Role of ancillary ligands in -nitrosothiol and NO generation from nitrite-thiol interactions at mononuclear zinc(ii) sites.

Generation of -nitrosothiol (RSNO) and nitric oxide (NO) mediated by zinc(ii) coordination motifs is of prime importance for understanding the role of zinc(ii)-based cofactors in redox-signalling pathways. This study uniquely employs a set of mononuclear [LZn] cores (where L = MePzPz/MePzPy/MePzQu) for introducing subtle alterations of the primary coordination sphere and investigates the role of ligand tuning in the transformation of NO in the presence of thiols. Single crystal X-ray diffraction (SCXRD) analyses on [LZn-X](X) (where X = perchlorate/triflate) illustrate consistent changes in the bond distances, thereby showing variations of the metal-ligand interactions depending on the nature of the heterocyclic donor arms (pyrazole/pyridine/quinoline).

Nitrite and Nitric Oxide Interconversion at Mononuclear Copper(II): Insight into the Role of the Red Copper Site in Denitrification.

Nitrite (NO ) and nitric oxide (NO) interconversion is crucial for maintaining optimum NO flux in mammalian physiology. Herein we demonstrate that [L Cu (nitrite)] moieties (in 2 a and 2 b; where, L = Me PzPy and Me PzQu) with distorted octahedral geometry undergo facile reduction to provide tetrahedral [L Cu ] (in 3 a and 3 b) and NO in the presence of biologically relevant reductants, such as 4-methoxy-2,6-di-tert-butylphenol (4-MeO-2,6-DTBP, a tyrosine model) and N-benzyl-1,4-dihydronicotinamide (BNAH, a NAD(P)H model). Interestingly, the reaction of excess NO gas with [L Cu (MeCN) ] (in 1 a) provides a putative {CuNO} species, which is effective in mediating the nitrosation of various nucleophiles, such as thiol and amine.

Metal-free Transformations of Nitrogen-Oxyanions to Ammonia via Oxoammonium Salt.

Transformations of nitrogen-oxyanions (NO ) to ammonia impart pivotal roles in sustainable biogeochemical processes. While metal-mediated reductions of NO are relatively well known, this report illustrates proton-assisted transformations of NO anions in the presence of electron-rich aromatics such as 1,3,5-trimethoxybenzene (TMB-H, 1 a) leading to the formation of diaryl oxoammonium salt [(TMB) N =O][NO ] (2 a) via the intermediacy of nitrosonium cation (NO ). Detailed characterizations including UV/Vis, multinuclear NMR, FT-IR, HRMS, X-ray analyses on a set of closely related metastable diaryl oxoammonium [Ar N =O] species disclose unambiguous structural and spectroscopic signatures.

Cobalt chloride attenuates hypobaric hypoxia induced vascular leakage in rat brain: molecular mechanisms of action of cobalt chloride.

This study reports the efficacy of cobalt preconditioning in preventing hypobaric hypoxia induced vascular leakage (an indicator of cerebral edema) using male Sprague-Dawley rats as model system. Exposure of animals to hypobaric hypoxia led to a significant increase in vascular leakage, reactive oxygen species (ROS), nitric oxide (NO), and vascular endothelial growth factor (VEGF) levels. There was a marked increase in Nuclear Factor kappaB (NFkappaB) DNA binding activity and levels of pro-inflammatory cytokines such as Monocyte chemoattractant protein (MCP-1), Interferon-gamma (IFN-gamma), Interleukin-1 (IL-1), and Tumor Necrosis Factor-alpha (TNF-alpha) and cell adhesion molecules such as Vascular Cell Adhesion Molecule-1 (VCAM-1), and P-selectin.

Elderly and depression.

It is believed that it is 'normal' for the elderly per sons to become depressed and many cases aren't recognized and thus lead to untold misery for the sufferers and their families. We have found that majority of the clients under study were females belonging to low socio economic status, uneducated and unemployed. Majority of the clients had moderate depression (58%), And about 19% of them had severe depression.