Catalytic battle of activated carbon supported transition metal atom towards adsorption and dissociation of molecular hydrogen: Progress towards quantum chemical application on renewable energy resource.

Density functional theory (DFT) investigation has been done to unravel the adsorption and dissociation nature of hydrogen molecule on 3d, 4d and 5d transition metal (M = Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt or Au) atom doped activated carbon (AC) surface. Transition metal doped AC are found to be active catalyst for storage of hydrogen and also gives the stability of M - H bonds formed after bond breakage of H molecule. Transition metals are found to occupy the position on the five member ring rather than six member ring of the AC.

Heme-induced loss of renovascular endothelial protein C receptor promotes chronic kidney disease in sickle mice.

Chronic kidney disease (CKD) is a major contributor to morbidity and mortality in sickle cell disease (SCD). Anemia, induced by chronic persistent hemolysis, is associated with the progressive deterioration of renal health, resulting in CKD. Moreover, patients with SCD experience acute kidney injury (AKI), a risk factor for CKD, often during vaso-occlusive crisis associated with acute intravascular hemolysis.

Environmentally relevant lead alters nuclear integrity in erythrocytes and generates oxidative stress in liver of Anabas testudineus: Involvement of Nrf2-Keap1 regulation and expression of biomarker genes.

Genotoxic and hepatotoxic effects of lead (Pb) on a freshwater fish, climbing perch (Anabas testudineus) were studied at an environmentally relevant concentration (43.3 ppm). The genotoxic potential of Pb was confirmed by micronucleus study, with increased frequencies of erythrocytic nuclear alterations like lobed, blebbed, notched, fragmented, and micronuclei were observed in erythrocytes in treated groups as compared to control.

Quantum Chemical Investigation on Hydrolysis of Orally Active Organometallic Ruthenium(II) and Osmium(II) Anticancer Drugs and Their Interaction with Histidine.

Influence of the metal center on hydrolysis of organometallic anticancer complexes containing an -phenyl-2-pyridinecarbothioamide (PCA) ligand, [M(η--cymene)(-phenyl-2-pyridinecarbothioamide)Cl] (M = Ru, , and Os, ), as well as their -fluorophenyl derivatives [M(η--cymene)(-fluorophenyl-2-pyridinecarbothioamide)Cl] (M = Ru, , and Os, ) have been investigated using the DFT method in aqueous medium. The activation energy barriers for the hydrolysis of (21.5 kcal/mol) and (20.

Environmentally Relevant Hexavalent Chromium Disrupts Elemental Homeostasis and Induces Apoptosis in Zebrafish Liver.

Although hexavalent chromium Cr [VI] is known as a toxicant in the aquatic environment, its effect in low, environmentally relevant concentration (ERC; 2 mg L) is less characterized. Against this backdrop, the effects of Cr [VI] in ERC on zebrafish liver has been investigated in this study. Fluorescence microscopy and gel electrophoresis detected excess DNA damage and cell death via apoptosis in 2 mg L Cr [VI]-treated fish when compared with that of control.

Quantum Chemical Investigations on the Hydrolysis of Gold(III)-Based Anticancer Drugs and Their Interaction with Amino Acid Residues.

A comprehensive hydrolysis mechanism of the promising class of Au(III) anticancer drugs [Au(DMDT)Cl] (DMDT = ,-dimethyldithiocarbamate) () and [Au(damp)Cl] (damp = 2-[(dimethylamino)methyl]phenyl) (') was done by means of density functional theory (DFT) in combination with the CPCM solvation model to explore the solution behavior and stability under physiological conditions. The activation free energies (Δ) for the second hydrolysis, (13.7 kcal/mol) and ' (10.

Involvement of a unique chemodosimeter in the selective estimation of noxious cyanide in common water hyacinth (): an environmental refinement.

A naphthaldehyde-pyridoxal conjugated chemodosimeter (NPLC) was developed and employed for the sensitive and selective detection and estimation of cyanide in common water hyacinth (), a free floating macrophyte used in the phytoremediation process since ancient times. The non-fluorescent nature of the probe NPLC, directed by the possibility of excited state intramolecular proton transfer process (ESIPT), was promptly changed due to CN induced di-deprotonation of the probe. The naked eye color change and turn on vivid fluorescent color of NPLC was attributed to the inhibition of the ESIPT mechanism in the deprotonated NPLC (NPLC-D).

A Density Functional Theory Study on Et-BAC-Catalyzed 1,6-Conjugate Addition of -Chlorobenzaldehyde to -Quinone Methide for the Synthesis of α,α-Diarylated Ketones.

Umpolung-based organocatalysis has made a remarkable breakthrough in the field of synthetic organic chemistry. Among a plethora of umpolung catalysts, bis(amino)cyclopropenylidenes (BACs) have emerged as efficient organocatalysts with potential applications in synthesizing numerous essential organic moieties. In this study, a plausible mechanism for bis(diethylamino)cyclopropenylidene (Et-BAC)-catalyzed synthesis of α,α-diarylated ketones has been established using the density functional theory (DFT) method.

Combined effect of arsenic and fluoride at environmentally relevant concentrations in zebrafish (Danio rerio) brain: Alterations in stress marker and apoptotic gene expression.

Arsenic and fluoride are two naturally occurring toxicants to which various organisms including a major part of the human populations are co-exposed to. However, interactions between them inside body are quite complicated and needs proper evaluation. Inconclusive reports regarding their combined effects on brain prompted us to conduct this study where we investigated their individual as well as combined effects on female zebrafish brain at environmentally relevant concentrations (50 μgL arsenic trioxide and 15 mgL sodium fluoride) after different time intervals (15, 30 and 60 days).

Calcium and Vitamin D Supplementation Effectively Alleviates Dental and Skeletal Fluorosis and Retain Elemental Homeostasis in Mice.

Fluoride (F) is an essential trace element, but chronic exposure beyond the permissible limit (1.5 ppm) effectuates dental and skeletal fluorosis. Although 200 million people across the world are suffering from toxic manifestations of F, till now proper treatment is not available.

Shinorine ameliorates chromium induced toxicity in zebrafish hepatocytes through the facultative activation of Nrf2-Keap1-ARE pathway.

Hexavalent chromium, a heavy metal toxicant, abundantly found in the environment showed hepatotoxic potential in zebrafish liver and instigated the Nrf2-Keap1-ARE pathway as a cellular stress response as reported in our previous studies. In the present study we have evaluated the ameliorating effect of shinorine, a mycosporine like amino acid (MAAs) and a mammalian Keap1 antagonist against chromium induced stress in zebrafish hepatocytes. Shinorine was found to be effective in increasing the cell viability of chromium treated hepatocytes through curtailing the cellular ROS content.

Environmental exposure of arsenic and fluoride and their combined toxicity: A recent update.

Environmental exposure to arsenic (As) and fluoride (F) in the recent year has been increased because of excessive use of naturally contaminated ground water. Surface water is also regularly contaminated with these elements in various industrial areas. Arsenicosis and fluorosis upon individual exposure of As and F are reported in many studies.

Environmentally relevant concentration of chromium induces nuclear deformities in erythrocytes and alters the expression of stress-responsive and apoptotic genes in brain of adult zebrafish.

Heavy metal contamination of water body has become a serious threat to aquatic life forms specially to fish. Hexavalent chromium (Cr [VI]) is one of the most potent heavy metal toxicant. It is present in aquatic environment at concentrations beyond permissible limit.

Mixture effect of arsenic and fluoride at environmentally relevant concentrations in zebrafish (Danio rerio) liver: Expression pattern of Nrf2 and related xenobiotic metabolizing enzymes.

Nrf2 is a crucial transcription factor that regulates the expression of cytoprotective enzymes and controls cellular redox homeostasis. Both arsenic and fluoride are potent toxicants that are known to induce Nrf2. They are reported to coexist in many areas of the world leading to complex mixture effects in exposed organisms.

Environmentally relevant concentration of chromium activates Nrf2 and alters transcription of related XME genes in liver of zebrafish.

Fish is an excellent model to decipher the mechanism of toxicity of aquatic contaminants such as hexavalent chromium (Cr [VI]). The present study looked into the manifestation of stress in liver of zebrafish exposed to an environmentally relevant concentration (2 mgL), and the functioning of the cytoprotective machinery that pacifies the formed stress. The results lead us to hypothesize that oxidative stress plays a key role in chromium-induced toxicity resulting in lipid peroxidation and extensive changes in tissue ultrastructure.

Coumarin Based Fluorescent Probe for Colorimetric Detection of Fe and Fluorescence Turn On-Off Response of Zn and Cu.

A new coumarin based Schiff-base chemosensor-(E)-7-(((8-hydroxyquinolin-2-yl)methylene) amino)-4-methyl-2H-chromen-2-one (H L) was synthesized and evaluated as a colorimetric sensor for Fe and fluorescence "turn on-off" response of Zn and Cu using absorption and fluorescence spectroscopy. Upon treatment with Fe and Zn, the absorption intensity as well as the fluorescence emission intensity increases drastically compared to other common alkali, alkaline earth and transition metal ions, with a distinct color change which provide naked eye detection. Formation of 1:1 metal to ligand complex has been evaluated using Benesi-Hildebrand relation, Job's plot analyses, H NMR titration as well as ESI-Mass spectral analysis.

Quantum Chemical Studies on Detail Mechanism of Nitrosylation of NAMI-A-HSA Adduct.

Hydrolysis of NAMI-A in NAMI-A-HSA (HSA = human serum albumin) and nitrosylation of hydrolyzed NAMI-A-HSA adduct have been studied in detail using density functional theory method. It has been observed that the chloride exchange reaction with water in the NAMI-A-HSA adduct follows an interchange dissociative mechanism passing through an unstable heptacoordinated activated complex. The computed free energy of activation (ΔG) and rate constant (k) for the hydrolysis process in aqueous medium are observed to be 24.

Novel water soluble neutral vanadium(IV)-antibiotic complex: Antioxidant, immunomodulatory and molecular docking studies.

A novel water soluble five coordinate oxovanadium(IV) complex, [VO(C16H15N4O8S)HSO4] incorporating cefuroxime, a cephalosporin group of antibiotic have been prepared from an interaction of vanadyl sulfate and cefuroxime in aqueous solution. The compound was characterized by Fourier transform infrared spectroscopy (FTIR), CHN microanalyses, ultraviolet-visible spectroscopy (UV-Vis), fast atom bombardment (FAB) mass spectrometry and thermogravimetric analysis (TGA). Density Functional Theory (DFT) computation using Gaussian 09 program at B3LYP level revealed a distorted square pyramidal energy optimized geometry for the vanadyl(IV) complex.

Synthesis and aggregation behaviour of luminescent mesomorphic zinc(II) complexes with 'salen' type asymmetric Schiff base ligands.

A new series of photoluminescent Zn(II)-salen type asymmetric Schiff base complexes, [ZnL], H2L = [N,N'-bis-(4-n-alkoxysalicylidene)-1,2-diaminopropane] (n = 12, 14 and 16) have been accessed and their mesomorphic and photophysical properties investigated. Though the ligands are non-mesomorphic, coordination to Zn(2+) ion induces liquid crystalline behaviour. The complexes exhibited a lamello-columnar phase (Coll) as characterized by a variable temperature powder X-ray diffraction (XRD) study.

Tunable emissive lanthanidomesogen derived from a room-temperature liquid-crystalline Schiff-base ligand.

A novel photoluminescent room-temperature liquid-crystalline salicylaldimine Schiff base with a short alkoxy substituent and a series of lanthanide(III) complexes of the type [Ln(LH)3(NO3)3] (Ln = La, Pr, Sm, Gd, Tb, Dy; LH = (E)-5-(hexyloxy)-2-[{2-(2-hydroxyethylamino)ethylimino]methyl}phenol) have been synthesized and characterized by FTIR, (1)H and (13)C NMR, UV/Vis, and FAB-MS analyses. The ligand coordinates to the metal ions in its zwitterionic form. The thermal behavior of the compounds was investigated by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC).

Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes.

Two new mixed-ligand iron(III) complexes, [Fe(L(n))(acac)(C(2)H(5)OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac)(3)] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H(2)L(1)) or 2-aminobenzoic acid (H(2)L(2)). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L(n))(acac)X] (n=1, 2; X=Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, (1)H and (13)C NMR spectroscopy.