RESUMO
The efficient dirubidium cobalt bis(dihydrogendiphosphate) dihydrate compound is successfully synthesized in a solution and used as a reactive sorbent for the CO2 and CH4 gases adsorption and storage. A crystal of this Rb2Co(H2P2O7)2·2H2O compound has been isolated and characterized by single X-ray diffraction analysis and was found to crystallize in the triclinic system ( P 1 ¯ ) with the cell parameters (Å): 6.980(1), 7.370(1), 7.816(1), 81.74(1), 70.35(1), 86.34(1); V = 374.68(9) Å3, Z = 2. The crystal-packing consists of a three-dimensional framework made upon corners and edges sharing of [RbO7], [H2P2O7] and [CoO6] entities, furthermore linked by a network of H-bonds. The UV-Vis spectroscopy revealed usual transitions between the ground state 4T1g and the upper levels 4T2g, 4A2g and 4T1g (P). Moreover, the CO2 and CH4 gases sorption measurements were successfully performed at two different temperatures (25 and 45 °C) and various pressures ranging from vacuum to 50 bar. Our results show that rate of CO2 and CH4 capturing was 3.10 mmol/g and 2.35 mmol/g at temperature 25 °C and pressure 50 bar, respectively. This compound showed a clear potential for CO2/CH4 adsorption and storage thereby paving the way towards its exploration and adaptation for capturing and collecting carbon dioxide and greenhouse gases from the air, and their conversion into hydrocarbon fuels using existing mature technologies. We have also conducted density functional theory calculations to study the CO2 and CH4 adsorption properties of Rb2Co(H2P2O7)2·2H2O. The simulation results show enhanced adsorption of both types of molecules on the surface of the material.
RESUMO
The present study was undertaken in normotensive anaesthetized male rats that received a continuous perfusion of a chrysin glucoside isolated from the flowers and leaves of Calycotome villosa subsp intermedia at a dose of 2.5 mg/kg, or furosemide (control diuretic) at a dose of 0.5 mg/kg. Compared with the control rats receiving NaCl (0.9%), the urine flow, glomerular filtration and electrolyte excretion (Na+, K+) increased significantly in rats treated with chrysin glucoside (p < 0.001). A similar effect was observed in the rats perfused with furosemide. Intravenous injections of bolus doses (1-3 mg/kg) of the chrysin glucoside to anaesthetized rats elicited an immediate and dose-dependent decrease in mean arterial blood pressure (MABP). Pretreatment of the rats with the nitric oxide synthase inhibitor, l-NOArg (10 mg/kg), reduced partially, but significantly (p < 0.01), the maximal decrease in MABP elicited by chrysin glucoside. In the rat isolated aorta preparation, chrysin glucoside (10-100 microm) inhibited in a concentration-dependent manner the noradrenaline (1 microm) induced contractions (IC(50) = 52 microm). This relaxant activity of chrysin glucoside was significantly reduced by incubation of the endothelium-intact rings with l-NOArg (100 microm), (80 +/- 4.7% vs 48 +/- 5.06% in the absence of L-NOArg). In conclusion, these results demonstrate a diuretic and hypotensive action of a chrysin glucoside from Calycotome villosa in anaesthetized rats and indicating an action on renal function, and an active vascular relaxation mediated partially through nitric oxide release.
