-toxic action of mycotoxins.

The effect of Se(IV) and Cu(II) ions on the antibacterial activity of aflatoxins and ochratoxin A (mycotoxins) was studied in BioArena as a complex bioautographic system. In the presence of 0.23 and 0.

Theoretical study on the vibrational spectra of methoxy- and formyl-dihydroxy-trans-stilbenes and their hydrolytic equilibria.

Compounds formed by exchanging one of the resveratrol hydroxy groups to methoxy or formyl groups are biologically important. Quantum chemical DFT calculations were applied for the simulation of some of their properties. Their optimized structures and charge distributions were computed.

[Role of formaldehyde and its reaction products in mechanism of action of some plant ingredients].

BioArena as a complex bioautographic system was successfully used for studying mechanism of action of some characteristic plant ingredients (e.g., 1'-methyl-ascorbigen, trans-resveratrol, salicylic acid, cinnamic acid).

Vibrational spectroscopy of resveratrol.

In this article the authors deal with the experimental and theoretical interpretation of the vibrational spectra of trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) of diverse beneficial biological activity. Infrared and Raman spectra of the compound were recorded; density functional calculations were carried out resulting in the optimized geometry and several properties of the molecule. Based on the calculated force constants, a normal coordinate analysis yielded the character of the vibrational modes and the assignment of the measured spectral bands.

Formaldehyde and some fully n-methylated substances in boar seminal fluids. Short communication.

On the basis of recent observations it is supposed that seminal fluids may contain--mainly in hydroxymethyl groups--formaldehyde (HCHO) and quaternary ammonium compounds as potential HCHO generators, therefore, preliminary investigations were carried out for the identification of these compounds in pig seminal fluids using OPLC, HPLC and MALDI MS techniques. The fresh pig seminal fluid was frozen in liquid nitrogen, powdered and aliquots (0.25 g) were treated with 0.

Simulated vibrational spectra of aflatoxins and their demethylated products and the estimation of the energies of the demethylation reactions.

The structure of four natural mycotoxins, the aflatoxin B1, B2, G1 and G2 and their demethylated products were optimized with quantum chemical method. The energies and the thermodynamic functions of the molecules were calculated and applied to calculation of the reaction energies of the demethylations. Further results of the calculations are the vibrational force constants, the infrared spectra of the molecules and the assignments of the spectral bands.

New terpenoids in cultivated and wild chamomile (in vivo and in vitro).

The effect of Chamomilla recutita (L.) Rauschert is made up by several groups of active substances, among which terpenoids in the inflorescences are of greatest importance. Among cultivated species, the Hungarian BK-2 contains more chamazulene in its essential oil than the German Degumil type, which is mainly cultivated for its (-)-alpha-bisabolol.

Role of arginine and its methylated derivatives in cancer biology and treatment.

Both L-arginine supplementation and deprivation influence cell proliferation. The effect of high doses on tumours is determined by the optical configuration: L-arginine is stimulatory, D-arginine inhibitory. Arginine-rich hexapeptides inhibited tumour growth.

Formaldehyde promotes and inhibits the proliferation of cultured tumour and endothelial cells.

Formaldehyde was applied in various doses (0.1-10.0 mM) to HT-29 human colon carcinoma and HUV-EC-C human endothelial cell cultures.

Dose-dependent effect of resveratrol on proliferation and apoptosis in endothelial and tumor cell cultures.

Experimental data suggest that Resveratrol, a compound found in grapes and other fruits may influence cell proliferation and apoptosis. The aim of our experiments was to study the effect of Resveratrol on tumor cell cultures and an endothelial cell culture in order to examine the effect of various doses of this compound on active cell death and cell proliferation. Human tumor (HT-29, SW-620, HT-1080) and endothelial (HUV-EC-C) cells were treated with various doses of (0.

HPLC-OPLC-MS investigation of change of formaldehyde and its generators in human teeth of different physiological stage.

Taking into consideration the unquestionable intracellular occurrence of formaldehyde (HCHO) and its generators in cells of plant, animal and human organisms as well as in body fluids it was resolved to determine their levels in hard tissues of physiologically and pathologically changed teeth. The aim of the work was to determine the relationship between the level of HCHO and the levels of its generators in pathologically changed teeth, mainly carietic teeth as tooth caries is still a serious and commonly occurring problem. The occurrence of HCHO (captured as its dimedone adduct) and some of its potential generators was demonstrated in the hard tissues of healthy and pathological human teeth by means of OPLC, HPLC and MS analyses.

Measurement of formaldehyde as dimedone adduct and potential formaldehyde precursors in hard tissues of human teeth by overpressured layer chromatography.

Simple, automatic overpressured layer chromatographic methods for the parallel determination of endogenous formaldehyde in the form of dimedone adduct and potential formaldehyde generators (betaines) in hard tissues of human teeth are described together with an efficient densitometric evaluation. These simple procedures involve the special preparation of teeth and extraction of formaldehyde, of different binding force in teeth, with methanol containing dimedone, and the isolation of betaines with an aqueous solution of methanol.

Effect of 1-methylascorbigen on the resistance potential of plants to pathogens.

We have studied the effect of 1'-methylascorbigen, an immunostimulating substance in animal systems on the resistance potential of barley, bean and wheat plants to the fungal pathogens Erysiphe graminis, Uromyces phaseoli and Puccinia recondita, respectively. The effectiveness of protection depends - as in the case of other endogenous, N-methylated compounds - on the dosage of applied 1'-methylascorbigen and on the time interval between the chemical pretreatment and inoculation. The time- and dose-dependent double immune response was clearly demonstrated in case of the barley - Erysiphe graminis and bean - Uromyces phaseoli host-parasite relationships while in case of the wheat -Puccinia recondita relationship the relatively long-time interval between pretreatment and inoculation allowed manifestation of only a single immune response.