Divalent manganese,cobalt, copper and cadmium complexes of (Z)‐N‐benzoyl‐N′‐(1H‐1,2,4‐triazol‐3‐yl)carbamimidothioic acid: Preparation,characterization, computational and biological studies

In this work, (Z)‐N‐benzoyl‐N′‐(1H‐1,2,4‐triazol‐3‐yl)carbamimidothioic acid and its Mn(II), Co(II), Cu(II) and Cd(II) complexes were introduced for the first time. This carbonyl thiourea ligand was prepared by the reaction of 1H‐1,2,4‐triazol‐3‐amine with benzoyl isothiocyanate. The structural elucidation of these compounds was performed using elemental analysis and spectral and magnetic measurements. Octahedral structures of all complexes, except Cd(II) complex with a tetrahedral geometry, were confirmed by applying DFT structural optimization. The thermal decomposition behaviour of metal complexes of carbonyl thiourea ligand is discussed. The calculation of kinetic parameters for prepared complexes (E_a, A, ΔH*, ΔS* and ΔG*) of all thermal degradation stages has been evaluated using two comparable approaches. Antimicrobial and ABTS‐antioxidant studies indicated potent activity of Cd(II) complex compared with the other investigated compounds. The cytotoxic activity of the prepared compounds was investigated in vitro. The results indicated potent activity of Mn(II) complex against both HePG2 (liver carcinoma) and MCF‐7 (breast carcinoma) cancer cells.     

Copper nanoclusters as peroxidase mimetics and their applications to H2O2 and glucose detection

Copper nanoclusters (Cu NCs) are found to possess intrinsic peroxidase-like activity for the first time. Similar to nature peroxidase, they can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine by H₂O₂ to produce a nice blue color reaction. Compared with horseradish peroxidase, Cu NCs exhibits higher activity near neutral pH, which is beneficial for biological applications. The increase in absorbance caused by the Cu NCs catalytic reaction allows the detection of H₂O₂ in the range of 10 μM to 1 mM with a detection limit of 10 μM. A colorimetric method for glucose detection was also developed by combining the Cu NCs catalytic reaction and the enzymatic oxidation of glucose with glucose oxidase. Taking into account the advantages of ultra-small size, good stability, and high biocompatibility in aqueous solutions, Cu NCs are expected to have potential applications in biotechnology and clinical diagnosis as enzymatic mimics.     

A novel reaction cascade leading to a spontaneous intramolecular dipolar cycloaddition through simultaneous generation of 1,3-dipole and dipolarophile

Ornithine methyl ester reacts with aromatic aldehydes to generate bis-Schiff bases, which depending on the structure of the aromatic aldehyde, further undergo an intramolecular cycloaddition through the transient formation of a reactive 1,3-dipole.     

A review on recent advances in hierarchically porous metal and metal oxide nanostructures as electrode materials for supercapacitors and non-enzymatic glucose sensors

The remarkable significance of electrode materials in industrial processes, energy, sustainability and diabetes monitoring has captivated scientists to develop advance nanomaterials for the benefit of life across the globe. Here in, the recent developments in nanostructured porous metal and metal oxide composite materials for supercapacitor applications and non-enzymatic glucose sensors (NEGS) has been extensively discussed. The essential and active electrode materials from the research and application perspective has been emphasized in detail. We have also evaluated the worthiness, taxonomical classification, efficiency, specific capacitance and sensitivity of these materials for the aforementioned potential applications. Eventually, we concluded the review by providing the aspect ratio, surface morphology, particle size and specific surface area of these materials that plays an indispensable role for their promising potential applications.     

Bucillamine Inhibits UVB-Induced MAPK Activation and Apoptosis in Human HaCaT Keratinocytes and SKH-1 Hairless Mouse Skin

Ultraviolet B (UVB) radiation is known as a culprit in skin carcinogenesis. We have previously reported that bucillamine (N-[2-mercapto-2-methylpropionyl]-L-cysteine), a cysteine derivative with antioxidant and anti-inflammatory capacity, protects against UVB-induced p53 activation and inflammatory responses in mouse skin. Since MAPK signaling pathways regulate p53 expression and activation, here we determined bucillamine effect on UVB-mediated MAPK activation in vitro using human skin keratinocyte cell line HaCaT and in vivo using SKH-1 hairless mouse skin. A single low dose of UVB (30 mJ cm⁻²) resulted in increased JNK/MAPK phosphorylation and caspase-3 cleavage in HaCaT cells. However, JNK activation and casaspe-3 cleavage were inhibited by pretreatment of HaCaT cells with physiological doses of bucillamine (25 and 100 µm ). Consistent with these results, bucillamine pretreatment in mice (20 mg kg⁻¹) inhibited JNK/MAPK and ERK/MAPK activation in skin epidermal cells at 6–12 and 24 h, respectively, after UVB exposure. Moreover, bucillamine attenuated UVB-induced Ki-67-positive cells and cleaved caspase-3-positive cells in mouse skin. These findings demonstrate that bucillamine inhibits UVB-induced MAPK signaling, cell proliferation and apoptosis. Together with our previous report, we provide evidence that bucillamine has a photoprotective effect against UV exposure.     

Synthesis and Structural Proof of a Potent 5-Lipoxygenase Inhibitor

Abstract  

5-Lipoxygenase inhibitor 3-O-acetyl-9,11-dehydro-β-boswellic acid was detected in the extract of Boswellia serrata gum resulting from unstable 11-hydroxy precursor. It was reported more potent than other Boswellic acids in its inhibition of 5-Lipoxygenase. Here, we report the method of conversion of 3-acetoxy-β-boswellic acid to 3-O-acetyl-9,11-dehydro-β-boswellic acid, and the crystal structure of later. This compound crystallizes in orthorhombic space group P2₁2₁2₁ with cell parameters of a = 12.726(1) ?, b = 16.597(1) ?, c = 27.332(2) ?, α = β = γ = 90°, V = 5772.7(5) ?³, D _c = 1.143 Mg/m³, and Z = 8. The X-ray structure investigation indicates that the rings A, B, D and E are exhibit chair and the ring C adopts a distorted half chair conformation. The conformational difference of the two structures in the arrangement is due to crystal packing of 3-O-acetyl-9,11-dehydro-β-boswellic acid. The molecular packing is stabilized by C–H···O and O–H···O types of hydrogen bonding interactions.     

Synthesis of primary amines: first homogeneously catalyzed reductive amination with ammonia

[reaction: see text] The synthesis of primary amines via reductive amination of the corresponding carbonyl compounds with aqueous ammonia is achieved for the first time with soluble transition metal complexes. Up to an 86% yield and a 97% selectivity for benzylamines were obtained in the case of various benzaldehydes by using a Rh-catalyst together with water-soluble phosphine and ammonium acetate. In the case of aliphatic aldehydes, a bimetallic catalyst based on Rh/Ir gave improved results.     

Varying Track Etch Rates along the Fission Fragments＇ Trajectories in CR-39 Detectors

We determine the behavior of track etch rate VT along the tracks in CR-39 detectors exposed to fission fragments from ^252Cf source. CR-39 detectors are etched at 70℃ in different concentrations of Na2COa-mixed 6M NaOH solutions for different etching time intervals of 5-10min starting from 15 min up to 210min. Two values of track etch rate are determined along the fission fragment trajectories. The variation in VT is correlated with the energy loss rate of the fission fragment in the detector material.     

A Validated LC Method for the Quantitation of Cefotaxime in pH-Sensitive Nanoparticles

A sensitive and rapid routine LC method was validated for measuring cefotaxime incorporated in three different pH-sensitive nanoparticles. The drug was chromatographed on a C18 reversed-phase column; the mobile phase used was 0.05 M aqueous ammonium acetate, acetonitrile and tetrahydrofuran (87:11:2, v/v) adjusted to pH 5.5 with acetic acid. The flow rate was 1 mL min^?1 and cefotaxime was quantified at 254 nm, with a sensitivity range of 0.005 AUFS. The validated method was specific, linear (R ² ≥ 0.999), precise and accurate in a concentration range of 0.2–50.0 μg mL^?1. The method was rapid, selective and suitable for evaluation of cefotaxime in pH-sensitive Eudragit nanoparticles.     

Living fungal hyphae-templated porous gold microwires using nanoparticles as building blocks

Abstract  

A simple and environmentally benign green method is reported to decorate growing fungal hyphae with high loading of gold nanoparticles, which were initially produced using aqueous tea extract as a sole reducing/stabilizing agent. Inoculation of fungal spores in aqueous suspension of nanoparticles led to the growth of intensely red-coloured fungal hyphae due to the accumulation of gold nanoparticles. Heat treatment of these hybrid materials led to the formation of porous gold microwires. This report is thus an interesting example of using green and sustainable approach to produce nanostructured materials which have potential applications in catalysis, sensing and electronics.