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Your search keyword '"Stanković Dalibor M."' showing total 197 results
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197 results on '"Stanković Dalibor M."'

1. Quality evaluation of wines from Kosovo and Metohija: Polyphenols content, antioxidant activity and elemental composition

Author

Jevtić Sonja, Mutić Jelena, Đurđić Slađana, Babincev Ljiljana, Gurešić Dejan, Stanković Dalibor M., and Petković Branka B.

Subjects
polyphenols, antioxidant activity, wine, elemental composition, Mathematics, QA1-939, Science (General), Q1-390
Abstract

Wine is a very rich source of polyphenols and essential elements which have multiple biological activities. This study evaluates the total phenolic content (TPC), antioxidant activity (AA) of sixteen wine samples made from different grape varieties in the territory of Kosovo and Metohija, mostly from the area of Orahovac and Velika Hoča. The obtained results, determined by using the Folin-Ciocalteu assay, showed that wines from territory of Kosovo and Metohija are rich in polyphenols, with TPC ranges from 276±16 to 371±46 (white wines) and 1467±32 to 2823±43 mg gallic acid equivalents GAE/L (red wines). The total antioxidant activities, determined by ABTS method, range from 8.7±0.4 to 22.8±0.7 mmol trolox equivalents TE/L for red wines and from 1.3±0.1 to 3.8±0.3 mmol TE/L for white wines. Elemental content of studied wines showed certain difference between wines from nearby regions.

Published
2022
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2. In-house-prepared carbon-based Fe-doped catalysts for electro-Fenton degradation of azo dyes

Author

Savić Slađana D., Roglić Goran M., Avdin Vyacheslav V., Zherebtsov Dmitry A., Stanković Dalibor M., and Manojlović Dragan D.

Subjects
reactive blue 52, granulation, decolorization, hydrogen peroxide, graphite, advanced oxidation processes, Chemistry, QD1-999
Abstract

Compounds used in the fashion industry effect the water bodies in the vicinity of textile factories, resulting in the visible coloration of surface water. Fe-doped graphite-based in house prepared electrodes were used in the Fenton- -like degradation of Reactive Blue 52 (RB52). The electrodes consisting of high-density graphite in three granulation sizes and three levels of Fe content were characterized using scanning electron microscopy (SEM). The amount of Fe in the electrodes and H2O2 concentration in synthetic textile wastewater were optimized. Additionally, the size of graphite grains was varied to investigate whether it effects the degradation rate. Under only 10 min of electro-Fenton degradation, a system with 10 mmol dm-3 of H2O2 and an electrode made of 7 % of Fe and 70 μm of granulation size of graphite, degraded over 75 % of RB52, and over 99 % after 40 min of treatment. The obtained results indicate that the proposed approach could be beneficial in the field of novel materials for environmental application and that in house prepared carbon could be an excellent replacement for commercially available supports.

Published
2022
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3. Redox properties of alkyl-substituted 4-aryl-2,4-dioxobutanoic acids

Author

Cvijetić Ilija N., Verbić Tatjana Ž., Drakulić Branko J., Stanković Dalibor M., Juranić Ivan O., Manojlović Dragan D., and Zloh Mire

Subjects
aryldiketo acids (ADKs), redox properties, structure-property relationship, acidity constants, Chemistry, QD1-999
Abstract

Redox properties of a set of aryldiketo acids (ADKs), small organic molecules that comprise 2,4-dioxobutanoic acid moiety, were studied. Along with well-known HIV-1 integrase (IN) inhibition, ADKs exert widespread biological activities. The aim of this work was to evaluate the effects of aryl substitutions on the properties of the dioxobutanoic moiety that is involved in key interactions with metal ions within the active sites of target enzymes. The effect of pH on the electronic properties of nine congeners was examined using cyclic voltammetry and differential pulse polarography. The compounds were chosen as a simple set of congeners bearing Me-groups on the phenyl ring, which should not be involved in electrochemical reactions, leaving the diketo moiety as the sole electrophore. The substitution pattern was systematically varied, yielding a set having different torsion between the phenyl ring and the aryl keto group (Ar–C(O)). The protonation state of the ADKs at different pH values was determined from the experimentally obtained pKa values. The results showed that an equal number of protons and electrons were involved in the oxidation and reduction reactions at the surface of the electrode. Quantitative linear correlations were found between the reduction potentials and the energies of the frontier orbitals, calculated for neutral, mono-anionic and the corresponding radical anionic species, and the steric parameter as two independent variables. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172035]

Published
2017
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4. Analytical possibilities for the relative estimation of the antioxidative capacity of honey varieties harvested in different regions of Serbia

Author

Gašić Uroš M., Stanković Dalibor M., Dabić Dragana Č., Milojković-Opsenica Dušanka M., Natić Maja M., Tešić Živoslav Lj., and Mutić Jelena J.

Subjects
antioxidant activity, Folin-Ciocalteu method, radical scavenging activity, Chemistry, QD1-999
Abstract

Two different approaches, spectroscopic and electrochemical, were applied for rough determination of antioxidative potential of honey samples. Honey samples of diverse botanical origin were collected in different geographical regions in Serbia. Total phenolic content (TPC) was determined by Folin-Ciocalteu method. Cyclic voltammograms on a glassy carbon electrode in KCl supporting electrolyte were used to check electrode sensitivity to the presence of honey. In order to calculate Trolox Equivalent Antioxidant Capacity (TEAC) of studied honey, cyclic voltammograms were recorded for Trolox standard. The results were expressed as μmol of Trolox Equivalents per kg of sample (μmol TE kg-1). Good correlations were observed between cyclic voltammetry data and total phenolic content (TPC) determined by Folin-Ciocalteu method and radical scavenging activity (RSA) determined using DPPH•(1,1-diphenyl-2-picrylhydrazyl radical) test. Cyclic voltammetry appears to be a highly attractive alternative method for rapid estimation of antioxidative potential of honeys. It was found that polyfloral honey samples had the highest, whereas acacia honey showed the lowest values of TPC. [Projekat Ministarstva nauke Republike Srbije, br. 172017 i br. 172030]

Published
2016
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