μM Fe2 Research Articles

Protective mechanism of turmeric (Curcuma longa) on carbofuran-induced hematological and hepatic toxicities in a rat model

Context: Turmeric (Curcuma longa L. [Zingiberaceae]) is used in the treatment of a variety of conditions including pesticide-induced toxicity. Objective: The study reports the antioxidant properties and the protective effects of turmeric against carbofuran (CF)-induced toxicity in rats. Materials and methods: The antioxidant potential was determined by using free radicals scavenging activity and ferric reducing antioxidant power values. Male Wistar rats were randomly divided into four groups, designated as control, turmeric (100 mg/kg/day), CF (1 mg/kg/day) and turmeric (100 mg/kg/day) + CF (1 mg/kg/day) treatments. All of the doses were administered orally for 28 consecutive days. The biological activity of the turmeric and CF was determined by using several standard biochemical methods. Results: Turmeric contains high concentrations of polyphenols (8.97 ± 0.15 g GAEs), flavonoids (5.46 ± 0.29 g CEs), ascorbic acid (0.06 ± 0.00 mg AEs) and FRAP value (1972.66 ± 104.78 μM Fe2+) per 100 g of sample. Oral administration of CF caused significant changes in some of the blood indices, such as, mean corpuscular volume, corpuscular hemoglobin, white blood cell, platelet distribution width and induced severe hepatic injuries associated with oxidative stress, as observed by the significantly higher lipid peroxidation (LPO) levels when compared to control, while the activities of cellular antioxidant enzymes (including superoxide dismutase and glutathione peroxidase) were significantly suppressed in the liver tissue. Discussion and conclusion: Turmeric supplementation could protect against CF-induced hematological perturbations and hepatic injuries in rats, plausibly by the up-regulation of antioxidant enzymes and inhibition of LPO to confer the protective effect.

Methane oxidation in response to iron reduction-oxidation metabolism in tropical soils

Experiments were carried out to understand how iron (Fe) reduction-oxidation (IRO) influences CH4 oxidation in soil. Soil samples (alluvial and vertisol) were induced to undergo microbial Fe reduction and aerobic oxidation consecutively for three cycles simulating natural wetting-drying soil cycle. After each IRO cycle, soils were incubated to determine CH4 oxidation rate, Fe mineral and methanotrophs abundance. Potential iron reduction rate k (μM Fe2+ produced g−1 soil d−1) increased from 1.26 to 2.16 in vertisol and 1.95 to 3.05 in alluvial soil. Potential iron oxidation (μM Fe2+ oxidized g−1 soil d−1) increased from 2.33 to 5.70 in vertisol and 2.43 to 9.58 in alluvial soil. The iron reduction-oxidation significantly (p < 0.05) stimulated CH4 oxidation rate k. The high affinity CH4 oxidation rate increased from 0.03 to 0.19. Low affinity CH4 oxidation rate increased from 0.05 to 0.47 in vertisol. A similar effect of IRO on k was observed in alluvial soil. X ray diffraction (XRD) revealed that diffraction intensity of magnetite and goethite decreased over IRO cycle. Real time PCR quantification of methanotrophs (pmoA gene) confirmed that IRO cycle stimulated (p < 0.05) methanotrophs abundance. The study highlights that iron reduction-oxidation cycles can significantly enhance CH4 oxidation in tropical soils.

Correlation between degradation pathway and toxicity of acetaminophen and its by-products by using the electro-Fenton process in aqueous media

The evolution of the degradation by-products of an acetaminophen (ACE) solution was monitored by HPLC-UV/MS and IC in parallel with its ecotoxicity (Vibrio fischeri 81.9%, Microtox® screening tests) during electro-Fenton (EF) oxidation performed on carbon felt. The aromatic compounds 2-hydroxy-4-(N-acetyl) aminophenol, 1,4-benzoquinone, benzaldehyde and benzoic acid were identified as toxic sub-products during the first stage of the electrochemical treatment, whereas aliphatic short-chain carboxylic acids (oxalic, maleic, oxamic, formic, acetic and fumaric acids) and inorganic ions (ammonium and nitrate) were well identified as non-toxic terminal sub-products. Electrogenerated hydroxyl radicals then converted the eco-toxic and bio-refractory property of initial ACE molecule (500 mL, 1 mM) and subsequent aromatic sub-products into non-toxic compounds after 2 h of EF treatment. The toxicity of every intermediate produced during the mineralization of ACE was quantified, and a relationship was established between the degradation pathway of ACE and the global toxicity evolution of the solution. After 8 h of treatment, a total organic carbon removal of 86.9% could be reached for 0.1 mM ACE at applied current of 500 mA with 0.2 mM of Fe2+ used as catalyst.

Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities

Context: Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research. Objective: This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties. Materials and methods: Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin–Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined. Results: Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2–5973.3 μM Fe2+/g DW; ORAC values of 1858.5–4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC50: 11.6–2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found. Conclusions: Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.

Rat liver mitochondrial dysfunction by addition of copper(II) or iron(III) ions

Increased copper (Cu) and iron (Fe) levels in liver and brain are associated to oxidative stress and damage with increased phospholipid oxidation process. The aim of this work was to assess the toxic effects of Cu2+ and Fe3+ addition to rat liver mitochondria by determining mitochondrial respiration in states 3 (active respiration) and 4 (resting respiration), and phospholipid peroxidation. Both, Cu2+ and Fe3+ produced decreases in O2 consumption in a concentration-dependent manner in active state 3: both ions by 42% with malate-glutamate as complex I substrate (concentration for half maximal response (C50) 60μM Cu2+ and 1.25mM Fe3+), and with succinate as complex II substrate: 64–69% with C50 of 50μM Cu2+ and with C50 of 1.25mM of Fe3+. Respiratory control decreased with Cu2+ (C50 50μM) and Fe3+ (C50 1.25-1-75mM) with both substrates. Cu2+ produced a 2-fold increase and Fe3+ a 5-fold increase of thiobarbituric acid-reactive substances (TBARS) content from 25μM Cu2+ (C50 40μM) and from 100μM Fe3+ (C50 1.75mM). Supplementations with Cu2+ and Fe3+ ions induce mitochondrial dysfunction with phospholipid peroxidation in rat liver mitochondria. Although is proved that a Fenton/Haber Weiss mechanism of oxidative damage occurs in metal-ion induced mitochondrial toxicity, slightly different responses to the metal ions suggest some differences in the mechanism of intracellular toxicity. The decreased rates of mitochondrial respiration and the alteration of mitochondrial function by phospholipid and protein oxidations lead to mitochondrial dysfunction, cellular dyshomeostasis and cell death.

Iron citrate reduces high phosphate-induced vascular calcification by inhibiting apoptosis

Background and aimsHigh phosphate-induced vascular calcification (VC) and iron deficiency-induced anemia are two major contributors of cardiovascular morbidity and mortality in patients affected by chronic kidney disease (CKD). Since phosphate (Pi) control and iron replacement are common therapies in CKD, the aim of our study was to investigate the effect of iron on high Pi-induced VC in rat vascular smooth muscle cells (VSMCs). MethodsWe treated VSMCs with 5 mM Pi and iron citrate (Fe3+) to evaluate Ca deposition by Alizarin Red destaining, DNA fragmentation by ELISA, gene expression by RT-PCR and protein expression by Western blot. ResultsPretreatment with Fe3+ prevents high Pi-induced calcium (Ca) deposition concentration-dependently, with 90.1% inhibition at 50 μM (0.716 ± 0.04 vs. 0.071 ± 0.01, OD/mg protein; Pi vs. Pi + Fe3+, p < 0.01). We found that 50 μM Fe3+ completely prevents high Pi-induced apoptosis measured as DNA fragmentation (1.51 ± 0.08 vs. 1.03 ± 0.06, Pi vs. Pi + Fe3+; p < 0.01), through the prevention of the downregulation of the pro-survival pathway GAS6/AXL. Moreover, Fe3+ stimulates autophagy, a protective phenomenon in VC, as demonstrated by electron microscopy and by autophagy flux detected by LC3IIβ protein expression. Finally, high Pi-induced osteoblastic differentiation is partially affected by Fe3+, since BMP2 increase is prevented and OPN is enhanced, but RUNX2 increase and α-actin and SM22α decrease are not modified. Interestingly, the addition of Fe3+ at different time points after Pi challenge completely blocks the progression of Ca deposition. ConclusionsIn conclusion, iron citrate inhibits high Pi-induced Ca deposition by prevention of apoptosis, induction of autophagy, and partially affecting osteoblastic differentiation.

Advanced oxidation treatment of malachite green dye using a low cost carbon-felt air-diffusion cathode

A low cost carbon-felt (CF) material has been successfully employed as an air-diffusion cathode for the generation of H2O2 from O2 reduction in 0.05M Na2SO4 at pH 3. Using a BDD (Boron Doped Diamond)/CF air-diffusion electrode (3cm2), a maximum of 94mgL−1 of H2O2 were accumulated for the best current density value identified (21.7mAcm−2). These results were technically and economically better than other performances observed for similar cathode materials in O2-saturated solutions. An electrochemical reactor utilizing these electrodes was employed to degrade malachite green (MG) dye in the same electrolyte containing 0.5mM of Fe2+ using the electro-Fenton (EF) and photoelectro-Fenton (PEF) processes. The main oxidant was HO formed at the BDD surface from water oxidation and in the bulk from Fenton’s reaction between H2O2 and added Fe2+. As expected, the PEF process was more powerful than the EF due to the enhancement of HO production by photolysis of Fe(III)-hydroxy species and of Fe(III) complexes of the oxalate of the dye, as well as of intermediates. The effect of MG concentration on decolorization and mineralization rates, mineralization current efficiency and energy consumption for both processes were assessed. The CF air-diffusion cathode lost progressively performance upon consecutive PEF treatment of a 150mgL−1 MG owed to the gradual deposition of Fe species, as well as an enrichment of O, Na and S species on its surface. The deposition of Fe species was reversible since these were dissolved in the medium in consecutive trials without the need of adding new amounts of Fe2+.

Excess iron alters the fatty acid composition of chloroplast membrane and decreases the photosynthesis rate: a study in hydroponic pea seedlings

As an essential micronutrient, iron (Fe) is directly involved in several fundamental processes in the photosynthetic cells. However, it is not clear if photosynthetic traits affected by high ferrous level are associated with changes in fatty acid composition in chloroplast membranes. To accomplish this, the effects of excess Fe2+ on the fatty acid composition and the fluidity properties of the chloroplast membrane, photosynthesis rate and the chlorophyll fluorescence were investigated in pea (Pisum sativum L.) seedlings grown hydroponically in nutrient solutions with 100, 200, 400 and 600 µM Fe2+ supplied as FeSO4. Increased fluidity of the chloroplast membranes was found under higher Fe2+ treatments, and this might be attributed to the increase in relative content of unsaturated fatty acids (USFA). Excess Fe2+ decreased the chlorophyll content and the electron transport rate, deactivated reaction center of photosystem II, and declined plant net photosynthetic rate. Finally, the reduced plant dry weight was observed. The results indicate that the effects of excess Fe on photosynthesis and fluidity of chloroplast membrane depend on the stress strength and duration, and the increased fluidity of chloroplast membrane may be critical in maintenance of cellular integrity under excess but not lethiferous Fe2+ treatment.

The Role of Fe&lt;sup&gt;2+&lt;/sup&gt; Ions on the Photocatalytic Reaction of Ag&lt;sub&gt;3&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt; for Rhodamine B Degradation

The Ag3PO4 crystal with 200-600 nm in diameter was successfully synthesized using co-precipitation method with AgNO3 and Na2HPO4.12H2O as starting materials. The product was characterized using XRD, DRS, FTIR and SEM. The photocatalytic activities were evaluated under blue light irradiation assisted by Fe2+. The 1 mL of Fe2+ aqueous solutions consisted of 1.00, 0.10, 0.01, 0.001 and 0.0001 mM Fe2+ was added into a 100 mL solution of Rhodamine B, and the photocatalytic oxidation of Rhodamine B was carried out under visible light irradiation. The highest photocatalytic activity was observed when 1 ml of 0.001 mM of Fe2+ aqueous solution was added in the Rhodamine B solution. The result inferred the possibility of in-situ peroxide generation during the photocatalysis reaction.

Green preparation of carbon dots by Jinhua bergamot for sensitive and selective fluorescent detection of Hg2+ and Fe3+

Green, low-cost, and water-soluble fluorescent carbon dots were prepared under hydrothermal conditions, with a plant of Jinhua bergamot as a carbon source. The as-synthesized C-dots have better stability and relatively high photoluminescence with a quantum yield of 50.78%, along with the fluorescence lifetime of ca. 3.84ns. Their photoluminescence can be significantly quenched by simply using the buffer solution of HAC–NaAC for Hg2+ and Tris–HCl for Fe3+. Based on this, we explored for selective detection of Hg2+ and Fe3+ with high selectivity, fast response, low cost, and broad linear ranges of 0.01–100μM for Hg2+ and 0.025–100μM for Fe3+, as well as low detection limits of 5.5nM (Hg2+) and 0.075μM (Fe3+) (S/N=3).

Reduction Kinetics of Polymeric (Soluble) Manganese (IV) Oxide (MnO2) by Ferrous Iron (Fe2+)

In numerous freshwater and marine environments, ferrous iron (Fe2+) can react with manganese oxides in a redox reaction. However, there are few quantitative data describing reaction rates. A “soluble” (colloidal and nanoparticulate) phase manganese dioxide (MnO2) was used to obtain kinetic data on MnO2 reduction by Fe2+ with a stopped flow UV–Vis method. Stopped flow experiments were carried out in unbuffered solutions between pH 4.9 and 5.36 and also at pH 7. The reaction was determined to be first order with respect to MnO2 and Fe2+ and second order overall. It is important to subtract absorbance of Fe(III) products from the UV–Vis data and to acquire data from the first milliseconds of the reaction. After subtracting Fe(III) product absorbance, the average second-order rate constant was determined to be 4338 ± 249 M−1 s−1 at 25 °C and pH 5. Reactions of 5 μM MnO2 with 50 and 100 μM Fe2+ were more than 50 % complete in 1.77 and 0.7 s, respectively. The reaction is an inner sphere electron transfer process as an outer sphere process is symmetry-forbidden. Studies show that Mn(III) intermediates are produced during the reaction. The fast kinetics makes this reaction significant to consider when modeling manganese oxide and reduced iron in environmental redox systems.

Quantitative analysis of phosphorus, iron, and arsenic in the inner and outer portions of rice roots: an interaction of arsenic with iron

Two experiments were conducted to observe the effect of arsenic (As; NaAsO2) and additional Fe3+ (Fe3+-EDTA) on phosphorus (P), iron (Fe), and As in inner and outer portions of rice roots (Oryza sativa L. cv. Akitakomachi) grown for 14 days. Measurement of elements was done with PIXE (particle-induced X-ray emission) system. The first experiment contained various rates of As ranging from 0 to as high as 26.8 µM with a constant rate of 10 µM Fe3+, while in the second experiment, the Fe concentrations were varied from 10 to 50 µM with As at 0 and 13.4 µM. The intensity of the reddish coloration in the roots increased with increasing As in the medium. Phosphorus adsorbed by apoplastic Fe and Fe-plaque (outer portion) was not detected, suggesting that P might not have complexed with apoplastic Fe or with Fe-plaque. Iron was mostly concentrated in the outer portion of the roots whereas As was mostly concentrated in the inner portion. High-Fe3+ in the medium caused a decrease in P and As concentrations in the inner portion of the roots.

Iron limitation enhances acyl homoserine lactone (AHL) production and biofilm formation in clinical isolates of Acinetobacter baumannii

Acinetobacter baumannii is an important source of infections in intensive care units (ICUs) of our hospitals in Kerman, Iran and the most frequently isolated strains produce biofilm. There is a little information about role of iron (Fe) levels on acyl homoserine lactone (AHL) production and biofilm formation in this microorganism. In the present study, we investigated the influence of iron-III limitation on AHL, siderophore, catechol and virulence factors in the biofilm forming clinical strains of A. baumannii. A total of 65 non-duplicated multidrug resistance (MDR) strains of A. baumannii were isolated from patients in ICUs of 2 hospitals in Kerman, Iran. Antibiotic susceptibility, siderophore and other iron chelators, hemolysis, cell twitching motility, capsule, gelatinase and DNase were studied. Presence of quorum sensing, LuxI and LuxR genes was detected by multiplex-PCR. AHL activity quantified by colorimetric method and the functional groups were determined by Fourier Transform Infra-Red Spectroscopy (FT-IR). Biofilm formation was detected by microtiter plate technique. All of the isolates were resistant to third generation of cephalosporins, ciprofloxacin, levofloxacin, tetracycline, whereas, 78% and 81% were resistant to amikacin and carbapenems, respectively. The siderophore activity was highest at 20 μM Fe3+ (70%); however, it decreased to 45% as concentration of Fe3+ increased to 80 μM. Furthermore, screening of the isolates for LuxI and LuxR genes showed that presence of both genes required in the isolates with high AHL activity. FT-IR analysis indicated C=O bond of the lactone ring and primary amides. Significantly, a higher amount of AHL (70%) was detected in the presence of low concentration of iron-III (20 μM); as iron concentration increased to 80 μM, the AHL activity was reduced to 40% (P ≤ 0.05). All the isolates exhibited twitching motility and had a capsule. No any gelatinase or DNase activity was detected. Quantification of the biofilm formation introduced 23 isolates with efficient attachment to microplate wells and strong biofilm. We found that both the AHL production and biofilm formation were regulated by iron concentration in a dose dependent manner. These findings provide evidence that iron limitation plays an important regulatory role in AHL and siderophore production resulting in strong or weak biofilm, thereby helping the organism to persist in less available micronutrient environment.

Effects of Low Doses of Quercetin and Genistein on Oxidation and Carbonylation in Hemoglobin and Myoglobin

ABSTRACTProtein-bound carbonyls have been shown to increase with age as well as in numerous diseases including rheumatoid arthritis, adult respiratory syndrome pulmonary fibrosis, diabetes, Parkinson's disease, and Alzheimer's just to mention a few. The effects of the flavonoids quercetin and genistein were investigated according to their ability to inhibit the oxidation of hemoglobin and myoglobin via the Fenton's pathway. Antioxidative activity of the flavonoids were determined by oxidizing hemoglobin and myoglobin in separate experiments with 50 μM Fe2+ and 0.01 mM hydrogen peroxide (H2O2) with and without quercetin and/or genistein. The samples were treated singly with either quercetin, genistein, or in combination at concentrations of 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 μM, respectively, dissolved in dimethyl sulfoxide (DMSO). Samples were then incubated in a water bath at 37°C for 8, 12, and 24 hr, respectively. Levels of carbonylation were assayed by the protein carbonyl assay and the carbonyl levels quantified and expressed per mg of protein. The results indicate that protein carbonyls for samples treated with quercetin or genistein decreased in a dose-dependent manner compared to the controls. That of quercetin compared to genistein was more efficient in reducing the levels of protein carbonylation in hemoglobin and myoglobin, respectively. The combination of both flavonoids did show a gradual decrease in carbonyl compounds for only hemoglobin for all the doses and times tested. The results indicate that both flavonoids at low doses inhibited carbonylation in both hemoglobin and myoglobin and the inhibition may be attributed to the prevention of protein oxidation.

Antioxidant and Immunomodulatory Potential of Cobra lily Species of North-western Himalayan Region: A Comparative Analysis

This study explored the antioxidant and immunomodulatory potential of two ethno-medicinally valuable species belonging to genus Arisaema viz., Arisaema flavum and Arisaema propinquum. The arial parts and tubers of these species were subjected to polarity based extraction using different solvents. In vitro antioxidant studies were performed in terms of DPPH radical scavenging, chelation power on ferrous ions, reducing power and FRAP assays. Immunomodulatory studies were also determined by evaluating Humoral antibody response (Hab) and Delayed type hypersensitivity response (DTH). The results depicted that A. flavum exhibited relatively better antioxidant and immunomodulatory potential than A. propinquum. Methanol extract of A. flavum leaves demonstrated promising antioxidant activity with DPPH radical scavenging IC value of 0.406±0.43 mg/ml (R2 = 0.9643), FRAP value of 2176 mM of Fe2+/mg extract (R2 = 0.9962) and reducing power with EC 1.25±0.27mg/ml (R2 = 0.9948) than the extracts of A.propinquum. Chelation capacity of methanol extracts of A. flavum (55 %) leaves was found to be quite significant as compared to that of A. propinquum (51 %) at 100 µg/ml concentration. A. flavum leaf methanol extract was also found have immune enhancing effect by increasing the humoral response by 83 % and DTH response by 100 % in immune suppressed mice. The present work concludes that the antioxidative power of A. flavum surpasses that of A. propinquum whereas in case of immunomodulation, A. flavum has considerable enhancing effect on humoral response and A. propinquum demonstrated better DTH response.

One-pot facile synthesis of PEGylated superparamagnetic iron oxide nanoparticles for MRI contrast enhancement

Polyethylene glycol (PEG)-coated superparamagnetic iron oxide nanoparticles (PEG·SPIONs) were prepared by a facile one-pot approach. The synthesized PEG·SPIONs were found to be uniform in size with an average hydrodynamic diameter of 11.7nm. PEG·SPIONs exhibited excellent dispersibility in water, colloidal stability, and biocompatibility. The magnetic resonance imaging (MRI) properties of PEG·SPIONs were characterized both in vitro and in vivo. The dual contrast both in T1 and T2-weighted imaging was well enhanced with longitudinal and transverse relaxivity (r1, r2) of 35.92s−1 per mM of Fe3+ and 206.91s−1 per mM of Fe3+ respectively. In vivo T2-weighted MRI shows pronounced enhancement in the liver and spleen but not in T1-weighted MRI. Accumulations of nanoparticles were found primarily in the liver, spleen, and intestine, while much lower uptake in the kidney, heart, and lungs. A gradual excretion of PEG·SPIONs was observed via hepatobiliary (HB) processing over a period of 14days. The toxicity of PEG·SPIONs was also evaluated in vitro and in vivo. PEG·SPIONs were found to be biocompatible by investigating organ tissues after hematoxylin–eosin staining. The conclusion of the study indicates a high potential of PEG·SPIONs in medical MRI.

Dark fermentative hydrogen production by the unicellular halotolerant cyanobacterium Aphanothece halophytica grown in seawater

Biohydrogen is an environmentally friendly alternative energy carrier that can be produced by a number of different microorganisms. The unicellular halotolerant cyanobacterium Aphanothece halophytica is one of the high potential H2 producers. Under dark fermentation, it is capable of producing H2 by the bidirectional hydrogenase activity via the catabolism of glycogen stored during photosynthesis. This work aimed to cultivate A. halophytica in natural seawater containing high salinity and minerals, with an addition of some essential nutrients, and to investigate effects of various nutritional and physical factors on its dark fermentative H2 production. A. halophytica was able to grow in natural seawater added with NaNO3. Cells grown in seawater supplemented with as little as 1.76 mM NaNO3 showed similar growth to those cultivated in normal BG11 supplemented with Turk Island salt solution. H2 production was the highest when incubating the cells in seawater without any supplementation of NaNO3. Under this condition, the highest rate of dark fermentative H2 production of 82.79 ± 3.47 nmol H2 mg-1 dry weight h−1 was found in cells incubated at 35 °C, pH 6 with the supplementation of 378 mmolC L−1 glucose, 0.25 M NaCl, and 0.4 μM Fe3+. Long-term H2 accumulation of 1,864 ± 81 nmol H2 mg−1 dry weight was observed after 8 days of dark incubation under anoxic condition, and the high yield of H2 was sustained at least up to 14 days, suggesting the possibility of utilizing natural seawater to grow A. halophytica for long-term production of H2.

Antioxidant Activities and Total Phenolic Content in Germinated and Non-Germinated Legume Extracts Following Alkaline-Acid Hydrolysis

This study was aimed to determine and compare Total Phenolic Content (TPC) and Antioxidant Activities (AA) in germinated and non-germinated legume [peanut (Arachis hypogeal) and soybean (Glycine max)] extracts prepared using alkaline-acid hydrolysis. Total phenolic content and antioxidant activities 1,1- diphenyl-2-picrylhydrazyl free radical (DPPH) scavenging and reducing Ferric Ion Antioxidant Potential (FRAP) in extracts were determined spectrophotometrically. Total phenolic content in non-germinated peanut and soybean were 1090.58 and 888.08 mg GAE/100g dry weight, respectively. After germination, total phenolic content in peanut increased to reach 1151.33 mg GAE/100g dry weight; while soybean significantly decreased. In non-germinated peanut and soybean DPPH was 1084.99 and 507.59 μM TE/100g dry weight; and FRAP was 47966.67 and 23010.00 μM Fe2+ equivalent/100g dry weight respectively. Following germination, DPPH and FRAP were decreased in peanuts but increased in soybeans. The process of germination has resulted to the increments of antioxidant activities in soybean and total phenolic content in peanut.

SPD602 Is a Selective Iron Chelator Which Is Able To Mobilise The Non-Transferrin-Bound Iron Pool

Currently there are three iron chelators in clinical use, deferoxamine, deferiprone and deferasirox. Each has its limitations and although both deferiprone and deferasirox have the advantage over deferoxamine of being orally active, both are associated with a range of side effects (Neufeld, Blood 2006;107:3436). SPD602 (formerly known as FBS0701) is a tridentate, orally administered iron chelator in clinical development that has shown evidence of effect in a phase 2 clinical trial (Neufeld et al. Blood 2012;119:3263). [Display omitted] Here, we present a comparison of clinically relevant physicochemical data for deferoxamine, a hexadentate chelator, deferiprone, a bidentate chelator and deferasirox and SPD602, both tridentate chelators, using techniques to allow direct comparison between chelators, which has not previously been possible due to differences in experimental methodology. Broadly speaking, all four compounds possess a high selectivity for iron(III) (Table) and thereby are associated with a strongly negative ligand–iron oxidation potential and thus a low tendency to redox cycle (Ma et al. Curr Med Chem 2012;19:2816). The pFe3+ value (1 µM Fe3+; 10 µM Ligand (L); pH 7.4) for SPD602 is very close to that of deferasirox, larger than that for deferiprone but smaller than found for deferoxamine, suggesting that SPD602 has at least equivalent affinity for the physiologically relevant form iron(III) as the clinical 1st line treatment deferasirox and has a low potential for cell damaging redox cycling activity. The separation in binding affinities between iron(II) and iron(III) for SPD602 was determined to be approximately 14 log units in favour of iron(III). For zinc(II) and copper(II) we have compared the logK1 values corresponding to the two tridentate ligands (Table) as the reported values of the two corresponding logK2 values for deferasirox are unreliable due to polymer formation (Heinz et al. Angew Chem Int Ed 1999;38:2568). Based on the logK1 values, SPD602 showed lower binding affinity for these two metals than deferasirox.Table shows iron chelator metal-binding data (stability constants and pFe3+ values) for physiologically relevant metalsIn patients with iron overload disorders, levels of iron exceed the iron binding capacity of transferrin, and non-transferrin bound iron (NTBI) is evident. Pre-clinically, SPD602 is efficient at mobilising iron from both mononuclear and oligonuclear iron(III) citrate and albumin-bound iron(III), which are believed to be the major components of NTBI. These data suggest that SPD602 has clinical utility in mobilising the NTBI pool in iron overload.There are differences in the partition coefficients (logD7.4) of SPD602 (L, -1.3; FeL2, -2.7) and deferasirox (L, 1.1; FeL2, < -3.0) and so whereas deferasirox is hydrophobic as the free ligand, SPD602 is relatively hydrophilic. The clinical implications of this difference in physicochemical properties are unknown. One area where the difference in hydrophobicity is reflected is in the albumin-binding properties: both the free ligand and FeL2 complex of deferasirox are almost completely bound to albumin (> 99%) whereas, in contrast, SPD602 (as the free ligand) is bound less extensively (85.5%).In summary, SPD602 is an iron chelator with good selectivity for iron(III) over other physiologically relevant metal ions, such as zinc(II) and copper(II), and has identical affinity for iron(III) as the clinical 1st line treatment, deferasirox. In models of NTBI, SPD602 was effective at mobilising iron under physiologically relevant conditions. Further pre-clinical studies are warranted to elucidate additional mechanistic features that may be of clinical importance. Disclosures:Hider:Shire: Consultancy, Research Funding. Kong:Shire: Research Funding. Luker:Shire: Employment. Conlon:Shire: Employment. Harland:Shire: Employment.Fe3+pFe3+Mg2+Ca2+Cu2+Zn2+Deferoxamine28.3 (logK1)26.54.3 (logK1)2.4 (logK1)7.9 (logK1)5.4 (logK1)Deferasirox36.9 (logβ2)22.57.6 (logK1)5.5 (logK1)18.8 (logK1)13.3 (logK1)SPD60233.1 (logβ2)22.36.0 (logK1)4.5 (logK1)14.8 (logK1)9.6 (logK1)Deferiprone37.0 (logβ3)20.59.1 (logK1)2.0 (logK1)19.1 (logβ2)13.5 (logβ2)

Application of Fered-Fenton process for m-phenylenediamine degradation

This study was undertaken to investigate the feasibility of applying the Fered-Fenton process to the degradation of m-phenylenediamine, by examining the effect of varying the initial H2O2 and Fe2+ concentrations, the initial pH and electric current on the process efficiency. The degradation behavior of m-phenylenediamine was also compared to that of aniline. The Fered-Fenton reactor consists of anodes and cathodes with mesh-type titanium metal coated with IrO2/RuO2 and stainless steel, respectively. The experiments showed that m-phenylenediamine was rapidly degraded by the Fered-Fenton process. Initial pH of 3.2 is optimal for the removal of m-phenylenediamine and chemical oxygen demand (COD). m-Phenylenediamine and COD removal efficiencies increased with the increasing electrical current from 0 A to 4 A, and decreased with a further increase in electrical current. Optimum efficiency resulting in 100% degradation of m-phenylenediamine and elimination of 30% of COD was achieved at pH 3.2 at 60 min in the presence of 10 mM of m-phenylenediamine, 0.268 mM of Fe2+, 43.6 mM of H2O2, and under a current of 4 A.