Spectrophotometric and uplc study of reaction between [AuCl4] - and quercetin

The equilibrium and kinetics of the reaction between tetrachloroaurate(III) ion (AuCl4 - ) and quercetin in 0.1 M HClO4 were studied spectrophotometrically. The fast and the slow reaction steps were distinguished in the reaction mechanism, depending on the ratio of AuCl4 - and quercetin concentration. The stoichiometry of reaction, determined by molar ratio and Jobb’s methods, was 1:1. The kinetics of complex formation was followed under the pseudo-first order conditions by measuring the absorbance at 294 nm vs. time as the function of quercetin concentration in 5 – 15 fold excess.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Kinetic study of competitive CO2+ and Sr2+sorption by bauxite residue

Multi-component sorption studies are essential to identify the applicability of red mud as a low-cost sorbent for the simultaneous removal of metal ions from wastewaters. Sorption kinetics of Co2+ and Sr2+ionswas studied, at their different molar ratios in the mixture. The pseudo-second-order rate model best described the kinetics of metal sorption from binary metal systems. The increase of initial concentration of each cationin the mixture provoked its increased sorption capacity, but decreased sorption rate. Co2+sorption was superior in terms of both the rate and the capacity, therefore exertedstrong inhibitory effect on Sr2+sorption

Comparison of various bovine bone treatments for the preparation of effective Ni(ii) sorbent material

Animal bones are reach source of calcium hydroxyapatite which was approved as a good sorbent material for heavy metals and radionuclides. Various treatments can reduce the content of bone organic phase and improve sorption properties. In this study sorption capacities of raw bovine bones (B) and samples obtained by chemical treatment using NaOH (BNaOH), by heating at 400 oC (B400) or by combined chemical and thermal treatment (BNaOH+400), were compared. It was shown that sorbents exhibited different sorption mechanisms towards Ni(II) ions, and that maximum sorption capacities increased in the order B<BNaOH<B400<BNaOH+400. Synergetic effect of chemical and thermal treatment produced the material with highest sorption efficiency

Kultivacija matičnih i progenitorskih ćelija hematopoeze iz kostne srži hrčka

Hamster, a hibernating animal, is an important experimental model in research on the influence of hypothermia on different physiological processes. A simple procedure for cultivation and identification of hamster hematopoetic stem cells (HSC) and hematopoetic progenitor cells (HPC) is a premise for a successful investigation upon hypothermia effects on hematopoiesis. The aim of this work was to evaluate the utilization of commercially available methylcellulose media (MC) and recombinant mouse and human cytokines for hamster HSC and HPC assays, in order to enable further studies on these cells. Hamster bone marrow mononuclear cells (BMMNC) were plated in MC containing cytokines that support mouse or human HPC growth. Also, BMMNC were resuspended in cytokine supplemented liquid media and incubated for 5 weeks with a four day monitoring of viable cell number. We demonstrated that hamster hematopoietic progenitor cells committed for erythroid lineage and myeloid lineage successfully formed recognizable colonies in both mouse and human MC, while multipotent progenitor cells formed colonies only in mouse MC. We also defined conditions for the evaluation of hamster HSC activity in liquid cultures, based on continuous 5 weeks HSC proliferation. The obtained results verify the utilization of mouse specific MC for further research on hamster HPC biology during hypothermia.Fiziološka hibernacija u koju hrčci ulaze prilikom izlaganja niskim temperaturama, čini ove životinje zanimljivim eksperimentalnim modelom za ispitivanje hematopoeze u uslovima hipotermije. Preduslov za ovo ispitivanje je postojanje jednostavne metode za kultivaciju i identifikaciju hematopoetskih ćelija hrčka. Cilj ovog rada je bio da se ispita mogućnost kultivacije progenitorskih ćelija hematopoeze hrčka u kompletnoj metil celulozi dizajniranoj za kultivaciju mišijih i humanih hematopoetskih ćelija, kao i da se odrede optimalni uslovi za kultivaciju matičnih ćelija hematopoeze hrčka u tečnoj kulturi. Mononuklearne ćelije kostne srži hrčka su posađene u metil celulozu i u tečnu kulturu. Oba medijuma su sadržala kombinacije rekombinantnih mišijih i/ili humanih citokina. Kolonije progenitorskih ćelija opredeljenih za mijelopoezu i opredeljenih za eritropoezu su se formirale u metil celulozi dizajniranoj za kultivaciju mišijih i humanih hematopoetskih ćelija, dok su se primitivnije kolonije sastavljene od oba tipa ćelija (mijeloidna i eritrocitna loza) formirale samo u metil celulozi dizajniranoj za kultivaciju mišijih hematopoetskih ćelija. Osim toga, populacija matičnih ćelija hematopoeze hrčka je proliferisala u tečnim kulturama tokom 5 nedelja bez znakova opadanja proliferativnog potencijala. Ova istraživanja pokazuju da se primenjene metode mogu uspešno koristiti za ispitivanje hematopoeze kod hrčka

Chemical Profiling and Antioxidant Activity of Wild and Cultivated Sage (<i>Salvia officinalis</i> L.) Essential Oil

Chemical profiling the sage essential oils (SEOs) from wild and cultivated (shaded or non-shaded) plants has been investigated. The yield of SEOs from wild plants (3.51 mL/100 g) was higher than that from cultivated plants(shaded plants: 3.20 mL/100 g and non-shaded plants: 2.56 mL/100 g).The main components of SEO from wild plants were cis-thujone (43.2%), camphor (17.6%), 1,8-cineole (13.8%), veridiflorol (3.8%) and borneol (3.4%).The chemical composition of SEO from cultivated plants included camphor > cis-thujone > 1,8-cineole. Net shading lowered the content of toxic cis-thujone in sage (23.5%) and is therefore recommended in order to achieve better quality of SEO compared to non-shaded plants (cis-thujone 28.3%).The thujone content of SEO from wild plants is much higher (43.2%), and this drastically reduces the quality of EO. Cultivated sage was found to have stronger antioxidant activity (shaded plants 6.16 mg/mL or non-shaded 7.49 ± 0.13 mg/mL) compared to wild sage plants (9.65 mg/mL). The isolated SEOs are good sources of natural antioxidants with potential applications in the food and pharmaceutical industries

Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption rates indicated faster sorption of Sr2+ ions. Removal of both cations rapidly increased with the initial pH increase from 2.5 to 3.5. With the further increase of pH, Co2+ sorption was nearly constant (98%-100%), whereas Sr2+ removal remained at the same level to initial pH ~8 and gradually increased to 100% at pH 12. Equilibrium sorption data followed the Langmuir model, with the maximum sorption capacities of 0.52 mmol/g for Co2+ and 0.31 mmol/g for Sr2+. Sorbed cations exhibited high stability in distilled water. Desorption of Co2+ was also negligible in the presence of the competing Ca2+ cation, while 42%-25% of Sr2+ ions were desorbed depending on the previously sorbed amount. The results indicate that red mud is of potential significance as Co2+ and Sr2+ immobilization agent due to its high efficiency, abundance, and low-cost. [Projekat Ministarstva nauke Republike Srbije, br. 43009

Concurrent Co2+ and Sr2+ sorption from binary mixtures using aluminum industry waste: Kinetic study

Multi-component sorption studies are essential to identify the applicability of red mud as a lowcost sorbent for the simultaneous removal of metal ions from wastewaters. Sorption kinetics of Co2+ and Sr2+ ions was investigated, at different total concentrations of mixtures and different molar ratios of two cations. Kinetics of metal sorption from binary systems was found to be well described by pseudo-second order rate model. Equilibrium sorbed amounts and equilibrium times for Co2+ sorption increased with the increase of its total concentration in the mixture, whereas pseudo-second order rate constants exhibited the opposite trend. Sr2+ sorption was strongly suppressed in the presence of Co2+ ions, and the removal efficiency decreased with increasing concentration and mole fraction of Co2+. Red mud can be used for simultaneous Co2+ and Sr2+ removal from mixtures of lower initial concentration, otherwise Co2+ sorption is dominant

Antioxidant and Antimicrobial Activity of Polyphenol Extracts from Wild Berry Fruits Grown in Southeast Serbia

Purpose: To assess the antioxidant and antimicrobial activities of polyphenolic extracts of three wild red wild berry fruit species from Southeast Serbia, viz, European cornel ( Cornus mas ), blackthorn ( Prunus spinosa L.) and wild blackberry ( Rubus fruticosus ). Methods: Polyphenol content was determined using spectrophotometric and High performance liquid chromatography (HPLC) methods. Antioxidant activity was estimated by 2,2`- diphenyl - 1 - picrylhydrazyl (DPPH) test while reliminary antimicrobial tests were carried out by disc diffusion method in which antibacterial activity was evaluated by measuring the zone of inhibition against test bacterial strains. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results: The highest amount of total phenols was found in European cornel (8625.89 mg kg-1FW). Galic acid, caffeic acid, p-coumaric acid, ferulic acid, (+)-catechin, procyanidin B2, (-)-epicatechin, quercetin, rutin and quercetin-3-glucoside were the main polyphenols in the fruit extracts. All extracts showed high scavenging effect on DPPH radical with IC50 values ranging from 22.19 to 31.18 ml g-1, as well as high antimicrobial activity on almost all the tested bacterial strains. Conclusion: Extracts of wild berry fruits may be suitable for the preparation of medicinal and nutritional products

Effect of experimental variables onto Co2+ and Sr2+ sorption behavior in red mud-water suspensions

The prospects of rinsed red mud (alumina production residue) utilization for liquid radioactive waste treatment have been investigated, with Co2+ and Sr2+ as model cations of radioactive elements. To evaluate the sorption effectiveness and corresponding binding mechanisms, the process was analyzed in batch conditions, by varying experimental conditions (pH, Co2+ and Sr2+ concentrations in single solutions and binary mixtures, contact time, and the concentration of competing cations and ligands common in liquid radioactive waste). Comparison of the Co2+ and Sr2+ sorption pH edges with the red mud isoelectric point has revealed that Co2+ removal took place at both positive and negative red mud surface, while Sr2+ sorption abruptly increased when the surface became negatively charged. The increase of initial cation content and pH resulted in increased equilibrium times and sorption capacity and decreased rate constants. From single metal solutions and various binary mixtures, Co2+ was sorbed more efficiently and selectively than Sr2+. While Sr2+ sorption was reduced by coexisting cations in the order Al3+ Ca2+ GT Na+ Cs+, removal of Co2+ was affected by Al3+ species and complexing agents (EDTA and citrate). Desorption of Co2+ was negligible in Ca2+ and Sr2+ containing media and in solutions with initial pH 4-7. Sr2+ desorption was generally more pronounced, especially at low pH and in the presence of Co2+. Collected macroscopic data signify that Co2+ sorption by red mud minerals occurred via strong chemical bonds, while Sr2+ was retained mainly by weaker ion-exchange or electrostatic interactions. Results indicate that the rinsed red mud represent an efficient, low-cost sorbent for Co2+ and Sr2+ immobilization

Shade-Induced Effects on Essential Oil Yield, Chemical Profiling, and Biological Activity in Some <i>Lamiaceae</i> Plants Cultivated in Serbia

Thyme, mint, and lemon balm were used to determine whether shading conditions could improve the yield, composition, antioxidant, and antimicrobial activity in plant essential oils (EOs) in comparison with non-shaded plants from an open field. The yield of the EOs of non-shaded thyme, mint, and lemon balm, was 3.44, 3.96, and 0.21 mL/100 g, respectively. Plants covered by nets produced different levels of EOs (3.46, 2.20, and 0.45 mL/100 g) after 120 min of hydrodistillation. The main components of the thyme essential oil are thymol (44.2–43.9%), γ-terpinene (18.3–16.8%), and p-cymene (16.5–17.4%). The predominant components of mint essential oil are piperitenone oxide (52.6–64.8%) and 1,8 cineole (25.9–16.3%), while lemon balm essential oil consists of the following main components: geranial (34.0–32.8%); neral (21.3–24.9%); and piperitenone oxide (17.2–16.7%). The EOs from non-shaded thyme and mint plants have the highest antioxidant activity (EC50 value 0.54 mg/mL and 3.03 mg/mL). However, shaded lemon balm showed a stronger antioxidant activity (EC50 3.43 mg/mL) than non-shaded plants (12.85 mg/mL) after 60 min of incubation. The EOs from all plants showed significant effects against Escherichia coli, Proteus vulgaris, Bacillus subtilis, Staphylococcus aureus, and Candida albicans. The most active EOs against most of the isolates originated from Thymus vulgaris L., plants. Adequate cultivation techniques, such as shading for Lamiaceae plants, has positive effects, especially in Melissa officinalis L. Shading can achieve a higher content and components in terms of the specific biological activity (antioxidant and microbial) of EOs