Hydrothermal synthesis of six new lanthanides coordination polymers based on 1-H-benzimidazole-5-carboxylic acid: Structure, Hirshfeld analysis, thermal and spectroscopic properties

Six novel lanthanide metal coordination polymers (LnCPs) [Ln(Hbic)3(H2O)]n [Ln = La (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6)] have been synthesized by reaction of 1H-benzimidazole-5-carboxylic acid (H2bic) with Ln2O3 under hydrothermal conditions, and characterized via elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder X-ray diffraction. The compounds 1–6 are isostructural and have a 1D layer architecture; the layers are linked by hydrogen bonding and π–π stacking interactions to form a 3D supramolecular framework. Hirshfeld surfaces and the luminescence properties of these complexes were also investigated. The 3-D Hirshfeld surfaces and 2-D fingerprint plots show that the main interactions are the O⋯H/H⋯O intermolecular interactions. Finely, preliminary emission experiments have been carried out on the compounds 3 and 5

Structural, electronic, elastic, and thermal properties of CaNiH3 perovskite obtained from first-principles calculations

A theoretical study of the structural, elastic, electronic, mechanical, and thermal properties of the perovskite-type hydride CaNiH3 is presented. This study is carried out via first-principles full potential (FP) linearized augmented plane wave plus local orbital (LAPW+lo) method designed within the density functional theory (DFT). To treat the exchange-correlation energy/potential for the total energy calculations, the local density approximation (LDA) of Perdew-Wang (PW) and the generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) are used. The three independent elastic constants (C 11, C 12, and C 44) are calculated from the direct computation of the stresses generated by small strains. Besides, we report the variation of the elastic constants as a function of pressure as well. From the calculated elastic constants, the mechanical character of CaNiH3 is predicted. Pertaining to the thermal properties, the Debye temperature is estimated from the average sound velocity. To further comprehend this compound, the quasi-harmonic Debye model is used to analyze the thermal properties. From the calculations, we find that the obtained results of the lattice constant (a 0), bulk modulus (B 0), and its pressure derivative () are in good agreement with the available theoretical as well as experimental results. Similarly, the obtained electronic band structure demonstrates the metallic character of this perovskite-type hydride

Anvillea garcinii extract inhibits the oxidative burst of primary human neutrophils

International audienceAbstractBackgroundAnvillea garcinii Coss. & Durieu (Anv) plant is used as a traditional North African medicine against several diseases associated with inflammation. At inflammatory sites, reactive oxygen species (ROS) produced in excess by activated phagocyte NADPH oxidase (NOX2) can accentuate inflammatory responses. Thus, we investigated if Anv-water soluble polysaccharides could modulate primary human neutrophil oxidative burst in vitro.MethodsHuman neutrophils were isolated from fresh whole blood and O2.- generation was measured by cytochrome c reduction assays. Western blots were used to analyse the translocation of PKC, p47phox (a key component of NOX2 activity) to neutrophil plasma membrane. Also, myeloperoxidase (MPO) release in the extracellular medium was studied by western blots. Flow cytometric analysis was used to detect CD11b membrane expression.ResultsWater soluble polysaccharides from Anv dose-dependently inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLF)- and phorbol myristate acetate (PMA)-induced O2.- generation by human neutrophils. Moreover, Anv-polysaccharides strongly inhibited PMA-induced PKCβ and p47phox translocation to membranes and p47phox phosphorylation on Ser328, a main PKC target. In contrast, polysaccharides extract from Zygophyllum gaetulum plant, which is also used as a traditional North African medicine against inflammatory diseases, was ineffective on this PKCβ-p47phox pathway. Further, Anv inhibited important neutrophil degranulation markers corresponding to myeloperoxidase (MPO) release and CD11b membrane expression.ConclusionThe process of down-regulating NADPH oxidase by polysaccharides extracts from Anv provides new insights into the mechanism of Anv’s anti-inflammatory actions