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A new hydroxo‐bridged ruthenium (II) complex [{Ru(η6‐p‐cymene)(iPr2P−O)}2(μ‐OH)]Cl (2) has fortuitously been isolated from the reaction between the known ruthenium(II) complex [RuCl2(η6‐p‐cymene)(iPr2P‐OH)] (1) in either CDCl3 or CHCl3 solutions in the presence of excess DBU (1,8‐diazabicyclo(5.4.0)undec‐7‐ene) at room temperature. Complex 2 is only formed under specific conditions as an orange‐colored air and moisture stable binuclear complex. It is formed via the deprotonation of the P−OH unit in [RuCl2(η6‐p‐cymene)(iPr2P‐OH)]. Complex 2 has been fully characterized by spectroscopic and analytical methods. Its structure was determined by single crystal X‐ray diffraction which reveals a boat‐shaped motif containing a bridging hydroxide unit which undergoes hydrogen bonding with a chloride counterion. Complex 2 was utilized as a catalyst for the hydrogenation of CO2 to formic acid salt using molecular hydrogen. The catalytic reactions were performed at 100 °C in THF in the presence of DBU as a base to isolate [DBU+H][OC(O)H] salt as the final product. Using catalyst loadings down to 0.01 mol%, it was possible to hydrogenate gaseous CO2 with TONs up to 9900. [ABSTRACT FROM AUTHOR]

A new hydroxo‐bridged ruthenium (II) complex [{Ru(η6‐p‐cymene)(iPr2P−O)}2(μ‐OH)]Cl (2) has fortuitously been isolated from the reaction between the known ruthenium(II) complex [RuCl2(η6‐p‐cymene)(iPr2P‐OH)] (1) in either CDCl3 or CHCl3 solutions in the presence of excess DBU (1,8‐diazabicyclo(5.4.0)undec‐7‐ene) at room temperature. Complex 2 is only formed under specific conditions as an orange‐colored air and moisture stable binuclear complex. It is formed via the deprotonation of the P−OH unit in [RuCl2(η6‐p‐cymene)(iPr2P‐OH)]. Complex 2 has been fully characterized by spectroscopic and analytical methods. Its structure was determined by single crystal X‐ray diffraction which reveals a boat‐shaped motif containing a bridging hydroxide unit which undergoes hydrogen bonding with a chloride counterion. Complex 2 was utilized as a catalyst for the hydrogenation of CO2 to formic acid salt using molecular hydrogen. The catalytic reactions were performed at 100 °C in THF in the presence of DBU as a base to isolate [DBU+H][OC(O)H] salt as the final product. Using catalyst loadings down to 0.01 mol%, it was possible to hydrogenate gaseous CO2 with TONs up to 9900. [ABSTRACT FROM AUTHOR]

The novel mononuclear Cd(II) metalloreceptor Cd[LH2I2] (complex 1), derived by the reaction of the Schiff base ligand 6,6′-(1E,1′E)(ethane-1,2 diylbis(azaneylidene))bis(methaneylylidene)bis(2-ethoxyphenol) (H2L) and CdI2, was successfully used to detect Zn(II) and Mg(II) in semi-aqueous and aqueous media, respectively, among several competitive cations. The single crystal data analysis revealed that the asymmetric unit of complex 1 consists of one ligand, H2L, and two I-ions, compensating the +2 oxidation state of Cd. The optically monitored sensing of Zn(II) and Mg(II) by complex 1 was further assessed by utilizing UV and fluorescence spectroscopic techniques. The remarkable enhancement of the fluorescence intensity of complex 1-Zn(II) and complex 1-Mg(II) in the presence of CH3COO− and SO4= indicated that a heteronuclear bridging complex could be obtained if two separate reactions of complex 1 with (CH3COO)2Zn and MgSO4 could be carried out. Interestingly, two different single crystals of Cd–Zn (complex 2) and Cd–Mg (complex 3) were obtained after conducting two separate reactions of complex 1 with Zn(II) and Mg(II). Single crystal data analysis showed that complex 2 is an octanuclear Zn(II)/Cd(II) complex with the presence of acetate and an hydroxy group, and both metal centers are in the +2 oxidation state. The IR and NMR spectra results confirmed the formation of complexes 2 and 3. The SPX and EDX studies confirmed the presence of Zn(II) and Mg(II) in complex 2 and complex 3, respectively. The limit of detection for sensing of both was measured in the nanomolar range. Although it is well-known that mononuclear Cd complexes are effective Schottky devices, there have been few reports of investigation of heteronuclear Cd(II) complexes as candidates for effective Schottky devices, or determination of the values of device performance, conductivity, and device parameters with heteronuclear Cd complexes 2 and 3. Surprisingly, all the results indicated that a potential Schottky device could be produced due to the efficacy of complex 2 with respect to complex 3. The effectiveness of the device would be satisfactory because of the lower band gap value and the presence of weak intramolecular π–π stacking interactions in complex 2. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae Stm1 protein is a ribosomal association factor, which plays an important role in preserving ribosomes in a nutrition-deprived environment. It is also shown to take part in apoptosis-like cell death. Stm1 N-terminal region (Stm1_N1-113) is shown to recognize purine motif DNA triplex and G-quadruplex. Circular dichroism (CD) spectra of Stm1_N1-113 (enriched in positively-charged Lysine and Arginine; negatively-charged Aspartate; polaruncharged Threonine, Asparagine, Proline and Serine; hydrophobic Alanine, Valine, and Glycine) collected after 0 and 24 h indicate that the protein assumes beta-sheet conformation at the higher concentrations in contrast to intrinsically disordered conformation seen for its monomeric form found in the crystal structure. Thioflavin-T kinetics experiments indicate that the lag phase is influenced by the salt concentration. Atomic force microscopy (AFM) images collected for a variety of Stm1_N1-113 concentrations (in the range of 1-400 μM) in the presence of 150 mM NaCl at 0, 24, and 48 h indicate a threshold concentration requirement to observe the time-dependent amyloid formation. This is prominent seen at the physiological salt concentration of 150 mM NaCl with the fibrillation observed for 400 μM concentration at 48 h, whereas oligomerization or proto-fibrillation is seen for the other concentrations. Such concentration-dependent fibrillation of Stm1_N1-113 explains that amyloid fibrils formed during the overexpression of Stm1_N1-113 may act as a molecular device to trigger apoptosis-like cell death. [ABSTRACT FROM AUTHOR]

D-Galactosamine (D-GalN) is a well-established hepatotoxic agent, whereas lipopolysaccharide (LPS) is a bacterial endotoxin; and both in a combination induces the liver damage, which is similar to a human hepatic diseases. In this study, we have evaluated the hepatoprotective activity of the Giant or Black Pigweed, Trianthema portulacastrum L. against D-galactosamine in the presence of lipopolysaccharide (LPS/D-GalN) induced hepatotoxicity using Swiss albino mice. LPS/D-GalN treatment elevated the liver marker enzymes. The combined action of LPS/D-GalN decreased the production of antioxidants such as reduced glutathione (GSH), catalase, superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST) and increase in the malondialdehyde (MDA) and nitric oxide (NO) formation. Pretreatment with T. portulacastrum (TP) extract showed dose dependently attenuated liver marker enzymes, increased GSH content, upregulated enzymatic activities of antioxidants in liver, decreased MDA and NO formation. The results also revealed that LPS/D-GalN-treatment increased the inflammation as observed through neutrophil infiltrations and increased the formation of sinusoids as evidenced from the histopathological studies of liver tissue and the TP extract pre-treatment mitigated the neutrophil infiltration and sinusoids formation dose dependently. [ABSTRACT FROM AUTHOR]

The common Giant Pigweed or Black Pigweed Trianthema portulacastrum L.is a well-known hepatoprotactant against chemical-induced toxicity. In this study, we evaluated the radioprotective activity of T. portulacastrum stem extract in Swiss albino mice through survival assay and confirmed by histopathology of the liver and jejunum. We observed that at higher concentrations (200 mg/kg body wt.) of extract, the survival of mice was 20% higher. The mechanism of protection was evaluated by endogenous colony-forming assay, bone marrow cell count, membrane integrity, and antioxidant enzymes of the liver. Histopathology of the liver and jejunum revealed that irradiated animals to have suffered loss of normal architecture of the liver in the form of hepatic sinusoid dilation and neutrophil infiltration, and distorted structure of villi in the jejunum of mice was observed. Pre-treatment of mice with extracts of Trianthema portulacastrum (50, 100 and 200 mg/kg body wt.) attenuated the effects of radiation in a dose-dependent manner. Further, the increased spleen colony numbers and augmented number of bone marrow cells in extract pre-treated mice, in comparison with untreated irradiated mice suggest the protective activity of T. portulacastrum. The treated group of mice also showed increased activities of antioxidant enzymes measured in tissue homogenates of the liver as compared to the untreated irradiated controls. Our present study demonstrated dose-dependent radioprotective property of T. portulacastrum against membrane damage. [ABSTRACT FROM AUTHOR]