108 research outputs found

    DFT ispitivanje antioksidativne aktivnosti alizarina Red S

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    Density functional theory calculations were performed to evaluate the antioxidant activity of alizarin red S molecule. The conformational behavior of molecule were analysed at the M06-2X/6-311++G(d,p) method. The most stable conformer of alizarin red S has two IHBs. The expected antioxidant activity of alizarin red S was justified from ionization potential (IPs) and homolytic O-H bond dissociation enthalpy (BDEs) values. Heterolytic O-H bond cleavages (proton dissociation enthalpies, PDEs) were also computed. Calculated IP, BDE, and PA values suggested that one-step H atom transfer (HAT), rather than SPLET or SET-PT, would be the most favored mechanism for explaining the antioxidant activity of alizarin red S in gas phase. In aqueous solution all of three mechanisms were competitive.Upotrebom DFT metode vršena su izračunavanja u cilju određivanja antioksidativne aktivnosti alizarina red S. Konformaciona priroda molekula analizirana ispitana je primenom M06-2X/6-311++G(d,p) metoda. Najstabilniji konformer alizarina red S ima dve unutrašnje vodonične veze. Očekivana antioksidativna aktivnost alizarina red S određena je izračunavanjem vrednosti jonizacionih potencijala (IP) i i vrednosti entalpija homolitičkog raskidanja O-H veza (BDE). Vrednosti entalpije heterolitičkog raskidanja O-H veza (entalpije disocijacije protona, PDE), su takođe izračunate. Izračunate IP, BDE i PA vrednosti ukazuju na to da je jednostepeni transfer H-atoma (HAT), pre nego SPLET ili SET-PT mehanizam, favorizovan u pogledu antioksidativne aktivnosti alizarina red S u gasnoj fazi. U vodenom rastvoru, sva tri mehanizma su konkurentna

    Ispitivanje antioksidativnih mehanizama kempferola sa hidroksi radikalom i superoksid radikal anjonom

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    Kaempferol, one of the most bioactive plant flavonoids was theoretically (at M05-2X/6-311G(d,p) level of theory) investigated for its ability scavange potentially highly damaging hydroxyl and superoxide anion radicals. Theoretical calculations point to HAT and SPLET mechanisms as operative for kaempferol in all solvents under investigations.Teoretski (na M05-2X/6-311G(d,p) nivou teorije) je ispitivana sposobnost kempferola, važnog bioaktivnog biljnog jedinjenja flavonoida, da reaguje sa potencijalno veoma štetnim hidroksi radikalom i superoksid radikal anjonom. Proračuni su pokazali da su HAT i SPLET mogući mehanizmi u svim rastvaračima

    Reaction of Diphenyldiazomethane with Phosphorus Monothioacids

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    The mechanism of the reaction of phosphorus monothioacids with diaryldiazomethanes was studied in different solvent systems at 20 °c. The thiolo to thiono product ratios were determined by 1H NMR spectroscopy and g.l.c. of the reaction mixtures. The results imply that the reaction involves two competing processes leading to the corresponding S- and 0-isomeric esters

    Chemistry of 2,4-Dioxothiazolidine. II. Ammonolysis of 2,4 Dioxothiazolidine and its Derivatives

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    It is found that the ammonolysis of 2,4-dioxothiazolidine gives 5-amino-2,3-dithiacaprohydroxamic·· add, while 3-plienyl-2,4-dioxothiazolidine is transformed in glycolic acid N-(2-amino-1-hydroxyethyl)- anilide. The product of ammonolysis of 3-(3-4-dichlorophenyl)- 2,4-dioxothiazolidine proved to be 3,4-dichlorophenylcarbamid

    Chemical Characterization and Antibacterial Activity of Essential Oil of Medicinal Plants from Eastern Serbia

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    The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication

    The effects of chronic administration of cisplatin on oxidative stress in the isolated rat heart [Efekti hronične primene cisplatine na oksidacioni stres izolovanog srca pacova]

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    Taken into consideration that molecular and cellular mechanisms involved in cardiotoxicity are still not clear the aim of this study was to compare the production of oxidative stress parameters in the isolated rat heart between animals chronically treated with cisplatin and saline. The hearts of male Wistar albino rats (n = 24, 12 per group, age 8 weeks, body mass 250±50 g) were excised and perfused according to the Langendorff technique at gradually increased coronary perfusion pressures (40-120 cmH2O). We followed the production of superoxide anion radicals, hydrogen peroxide, and nitrites and also index of lipid peroxidation during the changes of coronary perfusion pressure (CPP) (from 40 to 120 cm H2O) in coronary venous effluent. Modifications CPP were performed in order to determined if oxidative stress is involved in coronary endothelium response in conditions of hypoxia (lower than 60 cm H2O) and hyperoxia (higher than 80 cm H2O). Based on the results of this research we can conclude that with enhancement of CPP the values of oxidative stress statistically increased. However, this increment is more prominent in control group as a result of preserved endothelium and its more powerful response to hyperoxia. On the other hand, damaged endothelium of cisplatin-treated animals had weaker response to hyperoxia, and also lower antioxidant capacity. © 2018, University of Kragujevac, Faculty of Science. All rights reserved

    Nutritivni i socioekonomski status slučajnog uzorka ispitanika koji žive u Jugoistočnoj Srbiji - u smeru strategija personalizovane ishrane

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    South-Eastern Serbia is with traditionally acknowledged intake of spicy and energy-dense food. For the purposes of this study we presented official socio-economic determinants for the three counties within South-Eastern Serbia: jablanički, niški and pirotski. The objective of this study was to assess nutritional status of randomly selected 40 subjects (11-74 years) residing in South Eastern Serbia within the counties. By means of validated food and dietary data methodology, we interviewed subjects and analyzed in a cross-sectional design. Our data indicate low-carbohydrate-high-fat like dietary pattern within the subjects, irrespective of age and gender in the region. Demonstrated likely improper nutritional status of sodium, calcium, vitamins A, C, D and B9 (folate) warrants public health initiatives towards optimization of the intake within the region. Our results indicate inadequate micronutrient intake within the adolescent group. Overall our results underline the necessity of raising education and awareness of healthy nutrition benefits and sustainable food choices within South Eastern Serbia and foster the necessity of implementation of an individualized approach in nutrition healthcare in this middle-income country.U jugoistočnoj Srbiji se tradicionalno konzumira začinjena i energetski bogata i jaka hrana. Za potrebe ove studije, prikazali smo zvanične socioekonomske pokazatelje kroz tri okruga jugoistočne Srbije: jablanički, niški i pirotski. Cilj ove studije bio je evaluacija nutritivnog statusa slučajnog uzorka 40 ispitanika (11-74 godine) koji žive unutar pomenuta tri regiona jugoistočne Srbije. Korišćenjem validiranih metodoloških alata o prikupljanju podataka o kvalitetu ishrane i učestalosti konzumiranja namirnica, intervjuisali smo ispitanike i analizirali metodama studije preseka. Naši podaci ukazuju na dijetarni obrazac u regionu koji teži nižem unosu ugljenih hidrata i povišenom unosu masti, nezavisno od pola i starosne dobi. U našem radu ukazano je i na mogući neadekvatan unos mikronutrijenata u regionu, uključujući natrijum, kalcijum, vitamine A, C, D i B9 (folat), podatak koji zahteva inicijative javnog zdravlja u regionu. Naši podaci ukazuju da je neadekvatan unos mikronutrijenata prvenstveno prisutan u grupi adolescenata. Uopšte uzev, naši rezultati ukazuju na neophodnost podsticanja obrazovanja i podizanja svesti o značaju zdrave, adekvatne i balansirane ishrane kao i održivih izbora hrane i grupa hrane u okviru jugoistočne Srbije. Naši podaci ističu neophodnost implementacije individualizovanog pristupa u nutritivnim i dijetarnim strategijama i dijetnim planovima zemlje u razvoju kakva je Srbija

    Примена lc–ms/ms технике са јонском покретљивошћу за хемијску анализу екстраката прополиса са антимикробним потенцијалом.

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    The objective of this study was to test four-dimensional LC-ESI-MS/MS chromatography in analysis of complex mixture such as ethanol extracts of different propolis samples. In total more than 1200 picks were identified and only for 185 literature conformation was found. The given data represent the result of tentative identification, and summarized results are given in the text. Comparing the samples, from different altitudes, 96 components were detected as characteristic in high altitude samples and 18 in samples collected at low altitudes. Antimicrobial activity of ethanol extracts of propolis (EEP) and pro­pyl­ene glycol extracts of propolis (PGEP) were carried out on S. aureus, B. cereus, M. flavus, L. monocytogenes, P. aeruginosa, S. typhimurium, E. coli and E. cloacae bacterial strains and compared with broad-spectrum antibiotics, streptomycin and ampicillin. Anti-quorum sensing activity was performed on P. aeruginosa by testing the effect of representative propolis extracts on bio­film formation, twitching and motility activity and production of pyocyanin. We demonstrated that the majority of explored propolis extracts have greater or equal minimal inhibitory concentration and minimum bactericidal concen­tra­tion values compared to antibiotics, independently of the solvent used for the extraction. The samples collected from the highest altitude emerged as least active antimicrobial agents but with the greatest potential as anti-quorum sen­sing agents.Циљ овог истраживања је билo тестирање четвородимензионалне LC–ESI-MS/MS хроматографије у анализи комплексних смеша, као што су етанолни екстракти различитих узорака прополиса. Укупно је идентификовано више од 1200 пикова, а самo за 185 смо нашли литературну потврду. Приказани подаци представљају тентативну идентификацију и сумирани резултат је дат у тексту. Поређењем узорака са различитих надморских висина, за 96 једињења је утврђено да се налазе само у узорцима са високе надморске висине и 18 само у узорцима прикупљеним на нижим надморским висинама. Антибактеријске активности етанолних и пропиленгликолних екстрактата прополиса (EEP и PGEP, редом) тестиране су на S. aureus, B. cereus, M. flavus, L. monocytogenes, P. aeruginosa, S. typhimurium, E. coli и E. cloacae бактеријским линијама и поређене са анти- биотицима широког спектра деловања, стрептомицином и ампицилином. Anti-quorum sensing активност је тестирана на P. aeruginosa испитивањем ефекта репрезентативних екстраката прополиса на формирање биофилма, тестовима покретљивости руба коло- није (twitching и mobility) и производње пиоцианина. Показали смо да највећи број, коришћених екстраката прополиса, има истe и/или мање MIC и MBC вредности, у поре- ђењу са атибиотицима, независно од растварача коришћеног за екстракцију. Узорци прикупљени на високим надморским висинама су се показали као најмање активни антибактерициди али имају велики anti-quorum sensing потенцијал.Part of the theme issue honoring Professor Emeritus Slobodan Milosavljevićs 80th birthday

    Sinteza, strukturna karakterizacija i citotoksična aktivnost dva nova organorutenijum(II) kompleksa

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    Two new p-cymene ruthenium(II) complexes containing as additional ligands N-methylpiperazine ([(eta(6)-p-cymene)RuCl2(CH3NH(CH2)(4)NH)]PF6, complex 1) or vitamin K-3-thiosemicarbazone ([(eta(6)-p-cymene)RuCl2(K(3)tsc)], complex 2) were synthesized starting from [(eta(6)-p-cymene)(2)RuCl2](2) and the corresponding ligand. The complexes were characterized by elemental analysis, IR, electronic absorption and NMR spectroscopy. The X-ray crystal structure determination of complex 1 revealed "piano-stool" geometry. The differences in the cytotoxic activity of the two complexes are discussed in terms of the ligand present.Sintetisana su dva nova p-cimen-rutenijum(II) kompleksa koji sadrže kao dodatne ligande N-metilpiperazin ([(h6-p-cimen)RuCl2(CH3NH(CH2)4NH)]PF6, kompleks 1) i vitamin K3-tiosemikarbazon ([(h6-p-cimen)RuCl2(K3tsc)], kompleks 2). Oba nova kompleksa dobijena su polazeći od [(h6-p-cimen)2RuCl2]2 kompleksa i odgovarajućeg liganda. Kompleksi su okarakterisani elementalnom analizom, IC, elektronsko-apsorpcionom i NMR spektroskopijom. Rendgeno-strukturna analiza kompleksa 1 pokazala je “piano-stool” geometriju. U zavisnosti od prisutnog liganda diskutovana je razlika u citotoksičnoj aktivnosti ova dva dobijena kompleksa
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