BACKGROUND In soils and sediments, manganese oxides and oxygen usually participate in the oxidation of ferrous ions. There is limited information concerning the interaction process and mechanisms of ferrous ions and manganese oxides. The influence of air (oxygen) on reaction process and kinetics has been seldom studied. Because redox reactions usually occur in open systems, the participation of...

The title compound, [Fe(C(11)H(11)N(2)O)(2)], crystallizes with two independent mol-ecules in the asymmetric unit which have have different conformations. In one mol-ecule, the two ferrocene cyclo-penta-dienyl rings are fully eclipsed and the two pyrazole rings are syn to each other; in the other, the two cyclo-penta-dienyl rings are synclinal and the pyrazole rings are anti. In both mol-ecules...

Pyrazole-3-one compounds were designed on the basis of docking studies of previously reported antidiabetic pyrazole compounds. The amino acid residues found during docking studies were used as guidelines for the modification of aromatic substitutions on pyrazole-3-one structure. Depending on the docking score, the designed compounds were selectively prioritized for synthesis. The synthesized co...

Pyrazole dimer is observed for the first time in a free jet expansion. Its IR-active N−H stretching vibration is shifted by −269 cm−1 relative to the monomer. Along the 600 mm slit jet expansion, the average number density of pyrazole dimers is ≈ 10 cm−3. Exploratory quantum chemical calculations including electron correlation are in good agreement with the observed frequency shift and confirm ...

The complete binuclear complex in [Fe2(C7H4NO4)4(OH)2]·2H2O, is generated by the application twofold symmetry. The Fe(III) atom is coordinated by the O atoms of two bridging hydroxyl groups and by two N and two O atoms from two pyridine-2,5-di-carboxyl-ato ligands, forming a distorted octa-hedral geometry. The Fe⋯Fe separation within the dinuclear complex is 3.0657 (4) Å. In the crystal, O-H⋯O ...

Prolyl 4-hydroxylase (EC 1.14.11.2) is an essential enzyme in the post-translational modification of collagen. Inhibitors of this enzyme are of potential interest for the treatment of diseases involving excessive deposition of collagen. We have found that anthraquinones with at least two hydroxy groups ortho to each other are potent inhibitors of this enzyme. Kinetic studies revealed that 2,7,8...

Flavonoids are a class of natural phenolic compounds that show antioxidant properties. Besides the known mechanisms of action of flavonoids (binding/inactivation of free radicals and other reactive oxygen species) that determine this effect, an important factor is their ability to bind transition metal ions. In this paper, we used a HPLC method with a prechromatographic reaction of a sample wit...

In an attempt to identify components of a ferric citrate uptake system in Pseudomonas aeruginosa, a mutant library of a siderophore-deficient strain (IA614) was constructed and screened for defects in citrate-promoted growth in an Fe-restricted medium. A mutant disrupted in gene PA3901, encoding a homologue of the outer-membrane ferric citrate receptor, FecA, of Escherichia coli (FecA(E.c.)), w...

An investigation was carried out aiming at assessing the potential of vis-NIR reflectance spectroscopy, through comparison with the conventional X-ray powder diffraction (XRPD) technique, for the characterization of synthetic gleys, obtained in laboratory starting from Fe0 and Fe2+ under different conditions of initial pH (5.5, 7.0 and 8.5). XRPD analysis showed that in any case goethite formed...

The hexadentate, and ditopic ligand 2,5-bis([2,2']bipyridin-6-yl)pyrazine yields a chiral, tetrameric, square-shaped, self-assembled species upon complexation with Fe2+ ions. The racemate of this complex was resolved with antimonyl tatrate as the chiral auxiliary. The purity of the enantiomer was determined by NMR spectroscopy, by using a chiral, diamagnetic shift reagent, and by circular dichr...