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1.
Performance of synthesized cast and electrospun PVA/chitosan/ZnO-NH2 nano-adsorbents in single and simultaneous adsorption of cadmium and nickel ions from wastewater.
Bozorgi, M, Abbasizadeh, S, Samani, F, Mousavi, SE
Environmental science and pollution research international. 2018;(18):17457-17472
Abstract
The performance of synthesized cast and electrospun polyvinyl alcohol/chitosan/zinc oxide/aminopropyltriethoxylsilane (PVA/chitosan/ZnO-APTES) nano-adsorbents were compared in removal of Cd(II) and Ni(II) ions from wastewater. The adsorbents were characterized by SEM, BET, FTIR and TGA analyses. Furthermore, the swelling investigations were carried out to study the adsorbent stability in aqueous solution. The effect of several parameters such as contents of ZnO-NH2, contact time, initial Cd(II) and Ni(II) concentration and temperature on the adsorption capacity was investigated in a batch mode. In comparison with cast adsorbent, nanofiber adsorbent indicated the better adsorption performance. The experimental data well fitted the double-exponential kinetic model. In single metal ion system, the maximum adsorption capacity of nanofiber for Cd(II) and Ni(II) ions is estimated to be 1.239 and 0.851 mmol/g, respectively, much higher than qm of cast adsorbent for Cd(II) (0.625 mmol/g) and Ni(II) (0.474 mmol/g) ions. Thermodynamic parameters were investigated to identify the nature of adsorption process. In binary system of Cd(II)-Ni(II) ions, the inhibitory effect of competitive Cd(II) ion on the Ni(II) adsorption was greater than the inhibitory effect of competitive on the Cd(II) adsorption. The selectivity adsorption of both nanofiber and cast adsorbents was in order of Cd(II) > Ni(II).
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2.
Evaluation of antioxidant potencial of novel CaAl and NiAl layered double hydroxides loaded with olanzapine.
Pontes-Neto, JG, Fontes, DAF, de Lyra, MAM, Brito, MDRM, Chaves, LL, Rolim-Neto, PJ, De La Roca Soares, MF, Quintans Júnior, LJ, de Freitas, RM, Soares-Sobrinho, JL
Life sciences. 2018;:246-252
Abstract
Olanzapine (OLZ), is used in the treatment of bipolar disorder and schizophrenia, diseases that present oxidative stress in their physiopathology. It has low aqueous solubility, which may lead to low oral bioavailability. The search of new drug delivery systems (DDSs) that may increase dissolution rate of OLZ, associated with the investigation of the antioxidant potential of the loaded-systems become of major importance to understand improvement in bipolar disorder and schizophrenia therapy. Thus, this study aimed to evaluate the in vitro antioxidant potential of two different Layered Double Hydroxides (LDH) loaded with 5% of OLZ (CaAl and NiAl), by radical scavenging activity (2,2-Diphenyl-1-picrylhydrazyl and nitric oxid); radical cation scavenging activity (2,2'-azino-bis3-ethylbenzthiazoline-6-sulfonic acid ABTS) and evaluation of inhibition capacity of lipid peroxidation by thiobarbituric acid (TBARS). The results showed that both obtained LDH systems presented in vitro antioxidant capacity when associated with OLZ in all methods performed, and this activity is more pronounced with the systems containing OLZ compared to pure drug. The systems with CaAl was shown to have increased antioxidant potential, compared to NiAl, increasing the antioxidant activity up to 40,83%, 15,84% and 16,73%, as showed by the DPPH, nitric oxide and TBARS tests, respectively. The results revealed that the use of LDHs as a functional excipient may be promising in the pharmaceutical industry for bipolar disorder and schizophrenia therapy.
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3.
Deciphering the chemoselectivity of nickel-dependent quercetin 2,4-dioxygenase.
Wang, WJ, Wei, WJ, Liao, RZ
Physical chemistry chemical physics : PCCP. 2018;(23):15784-15794
Abstract
The reaction mechanism and chemoselectivity of nickel-dependent quercetin 2,4-dioxygenase (2,4-QueD) have been investigated using the QM/MM approach. The protonation state of the Glu74 residue, a first-shell ligand of Ni, has been considered to be either neutral or deprotonated. QM/MM calculations predict that Glu74 must be deprotonated to rationalize the chemoselectivity and steer the 2,4-dioxygenolytic cleavage of quercetin, which harvests the experimentally-observed product, 2-protocatechuoylphloroglucinol carboxylic acid, coupled with the release of carbon monoxide. If the enzyme has a neutral Glu74 residue, the undesired 2,3-dioxygenolytic cleavage of quercetin becomes the dominant pathway, leading to the formation of α-keto acid. The calculations suggest that the reaction takes place via three major steps: (1) attack of the superoxide on the C2 of the substrate pyrone ring to generate a NiII-peroxide intermediate; (2) formation of the second C-O bond between C4 and the peroxide to produce a peroxide bridge; (3) simultaneous cleavage of the C2-C3, C3-C4, and O1-O2 bonds with the formation of 2-protocatechuoylphloroglucinol carboxylic acid and carbon monoxide. The third step was found to be rate-limiting, with a barrier of 17.4 kcal mol-1, which is in very good agreement with the experimental kinetic data. For the second C-O bond formation, an alternative pathway is that the peroxide attacks the C3 of the substrate pyrone ring, leading to the formation of a four-membered ring intermediate, which then undergoes concerted C2-C3 and O1-O2 bond cleavages to produce an α-keto acid. This pathway is associated with a barrier of 30.6 kcal mol-1, which is much higher than the major pathway. When Glu74 is protonated, the 2,3-dioxygenolytic pathway, however, has a lower barrier (21.8 kcal mol-1) than the 2,4-dioxygenolytic pathway.
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4.
In-vitro anti-cancer activity of organic template-free hierarchical M (Cu, Ni)-modified ZSM-5 zeolites synthesized using silica source waste material.
Jesudoss, SK, Judith Vijaya, J, Kaviyarasu, K, Iyyappa Rajan, P, Narayanan, S, John Kennedy, L
Journal of photochemistry and photobiology. B, Biology. 2018;:178-188
Abstract
The present paper is focused on a simple and economical route to synthesize the organic template-free hierarchical pure and M (Cu, Ni)-modified ZSM-5 zeolites (1%, 3% and 5%) using hydrothermal treatment in the presence of silica rich rice husk ash and its application studies through the evaluation of their anti-cancer activity on A459 human lung epithelial cancer cell lines. The physical properties of the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, high resolution scanning electron microscopy, high resolution transmission electron microscopy, N2 adsorption/desorption techniques and thermogravimetric analysis respectively. These metals modified hierarchical ZSM-5 zeolites showed considerable in-vitro anticancer efficiency towards human lung cancer (A549) cell lines through (3-(4, 5-dimethyl thiazolyl)-2, 5-diphenyl tetrazolium bromide) MTT assay. Among the all M (Cu, Ni)-modified ZSM-5 zeolites, 5% Cu-ZSM-5 zeolites showed higher potential cytotoxicity against A459 cell lines. The possible mechanism was explored from the fundamental signaling pathways of cell death by hierarchical metal modified ZSM-5 zeolites in A459 human lung epithelial cancer cell lines. Finally, our experimental results revealed that the organic template-free hierarchical pure and M (Cu, Ni)-modified ZSM-5 zeolites have significant anti-cancer mediating action by inducing oxidative stress to intercede DNA damage and can be considered as a potential applicant in the biomedical field.
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5.
Nickel; whether toxic or essential for plants and environment - A review.
Shahzad, B, Tanveer, M, Rehman, A, Cheema, SA, Fahad, S, Rehman, S, Sharma, A
Plant physiology and biochemistry : PPB. 2018;:641-651
Abstract
Nickel (Ni) is becoming a toxic pollutant in agricultural environments. Due to its diverse uses from a range of common household items to industrial applications, it is essential to examine Ni bioavailability in soil and plants. Ni occurs in the environment (soil, water and air) in very small concentrations and eventually taken up by plants through roots once it becomes available in soil. It is an essential nutrient for normal plant growth and development and required for the activation of several enzymes such as urease, and glyoxalase-I. Ni plays important roles in a wide range of physiological processes including seed germination, vegetative and reproductive growth, photosynthesis as well as in nitrogen metabolism. Therefore, plants cannot endure their life cycle without adequate Ni supply. However, excessive Ni concentration can lead to induce ROS production affecting numerous physiological and biochemical processes such as photosynthesis, transpiration, as well as mineral nutrition and causes phytotoxicity in plants. ROS production intensifies the disintegration of plasma membranes and deactivates functioning of vital enzymes through lipid peroxidation. This review article explores the essential roles of Ni in the life cycle of plant as well as its toxic effects in details. In conclusion, we have proposed different viable approaches for remediation of Ni-contaminated soils.
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6.
Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes.
Fiedler, AT, Fischer, AA
Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry. 2017;(2-3):407-424
Abstract
The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.
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7.
Unveiling the effects of the in situ generated arene anion radical and imine radical on catecholase like activity: a DFT supported experimental investigation.
Dasgupta, S, Adhikary, J, Giri, S, Bauza, A, Frontera, A, Das, D
Dalton transactions (Cambridge, England : 2003). 2017;(18):5888-5900
Abstract
Two new dinuclear nickel(ii) complexes namely [Ni2(L1)2(OAc)2(H2O)2]·CH3CN (1) and [Ni2(L2)2(SCN)2(CH3OH)2]·CH3OH (2) have been synthesized from the designed Schiff-base ligand 4-bromo-2-[(2-hydroxy-1,1-dimethyl-ethylimino)-methyl]-phenol (HL1) and its reduced analogue 4-bromo-2-[(2-hydroxy-1,1-dimethyl-ethylamino)-methyl]-phenol (HL2), respectively. Both 1 and 2 have been characterised by usual physicochemical techniques (UV-Vis, FT-IR, ESI-MS study and single crystal XRD) and their variable temperature magnetic study has been performed. The nickel(ii) centres in the dinuclear complexes 1 and 2 are antiferromagnetically coupled through participation of the bridging phenoxyl oxygen. In acetonitrile solution both 1 and 2 retain their dinuclear structural integrity as is evident from the ESI-MS study. The catecholase-like activity of 1 and 2 has been performed in acetonitrile medium using 3,5-di-tert-butylcatechol (3,5-DTBC) as a model substrate. Complex 1 shows a higher catalytic activity than that of complex 2. The ESI-MS study suggests that dinuclear species undergo cleaving into a mononuclear entity in the presence of 3,5-DTBC and that mononuclear species are supposed to act as active catalysts in the catalytic cycle. The EPR study of catalytic reactions confirms that organic radicals have been generated during catalysis in both cases. However, in the case of complex 1 catalyzed reaction a single isotropic signal at g = 1.97 is obtained which is most likely due to imine radical formation. On the other hand, for complex 2 catalyzed reaction the spectrum shows a signal with hyperfine splitting (g = 2.11, 2.05 and 1.9), thereby suggesting the generation of a new radical i.e. an arene anion radical in this study on catecholase activity. Extensive DFT calculations have been performed to support the experimental observation and thus to put forward the most probable mechanistic pathways operating in the two cases. The higher efficiency of the imine radical pathway over the arene anion radical has been rationalized by DFT calculations.
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8.
Novel Microbial Assemblages Dominate Weathered Sulfide-Bearing Rock from Copper-Nickel Deposits in the Duluth Complex, Minnesota, USA.
Jones, DS, Lapakko, KA, Wenz, ZJ, Olson, MC, Roepke, EW, Sadowsky, MJ, Novak, PJ, Bailey, JV
Applied and environmental microbiology. 2017;(16)
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Abstract
The Duluth Complex in northeastern Minnesota hosts economically significant deposits of copper, nickel, and platinum group elements (PGEs). The primary sulfide mineralogy of these deposits includes the minerals pyrrhotite, chalcopyrite, pentlandite, and cubanite, and weathering experiments show that most sulfide-bearing rock from the Duluth Complex generates moderately acidic leachate (pH 4 to 6). Microorganisms are important catalysts for metal sulfide oxidation and could influence the quality of water from mines in the Duluth Complex. Nevertheless, compared with that of extremely acidic environments, much less is known about the microbial ecology of moderately acidic sulfide-bearing mine waste, and so existing information may have little relevance to those microorganisms catalyzing oxidation reactions in the Duluth Complex. Here, we characterized the microbial communities in decade-long weathering experiments (kinetic tests) conducted on crushed rock and tailings from the Duluth Complex. Analyses of 16S rRNA genes and transcripts showed that differences among microbial communities correspond to pH, rock type, and experimental treatment. Moreover, microbial communities from the weathered Duluth Complex rock were dominated by taxa that are not typically associated with acidic mine waste. The most abundant operational taxonomic units (OTUs) were from the genera Meiothermus and Sulfuriferula, as well as from diverse clades of uncultivated Chloroflexi, Acidobacteria, and Betaproteobacteria Specific taxa, including putative sulfur-oxidizing Sulfuriferula spp., appeared to be primarily associated with Duluth Complex rock, but not pyrite-bearing rocks subjected to the same experimental treatment. We discuss the implications of these results for the microbial ecology of moderately acidic mine waste with low sulfide content, as well as for kinetic testing of mine waste.IMPORTANCE Economic sulfide mineral deposits in the Duluth Complex may represent the largest undeveloped source of copper and nickel on Earth. Microorganisms are important catalysts for sulfide mineral oxidation, and research on extreme acidophiles has improved our ability to manage and remediate mine wastes. We found that the microbial assemblages associated with weathered rock from the Duluth Complex are dominated by organisms not widely associated with mine waste or mining-impacted environments, and we describe geochemical and experimental influences on community composition. This report will be a useful foundation for understanding the microbial biogeochemistry of moderately acidic mine waste from these and similar deposits.
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9.
Contact Dermatitis Due to Nickel Allergy in Patients Suffering from Non-Celiac Wheat Sensitivity.
D'Alcamo, A, Mansueto, P, Soresi, M, Iacobucci, R, Blasca, F, Geraci, G, Cavataio, F, Fayer, F, Arini, A, Di Stefano, L, et al
Nutrients. 2017;(2)
Abstract
BACKGROUND Non-celiac wheat sensitivity (NCWS) is a new clinical entity in the world of gluten-related diseases. Nickel, the most frequent cause of contact allergy, can be found in wheat and results in systemic nickel allergy syndrome and mimics irritable bowel syndrome (IBS). Objective: To evaluate the frequency of contact dermatitis due to nickel allergy in NCWS patients diagnosed by a double-blind placebo-controlled(DBPC)challenge,and to identify the characteristics of NCWS patients with nickel allergy. Methods: We performed a prospective study of 60 patients (54 females, 6 males; mean age 34.1 ± 8.1 years) diagnosed with NCWS from December 2014 to November 2016; 80 age- and sex-matched subjects with functional gastrointestina l symptoms served as controls. Patients reporting contact dermatitis related to nickel-containing objects underwent nickel patch test (Clinicaltrials.gov registration number: NCT02750735). RESULTS Six out of sixty patients (10%) with NCWS suffered from contact dermatitis and nickel allergy and this frequency was statistically higher (p = 0.04)than observed in the control group(5%. The main clinical characteristic of NCWS patients with nickel allergy was a higher frequency of cutaneous symptoms after wheat ingestion compared to NCWS patients who did not suffer from nickel allergy (p < 0.0001. CONCLUSIONS Contact dermatitis and nickel allergy are more frequent in NCWS patients than in subjects with functional gastrointestinal disorders;furthermore, these patients had a very high frequency of cutaneous manifestations after wheat ingestion. Nickel allergy should be evaluated in NCWS patients who have cutaneous manifestations after wheat ingestion.
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10.
The CO dehydrogenase accessory protein CooT is a novel nickel-binding protein.
Timm, J, Brochier-Armanet, C, Perard, J, Zambelli, B, Ollagnier-de-Choudens, S, Ciurli, S, Cavazza, C
Metallomics : integrated biometal science. 2017;(5):575-583
Abstract
In Rhodospirillum rubrum, maturation of Carbon Monoxide Dehydrogenase (CODH) requires three accessory proteins, CooC, CooT and CooJ, dedicated to nickel insertion into the active site, which is constituted by a distorted [NiFe3S4] cubane coordinated with a mononuclear Fe site. CooC is an ATPase proposed to provide the energy required for the maturation process, while CooJ is described as a metallochaperone with 16 histidines and 2 cysteines at the C-terminus, likely involved in metal binding and/or storage. Prior to the present study, no information was available on CooT at the molecular level. Here, the X-ray structure of RrCooT was obtained, which revealed that this protein is a homodimer featuring a fold that resembles an Sm-like domain, suggesting a role in RNA metabolism that was however not supported by experimental observations. Biochemical and biophysical evidence based on circular dichroism spectroscopy, light scattering, isothermal titration calorimetry and site-directed mutagenesis showed that RrCooT specifically binds a single Ni(ii) per dimer, with a dissociation constant of 9 nM, through the pair of Cys2, highly conserved residues, located at the dimer interface. Despite its role in the activation of RrCODH in vivo, CooT was thought to be a unique protein, found only in R. rubrum, with an unclear function. In this study, we extended the biological impact of CooT, establishing that this protein is a member of a novel Ni(ii)-binding protein family with 111 homologues, linked to anaerobic metabolism in bacteria and archaea, and in most cases to the presence of CODH.