The local structure of trace amounts of lead in an adsorbent matrix that contains a high concentration of iron and magnesium (Mg6Fe2(OH)16(CO3) x 3H2O) was successfully monitored by means of X-ray absorption fine structure spectroscopy combined with fluorescence spectrometry. A eutectic mixture of PbCO3 and Pb(OH)2 coagulated when Pb2+ was adsorbed from a 1.0 ppm aqueous solution, and in contra...

The ion-molecule reactions of ions from acetone, dimethyl ether, 2-methoxyethanol, and vinyl methyl ether with vincamine were investigated. Reactions with dimethyl ether result in [M+13](+) and [M+45](+) products, reactions with 2-methoxyethanol produce [M+13](+) and [M+89](+) ions, and reactions with acetone or vinyl methyl ether ions generate predominantly [M+43](+) ions. Collision-activated ...

The natural substrate cleaved by the hepatitis delta virus (HDV) ribozyme contains a 3',5'-phosphodiester linkage at the cleavage site; however, a 2',5'-linked ribose-phosphate backbone can also be cleaved by both trans-acting and self-cleaving forms of the HDV ribozyme. With substrates containing either linkage, the HDV ribozyme generated 2',3'-cyclic phosphate and 5'-hydroxyl groups suggestin...

Partially purified soluble rat liver guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] was activated by superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1). This activation was prevented with KCN or glutathione, inhibitors of superoxide dismutase. Guanylate cyclase preparations formed superoxide ion. Activation by superoxide dismutase was further enhanced...

The GAUSSIAN 2, GAUSSIAN 3, complete basis set-QB3, and complete basis set-APNO methods have been used to calculate DeltaH( composite function) and DeltaG( composite function) values for ionic clusters of hydronium and hydroxide ions complexed with water. Results for the clusters H3O+(H2O)n and OH-(H2O)n, where n=1-4 are reported in this paper, and compared against experimental values contained...

H3 O(+) and OH(-) , formed by the self-ionization of two coordinating water molecules during the crystal growing of a host molecule [1,3,5-tris(hydroxymethyl)2,4,6-triethylbenzene (1)], could be effectively stabilized by hydrogen-bonding interactions with the preorganized hydroxy groups of three molecules of 1. The binding motifs observed in the complex (1)3 ⋅H3 O(+) ⋅HO(-) show remarkable simi...

The mol-ecule of the title complex, [Ni(C(30)H(23)O(2)P(2))(OH)], adopts a slightly distorted square-planar geometry around Ni(II) defined by the coordination of the two mutually trans P atoms, the Csp(2) atom of the pincer ligand and the O atom of the hydroxide ligand. The largest distortions from ideal geometry are reflected in the smaller than usual P-Ni-P [163.95 (3)°] and P-Ni-C [82.06 (6)...

Hydroxy fatty acids from Euglena gracilis were identified by reverse-phase high performance liquid chromatography coupled to a mass spectrometer run in atmospheric pressure chemical ionization positive ion mode. These metabolites were converted to methyl esters to improve stability and chromatographic properties. A detection limit of 20 pg/microl per injection was determined for 5-HETE methyl e...