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Free radicals are atoms, compounds or ions with the odd numbers of electrons. They are usually more reactive than other chemical species and harmful to biological cells and the whole living organisms, like human beings. They are... more
Free radicals are atoms, compounds or ions with the odd numbers of electrons. They are usually more reactive than other chemical species and harmful to biological cells and the whole living organisms, like human beings. They are implicated in the pathogenesis of many diseases including, e.g., cancer, Alzheimer’s disease, rheumatoid arthritis, and Parkinson’s disease. Free radicals are inactivated by the free radicals scavengers and/or antioxidants. Sometimes, both terms are used convertib le. Usually, the antioxidants are also identified with the sample antiradical activity because free radicals or, more generally, reactive oxidant species (ROS) are main oxidants occurred in the biological samples. Total antioxidant potential (TAP) is proportional to the products of concentrations of all antioxidants in the sample and their antioxidant powers (rate constants). Due to components interaction in the sample, tap frequently better describes the antioxidant properties of the complex b iological samples, such as herbal extracts. The aim of the study was to determine the total antioxidant potential of water infusions of selected medicinal plants. In order to investigate the TAP we used spectrophotometric and chromatographic methods. The results were correlated with the TAPs values related to the DPPH and peroxyl radicals as well as to the total polyphenols content in the sample.
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The determination of free radicals and their reaction products in biological systems is discussed, with an emphasis on the use of liquid chromatographic methods for the analysis. Free radicals formed from oxygen and its reduction... more
The determination of free radicals and their reaction products in biological systems is discussed, with an emphasis on the use of liquid chromatographic methods for the analysis. Free radicals formed from oxygen and its reduction products, nitric oxide, and lipid radicals are considered. Whilst reversed-phase high-performance liquid chromatography has found wide application for these analyses, ion-exclusion chromatography also has significant potential and some developments in this area are described.
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Kompleksy metali z zasadami Schiffa znane s od ko ca XIX wieku. Zwi zki te wzbudzaj zainteresowanie ze wzgl du na obecno ugrupowania iminowego RCH=NR w chemii koordynacyjnej oraz w badaniach procesów metabolicznych zachodz cych w... more
Kompleksy metali z zasadami Schiffa znane s od ko ca XIX wieku. Zwi zki te wzbudzaj zainteresowanie ze wzgl du na obecno ugrupowania iminowego RCH=NR w chemii koordynacyjnej oraz w badaniach procesów metabolicznych zachodz cych w organizmach ywych. Zasady Schiffa tworz z metalami grup przejciowych kompleksy o ró nej strukturze, stabilizuj c ró ne stopnie utleniania tych e metali. W pracy przedyskutowano rozdzia kompleksów niklu (II) z pi cioma ligandami, zasadami Schiffa. Zosta y one rozdzielone w uk adzie faz odwróconych. Z danych literaturowych wiadomo, e zarówno jon centralny jak i ligandy badanych kompleksów ulegaj reakcj utleniania i redukcji. Okaza o si jednak e, e w niektórych przypadkach detektor elektrochemiczny charakteryzowa si du niepewno ci pomiaru i/lub ma czu o ci . Elektrochemiczne w asno ci kompleksów zbadano za pomoc woltamperometrii cyklicznej. Okaza o si , e niektóre z nich adsorbowa y si na elektrodzie i/lub tworzy y przewodz ce polimery na powierzchni elektrody, w rozpuszczalnikach o niskiej liczbie donorowej.
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Cyclodextrins-based nanocomplexes for encapsulation of bioactive compounds in food, cosmetics, and pharmaceutical products: principles of supramolecular complexes formation, their influence on the antioxidative properties of target chemicals, and recent advances in selected industrial applicationsmore
Abstract Cyclodextrins (CDs) are a group of toroidal oligosaccharides that contribute to several guest-associated phenomena in gas or liquid phases. For over 100 years these macrocycles have been of interest in both pure research as well... more
Abstract Cyclodextrins (CDs) are a group of toroidal oligosaccharides that contribute to several guest-associated phenomena in gas or liquid phases. For over 100 years these macrocycles have been of interest in both pure research as well as applied technologies. The host–guest nanocapsulation of low-molecular-mass compounds with cyclodextrins (host and guest molecules, respectively) is highly molecular shape selective and in modern analytical chemistry is the method of choice for resolution of various isomers, including enantiomers. Particularly, in separation systems involving liquid mobile phases, cyclodextrins are frequently used as very efficient chiral and nonchiral selectors. CD modification of stationary phase allows enantiomers separation by gas chromatographic techniques. Over the past few decades these compounds have found a wide range of applications, in pharmacy, cosmetology, analytical, and food chemistry. The polar/nonpolar nature of cyclodextrins results in that compounds capsulated within CD cavity are characterized by different physicochemical properties than the free ones. CDs are commonly used to (1) increase the solubility of included compounds; (2) stabilize oxygen sensitive substances; (3) stabilize highly volatile compounds, enabling easy storage or transport; (4) dispose of toxins; (5) modify the chemical reactivity of the included substance and change its physicochemical and/or biomedical properties (mask of color, unpleasant odor or taste); as well as (6) reduce the adverse effects of drugs. Inclusion phenomena can be studied using UV-Vis, IR, NMR, cyclic or differential pulse voltammetry. In cosmetology CDs are used to change the volatility of the target substances, particularly for maintaining longer aroma of the commercial products, removing unwanted odors, or releasing the active substances to the nails or skin. Practical applications in agriculture and environment include the delay of germination in seeds/potatoes and removing of heavy metals and organic micropollutants. By complexation of nonpolar molecules, CDs increase bioavailability of pharmaceutical formulations, especially drugs that are nonsoluble in pure water steroids. In the food industry cyclodextrins are used as stabilizers for butter, margarine, mayonnaise, or garlic dry extracts. This chapter summarizes the literature concerning general information about cyclodextrins and related macrocycles, their supramolecular nano-complexes with low-molecular mass compounds, physicochemical properties of host–guest complexes, encapsulation of bioactive target components in food and cosmetics products as well as pharmaceutical formulations, based on the research communications, mainly published over a period of the last 3 years (2012–15). Moreover, the research dealing with the influence of encapsulated target compounds by CDs on their antioxidant properties is discussed. Some aspects of antioxidants analysis and preservation of such chemicals in complex samples in the presence of macrocyclic additives as well as quantitative analysis of free radicals and radicals scavengers is presented from a practical point of view. In addition, a review concerning the use of macrocyclic nano-additives as an ingredient of food, pharmaceutical formulations, cosmetics, and related products that are considered theoretically as well as currently on the market is reported.
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There is limited literature on the antioxidative properties of food of animal origin. Measurements of antioxidative properties are usually performed using the reaction of reduction of colored 2,2-diphenyl-1-picrylhydrazyl (DPPH) radials.... more
There is limited literature on the antioxidative properties of food of animal origin. Measurements of antioxidative properties are usually performed using the reaction of reduction of colored 2,2-diphenyl-1-picrylhydrazyl (DPPH) radials. Changes of the DPPH color are tracked photometrically. These measurements are interfered by both, the tested samples and reduced DPPH. This study aims to demonstrate the ability to separate different forms of DPPH (DPPH• and DPPH-H) by thin-layer chromatography (TLC). Further, it has been practically applied in the study of the determination of antioxidative properties of the meat samples. It was found that TLC can be used for the separation of different forms of DPPH as well as for measurement of TAP (total antioxidant potential) values related to the DPPH•. The strongest antioxidant properties were observed for pork neck extracted in buffer pH 2 and for smoked salmon fish extracted in acetone, the lowest for veal and turkey fillet extracted in met...
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The antioxidative activities of honeys collected in Poland were screened. The total antioxidant potential (TAP) provides more information about the system than the determination of individual antioxidant. TAP is proportional to the sum of... more
The antioxidative activities of honeys collected in Poland were screened. The total antioxidant potential (TAP) provides more information about the system than the determination of individual antioxidant. TAP is proportional to the sum of products of concentrations of all antioxidants in the sample and their antioxidant powers (rate constants). To measure, compare and correlate TAPs, we used techniques which we had recently elaborated (i) related to hydroxyl radicals, (ii) RP-HPLC measurements with amperometric detection and (iii) differential pulsed voltammetry (DPV). They were correlated with techniques already described in the literature (i) related to the DPPH radicals, (ii) the total content of phenolic compounds and (iii) color intensity. All assays revealed the following order of obtained TAP values: buckwheat > honeydew > linden > multi-flower> acacia honey. Correlations were found between results obtained using different techniques. There was also a significant ...
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The aim of this preliminary study was to investigate whether the fermentation process affects the antioxidative properties of honeys. Therefore, the total antioxidant potential (TAP) of eleven meads was examined. TAPs were estimated using... more
The aim of this preliminary study was to investigate whether the fermentation process affects the antioxidative properties of honeys. Therefore, the total antioxidant potential (TAP) of eleven meads was examined. TAPs were estimated using DPPH, hydroxyl radicals, and amperometric measurements in the flow-through HPLC system. The results were correlated with the total content of polyphenols and anthocyanins. Additionally, the concentrations of ethanol, sugars, and hydrogen peroxide were measured. The influence of side reactions and the presence of hydrogen peroxide, glucose, ethanol, and anthocyanins on the free radicals generation were also tested. The use of HPLC electrochemical detection for TAP measurements is particularly preferred. Depending on the potential used, different antioxidants can be measured. It turned out that fruit and species meads are characterized by much higher TAPs measured at high potential of the working electrode than at lower potential due to the high conc...
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In this paper a new method for the determination of Total Antioxidant Potential (TAP) using mass spectrometry has been described. The method is based on the generation of hydroxyl radicals in Fenton reaction and analysis of the product of... more
In this paper a new method for the determination of Total Antioxidant Potential (TAP) using mass spectrometry has been described. The method is based on the generation of hydroxyl radicals in Fenton reaction and analysis of the product of their interaction with p-hydroxybenzoic acid - 3,4-dihydroxybenzoic acid. It has been found that the proposed assay is superior to the previously described chromatographic method with respect to analysis time. The method has been applied to the determination of TAP for some herbal extracts and melatonin.
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The anti-oxidative properties of bitriazines (BTs) were evaluated using HPLC and cyclic voltammetry. In the first case, a RP-HPLC assay was made, using a fluorescence detector, hydroxyl radicals generated in Fenton reaction, and... more
The anti-oxidative properties of bitriazines (BTs) were evaluated using HPLC and cyclic voltammetry. In the first case, a RP-HPLC assay was made, using a fluorescence detector, hydroxyl radicals generated in Fenton reaction, and terephthalic acid as a spin trap. The measurements were performed using aqueous or methanolic solutions. It was found that when the BTs were dissolved in water they were antioxidants, while dissolved in methanol they were pro-oxidants. Their different physicochemical properties in both solvents were confirmed by voltammetric, chromatographic as well as spectrophotometric measurements.
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HPLC has been already used for the TAP estimation. Phenylalanine, salicylic, p-hydroxybenzoic (pHBA) or terephthalic (TPA) acids have been used as sensor compounds. Products of their reaction with the hydroxyl radicals, generated in the... more
HPLC has been already used for the TAP estimation. Phenylalanine, salicylic, p-hydroxybenzoic (pHBA) or terephthalic (TPA) acids have been used as sensor compounds. Products of their reaction with the hydroxyl radicals, generated in the Fenton-like reaction, were analyzed using electrochemical or fluorescence detection. This paper describes the TAP assay based on the hydroxyl radicals reaction with pHBA, reversed-phase-HPLC separation and UV photometric detection. The elaborated assay has been used to evaluate TAP values of some apiculture products.
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... organizmów wyższych. Znacznie wyższa niż w wodzie jest jego rozpuszczalność wroz-puszczalnikach organicznych, co wpływa na lokalizację rodników tlenowych w hydrofobowych częściach błon biologicznych. W organizmach ...
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Research Interests: Free Radicals and HPLC
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Antioxidants are crucial group of compounds in food chemistry, cosmetology and medicine. Therefore, many methods of their analysis are already described in the literature. Constitution of real samples is usually unknown and many... more
Antioxidants are crucial group of compounds in food chemistry, cosmetology and medicine. Therefore, many methods of their analysis are already described in the literature. Constitution of real samples is usually unknown and many antioxidants can interact each other. Hence, more useful information frequently provides the summaric value - Total Antioxidant Potential (TAP) which reflects concentration of all antioxidants in the sample multiplied by their antioxidant power. Although many assays are presented in the literature, the methods based on true reactive oxygen species provide the most realistic measure of antioxidant activity and are still needed. The proposed assay is related to the hydroxyl radicals, generated in the Fenton reaction. The product of its reaction with the sensor, terephthalic acid, was analysed using reversed phase high performance liquid chromatography with the fluorescence detection. Decrease of the surface area of its peak, caused by competition between the s...
Preliminary results are presented from application of reversed-phase HPLC with electrochemical detection to analysis of L-dopa and total antioxidant potential. It was possible to perform both analyses by using the same chromatographic... more
Preliminary results are presented from application of reversed-phase HPLC with electrochemical detection to analysis of L-dopa and total antioxidant potential. It was possible to perform both analyses by using the same chromatographic conditions. The method was used to estimate their daily profiles in the blood plasma of patients treated with different types of drug.
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SUMMARY Results from application of reversed-phase HPLC with electroche- mical detection to analysis of catecholamines and total antioxidant poten- tial are presented. The assay was used to estimate their daily profiles in blood serum of... more
SUMMARY Results from application of reversed-phase HPLC with electroche- mical detection to analysis of catecholamines and total antioxidant poten- tial are presented. The assay was used to estimate their daily profiles in blood serum of patients treated with anti-Parkinson drugs. It was found that increases in the concentration of hydroxy radicals in blood serum, and of the total antioxidant potential related to the hydroxy radical, was inversely correlated with the concentration of catecholamines in the serum. This sug- gests that catecholamines are pro-oxidants of hydroxy radicals. The method also enabled us to study changes in the concentrations of catecholamines during their storage at room temperature. It was found that change of drug color was caused by the oxidation of benseraside.
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Total Antioxidant Potential (TAP) frequently better describes the antioxidant properties of the complex biological samples (such as herbal extracts or blood plasma) than concentrations of all individual antioxidants in the sample. In the... more
Total Antioxidant Potential (TAP) frequently better describes the antioxidant properties of the complex biological samples (such as herbal extracts or blood plasma) than concentrations of all individual antioxidants in the sample. In the paper improved fluorometric assays of the TAP measurements have been described. These tests adopt thermolabile diazocompound [2,2’-diazobis (2-amidinopropane) dihydrochloride – AAPH] generating peroxyl radical, Fenton reaction produced hydroxyl radicals and SIN-1 (3-morpholino-sydnonimine) generating peroxynitrite. These radicals oxidize the analyzed samples and so called „detector”. Sample competes with the reaction between detector and radical; therefore, it delays this reaction. Results are calculated from the delay time during which antioxidants are consumed. Assays related to different radicals are described and compared.
Stimulation of NMDA receptor increases NO-dependent cGMP synthesis. A significantly higher cGMP level was observed in hippocampus (about 8-fold increase) than in cerebral cortex (2.5-fold increase), as compared to basal value. The... more
Stimulation of NMDA receptor increases NO-dependent cGMP synthesis. A significantly higher cGMP level was observed in hippocampus (about 8-fold increase) than in cerebral cortex (2.5-fold increase), as compared to basal value. The activity of NO synthase (NOS) and the basal level of cGMP in unstimulated slices were only slightly higher in hippocampus than in the cortex. About 60% of NOS total activity was found in the brain membrane fraction. The enzyme activity was not affected by glucocorticoids, even after 20 days of hydrocortisone treatment in dose of 40 mg/kg b.w. Brain ischemia induced by ligation of the both common carotid arteries in gerbils (Meriones unquiculatus) significantly increased NOS activity as well as cGMP and putrescine concentrations but decreased mono-ADP-ribosolation of proteins. Changes of NOS activity and cGMP concentration evoked by ischemia were decreased by specific inhibitor of the neuronal form of NOS (nNOS), 7-nitrodazole and the inhibitor of guanylate...
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The stimulation of NMDA receptor activates NO dependent cGMP biosynthesis with dynamic and extent different for hippocampus and brain cortex. The significantly higher NO mediated cGMP level was observed in hippocampus than in brain... more
The stimulation of NMDA receptor activates NO dependent cGMP biosynthesis with dynamic and extent different for hippocampus and brain cortex. The significantly higher NO mediated cGMP level was observed in hippocampus than in brain cortex. NMDA receptor stimulation increases NO mediated cGMP formation about 8 fold in hippocampus and 2.5 fold in brain cortex as compared to basal value (2 mM CaCl2). The activity of NO synthase and the basal level of cGMP in unstimulated slices were only slightly higher in hippocampus then in brain cortex. The CA2+ calmodulin dependent NO synthase was found in brain membrane and cytosol fraction. The enzyme activity was not affected by glucocorticoids, even after 20 days of hydrocortisone treatment in a dose of 40 mg/kg b.w. Brain ischemia induced by ligation of both common carotid arteries in gerbils increases significantly NOS activities as well as the level of cGMP and putrescine but decreases mono-ADP-ribosylation of brain proteins during reperfusi...
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The application of HPLC in the antioxidative (antiradical) properties studies of various samples is discussed in this paper. The assay is based on the reaction of, characterized by strong oxidizing properties, hydroxyl radicals (generated... more
The application of HPLC in the antioxidative (antiradical) properties studies of various samples is discussed in this paper. The assay is based on the reaction of, characterized by strong oxidizing properties, hydroxyl radicals (generated in the Fenton-like reaction) with the sample and with the, so-called, sensor. The product of the sensor reaction with the radicals is analyzed using RP-HPLC with fluorescence detection. It is well known that antioxidants, which are healthy for living organisms, have a negative environmental effect. Therefore, the goal of the paper is to discuss if the same setup can be used to get rid of unwanted compounds (toxins) from the environment. It was found that the phenols and PAHs are degraded by hydroxyl radicals. The optimal (maximum degree of the degradation) conditions were obtained forpH=3.0and 0.1 mM Fe2+.
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ChP spowodowana jest niewydolnością pozapiramidowego układu ruchowego. Głównym procesem patologicznym jest postępujące zwyrodnienie neuronów dopaminergicznych w warstwie zbitej istoty czarnej [1]. Podobnie do choroby Alzheimera należy do... more
ChP spowodowana jest niewydolnością pozapiramidowego układu ruchowego. Głównym procesem patologicznym jest postępujące zwyrodnienie neuronów dopaminergicznych w warstwie zbitej istoty czarnej [1]. Podobnie do choroby Alzheimera należy do grupy ...
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Page 1. 278 VOL. 19. JULY/AUGUST 2006 Journal of Planar Chromatography Summary We have previously described unexpected two-dimensionality in the thin-layer chromatographic separation of pairs of enantiomers of ...
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Malonyldialdehyde (MDA) plays an important role as a marker of the cascade of free radical reactions with lipids. It is also responsible for their toxicity. In this paper, preliminary results of the analysis of MDA by means of ion... more
Malonyldialdehyde (MDA) plays an important role as a marker of the cascade of free radical reactions with lipids. It is also responsible for their toxicity. In this paper, preliminary results of the analysis of MDA by means of ion exclusion chromatography (IEC) is presented. Two methods based on IEC with photometric detection are discussed. The first one is based on
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ABSTRACT In the literature many different TAP assays are described. They use various analytical methods. However, it seems that natural methods of investigation of the redox reactions are electroanalytical techniques. Indeed, TAP has been... more
ABSTRACT In the literature many different TAP assays are described. They use various analytical methods. However, it seems that natural methods of investigation of the redox reactions are electroanalytical techniques. Indeed, TAP has been already estimated potentiometrically and voltammetrically. In the paper we propose new electrochemical assay of TAP measurements. In this case TAP measure is the integral of the product of current and exponent from the potential (related to the standard reduction potential of the hydroxyl radicals) along normal or differential pulse voltammetric peak. It was found that TAP values can be accurately and robustly measured using described assay. They are directly proportional to the sample concentration and dependent on its redox potential. The proposed assay has been tested on pure compounds and on the mixtures. It turned out that in the second case TAP is an additive value for non-interacted compounds. On the other side, it is non-additive for compounds interacting with each other. As the real samples to test elaborated assay the extracts of various herbs are selected. Melissa is characterized by the strongest antioxidative properties.(c) 2014 Elsevier B.V. All rights reserved.
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Research Interests: Engineering, Technology, Multivariate Statistics, Principal Component Analysis, Metabolomics, and 15 moreQuality Control, Food Analysis, FingerPrinting, Solvent Extraction, Cluster Analysis, EXTRACTION, CHEMICAL SCIENCES, Chip, Visible Light, Spirulina, Food Products, Thin Layer Chromatography, Parachor, Solvents, and Pharmaceutical Formulation
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SUMMARY Cellular oxidative stress has been implicated as a key mechanism of cell differentiation provoked by several compounds (doxorubicins, fibra- des, edelfosine). Phenylacetate and its derivatives in submillimolar to mil- limolar... more
SUMMARY Cellular oxidative stress has been implicated as a key mechanism of cell differentiation provoked by several compounds (doxorubicins, fibra- des, edelfosine). Phenylacetate and its derivatives in submillimolar to mil- limolar concentrations induce cell differentiation. Ion-exclusion chroma- tography is widely used for separation and analysis of weak acids. We ap- plied it to the analysis of phenylacetic acids and to the determination of the hydroxyl radical-trapping potential of some of these compounds. Their total antioxidant potential for peroxy radicals was also measured using a photometric method. It was found that phenylacetates are weak antioxidants and in the concentrations which induce cell differentiation effects may substantially reinforce intracellular antioxidative potential.
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ABSTRACT Total antioxidant potential (TAP) is proportional to the sum from products of concentrations of all antioxidants in the sample and their antioxidant powers (rate constants). Due to components interaction in the sample, TAP... more
ABSTRACT Total antioxidant potential (TAP) is proportional to the sum from products of concentrations of all antioxidants in the sample and their antioxidant powers (rate constants). Due to components interaction in the sample, TAP frequently better describes the antioxidant properties of the complex biological samples, such as herbal extracts or blood plasma, than other parameters involving concentrations of all individual antioxidants, standard redox potentials, kinetics constants, etc. In the present study improved high-performance liquid chromatographic (HPLC) assay with fluorometric detection has been used to evaluate TAP values of selected low-molecular mass compounds like biogenic polyamines, especially spermidine, spermine, 1,7-diaminoheptane, putrescine and cadaverine. Moreover, optimised analytical protocol was employed for the TAP estimation of complex mixtures such as food products including number of alcoholic and non-alcoholic beverages. The results of our study revealed that proposed assay gives additional information about the OH radical scavenging performance and antioxidant properties of pure chemicals and complex food samples, in contrary to the described in the literature assays based on weaker radicals (peroxyl radical, DPPH, NO, ABTS or superoxide anion radical).
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ABSTRACT The main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data... more
ABSTRACT The main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant peaks ratio of targeted phytochemical compounds. It has been found that despite the relatively high stability of flavonoids at high temperature and under binary mobile phase HPLC conditions, the reaction of target compounds with common ABTS, FCR and DPPH radicals at elevated regions (particularly above 100 °C) dramatically changes their antioxidant activity values expressed, for example, as TEAC (Trolox equivalent antioxidant capacity) parameters. In principle, separation and detection processes of antioxidant profiling assay must not significantly affect the antioxidant activity of target compounds. In the case of foods eaten by humans or animals, critical experimental parameters such as pH and temperature concerning interaction of target analytes with derivatisation reagent should be as close as possible to the real physiological values.
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Ion Exclusion Chromatography (IEC) finds application in the separation of a wide range of small, neutral or partially ionized molecules. In IEC, the strong as well as weak electrolytes are eluted unseparated, the first at the beginning... more
Ion Exclusion Chromatography (IEC) finds application in the separation of a wide range of small, neutral or partially ionized molecules. In IEC, the strong as well as weak electrolytes are eluted unseparated, the first at the beginning and the latter at the end of the elution. The retention volumes of the remaining electrolytes are found to be proportional to their dissociation constant values. The dead and inner volumes of the chromatographic column can be determined from the observed dependence of retention volumes on dissociation constant values. The retention mechanism is described by the analytical equations and by the results obtained from the computer simulation of the column performance (using global thermodynamic and chromatographic equations or the Craig method). The mixed retention mechanism involving hydrophobic adsorption and screening effect is observed for weak electrolytes and aromatic compounds. Aromatic compounds are found to be retained almost solely by a reverse-...
