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Fe(II)-activated potassium periodate (KIO4) oxidation was used to improve the dewaterability of waste-activated sludge for the first time. Compared with those of raw sludge, the capillary suction time (CST), specific resistance filtration (SRF), and water content of filter cake (WC) of sludge treated using the Fe(II)/KIO4 process under the optimal conditions (i.e., the initial pH = 6.8, KIO4 dose = 1.4 mmol/g volatile suspended solids, Fe(II)/KIO4 molar ratio = 1.2) decreased by 64.34%, 84.13%, and 6.69%, respectively. For conditioned sludge flocs, the Zeta potential and particle size were increased, and hydrophilic proteins in extracellular polymeric substances (EPS) were partly degraded, accompanied by the transformation of tightly bound EPS into soluble EPS and the conversion of dense sludge flocs into loose and porous ones. During Fe(II)/KIO4 oxidation, Fe(IV) and the accompanying •OH were determined as the predominant reactive species and the underlying mechanism of sludge EPS degradation was proposed. This work provides a prospective method for conditioning the sludge dewaterability.

This study aimed to improve the speed of the electrochemical process by graphene oxide nanoparticle as a current accelerator in Acid Blue 25 removal from aqueous solutions. To do so, the effect of different parameters including pH, dye concentration, sodium persulfate concentration, the ratio of sodium persulfate to iron (II) sulfate concentration, current density, and the distance between electrodes was investigated on dye removal. Under optimal conditions of pH = 5, dye concentration = 200 mg/L, sodium persulfate concentration = 500 mg/L, iron (II) sulfate concentration = 100 mg/L, current density = 16.67 mA/cm2, and electrode distance = 2 cm, 95% of dye was removed after 60 min in the electro-activated persulfate process; while the modified electro-activated persulfate process achieved 95% dye removal after only 40 min under the same conditions. This system was able to remove 90% of dye after 60 min at a higher concentration (300 mg/L). Also, the modified electro-activated persulfate process obtained the removal of 80% of COD, and 54% of TOC after 180 min in the mentioned conditions, for the dye concentration of 300 mg/L. HIGHLIGHTS Geraphene oxide nanoparticles raised the reaction rate by 17% by increasing the conductivity.; The increase in conductivity, decreased the energy consumption by 50%.; More 100 mg/L dye can be removed by the modified system.; The oxidation state reduction made the dye structure simpler with less toxicity.

Many plants are exposed to soil waterlogging, including soybean plants. Soil waterlogging exponentially increases the availability of iron (Fe) and causes O2 depletion, which may result in excessive uptake of Fe and shortage of O2 to the roots and also nodules in leguminous plants, resulting in overproduction of reactive oxygen species and lipid peroxidation. The present study aimed to evaluate physiological damage to soybean leaves at the second trifoliate (V2) stage when exposed to non-waterlogged and waterlogged soils and combined with one moderate and two toxic levels of Fe. Soybean plants were vulnerable to soil waterlogging at all Fe levels tested, presenting the highest values of malonaldehyde, hydrogen peroxide, and Fe accumulation in the shoot, which resulted in accentuated damage to gas exchange and chlorophyll content, consequently leading to lower shoot dry weight. In contrast, soybean plants cultivated under optimal water availability showed less damage caused by excess Fe, mainly at 125 mg dm-3 Fe, since the traits of net photosynthetic rate, water use efficiency, instantaneous carboxylation efficiency, malonaldehyde, and shoot dry weight were not affected. Keywords: chlorophylls; gas exchange; Glycine max; ferrous ion. Encharcamento do solo associado ao excesso de ferro potencializa os danos fisiológicos às folhas de soja RESUMO: Muitas plantas estão expostas ao encharcamento do solo, incluindo plantas de soja. O encharcamento do solo aumenta exponencialmente a disponibilidade de ferro (Fe) no solo e causa depleção de O2, o que pode resultar na absorção excessiva de Fe e escassez de O2 para as raízes e também nódulos em plantas leguminosas, resultando em superprodução de espécies reativas de oxigênio e peroxidação lipídica. O presente estudo teve como objetivo avaliar os danos fisiológicos às folhas de soja no segundo estádio trifoliado (V2) quando exposta a solos não encharcados e encharcados combinado com um nível moderado e dois níveis tóxicos de Fe. As plantas de soja foram vulneráveis ​​ao encharcamento do solo em todos os níveis de Fe testados, apresentando os maiores valores de malonaldeído, peróxido de hidrogênio e acúmulo de Fe na parte aérea, o que resultou em danos acentuados nas trocas gasosas e no conteúdo de clorofila, consequentemente levando a menor peso seco de parte aérea. Em contrapartida, plantas de soja cultivadas sob disponibilidade hídrica ótima apresentaram menos danos causados ​​pelo excesso de Fe, principalmente a 125 mg dm-3 Fe, uma vez que as características de taxa fotossintética líquida, eficiência do uso da água, eficiência de carboxilação instantânea, malonaldeído e peso seca da parte aérea não foram afetados. Palavras-chave: clorofilas; trocas gasosas; Glycine max; íon ferroso. Many plants are exposed to soil waterlogging, including soybean plants. Soil waterlogging exponentially increases the availability of iron (Fe) and causes O2 depletion, which may result in excessive uptake of Fe and shortage of O2 to the roots and also nodules in leguminous plants, resulting in overproduction of reactive oxygen species and lipid peroxidation. The present study aimed to evaluate physiological damage to soybean leaves at the second trifoliate (V2) stage when exposed to non-waterlogged and waterlogged soils and combined with one moderate and two toxic levels of Fe. Soybean plants were vulnerable to soil waterlogging at all Fe levels tested, presenting the highest values of malonaldehyde, hydrogen peroxide, and Fe accumulation in the shoot, which resulted in accentuated damage to gas exchange and chlorophyll content, consequently leading to lower shoot dry weight. In contrast, soybean plants cultivated under optimal water availability showed less damage caused by excess Fe, mainly at 125 mg dm-3 Fe, since the traits of net photosynthetic rate, water use efficiency, instantaneous carboxylation efficiency, malonaldehyde, and shoot dry weight were not affected. Keywords: chlorophylls; gas exchange; Glycine max; ferrous ion. Encharcamento do solo associado ao excesso de ferro potencializa os danos fisiológicos às folhas de soja RESUMO: Muitas plantas estão expostas ao encharcamento do solo, incluindo plantas de soja. O encharcamento do solo aumenta exponencialmente a disponibilidade de ferro (Fe) no solo e causa depleção de O2, o que pode resultar na absorção excessiva de Fe e escassez de O2 para as raízes e também nódulos em plantas leguminosas, resultando em superprodução de espécies reativas de oxigênio e peroxidação lipídica. O presente estudo teve como objetivo avaliar os danos fisiológicos às folhas de soja no segundo estádio trifoliado (V2) quando exposta a solos não encharcados e encharcados combinado com um nível moderado e dois níveis tóxicos de Fe. As plantas de soja foram vulneráveis ​​ao encharcamento do solo em todos os níveis de Fe testados, apresentando os maiores valores de malonaldeído, peróxido de hidrogênio e acúmulo de Fe na parte aérea, o que resultou em danos acentuados nas trocas gasosas e no conteúdo de clorofila, consequentemente levando a menor peso seco de parte aérea. Em contrapartida, plantas de soja cultivadas sob disponibilidade hídrica ótima apresentaram menos danos causados ​​pelo excesso de Fe, principalmente a 125 mg dm-3 Fe, uma vez que as características de taxa fotossintética líquida, eficiência do uso da água, eficiência de carboxilação instantânea, malonaldeído e peso seca da parte aérea não foram afetados. Palavras-chave: clorofilas; trocas gasosas; Glycine max; íon ferroso.

In order to investigate the anti-scaling and anti-corrosion characteristics of an electrostatic anti-fouling system in the application process, the influence of an electrostatic field (EF) on the structure and dynamics of hydrated Ca2+ and hydrated Fe2+ in a mixed aqueous system was studied through the calculation and analysis of the radial distribution function (RDF), self-diffusion coefficients, viscosity, and hydrogen bond structure by using molecular dynamics simulation. The study results show that the EF can decrease the radius of the first water shell of hydrated Ca2+ but increase that of Fe2+, which will reduce the possibility of forming calcite. The EF can make water molecules and Fe2+ more active, which can hinder iron release and thus decrease iron corrosion products. In addition, the EF can enhance the hydrogen structure of water molecules in the aqueous solution.

Ganodermaspecies have been known all over the world as highly medicinal mushrooms. Antimicrobial activity of it is an attractive approach which raises the global interests from the scientific community. In this study, the antimicrobial assay of ethanol and methanol extracts ofGanodermawere prepared by using the dried mycelial powder obtained from five different liquid media; was performed against seven plant pathogenic fungiviz., Alternaria macrospora, Aspergilus niger, A. flavus, Colletotrichum falcatum, Fusarium oxysporum, Pestalotiopsis mangiferaeandPenicillium sp. and two plant pathogenic bacteriaXanthomonas oryzaeandRalstonia solanacearum. The extracts of mycelia obtained from Yeast Wine Media exhibited the highest inhibition percentage as compared to rest. At concentration 1000ppm, there was complete inhibition of mycelial growth forAlternaria macrospora, Aspergilus nigerandA. flavuswhile forFusarium oxysporumandPenicillum sp. complete inhibition was observed at 500ppm but forColletotrichum falcatumandPestalotiopsis mangiferae, more than 80% mycelial inhibition at concentration 1000ppm in both ethanol and methanol extracts. In the case ofXanthomonas oryzaeandRalstonia solanacearum, at concentration 1000ppm, methanol extract showed the highest inhibition zone (3.50mm, 3.75mm).Ganodermaexhibited antagonistic effect against plant pathogenic fungi could add to the interest of developingGanodermaas a successful bioagent in the near future. Antioxidant activities were evaluated by using DPPH radical scavenging assay and Metal chelating activity on ferrous ions. The DPPH radical scavenging effect was detected in methanol extract (Inhibition% = 27.312%) was higher than that of the ethanol extract (Inhibition% = 24.79%) and also Ferrous ion chelating ability of methanol extract (Inhibition% =22.27%) was higher than the ethanol extract (Inhibition% =12.55%). It is clearly indicated that both methanol and ethanol extract of theGanodermashow antioxidant properties andGanodermaextracts act as an effective antioxidant agents.

Folates are required for the de novo biosynthesis of purines, thymine, methionine, glycine, and pantothenic acid, key metabolites that bacterial cells cannot survive without. Sulfonamides, which inhibit bacterial folate biosynthesis and are generally considered as bacteriostats, have been extensively used as broad-spectrum antimicrobials for decades. Here we show that, deleting relA in Escherichia coli and other bacterial species converted sulfamethoxazole from a bacteriostat into a bactericide. Not as previously assumed, the bactericidal effect of SMX was not caused by thymine deficiency. When E. coli ∆relA was treated with SMX, reactive oxygen species and ferrous ion accumulated inside the bacterial cells, which caused extensive DNA double-strand breaks without the involvement of incomplete base excision repair. In addition, sulfamethoxazole showed bactericidal effect against E. coli O157 ∆relA in mice, suggesting the possibility of designing new potentiators for sulfonamides targeting RelA. Thus, our study uncovered the previously unknown bactericidal effects of sulfonamides, which advances our understanding of their mechanisms of action, and will facilitate the designing of new potentiators for them.

A novel copper, zinc superoxide dismutase (CuZnSOD) was purified to homogeneity from the liver of an animal well adapted to the stressful living conditions of the desert, the camel (Camelus dromedarius). The biochemical properties of camel liver CuZnSOD were examined. The purified enzyme had a native molecular weight of 28 kDa, as judged by gel filtration chromatography, and showed a single band at 27 kDa on SDS-PAGE, indicating that it is a monomeric protein. Optimal activity of the purified enzyme occurred at 43 °C and pH 6.0, and the activation energy was 1.42 kJ/mol. CuZnSOD activity was strongly inhibited by ?-ME, DTT, H 2 O 2 and SDS and slightly inhibited by EDTA, NaN 3 and PMSF. Al 3+ , Ca 2+ , Cd 2+ , Mg 2+ and Zn 2+ stimulated CuZnSOD activity, whereas Ba 2+ , Co 2+ , Fe 2+ and Ni 2+ inhibited it. The purified enzyme contained 0.010 µg of Cu and 0.69 µg of Zn per mg of protein. K m , V max , k cat and k cat /K m values for NBT and riboflavin were 16.27 and 0.16 µM, 20.85 and 21.54 U/mg, 9.65 and 9.97 s ?1 , and 0.59 and 62.33 s -1 µM ?1 , respectively. Camel liver CuZnSOD exhibited unique biochemical properties compared to those of other CuZnSODs, including lower molecular weight with a monomeric structure, higher optimum temperature, very low E a , very low optimum pH, very low contents of Cu and Zn, and higher affinity, turnover number and catalytic efficiency for riboflavin. These unique properties of camel liver CuZnSOD might be related to the ability of this animal to inhabit stressful desert conditions. © 2019 Elsevier Inc.

Made available in DSpace on 2020-12-12T02:46:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Soil waterlogging is a common problem in some agricultural areas, including regions under soybean (Glycine max) cultivation. In waterlogged soils, soil O2 depletion occurs due to aerobic microorganisms and plants, affecting the metabolic and physiological processes of plants after suffering anoxia in their root tissue. Another harmful factor in this situation is the exponential increase in the availability of iron (Fe) in the soil, which may result in absorption of excess Fe. The present study sought to evaluate the response mechanisms in soybean leaves ‘Agroeste 3680’ by physiological and biochemical analyses associating them with the development of pods in non-waterlogged and waterlogged soil, combined with one moderate and two toxic levels of Fe. Gas exchange was strongly affected by soil waterlogging. Excess Fe without soil waterlogging reduced photosynthetic pigments, and potentiated this reduction when associated with soil waterlogging. Starch and ureide accumulation in the first newly expanded trifoliate leaves proved to be response mechanisms induced by soil waterlogging and excess Fe, since plants cultivated under soil non-waterlogged soil at 25 mg dm−3 Fe showed lower contents when compared to stressed plants. Thus, starch and ureide accumulation could be considered efficient biomarkers of phytotoxicity caused by soil waterlogging and excess Fe in soybean plants. The reproductive development was abruptly interrupted by the imposition of stresses, leading to a loss of pod dry biomass, which was largely due to the substantial decrease in the net photosynthetic rate, as expressed by area (A), the blockage of carbohydrate transport to sink tissues and an increase of malondialdehyde (MDA). The negative effect on reproductive development was more pronounced under waterlogged soil. São Paulo State University (UNESP) University of Western São Paulo (UNOESTE) São Paulo State University (UNESP) CAPES: 001 FAPESP: 2018 / 17380-4

Extensive use of CuO nanoparticles (CuO-NPs ) inevitably leads to their accumulation in wastewater and toxicity to microorganisms that effectively treat nitrogen pollution. Due to the effects of different mediums, the sources of CuO-NPs-induced toxicity to microorganisms and methods to mitigating the toxicity are still unclear. In this study, CuO-NPs were found to impact the nitrate reduction of Pseudomonas tolaasii Y-11 mainly through the action of NPs themselves while inhibiting the ammonium transformation of strain Y-11 through releasing Cu2+. As the content of CuO-NPs increased from 0 to 20 mg/L, the removal efficiency of NO3− and NH4+ decreased from 42.29% and 29.83% to 2.05% and 2.33%, respectively. Exogenous Fe2+ significantly promoted the aggregation of CuO-NPs, reduced the possibility of contact with bacteria, and slowed down the damage of CuO-NPs to strain Y-11. When 0.01 mol/L Fe2+ was added to 0, 1, 5, 10 and 20 mg/L CuO-NPs treatment, the removal efficiencies of NO3- were 69.77%, 88.93%, 80.51%, 36.17% and 2.47%, respectively; the removal efficiencies of NH4+ were 55.95%, 96.71%, 38.11%, 20.71% and 7.43%, respectively. This study provides a method for mitigating the toxicity of CuO-NPs on functional microorganisms.

Submitted by Allan de Marcos Lapaz (a.lapaz@unesp.br) on 2020-01-20T13:51:00Z No. of bitstreams: 1 _DISSERTAÇÃO - ALLAN DE MARCOS LAPAZ.docx: 15242520 bytes, checksum: b93ea81cc98dce86a259a86f917bad43 (MD5) Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2020-01-27T11:54:00Z (GMT) No. of bitstreams: 1 lapaz_am_me_ilha_ressalva.pdf: 4527 bytes, checksum: 5f96f8eb21272770da0a07ee6addc728 (MD5) Made available in DSpace on 2020-01-27T11:54:01Z (GMT). No. of bitstreams: 1 lapaz_am_me_ilha_ressalva.pdf: 4527 bytes, checksum: 5f96f8eb21272770da0a07ee6addc728 (MD5) Previous issue date: 2019-12-17 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O encharcamento do solo é um problema comum em algumas áreas agricultáveis, inclusive em regiões sob cultivo de soja (Glycine max). Em solos encharcados, ocorre a depleção de O2 do solo pelos microrganismos aeróbicos e plantas, afetando os processos metabólicos e fisiológicos das plantas após sofrerem anoxia no tecido radicular. Outro fator prejudicial neste contexto, é o aumento exponencial da disponibilidade de ferro (Fe) no solo, o que pode resultar na absorção excessiva do Fe pelas plantas. No primeiro experimento, o objetivo foi avaliar a vulnerabilidade do aparato fotossintético e produção de biomassa de duas cultivares de soja no estágio fenológico V2, sob condição hídrica adequada e diferentes níveis de encharcamento do solo associada a uma concentração moderada e duas concentrações tóxicas de Fe. No segundo experimento, o objetivo foi avaliar o comportamento fisiológico e bioquímico da soja cultivar Agroeste 3680 associado ao desenvolvimento das vagens (estágio fenológico R3) sob solo não encharcado e encharcado combinado com uma concentração moderada e duas concentrações tóxicas de Fe. No primeiro experimento, o aparato fotossintético das cultivares de soja responderam diferentemente ao encharcamento e à disponibilidade de Fe no solo. Ambas cultivares foram vulneráveis ao encharcamento de 100% em todas as concentrações Fe, o que resultou em danos acentuados às trocas gasosas, concentração de clorofilas e, consequentemente, levou à diminuição da biomassa seca da parte aérea e da raiz. O desempenho fotossintético e a produção de biomassa seca do Agroeste 3680 não foram afetados quando expostos a concentrações moderadas de Fe associadas ao encharcamento de 50%. A cultivar NS 6601 IPRO apresentou tolerância moderada ao Fe quando não cultivada em solo encharcado, uma vez que a taxa de assimilação de CO2, a eficiência instantânea da carboxilação e a concentração da clorofila a não foram afetadas. No segundo experimento, as trocas gasosas foram fortemente afetadas pelo encharcamento do solo. O excesso de Fe sem encharcamento do solo reduziu os pigmentos fotossintéticos e potencializou a redução quando associado ao encharcamento do solo. O acúmulo de amido e ureídeos no primeiro trifólio totalmente expandido podem ser considerados biomarcadores eficientes para indicar a fitotoxicidade causada pelo encharcamento do solo e excesso de Fe em plantas de soja. O comportamento da biomassa seca das vagens revelou que o desenvolvimento reprodutivo é bruscamente interrompido com a imposição dos estresses, principalmente sob efeito do encharcamento do solo, o que se deve em grande parte à diminuição substancialmente da A, ao bloqueio no transporte de carboidratos para os tecidos drenos e ao aumento de MDA. Soil waterlogging is a common problem in some agricultural areas, including regions under soybean (Glycine max) cultivation. In waterlogged soils, soil O2 depletion occurs due to aerobic microorganisms and plants, affecting the metabolic and physiological processes of plants after suffering anoxia in their root tissue. Another harmful factor of this situation is the exponential increase in the availability of iron (Fe) in the soil, which may result in excessive Fe uptake by plants. In the first experiment, the objective was to evaluate the vulnerability of the photosynthetic apparatus and biomass production of two soybean cultivars at the phenological stage V2, under optimal water condition and different levels of soil waterlogging, combined with one moderate and two toxic levels of Fe. While in the second experiment, the objective was to evaluate the physiological and biochemical behaviour of soybean cultivar Agroeste 3680, associated with the development of pods (at the phenological stage R3) in non-waterlogged and waterlogged soil, combined with one moderate and two toxic levels of Fe. In the first experiment, the photosynthetic apparatus of the two soybean cultivars responded differently to waterlogging and the availability of Fe in the soil. Both cultivars were vulnerable to waterlogging of 100% at all concentrations Fe, which resulted in damage to gas exchange and chlorophyll levels, and consequently, led to lower shoot and root biomass accumulation. The photosynthetic performance and dry biomass production of Agroeste 3680 were not affected when exposed to moderate levels of Fe associated with waterlogging of 50%. NS 6601 IPRO cultivar also showed a moderate tolerance to excess Fe when not waterlogged, since net photosynthetic rate, instantaneous carboxylation efficiency and chlorophyll a content were not affected. In the second experiment, gas exchange was strongly affected by soil waterlogging. Excess Fe without soil waterlogging reduced photosynthetic pigments, and potentiated this reduction when associated with soil waterlogging. Starch and ureides accumulated in the first newly expanded trifoliate leaves could be considered efficient biomarkers, indicating phytotoxicity caused by soil waterlogging and Fe excess in soybean plants. Thus, this finding can be used as a parameter to identify tolerable varieties to these abiotic conditions. The reproductive development was abruptly interrupted by the imposition of the stresses, leading to loss of pod dry biomass, particularly under soil waterlogging, which was largely due to the substantial decrease in A, the blockage of carbohydrate transport to sink tissues and an increase of MDA. FAPESP: 18 / 17380-4 CAPES: 001

p-Anisidine being a component of wastewater generated through dye and pharmaceutical industries is highly toxic and carcinogenic in nature. Therefore, its presence in wastewater requires prior treatment before its disposal from the point of safety of human and aquatic life. Fenton’s oxidation is a type of advanced oxidation processes which is efficient, ecofriendly and reliable, and this was not studied for the removal of p-anisidine from wastewater. In this study, the effect of influent pH, hydrogen peroxide (H2O2) concentration and ferrous ion (Fe2+) concentration on the removal of p-anisidine by Fenton’s reagent was carried out on a laboratory scale. All samples were examined for initial and final concentrations of p-anisidine using UV–Vis spectrophotometry, and also initial and final COD was analyzed. p-Anisidine shows maximum absorbance at 296 nm. At pH 2.5 and [H2O2]/[Fe2+] of 70:1 for the initial p-anisidine concentration of 0.5 mM and for 24 h reaction time, the maximum removal of p-anisidine was found to be 88.95% and maximum COD removal was 76.43%.

Aroma deterioration is one of the biggest problems in processing tea beverages. The aroma of tea infusion deteriorates fast during heat sterilization and the presence of ferrous ion (Fe2+) aggravates it. The underlying mechanism remains unveiled. In this study, Fe2+ was verified to deteriorate the aroma quality of green tea infusion with heat treatment. Catechins were necessary for Fe2+-mediated aroma deterioration. By enhancing the degradation of catechins, Fe2+ dramatically increased the production of hydrogen peroxide (H2O2). Fe2+ and H2O2 together exacerbated the aroma of green tea infusion with heat treatment. GC-MS analysis revealed that the presence of Fe2+ enhanced the loss of green/grassy volatiles and promoted the formation of new volatiles with diversified aroma characteristics, resulting in a dull scent of green tea infusion. Our results revealed how Fe2+ induced aroma deterioration of green tea infusion with heat treatment and could help guide tea producers in attenuating the aroma deterioration of tea infusion during processing.

The transformation between hexavalent chromium (Cr6+) and trivalent chromium (Cr3+) has a significant impact on ecosystems, as Cr6+ has higher levels of toxicity than Cr3+. In this regard, a variety of Cr6+ reduction processes occurring in natural environments have been studied extensively. In this work, we investigate the reductive transformation of Cr6+ by ferrous ions (Fe2+) in ice at −20 °C, and compare the same process in water at 25 °C. The Fe2+-mediated reduction of Cr6+ occurred much faster in ice than it did in water. The accelerated reduction of Cr6+ in ice is primarily ascribed to the accumulation of Cr6+, Fe2+, and protons in the grain boundaries formed during freezing, which constitutes favorable conditions for redox reactions between Cr6+ and Fe2+. This freeze concentration phenomenon was verified using UV–visible spectroscopy with o-cresolsulfonephthalein (as a pH indicator) and confocal Raman spectroscopy. The reductive transformation of Cr6+ (20 µM) by Fe2+ in ice proceeded rapidly under various Fe2+ concentrations (20–140 µM), pH values (2.0–5.0), and freezing temperatures (–10 to −30 °C) with a constant molar ratio of oxidized Fe2+ to reduced Cr6+ (3:1). This result implies that the proposed mechanism (i.e., the redox reaction between Cr6+ and Fe2+ in ice) can significantly contribute to the natural conversion of Cr6+ in cold regions. The Fe2+-mediated Cr6+ reduction kinetics in frozen Cr6+-contaminated wastewater was similar to that in frozen Cr6+ solution. This indicates that the variety of substrates typically present in electroplating wastewater have a negligible effect on the redox reaction between Cr6+ and Fe2+ in ice; it also proposes that the Fe2+/freezing process can be used for the treatment of Cr6+-contaminated wastewater.

Extensive use of CuO nanoparticles (CuO-NPs ) inevitably leads to their accumulation in wastewater and toxicity to microorganisms that effectively treat nitrogen pollution. Due to the effects of different mediums, the sources of CuO-NPs-induced toxicity to microorganisms and methods to mitigating the toxicity are still unclear. In this study, CuO-NPs were found to impact the nitrate reduction of Pseudomonas tolaasii Y-11 mainly through the action of NPs themselves while inhibiting the ammonium transformation of strain Y-11 through releasing Cu2+. As the content of CuO-NPs increased from 0 to 20 mg/L, the removal efficiency of NO3− and NH4+ decreased from 42.29% and 29.83% to 2.05% and 2.33%, respectively. Exogenous Fe2+ significantly promoted the aggregation of CuO-NPs, reduced the possibility of contact with bacteria, and slowed down the damage of CuO-NPs to strain Y-11. When 0.01 mol/L Fe2+ was added to 0, 1, 5, 10 and 20 mg/L CuO-NPs treatment, the removal efficiencies of NO3- were 69.77%, 88.93%, 80.51%, 36.17% and 2.47%, respectively; the removal efficiencies of NH4+ were 55.95%, 96.71%, 38.11%, 20.71% and 7.43%, respectively. This study provides a method for mitigating the toxicity of CuO-NPs on functional microorganisms.

Selama proses fermentasi bioetanol, ragi Saccharomyces cerevisiae terpapar berbagai cekaman lingkungan. Ion logam yang berpotensi untuk meningkatkan kinerja fermentasi dan toleransi sel terhadap cekaman ialah ion logam besi II (Fe2+) yang berperan sebagai kofaktor dalam berbagai proses metabolisme. Tujuan dari penelitian ini adalah mempelajari pengaruh suplementasi ion Fe2+ dalam media fermentasi terhadap kinerja fermentasi, serta toleransi sel ragi terhadap cekaman etanol, oksidatif, asam lemah dan tekanan osmotik. Penelitian diawali dengan melakukan fermentasi glukosa menggunakan S. cerevisiae A12 selama 120 jam dengan pengambilan sampel dengan interval waktu 6 jam untuk 24 jam pertama serta 12 jam untuk sisanya. Masing-masing sampel ditentukan nilai OD600nm, persentase sel hidup, jumlah sel hidup, kadar glukosa, kadar etanol. Pada jam ke 24, sel diuji daya tahannya terhadap cekaman. Hasil penelitian menunjukkan bahwa suplementasi ion logam Fe2+ hanya mampu meningkatkan laju produksi etanol, tetapi tidak mempengaruhi parameter lain.During bioethanol fermentation process, Saccharomyces cerevisiae yeast cells are exposed to various environmental stress factors. One of metal ions that have potency for improving fermentation performance and yeast stress tolerance is ferrous ion (Fe2+) that acts as cofactors in various metabolism process. The present study was directed to investigate the effect of ferrous ion supplementation to the fermentation media on fermentation performance, improving yeast stress tolerance against ethanol, oxidative, weak acid and hyperosmotic stresses. The fermentation was conducted by fermenting glucose using S. cerevisiae strain A12 for 120 hours. The sampling was performed every 6 hours during the first 24 hours and 12 hours for the rest of fermentation. The sample was examined for their OD600nm, total cell number, viable cell number, glucose content and ethanol content. At 24 hours the cell was examined for their stress tolerance. The result of the present study indicates that supplementation using ferrous ion improve the rate of ethanol production, but not other parameters.

The ability of ferrous chelates including hairtail protein hydrolysates to prevent and reduce fatigue was studied in rats. After hydrolysis of hairtail surimi with papain, the hairtail protein hydrolysates (HPH) were separated into three groups by range of relative molecular weight using ultrafiltration membrane separation. Hairtail proteins were then chelated with ferrous ions, and the antioxidant activity, the amino acid composition and chelation rate of the three kinds of ferrous chelates including hairtail protein hydrolysates (Fe-HPH) were determined. Among the three groups, the Fe-HPH chelate showing the best conditions was selected for the anti-fatigue animal experiment. For it, experimental rats were randomly divided into seven groups. Group A was designated as the negative control group given distilled water. Group B, the positive control group, was given glutathione. Groups C, D and E were designated as the Fe-HPH chelate treatment groups and given low, medium, and high doses, respectively. Group F was designated as HPH hydrolysate treatment group, and Group G was designated as FeCl2 treatment group. The different diets were orally administered to rats for 20 days. After that time, rats were subjected to forced swimming training after 1 h of gavage. Rats given Fe-FPH chelate had higher haemoglobin regeneration efficiency (HRE), longer exhaustive swimming time and higher SOD activity. Additionally, Fe-FPH chelate was found to significantly decrease the malondialdehyde content, visibly enhance the GSH-Px activity in liver and reduce blood lactic acid of rats. Fe-HPH chelate revealed an anti-fatigue effect, similar to or better than the positive control substance and superior to HPH or Fe when provided alone.

The synthesis of iron oxide nanoparticles, i.e., magnetite was attempted by using only ferrous ion (Fe2+) as a magnetite precursor, under an ambient atmosphere. The room temperature reverse co-precipitation method was used, by applying two synthesis protocols. The freshly prepared iron oxide was also immediately coated with Stober silica (SiO2) layer, forming the coreshell structure. The phase, stoichiometry, crystallite and the particle size of the synthesized powders were determined by using X-ray diffraction (XRD) and transmission electron microscope (TEM), while the magnetic and oxidation behaviors were studied by using the vibrating sample magnetometer (VSM) and Mossbauer spectroscopy. Based on the results, the bare iron oxide nanoparticles are in the stoichiometry between the magnetite and the maghemite stoichiometry, i.e., oxidation occurs. This oxidation is depending on the synthesis protocols used. With the silica coating, the oxidation can be prevented, as suggested by the fits of Mossbauer spectra and low temperature magnetic measurement.

International audience; In this study the activation of persulfate induced by Fe(III) species, including 5 kinds of iron oxhydroxides (IOs) and dissolved Fe3+ under dark condition were investigated. Ferrihydrite (FH) and akaganeite (AK) showed the highest activity in 4-tert-butylphenol (4tBP) removal. The 4tBP degradation rate constant decreased as the solution pH increased from pH 3.2 to 7.8 in FH/S2O82- system. However, the pH value had no significant effect on the 4tBP degradation in AK/S2O82- system. The degradation of 4tBP in Fe3+/S2O82- system was also performed to investigate the role of ferric species in persulfate activation. The pH dependency of 4tBP degradation rate was closely related to the speciation of Fe-III, whereas the Fe(H2O)(6)(3+) was found to be the most active soluble iron complex form in the activation of S2O82-. 4tBP degradation was mainly due to the SO4 center dot- in IOs/S2O82- system, while SO4 center dot- and HO2 center dot both had great contribution on 4tBP degradation in Fe3+/S2O82- system. Further investigations showed clearly that 4tBP degradation efficiency was decreased significantly due to the trapping of SO4 center dot- by chloride. This finding may have promising implications in developing a new technology for the treatment of contaminated waters and soils, especially where Fe3+ species are naturally occurring.

Pyrazinamidase of Mycobacterium tuberculosis catalyzes the conversion of pyrazinamide to the active molecule pyrazinoic acid. Reduction of pyrazinamidase activity results in a level of pyrazinamide resistance. Previous studies have suggested that pyrazinamidase has a metal-binding site and that a divalent metal cofactor is required for activity. To determine the effect of divalent metals on the pyrazinamidase, the recombinant wild-type pyrazinamidase corresponding to the H37Rv pyrazinamide-susceptible reference strain was expressed in Escherichia coli with and without a carboxy terminal. His-tagged pyrazinamidase was inactivated by metal depletion and reactivated by titration with divalent metals. Although Co(2+), Mn(2+), and Zn(2+) restored pyrazinamidase activity, only Co(2+) enhanced the enzymatic activity to levels higher than the wild-type pyrazinamidase. Cu(2+), Fe(2+), Fe(3+), and Mg(2+) did not restore the activity under the conditions tested. Various recombinant mutated pyrazinamidases with appropriate folding but different enzymatic activities showed a differential pattern of recovered activity. X-ray fluorescence and atomic absorbance spectroscopy showed that recombinant wild-type pyrazinamidase expressed in E. coli most likely contained Zn. In conclusion, this study suggests that M. tuberculosis pyrazinamidase is a metalloenzyme that is able to coordinate several ions, but in vivo, it is more likely to coordinate Zn(2+). However, in vitro, the metal-depleted enzyme could be reactivated by several divalent metals with higher efficiency than Zn.

In this study, advanced oxidation technologies, namely Fenton Process (FP), Fenton-Like Process (FLP), ozonation (O-3) and O-3/H2O2 processes, were applied to synthetic wastewater containing 3-indolebutyric acid (IBA). The effectiveness of each process was investigated at different pH values, Fe+2, Fe+3, O-3 and H2O2 concentrations with respect to the removal efficiencies for chemical oxygen demand (COD) and total organic carbon (TOC). The best removal efficiencies were seen at pH 3 and 2 mM Fe concentration in both FP and FLP, in which the optimum H2O2 concentrations were 6 mM for FP and 10 mM for FLP. Optimum process conditions were pH 12 for the O-3 process, pH 9 for the O-3/H2O2 process and 1:1 O-3/H2O2 molar ratio. The highest COD removal efficiency was 86 percent, obtained in the O-3/H2O2 process and the highest TOC removal efficiency was obtained at 77 percent in the FP. Water Environ. Res., 84, 100 (2012).

La producción de etanol por fermentación es influenciada por la presencia de iones metálicos como hierro y zinc dado que son cofactores de la enzima alcohol deshidrogenasa. El estudio de este efecto permitiría identificar el comportamiento de los microorganismos fermentadores en sustratos industriales que contienen altas concentraciones de este tipo de iones. Este trabajo evaluó la producción de biomasa, los azúcares residuales y la producción de etanol por fermentación de tres cepas de S. cerevisiae, CBS8066, recombinantes GG570-CIBI y GG570-CIBII, bajo el efecto de la adición de hierro a 0, 50 y 150 M, y zinc a 0 y 50 M. Las cepas presentaron inhibición en la producción de biomasa y etanol bajo efecto de iones de hierro y zinc, siendo dicha inhibición mayor al estar en presencia de zinc o alta concentración de hierro. GG570-CIBI mostró disminución en producción de biomasa de 4 g/L y una caída en producción de etanol de 40% en el tratamiento 150 M hierro-50 M zinc (con respecto al tratamiento basal). GG570-CIBII fue la menos afectada con inhibición en la producción de etanol inferior a 11% a las 20 h de fermentación. Adicionalmente, presentó la mayor producción de etanol cuando hubo adición de 150 M Fe con o sin adición de zinc, siendo dicha producción entre un 9 y 14% superior a la de las cepas CBS8066 y GG570-CIBI respectivamente, bajo las mismas condiciones. Posteriormente, GG570-CIBII será evaluada en sustratos industriales debido a su menor inhibición en la producción de etanol, permitiendo así obtener mejores rendimientos. Palabras clave: gen pdc, gen adhII, Zymomonas mobilis, ión ferroso, ión zinc. ABSTRACT: The ethanol production by fermentation is influenced by the presence of metallic ions like iron and zinc because these are alcohol dehydrogenase enzyme cofactors. The study of this effect would allow for identifying the behavior of microorganisms in industrial substrates that contain high concentrations of this kind of ions. This work evaluated biomass production, residual sugars and ethanol production by fermentation of three S. cerevisiae strains, CBS8066, recombinants GG570-CIBI and GG570-CIBII, under the effect of the addition of ferrous ion at 0, 50 and 150 M and zinc ion at 0 and 50 M. The strains showed inhibition on biomass and ethanol production under the effect of zinc and ferrous ions, however, this inhibition was greater in the presence of zinc or iron at high concentration. GG570-CIBI showed reduction in biomass production of 4 g/L and an ethanol production drop of 40 % in the treatment 150 M iron–50 M zinc (with respect to the basal treatment). GG570-CIBII was the less affected with an inhibition on ethanol production below 11 % at 20 h of fermentation. Additionally, GG570-CIBII presented the greatest ethanol production when 150 M iron was added to the culture medium with or without zinc addition. In this case, the production was 9 and 14 % greater than ethanol production of CBS8066 and GG570-CIBI respectively, at the same conditions. Later, GG570-CIBII will be evaluated in industrial substrates due to its lower ethanol production inhibition, allowing for obtaining better yields. Key word: pdc gene, adhII gene, Zymomonas mobilis, ferrous ion, zinc ion.

The members of Scutellaria L. (Lamiaceae) is known to be rich particularly in flavonoids and among them, S. baicalensis has been recorded to be used for memory-enhancing purpose. Therefore, we initiated a study to screen the methanol extracts prepared from the aerial parts of 33 Turkish Scutellaria species for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, which are the key enzymes taking place in pathogenesis of Alzheimer's disease. Besides, the methanol extracts were tested in vitro against another enzyme, tyrosinase, which is associated with melanin hyperpigmentation. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenger effect, ferrous ion-chelating ability, and ferric-reducing antioxidant power (FRAP) of the ethyl acetate and methanol extracts were also determined. AChE, BChE, and tyrosinase inhibition of the extracts were performed on ELISA microplate reader by spectrophotometric method. The extracts showed weak inhibition against AChE and BChE, while the best tyrosinase inhibition was caused by the methanol extract of S. brevibracteata subsp. subvelutina. The extracts had a very high DDPH radical scavenging effect and moderate antioxidant activity in ferrous ion-chelating and FRAP tests. (C) 2009 Elsevier Ltd. All rights reserved.

In this research the phenolic composition, and antioxidant, antibacterial and cytotoxic activities of the methanolic extracts obtained from three Alyssum L. taxa (A. foliosum var. megalocarpum, A. simplex and A. strigosum subsp. strigosum) were investigated for the first time. The antioxidant activity of the extracts was evaluated by DPPH, metal chelating, phosphomolybdenum, ß-carotene/linoleic acid and ferric reducing power assays. In addition, total phenolic and flavonoid contents in the extracts were determined. The brine shrimp lethality test was used to screen for possible cytotoxic activity of the extracts. Also, the extracts were evaluated for cytotoxicity against three human cancer cell lines: MCF-7, H1299 and HeLa. HPLC analysis showed that cinnamic acid, chlorogenic acid and rutin were the major phenolics in extracts tested. Among the three Alyssum extracts evaluated, the highest biological activities were obtained from A. simplex compared to other two Alyssum L. taxa. Based upon its name, future studies will be targeted at investigating which components can be caused neurorehabilitation in Alyssum. © 2016, Polish Pharmaceutical Society. All rights reserved.

金沢大学理工研究域機械工学系, Wastewater from electroplating plants contains several metallic ions such as iron, nickel and zinc. In general, neutralization followed by sedimentation has been used for the treatment of electroplating wastewater. However, this process results in the production of large amounts of heavy metal sludge. The objective of this research is to achieve selective metal separation, metal recovery and reduction in sludge volume. We have examined the feasibility of a biological process using iron-oxidizing bacteria in the treatment of electroplating wastewater from steel works. It was proved that iron-oxidizing bacteria acclimated from activated sludge have the ability to oxidize ferrous ion (Fe2+) to ferric ion (Fe3+) in electroplating wastewater. A bioslurry reactor, which promotes both Fe2+ oxidation and Fe(OH)3 generation in the pH range from 3.0 to 4.0, showed an almost complete Fe2+ oxidization after 2 hours of hydraulic retention time. The produced Fe(OH)3 was recovered by sedimentation in the same pH range with almost no trace of nickel or zinc. Nickel and zinc hydroxides were easily recovered by sedimentation at pH 9.0.

A microcontrolled, portable and inexpensive photometer is described. It uses six light-emitting diodes (LEDs) as radiation sources and a phototransistor as detector, as well as a microcontroller (PIC - Programmable Controller of Interruption). This device provided total autonomy to the proposed photometer, which was successfully applied to determination of Fe2+ in ferrous syrups and of seven clinical biochemical parameters. As the components are cheap (~U$30.00) and easy to find, the proposed photometer is an economical alternative for routine chemical analyses in small laboratories, for research and teaching. Being portable and microcontrolled, it allows doing field chemical analyses.

An undecasubstituted chloroiron corrolate, octamethyltriphenylcorrolatoiron chloride, (OMTPCorr)FeCl, has been synthesized and studied by X-ray crystallography and (1)H and (13)C NMR spectroscopy. It is found that, although the structure is slightly saddled, the average methyl out-of-plane distance is only 0.63 Angstroms, while it is much greater for the dodecasubstituted porphyrinate analogue (OMTPP)FeCl (1.19 Angstroms) (Cheng, R.-J.; Chen, P.-Y.; Gau, P.-R.; Chen, C.-C.; Peng, S.-M. J. Am. Chem. Soc. 1997, 119, 2563-2569). In addition, the distance of iron from the mean plane of the four macrocycle nitrogens is also smaller for (OMTPCorr)FeCl (0.387 Angstroms) than for (OMTPP)FeCl (0.46 Angstroms). The (1)H and (13)C NMR spectra of (OMTPCorr)FeCl, as well as the chloroiron complexes of triphenylcorrolate, (TPCorr)FeCl; 7,13-dimethyl-2,3,8,12,17,18-hexaethylcorrolate, (DMHECorr)FeCl; 7,8,12,13-tetramethyl-2,3,17,18-tetraethylcorrolate, (TMTECorr)FeCl; and the phenyliron complex of 7,13-dimethyl-2,3,8,12,17,18-hexaethylcorrolate, (DMHECorr)FePh, have been assigned, and the spin densities at the carbons that are part of the aromatic ring of the corrole macrocycle have been divided into the part due to spin delocalization by corrole --Fe pi donation and the part due to the unpaired electron present on the corrole ring. It is found that although the spin density at the beta-pyrrole positions is fairly similar to that of (TPCorr)FeCl, the meso-phenyl-carbon shift differences delta(m) - delta(p) are opposite in sign of those of (TPCorr)FeCl. This finding suggests that the radical electron is ferromagnetically coupled to the unpaired electrons on iron, rather than antiferromagnetically coupled, as in all of the other chloroiron corrolates. The solution magnetic moment was measured for (OMTPCorr)FeCl and found to be mu(eff) = 4.7 +/- 0.5 micro(B), consistent with S = 2 and ferromagnetic coupling. From this study, two conclusions may be reached about iron corrolates: (1) the spin states of chloroiron corrolates are extremely sensitive to the out-of-plane distance of iron, and (2) pyrrole-H or -C shifts are not useful in delineating the spin state and electron configuration of (anion)iron corrolates.

The kinetics of the electrolytic Fe+2/Fe+3 oxidation, relevant to hydro-electrometallurgical processing, have been studied on lead, platinum, ruthenium oxide, iridium oxide and graphite anodes in ferrous sulfate-sulfuric acid solutions. The oxidation rate depends on ferrous sulfate concentration, solution temperature and degree of agitation. Potentiodynamic studies show that: a) the highest oxidation rate is obtained on platinum; b) lead is unsuitable as anodic material for the said reaction; c) the remaining anode materials show a similar and satisfactory performance.Se ha estudiado la cinética de la oxidación electrolítica Fe+2/Fe+3 -relevante para el procesamiento hidroelectrometalúrgico- sobre plomo, platino, óxido de rutenio, óxido de iridio y grafito en soluciones de sulfato ferroso en ácido sulfúrico. La velocidad de oxidación depende de la concentración de sulfato ferroso, la temperatura de la solución y el grado de agitación. Estudios potenciodinámicos demuestran que: a) las mayores velocidades de oxidación se obtienen sobre platino; b) el plomo es inadecuado como material anódico para la reacción mencionada; c) los materiales anódicos restantes exhiben un desempeño similar y satisfactorio.

Among advanced oxidation processes (AOPs), the photo chemically enhanced Fenton reaction (photo-Fenton) may be particularly effective for the treatment of industrial wastewater. In the present work, ferrous sulphate/ferrioxalate with H2O2 and ZnO particles was tested as a combined homogeneous and heterogeneous photo-Fenton process for the degradation of the model organic pollutant, benzyl alcohol. Enhancement in the photo-Fenton processes has been observed by the addition of ZnO. UV/ferrous/H2O2/ZnO and UV/ferrioxalate/H2O2/ZnO processes are found to be more efficient than the individual photo-Fenton and UV/ZnO processes. The use of ferrioxalate in the combined process is found to be more advantageous. The effect of various experimental parameters such as pH, initial H2O2, Fe2+, Fe3+, ZnO and pollutant concentrations on these combined photocatalytic process have been investigated. All these parameters strongly influenced the removal rate. The efficiency of chemical oxygen demand (COD) removal was tested. The optimum operating conditions of these combined processes are reported.

We describe the design, synthesis, and "stimuli-responsive" study of ferrocene-linked Fr�chet-type [poly(aryl ether)]-dendron-based organometallic gels, in which the ferrocene moiety is attached to the dendron framework through an acyl hydrazone linkage. The low-molecular-weight gelators (LMWGs) form robust gels in both polar and non-polar solvent/solvent mixtures. The organometallic gels undergo stimuli-responsive behavior through 1) thermal, 2) chemical, and 3) electrochemical methods. Among them, conditions 1 and 3 lead to seamlessly reversible with repeated cycles of identical efficiency. Results indicate that the flexible nature of the poly(aryl ether) dendron framework plays a key role in retaining the reversible electrochemical behavior of ferrocene moiety in the LMWGs. Further, the organometallic gelators have exhibited unique selectivity towards Pb2+ ions (detection limit ?10-8 M). The metal ion-sensing results in a gel-sol phase transition associated with a color change visible to the naked eye. Most importantly, decomplexing the metal ion from the system leads to the regeneration of the initial gel morphology, indicating the restoring ability of the organometallic gel. The metal-ligand binding nature has been analyzed by using 1H NMR spectroscopy, mass spectrometry, and DFT calculations. Receptive dendritic gelators: Ferrocene-containing poly(aryl ether) dendron based low-molecular-weight organometallic gels exhibit multi-stimuli-responsive behavior under thermal, chemical, and electrochemical conditions, and in also presence of Pb2+ ions. Results suggest the reversible thermal and redox switching of the gel, in addition to its ability to sense Pb2+ ions with restorable tendency (see figure). � 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Infectious mononucleosis is caused by Epstein-Barr virus, and is rarely seen in infancy. Clinical findings include exudative tonsillitis, generalized or cervical lymphadenopathy, and hepatosplenomegaly. Many complications can arise, but these rarely include facial paralysis. We reported a 19-month-old patient who developed facial paralysis secondary to infectious mononucleosis. © 2006 Elsevier Ireland Ltd. All rights reserved.

Background Fenton reaction (Fe2++H2O2→Fe3++•OH+OH−) is of special significance in the thyroid gland, as both its substrates, i.e. H2O2 and Fe2+, are required for thyroid hormone synthesis. Also iodine, an essential element supplied by the diet, is indispensable for thyroid hormone synthesis. It is well known that iodine affects red-ox balance. One of the most frequently examined oxidative processes is lipid peroxidation (LPO), which results from oxidative damage to membrane lipids. Fenton reaction is used to experimentally induce lipid peroxidation. The aim of the study was to evaluate effects of iodine, used as potassium iodide (KI) or potassium iodate (KIO3), on lipid peroxidation in porcine thyroid homogenates under basal conditions and in the presence of Fenton reaction substrates. Methods Porcine thyroid homogenates were incubated in the presence of either KI (0.00005 – 500 mM) or KIO3 (0.00005 – 200 mM), without or with addition of FeSO4 (30 μM) + H2O2 (0.5 mM). Concentration of malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) was measured spectrophotometrically, as an index of lipid peroxidation. Results Potassium iodide, only when used in the highest concentrations (≥50 mM), increased lipid peroxidation in concentration-dependent manner. In the middle range of concentrations (5.0; 10; 25; 50 and 100 mM) KI reduced Fenton reaction-induced lipid peroxidation, with the strongest protective effect observed for the concentration of 25 mM. Potassium iodate increased lipid peroxidation in concentrations ≥2.5 mM. The damaging effect of KIO3 increased gradually from the concentration of 2.5 mM to 10 mM. The strongest damaging effect was observed at the KIO3 concentration of 10 mM, corresponding to physiological iodine concentration in the thyroid. Potassium iodate in concentrations of 5–200 mM enhanced Fenton reaction-induced lipid peroxidation with the strongest damaging effect found again for the concentration of 10 mM. Conclusions Potassium iodide, used in doses generally recommended in iodide prophylaxis, may prevent oxidative damage to membrane lipids in this gland. Toxic effects of iodide overload may result from its prooxidative action. Potassium iodate does not possess any direct beneficial effects on oxidative damage to membrane lipids in the thyroid, which constitutes an additional argument against its utility in iodine prophylaxis.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:23Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:36:40Z : No. of bitstreams: 1 2-s2.0-84856478927.pdf: 528507 bytes, checksum: 9441d2c1fdb167554d5316a2709a405e (MD5) Made available in DSpace on 2014-05-27T11:26:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-01 Baccharis dracunculifolia DC (Asteraceae) is the main botanical source used by honeybees to produce Brazilian green propolis whose hepatoprotective properties have been already described. In this work we investigated the protective effects of the glycolic extract of B. dracunculifolia (GEBd) against oxidative stress in isolated rat liver mitochondria (RLM). The GEBd was prepared by fractionated percolation using propylene glycol as solvent. The total phenols and flavonoids, which are substances with recognized antioxidant action, were quantified in GEBd and the phytochemical analysis was carried out by HPLC. GEBd exhibited significant scavenger activity towards DPPH radicals and superoxide anions in a concentration-dependent manner, and also a Fe 2+ chelating activity. GEBd decreased the basal H 2O 2 generation and the Fe 2+- or t-BuOOH-induced ROS production in isolated mitochondria. Lipid oxidation of mitochondrial membranes, protein thiol groups and GSH oxidation were also prevented by GEBd. This shows that B. dracunculifolia exhibit potent antioxidant activity protecting liver mitochondria against oxidative damage and such action probably contribute to the antioxidant and hepatoprotective effects of green propolis. © 2011 Elsevier Ltd. Centro Interdisciplinar de Investigação Bioquímica (CIIB) Universidade de Mogi das Cruzes (UMC) Research, Development and Innovation Laboratory of Apis Flora Indl. Coml. Ltda. Instituto de Química Universidade Estadual Paulista (UNESP) Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP/USP) Departamento de Bioquímica Universidade Federal de São Paulo (UNIFESP) Centro de Ciências Naturais e Humanas (CCNH) Universidade Federal do ABC (UFABC) Instituto de Química Universidade Estadual Paulista (UNESP)

[EN] A new selective chromo-fluorogenic probe for Fe 3+, Cr 3+ and Al 3+ is reported. Detection limits are in the ¿M range and the fluorogenic sensing ability could be observed by the naked eye when illuminated with UV-light. No response is observed with divalent cations. © 2012 The Royal Society of Chemistry., AECID (A/026355109), DGICYT (projects MAT2009-14564-C01 and MAT 2009-14564-C04-3) and Generalitat Valenciana (project PROMETEO/2009/016) are gratefully acknowledged. A.B.B. thanks MICINN for a pre-doctoral FPI fellowship.

Using first-principles molecular-dynamics simulations, probable inner-sphere complexes of Fe adsorbed on the edge surfaces of clay minerals were investigated. Ferrous ions are important reductants in natural processes and their properties can be altered significantly by complexation on edge surfaces of clay minerals. However, the microscopic picture of adsorption sites and structures of Fe is difficult to reveal with modern experimental techniques and, therefore, remains unclear. From the results of first-principles molecular-dynamics simulations, evidence has been provided that complexes on:Si-O sites were the most stable forms, which should be responsible for the experimentally observed pHdependent uptake. Such complexation was found to be strong enough to distort the local coordination structures of Si-O tetrahedra in the substrate. Analyses showed that Fe-O coordination structures were dominated by the solvent with surface groups participating in the complexes via H bonding. The present study provided a microscopic basis for understanding the chemical processes involving surfacecomplexed Fe ions.

The oxidation of Fe 2+ in uranium leaching solutions with gaseous mixture of SO 2 and air has been studied. The variables studied include H 2SO 4 concentration, temperature, SO 2 concentration and time. The oxidation rate was founded to increase greatly with an increase in the solution temperature. The almost total oxidation of Fe 2+ is readily achieved at 95 °C. By appropriately adjusting the temperature of solution and SO 2/O 2 in the gas, oxidation of ferrous ion and generation of sulphuric acid can be carried out. It was founded that solutions produced by such oxidation processing are very suitable for the uranium ore leaching. © 2012 Akadémiai Kiadó, Budapest, Hungary.

The synthesis, electrochemical, optical, and metal-cation-sensing properties of ferrocene-glycine conjugates C 30H 38O 8N 8Fe (2) and C 20H 24O 4N 4Fe (3) have been documented. Both compounds 2 and 3 behave as very selective redox (?E 1/2 = 217 mV for 2 and ?E 1/2 = 160 mV for 3), chromogenic, and fluorescent chemosensors for Hg 2+ cations in an aqueous environment. The considerable changes in their absorption spectra are accompanied by the appearance of a new low-energy peak at 630 nm (2, ? = 1600 M -1 cm -1; 3, ? = 822 M -1 cm -1). This is also accompanied by a strong color change from yellow to purple, which allows a prospective for the "naked eye" detection of Hg 2+ cations. These chemosensors present immense brightness and fluorescence enhancement (chelation-enhanced fluorescence = 91 for 2 and 42 for 3) following Hg 2+ coordination within the limit of detection for Hg 2+ at 7.5 parts per billion. � 2011 American Chemical Society.

Mitochondrial lipid peroxidations were usually detected by the thiobarbituric acid (TBA) color reaction under the acidic conditions with hydrochloric and trichloroacetic acids. The time response curve of Fe(2+)-induced lipid peroxidation, accompanied the lag time of induction period, of mouse liver mitochondria was measured with detection of the produced lipid peroxides by the TBA method under the acidic conditions with acetic acid. Fe(2+)-induced lipid peroxidation was terminated by the addition of ethylenediaminetetraacetate (EDTA). The lag time of the peroxidation detected by TBA method in the acetic acid conditions was obtained as well as that detected in the hydrochloric and trichloroacetic acids conditions. The fact indicates that Fe(2+)-induced lipid peroxidation of mitochondria and its lipid peroxides are able to be measured by the TBA color reaction in the acetic acid conditions with EDTA.

This paper presents an experimental study of calcium bisulfite oxidation, a key step in the wet limestone-gypsum flue gas desulfurization (FGD) process, in the presence of catalysts (e.g., cobalt ions and a mixture of ferrous and cobalt ions). A fundamental approach is followed, by reproducing a simplified synthetic FGD liquor in which both catalyst ions, alone or mixed together, are present. A laboratory-scale apparatus is used, in which sulfurous solution is contacted with a gas phase at a fixed oxygen partial pressure (21.3 kPa) and at different temperature levels (25, 45, and 55 degrees C). The experimental results are analyzed using the theory of gas-liquid mass transfer with chemical reaction, showing that the slow reaction regime is explored and the transition from the kinetic to the diffusional subregime is identified. The experimental results are compared with those obtained in the presence of other catalytic species (manganese and ferrous ions), showing that cobalt is effective in catalyzing the oxidation of calcium bisulfite to sulfate, but to a minor extent with respect to iron and manganese.

La producción de etanol por fermentación es influenciada por la presencia de iones metálicos como hierro y zinc dado que son cofactores de la enzima alcohol deshidrogenasa. El estudio de este efecto permitiría identificar el comportamiento de los microorganismos fermentadores en sustratos industriales que contienen altas concentraciones de este tipo de iones. Este trabajo evaluó la producción de biomasa, los azúcares residuales y la producción de etanol por fermentación de tres cepas de S. cerevisiae, CBS8066, recombinantes GG570-CIBI y GG570-CIBII, bajo el efecto de la adición de hierro a 0, 50 y 150 µM, y zinc a 0 y 50 µM. Las cepas presentaron inhibición en la producción de biomasa y etanol bajo efecto de iones de hierro y zinc, siendo dicha inhibición mayor al estar en presencia de zinc o alta concentración de hierro. GG570-CIBI mostró disminución en producción de biomasa de 4 g/L y una caída en producción de etanol de 40% en el tratamiento 150 µM hierro-50 µM zinc (con respecto al tratamiento basal). GG570-CIBII fue la menos afectada con inhibición en la producción de etanol inferior a 11% a las 20 h de fermentación. Adicionalmente, presentó la mayor producción de etanol cuando hubo adición de 150 µM Fe con o sin adición de zinc, siendo dicha producción entre un 9 y 14% superior a la de las cepas CBS8066 y GG570-CIBI respectivamente, bajo las mismas condiciones. Posteriormente, GG570-CIBII será evaluada en sustratos industriales debido a su menor inhibición en la producción de etanol, permitiendo así obtener mejores rendimientos. Ethanol production by fermentation is influenced by the presence of metallic ions such as iron and zinc because these are alcohol dehydrogenase enzyme cofactors. Studying this effect leads to identifying the behaviour of microorganisms in industrial substrates containing high concentrations of these kinds of ions. This work therefore evaluated biomass production, residual sugars and ethanol production by fermenting three S. cerevisiae strains (CBS8066, recombinants GG570-CIBI and GG570-CIBII) under the effect of adding ferrous ion at 0, 50 and 150 µM and zinc ion at 0 and 50 µM. The strains had inhibited biomass and ethanol production when zinc and ferrous ions were added; such inhibition was greater in the presence of zinc or iron having higher concentrations. GG570-CIBI had 4 g/L reduction in biomass production and ethanol production dropped by 40% in the 150 µM iron-50 µM zinc treatment (compared to base treatment). GG570-CIBII was the less affected, having less than 11% inhibition of ethanol production at 20 h fermentation. GG570-CIBII presented the greatest ethanol production when 150 µM iron was added to the culture medium with or without adding zinc; in this case, production was 9% and 14% greater than CBS8066 and GG570-CIBI ethanol production, respectively, in the same conditions. GG570-CIBII will be evaluated later on using industrial substrates due to its lower ethanol production inhibition, thereby leading to better yields being obtained.

Serum lipid peroxides were measured by a thiobarbituric acid (TBA) method. TBA color reactions carried out under the conditions with acetic acid (TBA-AA) or hydrochloric acid (TBA-HCl) systems, and then TBA value was detected by colorimetric ([OD]) and fluorometric ([FR]) measurements. Effects of ferrous ion, ferric ion and EDTA on the both systems were examined. Equal TBA value dependent upon concentrations of MDA (tetraethoxypropane) were obtained on both systems detected by [OD], but the relative fluorescence of TBA-AA system was higher than that of TBA-HCl system. Fluorometric determination was suitable for low TBA value, and colorimetric one was for high TBA value. Good correlation between TBA[OD] values and TBA[FR] values of serum from patients was estimated, but it was suggested that effects of serum substance were differ on the both systems. Effects of iron on TBA-AA and TBA-HCl systems were different significantly, particularly high Fe-TBA values obtained from TBA-AA system in the presence of ferrous ion. The fact suggests that serum lipid peroxidation is induced by ferrous ion during a heating of TBA color reaction. Same effect of ferric ion in TBA-AA system was observed. The increment of TBA values by ferrous and ferric ions was inhibited by a addition of EDTA. It was considered that the difference effect of iron on the both systems was due to pH and acetic acid concentration. The relationship of TBA values and Fe-TBA values of serum from patients was no correlated, and the various inhibition ratios of EDTA for the TBA value was calculated. It is suggested that Fe-TBA value is possible to detemine the qualitative difference of serum lipid peroxides., 患者血清を試料に脂質過酸化物をTBA法を用い、酢酸酸性下(TBA－AA系）、塩酸酸性下（TBA-HCl系）で加熱反応させ、比色法（TBA[OD]値）と蛍光法（TBA[FR]値）で計測した。併せてFe(++)（Fe-TBA値）、Fe(+++)、EDTAの影響を検討した。両系においてMDAの検量を行った結果、TBA[OD]値は同一数値が得られたが、TBA[FR]値は異なって示された。低TBA値では蛍光法が、高TBA値では比色法が適している結果をみた。しかし、患者血清の定量からはTBA[OD]値、TBA[FR]値で相関は得られたものの、両測定方法に関与する血清内在因子の影響は異なることが示唆された。TBA-AA,TBA-HCl両系に対するFeの影響は異なり、特にTBA-AA系では著しいFe-TBA値が得られ、Fe誘導脂質過酸化反応が加熱発色反応中に誘起されていることが示されたが、EDTA添加でその誘導は抑制された。また、TBA-AA系ではFe(++),Fe(+++)で同様の影響がみられたが、TBA-HCl系では異なった影響がみられた。両系のTBA値、Fe-TBA値の相違の原因としてpH、酢酸の影響が考えられた。患者血清でTBA値とFe-TBA値に相関は得られず、Fe(++)誘導反応に相違がみられ、また、EDTAの抑制作用も血清試料で異なることから、Fe-TBA値で血清の質的な相違が計測できる可能性が示唆された。

The interaction of ferrocene- 1, 1' -dithiol (FDT) with two parallel Ag(111) surfaces has been theoretically studied at density-functional level. The effect of surface defects on the energetic and electronic structure was investigated. The electronic transport properties are studied with the nonequilibrium Green's function approach. The adsorption geometry has a strong effect on the electronic levels and conductivity. The presence of point defects strongly enhances the molecule-surface interaction but has a surprisingly small effect on the density of states near the Fermi energy. The FDT-surface bond is particularly strong near terraces or steps and leads to significant shifts of the molecular orbitals relative to the gas phase. For all considered defect types except the single adatom the electronic conductivity through the FDT molecule is decreased compared to adsorption on perfect surfaces. © 2008 American Institute of Physics.

Lipid hydroperoxides (LOOH) present even in traces, easily degrade under effects of different initiators including transition metals. In previous lipid peroxidation investigations, the ferrous addition to lipid systems caused the simultaneous production of hydroxyl and alkoxyl radicals, leading to the propagation of lipid oxidation process. Consequently, the individual steps in lipid peroxidation could not be distinguished. This was the reason for rather difficult interpretations and disagreements between the molecular mechanisms proposed for the different phases of peroxidation. We have established the simple model system which allows the selective study of the propagation of lipid peroxidation. Mixed micelles formed from nonionic surfactant (Tween 20) and polyunsaturated fatty acids (PUFA) have been used as a model system in which autoxidation of ferrous ions and thereby reactive oxygen species generation does not occur. Various subsystems were analyzed in order to better understand the involved processes. Decreasing pH makes iron(II) and iron(III) ions more available for oxidative processes. With exception of the normal tissue of the gastric system having ordinary high acidity, in comparison with normal tissue, tumors have relatively low pH levels. Thus, it is important to consider the mechanism of LH oxidation under conditions other than normal physiological ones. Under optimum experimental conditions, oxidative susceptibility of different PUFA under influence of ferrous ion, with a special attention given to the oxidation rate as affected by the ferrous concentration, will be determined. It was found that the oxidative stability of PUFA decreases with increasing number of double bonds or number of bis-alylic position. The susceptibility of PUFA to peroxidation in aqueous micellar solution could be associated with their individual conformations. Dependence of linoleic acid peroxidation on ferrous concentrations revealed that chosen model allow study of either the propagation or the termination phase of lipid peroxidation.

A method for the preconcentration of the total chromium based on coprecipitation with cerium (IV) hydroxide is proposed for determination of chromium by flame atomic absorption spectrometry. Different factors including carrier element amount, pH, sample volume and matrix ion effects for the precipitation were examined. The detection limit of the total chromium (k=3, N=5) was 0.18 μl-1. The presented method was applied or the determination of chromium in the wastewater samples from Kayseri and Nigde Organized Industrial Region-Turkey and in drinking water from our laboratory, Kayseri with satisfactory results (relative standard deviations below 8%, recoveries 95%). The analytical results obtained by the proposed method for certified copper sample was in good agreement with the certified value. © Springer Science+Business Media B.V. 2007.

The small pool of non-bound ferrous iron in cells is known to provide one of the active species involved in probably the most important route for free radical formation leading to increased levels of lipid peroxidation. One of the pathways for excessive production of free radicals is decomposition of hydroperoxides of unsaturated fatty acids catalyzed by iron. Ferrous ions-chelate ligand systems in the presence of LOOH serve as models to establish the reactions that result in the formation of reactive oxyradicals. Rate constants of these reactions are essential to determine which reaction will dominate under selected conditions. However, the literature is scarce and inconsistent with regard to the oxidation of Fe2+ with LOOH in the absence of macromolecular ligands or in the presence of simple unidentate ligands. All potentially occurring subsequent radical reactions are much faster than the rate of the reaction. Thus, the overall reaction rate should be determined only by this reaction. The aim of this work was determination of the overall rate constants of oxidation of Fe2+ with various LOOH and with several non-lipidic hydroperoxides in CH2Cl2:CH3OH solvent mixture at 8 × 10–4 mol dm–3 HCl. The course of the reactions was followed by spectrophotometric determination of ferric ion complexed with thiocyanate. Stoichiometry and the rate constant of the oxidation of Fe2+ with ROOH depended on their structure. The average second-order rate constant of the oxidation of Fe2+ with tertiary ROOH was 250 ± 40 M-1 s-1, while with secondary lipid LOOH was 1390 ± 340 M-1 s-1 ; the rate constants of the oxidation of Fe2+ with LOOH from different biological materials were in the same range. There was no difference between activation enthalpies of geometrical isomers, methyl esters of OlH, and the rate constant of saturated fatty acid hydroperoxides (CeOOH) was very comparable with others. However, discreet differences among the rate constants of the oxidation of Fe2+ with mono- (920 ± 160 M-1 s-1) and poly-unsaturated fatty acids (1420 ± 90 M-1 s-1) were observed. The activation energies for these reactions average 30 kJ mol-1, the value which was relatively small. All these values obtained were comparable. The small activation enthalpy of 28.5 kJ mol–1 indicated the entropy controlled reaction. We assume that the oxidation proceeds by an inner-sphere mechanism considering that the breakdown of the successor inner-sphere complex forming reactive alkoxyl radicals probably is the rate-limiting step.

15 pages, 4 figures, 3 tables.-- PMID: 17899439 [PubMed].-- ISI Article Identifier: 000251368300004.-- Printed version published Dec 2007., It has been postulated that the oceans on early Earth had a salinity of 1.5 to 2 times the modern value and a pH between 4 and 10. Moreover, the presence of the banded iron formations shows that Fe(+2) was present in significant concentrations in the primitive oceans. Assuming the hypotheses above, in this work we explore the effects of Fe(+2) and other ions in the generation of biomolecules in prebiotic simulation experiments using spark discharges and aqueous aerosols. These aerosols have been prepared using different sources of Fe(+2), such as FeS, FeCl(2) and FeCO(3), and other salts (alkaline and alkaline earth chlorides and sodium bicarbonate at pH = 5.8). In all these experiments, we observed the formation of some amino acids, carboxylic acids and heterocycles, involved in biological processes. An interesting consequence of the presence of soluble Fe(+2) was the formation of Prussian Blue, Fe(4)[Fe(CN)(6)](3), which has been suggested as a possible reservoir of HCN in the initial prebiotic conditions on the Earth., The authors have used the research facilities of Centro de Astrobiología and have been supported by Instituto Nacional de Técnica Aeroespacial "Esteban Terradas" and the project AYA2006-15648-C02-02 of the Ministerio of Educación y Ciencia (Spain).

Globin-coupled sensors (GCSs) are multiple-domain transducers, consisting of a regulatory globin-like heme-binding domain and a linked transducer domain(s). GCSs have been described in both Archaea and bacteria. They are generally assumed to bind O2 (and perhaps other gaseous ligands) and to transmit a conformational change signal through the transducer domain in response to fluctuating O2 levels. In this study, the heme-binding domain, AvGReg178, and the full protein, AvGReg of the Azotobacter vinelandii GCS, were cloned, expressed, and purified. After purification, the heme iron of AvGReg178 was found to bind O2. This form was stable over many hours. In contrast, the predominant presence of a bis-histidine coordinate heme in ferric AvGReg was revealed. Differences in the heme pocket structure were also observed for the deoxygenated ferrous state of these proteins. The spectra showed that the deoxygenated ferrous derivatives of AvGReg178 and AvGReg are characterized by a penta-coordinate and hexa-coordinate heme iron, respectively. O2 binding isotherms indicate that AvGReg178 and AvGReg show a high affinity for O2 with P50 values at 20 °C of 0.04 and 0.15 torr, respectively. Kinetics of CO binding indicate that AvGReg178 carbonylation conforms to a monophasic process, comparable with that of myoglobin, whereas AvGReg carbonylation conforms to a three-phasic reaction, as observed for several proteins with bis-histidine heme iron coordination. Besides sensing ligands, in vitro data suggest that AvGReg(178) may have a role in O2-mediated NO-detoxification, yielding metAvGReg(178) and nitrate.

A microcontrolled, portable and inexpensive photometer is described. It uses six light-emitting diodes (LEDs) as radiation sources and a phototransistor as detector, as well as a microcontroller (PIC - Programmable Controller of Interruption). This device provided total autonomy to the proposed photometer, which was successfully applied to determination of Fe2+ in ferrous syrups and of seven clinical biochemical parameters. As the components are cheap (~U$30.00) and easy to find, the proposed photometer is an economical alternative for routine chemical analyses in small laboratories, for research and teaching. Being portable and microcontrolled, it allows doing field chemical analyses.

Reaction pathways in the enzymatic formation and cleavage of the N-N and N-O bonds, respectively, are difficult to verify without the structure of the intermediates, but we now have such information on the heme a3 2+-NO species formed in the reaction of ba3-oxidase with NO from resonance Raman spectroscopy. We have identified the His-heme a 3 2+-NO/CuB 1+ species by its characteristic Fe-NO and N-O stretching frequencies at 539 and 1620 cm -1, respectively. The Fe-NO and N-O frequencies in ba 3-oxidase are 21 and 7 cm-1 lower and higher, respectively, than those observed in Mb-NO. From these results and earlier Raman and FTIR measurements, we demonstrate that the protein environment of the proximal His384 that is part of the Q-proton pathway controls the strength of the Fe-His384 bond upon ligand (CO vs NO) binding. We also show by time-resolved FTIR spectroscopy that CuB 1+ has a much lower affinity for NO than for CO. We suggest that the reduction of NO to NaO by ba 3-oxidase proceeds by the fast binding of the first NO molecule to heme a3 with high-affinity, and the second NO molecule binds to CuB with low-affinity, producing the temporal co-presence of two NO molecules in the heme-copper center. The low-affinity of CUB for NO binding also explains the NO reductase activity of the ba3-oxidase as opposed to other heme-copper oxidases. With the identification of the His-heme a 3 2+-NO/CuB 1+ species, the structure of the binuclear heme a3-CuB 1+ center in the initial step of the NO reduction mechanism is known. © 2005 American Chemical Society. 127 43 15161 15167 Cited By :49

In this study, feral leaping mullet (Liza saliens) liver microsomal 7-ethoxyresorufin O-deethylase (EROD), and cytosolic glutathione S-transferases (GSTs) activities were investigated using 7-ethoxyresorufin, 1-chloro-2,4-dinitrobenzene (CDNB), and ethacrynic acid (EA) as substrates, respectively. The average EROD activity was found as 1139±175 pmol resorufin/min/mg protein. The average GST activities towards CDNB and EA were found as 1364±41 and 140±19 nmol/min/mg protein, respectively. We have, then, investigated the in vitro effects of some metals and detergents on CYP1A and GST activities in leaping mullet liver. Leaping mullet liver microsomal EROD activity was significantly inhibited by Hg (0.1 mM), Ni (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Sb (0.1 mM), Fe2+ (1 mM), Co (1 mM), Al (1 mM), and Fe3+ (1 mM), with the percent inhibition of 80, 80, 77, 75, 70, 69, 56, 53, 46, and 44, respectively. Similarly, conjugation of CDNB catalyzed by GST was inhibited significantly to lesser extend by Hg (0.1 mM), Sb (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Fe3+ (1 mM), Co (1 mM), and Fe2+ (1 mM), with the percent inhibition of 70, 69, 65, 61, 54, 51, 47, and 43, respectively. The degrees of inhibition observed on GST catalyzed EA conjugation by Hg (0.1 mM), Cd (0.1 mM), Sb (0.1 mM), Cu (0.1 mM), and Zn (0.1 mM) were 86, 78, 69, 51, and 42, respectively. In addition to metals, the effect of various detergents on leaping mullet liver EROD, GST-CDNB, and GST-EA activities were studied. It was found that ionic detergents strongly inhibited the EROD activity, whereas much less inhibitions were observed with GST catalyzed activities. Therefore, the CYP1A inhibition potencies of metals and detergents suggest that their contribution to the overall CYP1A induction in polycyclic aromatic hydrocarbons contaminated environmental samples has to be taken into account for better interpretation of environmental studies. © 2006 Elsevier Inc. All rights reserved.

A number of studies have shown that tea catechins can inhibit intestinal iron absorption, mostly iron in the nonhaem form. This randomized, double-blind, placebo-controlled, 3-periods cross-over study examined the degree of inhibition of nonhaem iron absorption by pure crystalline epigallocatechin gallate (EGCG). The study was designed to show the maximum inhibitory action of EGCG by selecting 30 healthy women with low iron stores. Treatments were 150 mg, 300 mg EGCG and placebo each for 8 consecutive study days with a wash-out period of 14 days between treatments. Iron incorporation was assessed by supplying 57Fe orally and 58Fe intravenously. Differences in fractional nonhaem iron absorption between the treatments were evaluated by using two-sided ANOVA. Results showed a relative nonhaem iron absorption reduction of 14% with 150 mg EGCG and 27% for 300 mg EGCG treatment compared to placebo. Differences were statistically significant (p≤0.05) between the placebo and the 300 mg EGCG treatments and between the 150 and 300 mg EGCG treatments. The inverse relation between EGCG dose and fractional nonhaem iron absorption was linear (p=0.0002). In this study the magnitude of the inhibitory action of EGCG on nonhaem iron absorption was found to be much lower than that reported in the literature for black tea and similar compounds. The doses of EGCG in supplements, which will be lower than those used in this study, are not expected to have any health relevant effects on iron absorption in subjects with normal iron stores. © 2005 Elsevier GmbH. All rights reserved.