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Resistance to β-lactam antibiotics caused by β-lactamases such as New-Delhi lactamase (NDM-1) has become one of the major challenges in the current antimicrobial therapy. Pyridine-2,6-dicarboxylic acid (DPA) derivatives have been demonstrated to inhibit NDM-1 in a due to the interactions with Zn ion and amino acid residues of the enzyme's active site. In this study, a series of new 4-substituted DPA derivatives was synthesized. The SAR study has proven that the presence of a substituent at the 4-position of pyridine-2,6-dicarboxylic acid had a certain impact on the NDM-1 inhibitory. Some representatives, e.g., 4e exhibited IC50 values against NDM-1 close to the previously reported hit-compound 4-(3-aminophenyl)pyridine-2,6-dicarboxylic acid. The microdilution broth test confirmed an ability of derivative 4e to increase susceptibility of NDM-1-producing E. coli strain and did not demonstrate cytotoxicity to eukaryotic cells. However, NDM-1 inhibition by 4-substituted derivatives dramatically dropped when Zn2+ was added. We observed a strong complexation of 4-modified derivatives with Zn2+ similar to unsubstituted pyridine-2,6-dicarboxylic acid. Taken together, a complexation mode of NDM-1 inhibition leading to potential off-target action on other metalloenzymes and low efficiency of structure optimization make DPA derivatives an unproductive scaffold for future development of clinically relevant metallo-β-lactamase inhibitors. [ABSTRACT FROM AUTHOR]

Quantum‐confined perovskite CsPbBr3 Nanoplatelets (NPLs) have recently emerged as promising blue‐emitting materials for perovskite light‐emitting diodes (PeLEDs). Yet, their susceptibility to optical instability in solid films under ambient conditions poses a significant hindrance. This study introduces a novel chelating strategy that utilizes metal manganese ions and multidentate ligands, markedly improving the structural stability, and emission efficiency of NPLs. The approach involves adding Diethylenetriaminepentaacetic acid (DTPA) to the perovskite precursor solution, which allows for strong coordination to surface [PbBr6]4− octahedrons via its multiple chelation sites. Ensuing metal manganese ion integration during the purification phase addresses Pb2+ and Br− site vacancies, culminating in near‐perfect octahedral structures with significantly fewer vacancies. These metal manganese ions are then further immobilized on the NPLs surface by the chelating effect of unbound DTPA functional groups. The resultant CsPbBr3 NPLs films demonstrate an impressive PLQY of 66%, showcasing remarkable air stability with consistent blue emission for up to 5 days. The CsPbBr3 NPLs‐based PeLEDs show electroluminescence at 460 nm with a current efficiency of 1.07 cd A−1 and a maximum luminance of 220 cd m−2. The proposed chelating strategy positions perovskite NPLs as an extremely promising prospect in future applications of high‐definition displays and high‐quality lighting. [ABSTRACT FROM AUTHOR]

The anti-corrosive effect of the extract in ethanol of Justicia brandegeeana (Acanthaceae) against carbon steel AISI 1020 in sulfuric acid medium 1 mol L−1 was investigated. In addition to the effect of seasonality, several techniques were used to investigate the anti-corrosive activity, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), linear polarization resistance (LPR), and weight loss. The chelating effect was analyzed by UV-Vis spectrophotometry and the surface was analyzed by scanning electron microscopy (SEM). The results showed that the inhibition efficiency is dependent on the concentration of the extract, reaching its maximum at 1500 ppm and despite having good thermal stability (82.41% inhibition at 70°C), it decreases with increasing temperature, indicating a physisorption behavior. The extract obeyed the Langmuir isotherm and the Tafel curves characterized it as a mixed inhibitor, with a tendency to cathodic region. It also presented a 52% chelating effect against Fe+2 ions, and the SEM analysis indicated a protection with the presence of plant extract, thus minimizing surface roughness. These results indicated the J. brangeeana ethanol extract as a green anti-corrosive agent.

Although Zn metal has been regarded as the most promising anode for aqueous batteries, its practical application is still restricted by side reactions and dendrite growth. Herein, an in‐situ solid electrolyte interphase (SEI) film formed on the interface of electrode/electrolyte during the plating/stripping of zinc anodes by introducing trace amounts of multidentate ligand sodium diethyldithiocarbamate (DDTC) additive into 1 m ZnSO4. The synergistic effect of in‐situ solid electrolyte interphase forming and chelate effect endows Zn2+ with uniform and rapid interface‐diffusion kinetics against dendrite growth and surface side reactions. As a result, the Zn anode in 1 m ZnSO4 + DDTC electrolytes displays an ultra‐high coulombic efficiency of 99.5% and cycling stability (more than 2000 h), especially at high current density (more than 600 cycles at 40 mA cm−2). Moreover, the Zn//MnO2 full cells in the ZnSO4 + DDTC electrolyte exhibit outstanding cyclic stability (with 98.6% capacity retention after 2000 cycles at 10 C). This electrode/electrolyte interfacial chemistry modulated strategy provides new insight into enhancing zinc anode stability for high‐performance aqueous zinc batteries. [ABSTRACT FROM AUTHOR]

The anti-corrosive effect of the extract in ethanol of Justicia brandegeeana (Acanthaceae) against carbon steel AISI 1020 in sulfuric acid medium 1 mol L−1 was investigated. In addition to the effect of seasonality, several techniques were used to investigate the anti-corrosive activity, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), linear polarization resistance (LPR), and weight loss. The chelating effect was analyzed by UV-Vis spectrophotometry and the surface was analyzed by scanning electron microscopy (SEM). The results showed that the inhibition efficiency is dependent on the concentration of the extract, reaching its maximum at 1500 ppm and despite having good thermal stability (82.41% inhibition at 70°C), it decreases with increasing temperature, indicating a physisorption behavior. The extract obeyed the Langmuir isotherm and the Tafel curves characterized it as a mixed inhibitor, with a tendency to cathodic region. It also presented a 52% chelating effect against Fe+2 ions, and the SEM analysis indicated a protection with the presence of plant extract, thus minimizing surface roughness. These results indicated the J. brangeeana ethanol extract as a green anti-corrosive agent. [ABSTRACT FROM AUTHOR]

Context Chondroitin 6 sulphate (C6S) is a glycosaminoglycan (GAG) whose accumulation is notable in mucopolysaccharidosis type IVA and VII. Flaxseed, Linum usitatissimum L. (Linaceae) (FS), is reported to have comparable properties to those of soybean, a source of genistein, a potential new treatment for MPSs.Objective We assess the effect of total ethanol flaxseed extract (EFSE) in an animal model of C6S accumulation.Materials and methods The study was performed in adult male Wistar rats (n = 24) for 15 successive days. The animals were divided into four groups: (1) control injected with physiological saline buffer, (2) intoxicated rats injected intraperitoneally with C6S, (3) intoxicated with C6S and treated with EFSE, and (4) treated with EFSE. All groups were subjected to histopathological and biochemical studies. The antioxidant and phytochemical properties of EFSE were examined.Results Dry EFSE contains total phenols (6.28 mg EAG/g), condensed tannins (2.98 mg ECAT/g) and flavonoids (0.44 mg ECAT/g) with high antioxidant potential [RPE (IC50 = 8.37 ± 0.176), DPPH (IC50 = 12.79 ± 0.273)]. The LD50 is higher than 5000 mg/kg. The histopathological examination showed an accumulation of C6S in the C6S intoxicated group, which disappeared in the C6S-EFSE treated group. GAGs assays showed an increased excretion in the C6S intoxicated group and increased excretion of 14% in the C6S-EFSE group compared to the C6S group.Discussion and conclusions EFSE showed significant potential for chelation. Its use for the treatment of GAG accumulation could be suggested and generalized to a larger study population.

Context: Chondroitin 6 sulphate (C6S) is a glycosaminoglycan (GAG) whose accumulation is notable in mucopolysaccharidosis type IVA and VII. Flaxseed, Linum usitatissimum L. (Linaceae) (FS), is reported to have comparable properties to those of soybean, a source of genistein, a potential new treatment for MPSs. Objective: We assess the effect of total ethanol flaxseed extract (EFSE) in an animal model of C6S accumulation. Materials and methods: The study was performed in adult male Wistar rats (n=24) for 15 successive days. The animals were divided into four groups: (1) control injected with physiological saline buffer, (2) intoxicated rats injected intraperitoneally with C6S, (3) intoxicated with C6S and treated with EFSE, and (4) treated with EFSE. All groups were subjected to histopathological and biochemical studies. The antioxidant and phytochemical properties of EFSE were examined. Results: Dry EFSE contains total phenols (6.28mg EAG/g), condensed tannins (2.98mg ECAT/g) and flavonoids (0.44mg ECAT/g) with high antioxidant potential [RPE (IC50 = 8.37 ± 0.176), DPPH (IC50 = 12.79 ± 0.273)]. The LD50 is higher than 5000mg/kg. The histopathological examination showed an accumulation of C6S in the C6S intoxicated group, which disappeared in the C6S-EFSE treated group. GAGs assays showed an increased excretion in the C6S intoxicated group and increased excretion of 14% in the C6S-EFSE group compared to the C6S group. Discussion and conclusions: EFSE showed significant potential for chelation. Its use for the treatment of GAG accumulation could be suggested and generalized to a larger study population. [ABSTRACT FROM AUTHOR]

• Parkia roxburghii ; lesser known, multipurpose leguminous tree species. • Antioxidant and Free radical-scavenging potential of different parts of the plant. • Specific phenolic composition using HPLC and MS/MS. • Promotion and augmentation of scientific information of such traditional food plants for nutritional security and disease prevention and management through diets. Total phenolics in extracts of different parts of Parkia roxburghii varied from 80.1 (flowers) to 311.6 mg/ g GAE (Pods) with moderate amounts of flavonoids and high antioxidant activity (50.1–92.4%). The pods of Parkia roxburghii were found to be potent DPPH radical scavengers followed by leaves, seeds and then flowers as evident by their low IC 50 , EC 50 values and reasonably high ARP values (34.5–230.4). The pod and seed extracts exhibited good reducing power expressed as ascorbic acid equivalents (ASE/ ml) and significant protection against DNA damage caused by free radicals too. The extracts of Tree bean studied showed appreciable free radical scavenging activities through inhibition of lipid per oxidation (LPO) measured by ammonium thiocyanate assay, inhibition of hydroxyl radical observed in non-site specific and site specific assays, metal chelating capacity and superoxide radical scavenging activity. In most of the assays, the pod extracts showed higher potency in scavenging of free radicals than quercetin which was used as a standard. The specific phenolic composition of Parkia roxburghii extracts performed through HPLC and LC-MS/MS showed presence of gallic acid, caffeic acid, chlorogenic acid, ellagic acid ferulic acid. Low amounts of flavonoids like kaempferol, quercetin, diadzein and genestein were also observed in some parts of the plant. Such scientific evidences in the present investigation on the functional attributes of Parkia roxburghii , a traditional food plant would hold significant importance in genetic diversity studies and also for disease prevention and management through diets. [ABSTRACT FROM AUTHOR]

In order to determine the chelating effect of activated charcoal, a total of 150 beluga (270 g) were fed for 60 days with a diet containing 0 (control), 5, 10, 15 and 20 g activated charcoal per kg. Afterwards, the fish were subjected to challenging with 1 mg/L of each of heavy metals including lead, cadmium and copper during seven days. As results, the highest percentage of body weight gain, specific growth rate, condition factor, protein efficiency ratio and the lowest feed conversion ratio before and after challenging with heavy metals were obtained in 15 g treatment with significant differences comparing to other treatment (p < .05). In all treatments, considerable differences were observed between two experimental stages of all parameters except condition factor and feed conversion ratio (p < .05). No mortalities were observed during the experiment. Before challenging with heavy metals, 15 g treatment showed the lowest activities of AST and ALT enzymes, and uric acid, protein, albumin and cholesterol amounts. The minimum amounts of creatinine and glucose were recorded in the control and 20 g treatments respectively. The highest levels of these parameters, except for creatinine and uric acid, were measured in the control group. After challenging with heavy metals, the lowest levels of AST and ALT enzyme activities, uric acid, creatinine, and glucose, and the highest amounts of protein, albumin and cholesterol belonged to 15 g, whereas the results in the control group were almost opposite. In all treatments, significant differences were observed between two experimental stages of all parameters except AST, uric acid, glucose and cholesterol (p < .05). In the pre‐challenge stage, the maximum amount of carcass protein was observed in 15 g while the differences in lipid content were not significant (p > .05). Moreover, the highest contents of moisture and ash were measured in the control group and 20 g respectively. After the challenge, the highest values of protein and lipid were quantified in 15 g, while the maximum values of ash and moisture were observed in 20 g and control group respectively. Also, significant differences were observed just in ash and moisture amounts in both stages (p < .05). Accumulations of cadmium, copper and lead were maximal in the control group in both stages, and their amount were decreased in sample with 15 g of activated charcoal until they reached to their lowest value in sample with 20 g of activated charcoal. The only different parameter between two treatments was copper amount. Also, significant differences were observed in all treatments in both stages (p < .05). Although activated charcoal at 20 g/kg diet yielded the best results in metal chelation, it is recommended to add 15 g/kg of activated charcoal to the diet of beluga because of other parameters. [ABSTRACT FROM AUTHOR]

Environmental stressors such as mercury are important for the search of substances to lower induced oxidative damage. Accordingly, secondary metabolites from plants with antioxidant activity represent an interesting alternative. The aim of this work was to evaluate the cytoprotective effect of the ethanol extract of Eugenia uniflora against mercury chloride. The main antioxidant phytochemicals were quantified by HPLC. The chelating effect was evaluated using the O-phenanthroline method. The cytoprotective effect was assayed using bacterial and plant models. The cytotoxic and the negative geotaxis effect was determined using Drosophila melanogaster. The ethanol extract of E. uniflora demonstrated chelating effect against iron, and these results can be related to the total phenols (1079 mg/g) and flavonoids (946.9 mg/g), detected by HPLC and quantified. The same extract demonstrated a cytoprotective effect in both models and a non-toxic effect against D. melanogaster , with low mortality and low inhibition of geotaxis, demonstrating that the extract can reduce the toxicity of this heavy metal against prokaryotic and Eukaryotic organisms. Due the results, we can conclude that the phytocompounds in the ethanol extract of E. uniflora , possibly phenols and flavonoids, could be interesting agents to protect different organisms against the heavy metal damages by a chelating or an antioxidative mechanism. Other studies are still necessary; however, these findings can open a new perspective to the recuperation of environments contaminated by heavy metals. [ABSTRACT FROM AUTHOR]

Abstract Even though TiO 2 is the most widely used electron transport layer (ETL) in high-efficiency perovskite solar cells (PSCs), ultraviolet photocatalysis and existence of intrinsic oxygen vacancies result in interfacial charge recombination and poor long-term photo-stability for TiO 2 -based PSCs under full spectral continuous illumination. To solve the issues, here we report dopamine-capped TiO 2 nanoparticles as ETL via chelating effect to improve interfacial binding with perovskite active layer. The introduction of dopamine can substantially reduce oxygen vacancies and suppress deep trap states within TiO 2. In addition, the terminal amino groups in dopamine can passivate the uncoordinated Pb atoms and decrease the Pb-I/Br antisite defects on the interface of perovskite/TiO 2. As an interfacial crosslinking agent, dopamine can not only reduce charge-accumulation and charge-recombination rate, but also increase charge-extraction efficiency at the TiO 2 and perovskite interface. Based on the dopamine-capped TiO 2 nanoparticles surface, the corresponding planner Cs 0.05 FA 0.81 MA 0.14 PbI 2.55 Br 0.45 PSCs deliver a power conversion efficiency of nearly 21% with negligible hysteresis. Moreover, unencapsulated devices retain 80% of their initial performance after 1200 h operation under constant full-sun illumination in nitrogen atmosphere. Ideally, this chemical-bath-deposited dopamine-modified TiO 2 provides an effective commercialized route for efficient and photostable planar PSCs. Graphical abstract fx1 Highlights • Dopamine-capped TiO 2 is obtained via sub-150 °C solution-processed method. • Defects of TiO 2 are decreased via chelating effect of dopamine. • Dopamine can effectively crosslink perovskite/TiO 2 interface. • Dopamine leads to a PCE of 20.93% with negligible hysteresis. • PSC retains ~80% of its performance under continuous 1200 h full spectral illumination. [ABSTRACT FROM AUTHOR]

The fruit fly Drosophila melanogaster is often utilized in genetic research, and in the last decades, it has become one of best organisms for studies of human diseases and toxicological research. Mercury chloride (HgCl2), the main representative of mercury compounds, is the target of numerous investigations, not only because of its intrinsic toxicity but also because it accounts for the toxicity of elemental mercury since the latter is converted to Hg+2 by oxidation. Eugenia jambolana Lam. Myrtaceae, known in Brazil as “jambolão”, is of great interest because of its medicinal applications, especially its leaves and fruits. The aim of this work was to characterize, by CG–MS, the chemical constituents of the essential oil of Eugenia jambolana and to evaluate its bioinsecticidal action in the Drosophila melanogaster model, as well as to determine the cytoprotective and chelating effect of the extract of E. jambolana. The results obtained here point to the potential of essential oils as a source in biological prospecting for bioinsecticides. Because of their biodegradability, essential oils can be important tools in the biological control of pests. The results demonstrated that the extract has an allelopathic effect on lettuce seeds and that its interaction with mercury chloride allows a greater growth of the radicle and plumule of Lactuta sativa seedlings, showing that this plant can provide an alternative solution to the problem of contamination by heavy metals, besides having cytoprotective potential and moderate chelating activity.

Mercury is a heavy metal that does not present any biological function and is considered toxic since it offers great environmental contamination risks to human beings. Psidium brawnianum is a plant found in the town of Araripe, in the Ceará State of Brazil, and is commonly known as “araçá de veado” – guava tree. The current study has the aim to determine the cytoprotective and metal chelating effect of P. brownianum extract. The results show that the tested HgCl 2 concentrations damage the germination and development of Lactuta sativa (lettuce) seeds. However, when sub-allelopathic concentrations (128 μg/mL) of the extract are used in association with HgCl 2 , a cytoprotective effect can be observed in assayed bacterial and plant models which correlated to metal chelation by phyrocompounds from the extract. Thus, the current study shows that this plant may be an interesting source of products against the heavy metal toxicity problem and contamination. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum (Leyss.:Fr.) Karst is one of the medicinal mushrooms, which possesses enviable antioxidant properties. Objective of this investigation was to evaluate antioxidant activity, reducing power, scavenging abilities on 1.1-diphenyl-2-picrylhydrazyl (DPPH) radicals and chelating effects on ferrous ions of hot water extracts obtained from carpophore and spores of this mushroom. Hot water extract from carpophore (Gl-I) showed high antioxidant activity of 85.7 ± 0.7%, at 10 mg/ml, while antioxidant activity of hot water extract from spores (Gl-Is) was 9.2 ± 0.3% at 10 mg/ml. Reducing power of Gl-I reached a plateau of 3.4 ± 0.1 at 20 mg/ml, and 0.3 ± 0.0 at 20 mg/ml for Gl-Is. At 10 mg/ml, scavenging ability on DPPH radicals of Gl-I increased to 96.8 ± 2.5%, whereas Gl-Is scavenged DPPH radicals by 69.6 ± 2.5% at 10 mg/ml. Gl-I chelated 81.6 ± 3.6 % of ferrous ions at 20 mg/ml, while the chelating effect of Gl-Is was 73.8 ± 1.7%. The antioxidative activities of hot water extracts from carpophore and spores of the mushroom G. lucidum were concentration dependent and increased with an increase in the concentration.

Three porous organic polymers (POPs) containing H, COOMe, and COO− groups at 2,6-bis(1,2,3-triazol-4-yl)pyridyl (BTP) units (i.e., POP-1, POP-2, and POP-3, respectively) were prepared for the immobilization of metal nanoparticles (NPs). The ultrafine palladium NPs are uniformly encapsulated in the interior pores of POP-1, whereas uniform- and dual-distributed palladium NPs are located on the external surface of POP-2 and POP-3, respectively. The presence of carboxylate groups not only endows POP-3 an outstanding dispersibility in H2O/EtOH, but also enables the palladium NPs at the surface to show the highest catalytic activity, stability, and recyclability in dehalogenation reactions of chlorobenzene at 25 °C. The palladium NPs on the external surface are effectively stabilized by the functionalized POPs containing BTP units and carboxylate groups, which provides a new insight for highly efficient catalytic systems based on surface metal NPs of porous materials. [ABSTRACT FROM AUTHOR]

The ethanolic extract of sugar beet pulp at 100% exibited good antioxidant activity of 69.74%. It showed an excellent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl radicals (84.94%) and was a mild chelator for ferrous and cupric ions. On the basis of some identified phenolic acids in ethanolic extract from sugar beet pulp it is concluded that predominant acids (ferulic, gentisic and p-coumaric acid), which have been previously evidented as relatively potent antioxidants, contribute to the antioxidant properties of the investigated extract. Antioxidative nature of ethanolic extract from sugar beet pulp, that is sugar beet pulp itself, indicate that it could be used as antioxidative component for decreasing oxidative changes in foods.

Objective: To evaluate the ethyl acetate, methanol and aqueous extracts of dried fruiting bodies of Pleurotus eous for its anti-platelet activity on human volunteer's blood. And also to analyze the free radical scavenging property of the extracts of P.eous by using various in vitro models. Methods: Anti-platelet activity of dried fruiting bodies of P.eous was evaluated by in vitro model using blood platelets. Inhibition of platelet aggregation was monitored after pre-incubation of platelets with the crude extracts of mushroom P.eous. Antioxidant activities of extracts of P.eous were evaluated by different in vitro experiments, namely, 1, 1-diphenyl-2-picryl hydrazyl (DPPH), superoxide, hydroxyl radical and lipid peroxide radical models. Results: Crude extracts of mushroom P.eous inhibited platelet aggregation dose-dependently which was induced by adenosine diphosphate (ADP). At a maximum concentration of 10 mg/mL, methanol extract effected 64.02% inhibition of lipid per-oxidation and 50.12% scavenging effect on superoxide anion radical. Aqueous extract of P.eous have shown 69.43% chelating ability on ferrous ions, 24.27% scavenging effect on hydroxyl radical and 49.57% scavenging effect on DPPH radical at 10 mg/mL. Increasing concentrations of the extract were found to cause progressively decreasing of the intensity of absorbance. Conclusions: Anti-platelet effects could be related in part to the polyphenolic compounds present in the extracts. Antioxidant activity results indicated the free radical scavenging property of the extracts of P.eous which might be due to the high content of phenolic compounds and flavonoids. [ABSTRACT FROM AUTHOR]

Gold(III) complexes are promising compounds for cancer chemotherapy, whose action depends on their redox stability. In this context, the choice of ligands is crucial to adjust their reactivity and biological response. The present study addressed the effect of the gold coordination sphere on the reduction potential (Eo) for ten gold(III) complexes containing five or six-membered rings tridentate ligands – [AuIII(trident)Cl]3+n (trident = N^N^N, C^N^N, C^C^N, C^N^C, and N^C^N). The calculated Eo covered a broad range of 2500 mV with the most stable complexes containing two Au C bonds (Eo = −1.85 V for [AuIII(C^C^N)Cl] – f). For complexes with one Au C bond, the N^C^N ligands stabilize the gold(III) complex more efficiently than N^N^C; however, the inclusion of the non-innocent ligand bipy (2,2′-bipyridine) in N^N portion provides an extra stabilization effect. Among the derivatives with one Au C bond, [AuIII(N^N^C)Cl]+ (N^N = bipy) (a) showed Eo = −1.20 V. For the complexes with N^N^N ligands, Eo was positive and almost constant (+0.60 V). Furthermore, the kinetics for ligand exchange reactions (Cl−/H 2 O, H 2 O/Cys and Cl−/Cys) were monitored for the most stable compounds and the energy profiles compared to the reduction pathways. The reduction process of gold(III) complexes is strongly dependent on the chelating mode and can be modulate by selecting appropriate tridentate ligand. [Display omitted] • Redox stability of Au(III) complexes is dependent on the chelating mode of tridentate ligand. • Ligands containing the bipyridine portion contribute to the gold(III) complex stabilization. • Stability of Au(III) complexes with N^N^N tridentate ligands is enhanced by imidazole groups. • Charge transfer to the tridentate ligand upon reduction favors Au(III) stability. [ABSTRACT FROM AUTHOR]

In vitro screening of a Fe2+-chelating effect using a Fenton's reaction-luminol chemiluminescence (CL) system is described. The luminescence between the reactive oxygen species generated by the Fenton's reaction and luminol was decreased on capturing Fe2+ using a chelator. The proposed method can prevent the consumption of expensive seed compounds (drug discovery candidates) owing to the high sensitivity of CL detection. Therefore, the assay could be performed using small volumes of sample solution (150 μL) at micromolar concentrations. After optimization of the screening conditions, the efficacies of conventional chelators such as ethylenediaminetetraacetic acid (EDTA), diethylentriaminepentaacetic acid (DETAPAC), deferoxamine, deferiprone and 1,10-phenanthroline were examined. EC50 values for these compounds (except 1,10- phenanthroline) were in the range 3.20 ± 0.87 to 9.57 ± 0.64 μM (n = 3). Rapid measurement of the Fe2+-chelating effect with an assay run time of a few minutes could be achieved using the proposed method. In addition, the specificity of the method was discussed. [ABSTRACT FROM AUTHOR]

Abstract: The fruit fly Drosophila melanogaster is often utilized in genetic research, and in the last decades, it has become one of best organisms for studies of human diseases and toxicological research. Mercury chloride (HgCl2), the main representative of mercury compounds, is the target of numerous investigations, not only because of its intrinsic toxicity but also because it accounts for the toxicity of elemental mercury since the latter is converted to Hg+2 by oxidation. Eugenia jambolana Lam. Myrtaceae, known in Brazil as “jambolão”, is of great interest because of its medicinal applications, especially its leaves and fruits. The aim of this work was to characterize, by CG–MS, the chemical constituents of the essential oil of Eugenia jambolana and to evaluate its bioinsecticidal action in the Drosophila melanogaster model, as well as to determine the cytoprotective and chelating effect of the extract of E. jambolana. The results obtained here point to the potential of essential oils as a source in biological prospecting for bioinsecticides. Because of their biodegradability, essential oils can be important tools in the biological control of pests. The results demonstrated that the extract has an allelopathic effect on lettuce seeds and that its interaction with mercury chloride allows a greater growth of the radicle and plumule of Lactuta sativa seedlings, showing that this plant can provide an alternative solution to the problem of contamination by heavy metals, besides having cytoprotective potential and moderate chelating activity. [Copyright &y& Elsevier]

Abstract: Crude polysaccharides were extracted from Athyrium multidentatum (Doll.) Ching (AMC) rhizome and fractionated by DEAE-Cellulose 52 ion-exchange column chromatography. Two polysaccharide fractions (F1 and F2) were obtained and had their antioxidant activities investigated employing various established in vitro systems. All fractions possessed considerable antioxidant activity. Chemical analysis suggested that F1 and F2 were neutral heteropolysaccharide in which glucose was the major component. Available data suggested that the molecular weight and sulfate content played very important roles on antioxidant activity. Our results indicated that the polysaccharides may contribute to the medicinal functions of AMC. [Copyright &y& Elsevier]

Abstract: Antioxidant properties of hot water extract (HWE), hot water extracted polysaccharides (HWP) and hot alkali extracted polysaccharides (HWAE) were obtained from fruiting bodies of the wild basidiomycete Schizophyllum commune. All extracts contained both α- and β-glucans as determined by Megazyme β-glucan assay kit. Glucose was found by TLC and NMR to be the prevalent monosaccharide in all extracts. Total phenol contents were in descending order of HWP ≈ HWE > HWAE. Median effective concentrations (EC50 values) of antioxidant activities were 8.3 ± 0.1, 6.9 ± 0.0 and 8.9 ± 0.1 mg/mL, and of the DPPH scavenging activity 0.8 ± 0.0, 0.6 ± 0.0 and 1.8 ± 0.0 mg/mL, for HWE, HWP and HWAE, respectively. EC50 values of reducing power were 7.6 ± 0.1, 7.9 ± 0.0 and 12.5 ± 0.1 mg/mL, whereas those of the chelating abilities on ferrous ions were 3.1 ± 0.0, 4.6 ± 0.1 and 4.9 ± 0.1 mg/mL. The EC50 values of the antioxidant activity, of the DPPH scavenging, and of the reducing power were correlated with total polysaccharide as well as with total phenol content. The antioxidant activities of all the extracts may be caused by both polysaccharides and polyphenols or by a complex of both. [Copyright &y& Elsevier]

Ganoderma lucidum (Leyss.:Fr.) Karst is one of the medicinal mushrooms, which possesses enviable antioxidant properties. Objective of this investigation was to evaluate antioxidant activity, reducing power, scavenging abilities on 1.1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and chelating effects on ferrous ions of hot water extracts obtained from carpophore and spores of this mushroom. Hot water extract from carpophore (G1-I) showed high antioxidant activity of 85.7 ± 0.7%, at 10 mg/ml, while antioxidant activity of hot water extract from spores (G1-Is) was 9.2 ± 0.3% at 10 mg/ml. Reducing power of G1-I reached a plateau of 3.4 ± 0.1 at 20 mg/ml, and 0.3 ± 0.0 at 20 mg/ml for G1-Is. At 10 mg/ml, scavenging ability on DPPH radicals of Gl-I increased to 96.8 ± 2.5%, whereas G1-Is scavenged DPPH radicals by 69.6 ± 2.5% at 10 mg/ml. G1-I chelated 81.6 ± 3.6 % of ferrous ions at 20 mg/ml, while the chelating effect of G1-Is was 73.8 ± 1.7%. The antioxidative activities of hot water extracts from carpophore and spores of the mushroom G. lucidum were concentration dependent and increased with an increase in the concentration. [ABSTRACT FROM AUTHOR]

Abstract: Chitosan (CS) with two different molecular weight were modified by reacting with methyl hydrazine-dithiocarboxylate and methyl phenylhydrazine-dithiocarboxylate to give 2-(hydrazine-thiosemicarbazone)-chitosan (2-HTCHCS, 2-HTCLCS) and 2-(phenylhydrazine-thiosemicarbazone)-chitosan (2-PHTCHCS, 2-PHTCLCS). The structure of the derivatives was characterized by FT-IR spectroscopy and elemental analysis. The antioxidant activities of the derivatives were investigated employing various established systems, such as hydroxyl radical (oxide anion (O2 .−) scavenging/reducing power and chelating activity. All of the derivatives showed strong scavenging activity on hydroxyl radical than chitosan and ascorbic acid (Vc), and IC50 of 2-HTCHCS, 2-HTCLCS, 2-PHTCHCS and 2-PHTCLCS was 0.362, 0.263, 0.531 and 0.336mg/mL respectively. The inhibitory activities of the derivatives toward superoxide radical by the PMS-NADH system were strong. The results showed that the superoxide radical scavenging effect of 2-[phenylhydrazine (or hydrazine)-thiosemicarbazone]-chitosan were higher than that of chitosan. The derivatives had obviously reducing power and chelating activity. The data obtained from vitro models clearly establish the antioxidant potency of 2-[phenylhydrazine (or hydrazine)-thiosemicarbazone]-chitosan. [Copyright &y& Elsevier]

This study evaluates the effect of corrosion on the pullout and tensile properties of ultra-high-performance concrete (UHPC) including steel fibers treated with ethylenediaminetetraacetic acid (EDTA) containing electrolyte solution for 3–9 h. For this, the steel fibers were intentionally corroded through a 3.5% sodium chloride (NaCl) solution to obtain two different corrosion degrees of 2% and 5% by weight. The roughness of the smooth steel fiber surface increases, owing to the chelating effect of the EDTA electrolyte solution, which is positive in enhancing the pullout and tensile performances of UHPC. The pullout resistance of steel fiber from UHPC increased after the treatment for up to 9 h, while the best tensile performance was obtained after 6-h treatment under non corrosive environments. The steel fibers were more severely oxidized when treated with the EDTA electrolyte solution. The pullout performance of the plain and 3-h treated steel fibers from UHPC improved for up to 2% degree of corrosion. Beyond this value, the pullout energy was deteriorated by premature ruptures. The pullout energy of steel fibers treated for 6 h or more decreased by corrosion. Under corrosive conditions, the best tensile performance was found for the steel fibers treated with the EDTA electrolyte solution for 3 h. Therefore, by considering inevitable corrosive environmental conditions, the steel fiber treated for 3 h is recommended as a suitable reinforcement for UHPC. [ABSTRACT FROM AUTHOR]

Abstract: The antioxidant potential of an ethanolic extract of the oyster mushroom, Pleurotus ostreatus, was investigated. The extract exhibited the most potent radical-scavenging activity at a maximum concentration of 10 mg/ml, and the scavenging effects were 56.20% and 60.02% on hydroxyl and superoxide radicals, respectively. The IC50 values of the extract were found to be 8 mg/ml for hydroxyl and superoxide radicals. Ascorbic acid used as a standard was highly effective in inhibiting hydroxyl and superoxide radicals, showing IC50 values of 6 mg/ml and 4 mg/ml respectively. At a maximum concentration of 10 mg/ml, the extract effected 56.12% inhibition of lipid peroxidation and 60.68% chelation of ferrous ions; also, at a maximum concentration 10 mg/ml, the extract manifested significant (p <0.05) reducing power (1.367) which exceeded even that of butylated hydroxyl toluene (1.192). Increasing concentrations of the extract were found to cause progressively decreasing intensity of fluorescence 2, 3-diazabicyclo [2, 2, 2] oct-2-ene (DBO). In addition, the known antioxidants were identified as components of the extract. The data generated by this study strongly suggest that an ethanolic extract of the oyster mushroom, P. ostreatus, has potent antioxidant activity. Industrial relevance: The present study suggests that an ethanolic extract of the mushroom, Pleurotus ostreatus, could serve as an easily accessible item of food rich in natural antioxidants, as a possible food supplement or even as a pharmaceutical agent. Hence this study is considerable relevant to the food and pharmaceutical industries. [Copyright &y& Elsevier]

Chitosan (CS) with two different molecular weights was modified by reacting with 4-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride or 2-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride to give new 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-di-sulfanimide)-chitosan (2-HCBSAHCS, 2-HCBSALCS, 4-HCBSAHCS, 4-HCBSALCS). The structure of the derivatives was characterized by FT-IR and 13C NMR spectroscopy. The antioxidant activities of the derivatives were investigated employing various established systems, such as hydroxyl radical (•OH)/superoxide anion (O2•) scavenging/reducing power and chelating activity. All the derivatives showed stronger scavenging activity on hydroxyl radical than chitosan and ascorbic acid (Vc), and IC50 of 4-HCBSAHCS, 4-HCBSALCS, 2-HCBSAHCS and 2-HCBSALCS was 0.334, 0.302, 0.442, 0.346mg/mL, respectively. The inhibitory activities of the derivatives toward superoxide radical by the PMS–NADH system were strong. The results showed that the superoxide radical scavenging effect of 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-di-sulfanimide)-chitosan was higher than chitosan. The derivatives had obviously reducing power and slight chelating activity. The data obtained in in vitro models clearly establish the antioxidant potency of 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-disulfanimide)-chitosan. [Copyright &y& Elsevier]

Abstract: Fucoidan, a group of sulfated heteropolysaccharide, was extracted from Laminaria japonica, an important economic alga species in China. Three sulfated polysaccharide fractions (F1, F2, and F3) were successfully isolated through anion-exchange column chromatography and had their antioxidant activities investigated employing various established in vitro systems, including superoxide and hydroxyl radical scavenging activity, chelating ability, and reducing power. Chemical analysis suggested that F1 and F3 were heteropolysaccharide in which galactose was the major component, while F2 was a typical fucoidan. All fractions possessed considerable antioxidant activity, and F1, F2 and F3 had stronger antioxidant ability than fucoidan in certain tests. The correlation between the sulfate content and scavenging superoxide radical ability was positive. Available data obtained with in vitro models suggested that the ratio of sulfate content/fucose was an effective indicator to antioxidant activity of the samples. [Copyright &y& Elsevier]

The antioxidant potency of high/low molecular weight quaternary chitosan derivatives was investigated employing various established systems in vitro, such as superoxide (O2·−) and hydroxyl (·OH) radicals scavenging, reducing power and iron ion chelating. As expected, we obtained several satisfying results, as follow: firstly, low molecular weight quaternary chitosan had stronger scavenging effect on O2·− and ·OH than high molecular weight quaternary chitosan. Secondly, the reducing power of low molecular weight quaternary chitosan was more pronounced than that of high molecular weight quaternary chitosan. Thirdly, ferrous ion chelating potency were showed to increase first and decrease afterwards with increasing concentration for two kinds of quaternary chitosans, namely, they have not concentration-dependence. However, the scavenging rate and reducing power of high and low molecular weight quaternary chitosans increased with their increasing concentrations, and hence were concentration-dependent. [Copyright &y& Elsevier]

Abstract: In order to find antioxidant potential, seeds of 30 varieties of Glycine max were studied for their total phenolic contents (TPC), flavonoids and antioxidant activity (AOA). The seed extracts showed wide variation of TPC from 6.4 to 81.7mgGAE/g, flavonoids 3.5 to 44.6mg QE/g and AOA 7.5% to 74.7%. Free radical-scavenging activity (FRSA), assayed by DPPH in terms of IC50 (inhibitory concentration), ranged from 0.14 to 0.80mg/ml, EC50 (efficiency concentration) from 6.1 to 34.8mg/mgDPPH, ARP (anti-radical power) 2.9 to 16.4 and reducing power from 1.9 to 4.7ASE/ml. Variety Kalitur showed highest the FRSA followed by Alankar and Hara soya, as evident from their low IC50, EC50 and high ARP values. Alankar, Kalitur NRC-37, PK-472, VLS-47, Hara soya varieties were with comparatively higher TPC (52.7–81.7mgGAE/g), AOA (50.5–74.7%) and showed better inhibition of peroxide formation assayed through ammonium thiocyanate and egg yolk, non-site-specific and site-specific inhibition of hydroxyl radical induced deoxyribose degradation and ferrous ion-chelating capacity than did the other varieties. Seed extracts of these varieties and leaves of Kalitur showed significant protection against DNA damage caused by free radicals. The agri-wastes of some promising varieties, e.g. Alankar, Kalitur, NRC-37 and PK-472, showed TPC ranging from 27.4 to 167mg GAE/g, total flavanoids from 10.4 to 63.8mgQE/g and AOA from 26.5% to 84.7% and their values were highest in the leaves, followed by pod pericarp and twigs. Out of all the varieties studied, leaves of Alankar and Kalitur varieties were more potent free radical-scavengers than were seeds, pod pericarp or twigs. The specific phenolic compositions and their quantifications were performed by HPLC and MS/MS, which showed that the seeds of Kalitur were higher in genistin (127μg/g), seeds and leaves of Alankar in diadzin (113μg/g) and gallic acid (87.2μg/g), respectively. The present studies may be of importance in varietal improvement, nutraceuticals, bio-pharmaceuticals and utilization of agri-wastes as possible cost-effective natural antioxidants. [Copyright &y& Elsevier]

Abstract: Four (red, violet, white and green) varieties of Allium cepa were studied for their total phenolic contents (TPC), antioxidant (AOA) and free radical scavenging activities (FRSA). The TPC varied from 4.6 to 74.1mg/g GAE, AOA varied from 13.6% to 84.1% and FRSA showed wide range in terms of IC50 (inhibitory concentration) from 0.1 to 15.2mg/ml, EC50 (efficient concentration) from 4.3 to 660.8mg/mg and ARP (antiradical power) from 0.15 to 23.2. The outer dry layers of red and violet varieties showed better inhibition of lipid peroxidation assayed by ammonium thiocyanate than α-tocopherol. The non-site-specific inhibition of hydroxyl radical induced deoxyribose degradation was also higher in the outer dry layers of red and violet varieties than in their middle and inner layers. The outer layers were also potential inhibitors of nitroblue tetrazolium chloride (NBT) reduction caused by superoxide anions. On the other hand the ferrous ion chelating capacity of the red and violet varieties was highest in the inner layers. Specific phenolic composition performed through HPLC and LC–MS/MS showed the presence of gallic acid, ferulic acid, protocatechuic acid, quercetin, and kaempferol. The unutilised outer layers of the red variety were a rich source of quercetin (5110μg/g) with high AOA, FRSA and also showed significant protection of DNA damage caused by free radicals. [Copyright &y& Elsevier]

Abstract: A novel fluorescent sensing film for organic copper(II) salts was developed by covalently attaching pyrene moieties onto glass slide surfaces via a long flexible spacer. Fluorescence measurements demonstrated that the emission of the film was efficiently quenched by organic copper(II) salts, including copper acetate, cupric tartrate and cupric citrate. Presence of any of other divalent metal acetates, such as Ni(Ac)2, Co(Ac)2, Pb(Ac)2, Cd(Ac)2 and Zn(Ac)2, has little effect upon the emission of the film. The quenching efficiency of Cu(Ac)2, however, was reduced moderately in the presence of these similar divalent metal acetates. The interference of these salts to the sensing of organic copper(II) salts was attributed to the competition of the complexation sites in the spacer, which may be one of the reasons that enhance the enrichment of Cu(II) into the spacer layer. The detection limit of the film to Cu(Ac)2 is 0.26μM, which is much lower than those reported earlier. The quenching by copper acetate of the emission of the film is static in nature due to complexation of the spacers to the metal ions. Furthermore, the sensing process is fully reversible. [Copyright &y& Elsevier]

Abstract: A novel fluorescent Cu(II) sensing film was developed by covalently attaching dansyl (5-dimethylamino-1-naphthalenesulfonyl) moieties onto glass slide surface based on self-assembled monolayer technique. Fluorescence measurements showed the emission of the dansyl-functionalized film was selectively quenched by Cu(II) ions and slightly influenced by the presence of other similar divalent metal ions (Pb(II), Zn(II), Ni(II), Co(II), etc.). In addition, the sensitivity of the film towards Cu(II) was increased as expected since more binding sites, the diethylenetriamine moieties, were incorporated into the spacer. It was also found that the presence of organic anions like acetate, citrate, and tartrate, etc. could enhance the quenching efficiency of Cu(II) compared with inorganic anions such as chloride, sulfate, and nitrate. This observation was explained by considering the spacer screening effect as discovered previously. Moreover, the response of the film toward Cu(II) is fully reversible which makes it attractive for sensing application. [Copyright &y& Elsevier]

The antioxidant potency of chitin derivative-glucosamine hydrochloride was investigated employing various established in vitro systems, such as superoxide (O2 ·-)/hydroxyl (·OH)-radical scavenging, reducing power, and ferrous ion chelating potency. As expected, we obtained several satisfying results, as follows: first, glucosamine hydrochloride had pronounced scavenging effect on superoxide radical. For example, the O2 ·- scavenging activity of glucosamine hydrochloride was 83.74% at 0.8mg/mL. Second, the ·OH scavenging activity of glucosamine hydrochloride was also strong and was about 54.89% at 3.2mg/mL. Third, the reducing power of glucosamine hydrochloride was more pronounced. The reducing power of glucosamine hydrochloride was 0.632 at 0.75mg/mL. However, ferrous ion-chelating potency was soft. Furthermore, ferrous ion-chelating potency, the scavenging rate of radical, and the reducing power of glucosamine hydrochloride increased with their increasing concentration, and they were concentration dependent. The multiple antioxidant activity of glucosamine hydrochloride was evident as it showed considerable reducing power, superoxide/hydroxyl-radical scavenging ability. These in vitro results suggest the possibility that glucosamine hydrochloride could be effectively employed as an ingredient in health or functional food, to alleviate oxidative stress. [Copyright &y& Elsevier]

Abstract: The aims of this work were to assess the influence of concentration, heat treatment, and pH value on antioxidant activity of ethanolic extracts obtained from Holy basil (Ocimum sanctum Linn) and Galangal (Alpinia galanga). The antioxidative properties were evaluated. The ethanolic extracts of Holy basil and Galangal showed good heat stability (80 °C, 1 h). At neutral and acidic pH, Holy basil extracts had high antioxidative stability, whereas Galangal extracts showed higher antioxidative stability at neutral than at acidic pH ranges. Antioxidant activity of both extracts at neutral pH was higher than at acidic pH ranges. Holy basil and Galangal extracts exhibited strong superoxide anion scavenging activity, Fe2+ chelating activity, and reducing power in a concentration-dependent manner. Antioxidant activity of both extracts correlated well with reducing power. Furthermore, ethanolic extracts of Holy basil and Galangal acted as radical scavenger and also as lipoxygenase inhibitor. [Copyright &y& Elsevier]

The antioxidant potency of different molecular weight (DMW) chitosan and sulfated chitosan derivatives was investigated employing various established in vitro systems, such as superoxide (O2·-)/hydroxyl (·OH) radicals scavenging, reducing power, iron ion chelating. As expected, we obtained several satisfying results, as follows: Firstly, low molecular weight chitosan had stronger scavenging effect on and ·OH than high molecular weight chitosan. For example the scavenging activity of low molecular weight chitosan (9kDa) and high molecular weight chitosan (760kDa) were 85.86% and 35.50% at 1.6mg/mL, respectively. Secondly, comparing with DMW chitosan, DMW sulfated chitosans had the stronger inhibition effect on . At 0.05mg/mL, the scavenging activity on reached 86.26% for low molecular weight chitosan sulfate (9kDa), but that of low molecular weight chitosan (9kDa) was 85.86% at 1.6mg/mL. As concerning chitosan and sulfated chitosan of the same molecular weight, scavenging activities of sulfated chitosan on superoxide and hydroxyl radicals were more pronounced than that of chitosan. Thirdly, low molecular weight chitosan sulfate had more effective scavenging activity on O2·- and ·OH than that of high molecular weight chitosan sulfate. Fourthly, DMW chitosans and sulfated chitosans were efficient in the reducing power, especially LCTS. Their orders were found to be LCTS>CTS4>HCTS>CTS3>CTS2>CTS1>CTS. Fifthly, CTS4 showed more considerable ferrous ion-chelating potency than others. Finally, the scavenging rate and reducing power of DMW chitosan and sulfated derivatives increased with their increasing concentration. Moreover, change of DMW sulfated chitosans was the most pronounced within the experimental concentration. However, chelating effect of DMW chitosans were not concentration dependent except for CTS4 and CTS1. [Copyright &y& Elsevier]

Three species of mushroom mycelia are commercially available in Taiwan, namely Grifola frondosa (maitake), Morchella esculenta (morel), and Termitomyces albuminosus (termite mushroom). Methanolic extracts were prepared from these three mycelia and their antioxidant properties were studied. Methanolic extracts from the three mycelia showed high antioxidant activities (85.4–94.7%) at 25 mg ml−1. Reducing powers of the three methanolic extracts were 0.97–1.02 at 25 mg ml−1. Scavenging effects on 1,1-diphenol-2-picrylhydrazyl radicals were 78.8–94.1% at 10 mg ml−1. These three mycelia showed no scavenging effect on hydroxyl radicals. Chelating effects on ferrous ions were high (90.3–94.4%) at 10 mg ml−1. Total phenols were the major naturally occurring antioxidant components found in methanolic extracts. Contents of ascorbic acid and tocopherols were similar for these three mycelia. All EC50 values were below 10 mg ml−1, indicating that the three mycelia had good antioxidant properties except for the scavenging effect on hydroxyl radicals. [Copyright &y& Elsevier]

Red and white mycelia of Antrodia camphorata (Zang and Su) were obtained due to different fermentation operations. The antioxidant properties and antioxidant components of methanolic extracts from these two mycelia were studied. Using the conjugated diene method, the antioxidant activity of methanolic extracts from white mycelia was better than that from red mycelia (EC50 3.11 vs. 19.8 mg ml−1). Both mycelia were efficient in the reducing power and scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radicals but white mycelia showed significantly lower EC50 values (1.56 and 1.70 mg ml−1, respectively). At 7.5–10 mg ml−1, the chelating effects on ferrous ions reached a plateau of 95.7–98.7% for both mycelia. However, the EC50 value was lower for red mycelia. Contents of antioxidant components were found to be in the order of tocopherols > total phenols > ascorbic acid > β-carotene. Methanolic extracts from A. camphorata red and white mycelia were good in the antioxidant properties tested, except for the scavenging effect on hydroxyl ions. Although contents of total antioxidant components were relatively high in red mycelia, the antioxidant properties were better with the methanolic extract from white mycelia. [Copyright &y& Elsevier]

Curcuma zedoaria (Berg.) Rosc. (Zingiberaceae) has long been used as a folk medicine. The essential oil of its dried rhizome was isolated using simultaneous steam-distillation and solvent-extraction apparatus and its fractions were prepared by silica gel column chromatography. Totally, 36 compounds were identified in the essential oil, including 17 terpenes, 13 alcohols and 6 ketones. The yields of Fractions 2 and 3 were 83.66 and 10.71%, respectively. Epicurzerenone and curzerene were found in the first and second highest amounts (24.1 and 10.4%). At 20 mg ml−1, the essential oil of C. zedoaria was moderate to good in antioxidant activities by three different methods, good in reducing power and excellent in scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical but low in chelating effect on ferrous ion. However, after fractionation, with regard to all antioxidant properties assayed, fraction 4 showed consistently better effects than the essential oil did. The compound in fraction 4 responsible for better antioxidant properties might be 5-isopropylidene-3,8-dimethyl-1(5H)-azulenone. [Copyright &y& Elsevier]

The effect of ammonium acetate on the preparation of alumina particles as precipitating agent was investigated. Alumina particles were prepared by precipitation of aqueous aluminum chloride solution by using ammonium acetate and ammonium hydroxide. The thermal behaviors, morphologies and surface area were studied for alumina particles formed by ammonium acetate and compared with those of particles formed by ammonium hydroxide. The particles formed by ammonium acetate showed a narrower size distribution, spherical shape, larger surface area and lower crystallinity. These results were explained based on the chelating effects of acetate ions. [Copyright &y& Elsevier]

Solvent extracts were prepared from green, yellow fallen and red fallen leaves of Terminalia catappa L. and their antioxidant activities were evaluated. Other antioxidant properties of methanolic extracts, including reducing power, scavenging and chelating effects, were also determined. The yields were consistently in the order of yellow fallen (6.34–10.50%)>red fallen (5.12–9.98%)>green leaf extracts (2.36–6.08%) for four solvents used. Higher yields were obtained from extraction with ethyl acetate or methanol than with dichloromethane or pentane. For three different leaves, the antioxidant activities were in the order methanol>ethyl acetate>dichloromethane>pentane extracts and all showed a parabolic-like curve with the maximum at 0.1–0.5 mg ml−1 of solvent extract. Reducing powers of three methanolic extracts and their scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals were excellent at 0.5 and 0.1 mg ml−1, respectively. At 30 mg ml−1, chelating effects of methanolic extracts from green, yellow fallen and red fallen leaves on ferrous ions were 77.3, 48.6 and 48.3%, respectively. [Copyright &y& Elsevier]

Four specialty mushrooms are commercially available in Taiwan, including Dictyophora indusiata (basket stinkhorn), Grifola frondosa (maitake), Hericium erinaceus (lion''s mane), and Tricholoma giganteum (white matsutake). Methanolic extracts were prepared from these specialty mushrooms and their antioxidant properties were studied. The antioxidant activities at 1.2 mg ml−1 were in the order of basket stinkhorn>lion''s mane>maitake>white matsutake. Basket stinkhorn showed an excellent reducing power of 1.09 at 3 mg ml−1. At 6.4 mg ml−1, scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals were 92.1% for basket stinkhorn and 63.2–67.8% for other specialty mushrooms. At 40 mg ml−1, scavenging effects were 75.0 and 69.4% for basket stinkhorn and lion''s mane and 39.6 and 47.4% for maitake and white matsutake, respectively. At 24 mg ml−1, chelating effects on ferrous ions were 91.9% for basket stinkhorn and 46.4–52.0% for other specialty mushrooms. Total polyphenols were the major naturally occurring antioxidant components found in the methanolic extracts from these specialty mushrooms. [Copyright &y& Elsevier]

The effect of precipitating agent on the preparation of iron(III) oxide particles was investigated. Iron(III) oxide particles were prepared by precipitation of aqueous ferric nitrate solution by using ammonium acetate and ammonium hydroxide as precipitating agents. Particle size, shape, chemical composition, crystalline formation rate, crystallinity and magnetic property were measured for Fe2O3 particles obtained by precipitating with ammonium acetate, and compared with those of particles formed by using ammonium hydroxide. TGA, DTA, IR, XRD, TEM and VSM were used to characterize the particles. The nanoparticles synthesized with ammonium acetate showed a narrow size distribution, spherical shape, fast crystalline formation rate, high crystallinity and complete hysteresis loop. The better properties of particles formed by using ammonium acetate were originated from the chelating effect of carboxylate ions and higher crystallinity than those synthesized with ammonium hydroxide. [ABSTRACT FROM AUTHOR]

• Preparation of large Bi 2 O 3 single crystals by AACVD for the first time. • Chelating agent enables single crystal growth on amorphous substrates. • Substrate temperature (T s) enhances crystal growth under a critical T s. • Deposition time enhances mainly the lateral crystal growth. • Crystal size exhibits a T s dependent lognormal distribution. Large Bi 2 O 3 single crystals over tens of microns were grown on amorphous glass substrates from an aqueous solution by using aerosol assisted chemical vapor deposition. The chelating agent not only stabilizes bismuth ions, but also modifies the kinetic crystal growth dynamics on substrates, resulting in well-developed parallelepiped-shaped single crystals. The crystal shape, size and its growth process are investigated with respect to both substrate temperature (T s) and deposition time (t d). Under low T s , it is more like a layer-by-layer growth mechanism with well-defined crystal habit, crystal size and its distribution, while as increasing t d , crystals grow mainly laterally along the substrate surface with nearly constant crystal thickness, which finally coalesce with each other without observable boundaries. [ABSTRACT FROM AUTHOR]