ABSTRACT
Gerty T. and Carl F. Cori discovered, during research on the metabolism of sugars in organisms, the important role of the phosphate ester of a simple sugar. Glucose molecules are released from glycogen-the glucose stored in the liver-in the presence of phosphates and enter the blood as α-D-glucose-1-phosphate (Glc-1PH2). Currently, the crystal structure of three phosphates, Glc-1PNa2·3.5·H2O, Glc-1PK2·2H2O, and Glc-1PHK, is known. Research has shown that reactions of Glc-1PH2 with carbonates produce new complexes with ammonium ions [Glc-1P(NH4)2·3H2O] and mixed complexes: potassium-sodium and ammonium-sodium [Glc-1P(X)1.5Na0.5·4H2O; X = K or NH4]. The crystallization of dicationic complexes has been carried out in aqueous systems containing equimolar amounts of cations (1:1; X-Na). It was found that the first fractions of crystalline complexes always had cations in the ratio 3/2:1/2. The second batch of crystals obtained from the remaining mother liquid consisted either of the previously studied Na+, K+ or NH4+ complexes, or it was a new sodium hydrate-Glc-1PNa2·5·H2O. The isolated ammonium-potassium complex shows an isomorphic cation substitution and a completely unique composition: Glc-1PH(NH4)xK1-x (x = 0.67). The Glc-1P2- ligand has chelating fragments and/or bridging atoms, and complexes containing one type of cation show different modes of coordinating oxygen atoms with cations. However, in the case of the potassium-sodium and ammonium-sodium structures, high structural similarities are observed. The 1D and 2D NMR spectra showed that the conformation of Glc-1P2- is rigid in solution as in the solid state, where only rotations of the phosphate group around the C-O-P bonds are observed.
ABSTRACT
The asymmetric unit in the title compound, {[Cd(2)(C(4)H(4)O(6))(SO(4))(H(2)O)(5)].3H(2)O}(n), is composed of two cadmium cations, one (R,R)-tartrate and one sulfate anion, five aqua ligands and three solvent water molecules. One of the cadmium ions is coordinated in an octahedral environment, whereas the second is surrounded by seven O atoms in a pentagonal-bipyramidal geometry. Both types of coordination polyhedra form two sets of perpendicular non-intersecting polymeric chains. CdO(6) octahedra share two corners, while CdO(7) units are joined by a bridging carboxylate group. An extensive hydrogen-bond pattern involving all of the OH groups contributes to the stabilization of the structure.
ABSTRACT
In the reaction of (4-phenyl- or 3,4-diphenyl-5-oxo-1,2,4-triazeolin-1-ylmethyl)-carbohydrazide (IIa, IIb) with isothiocyanates the thiosemicarbazide derivatives [IIIa, b - IXa, b] were obtained. Cyclization of those compounds in the presence of 2% or 10% NaOH led to formation of derivatives with the 1,2,4-triazolin-5-thione system [Xa, b - XV[a, b]. Molecular structure proposed for this group of compounds was confirmed by X-ray structure analysis of Xa and XIVa. Compounds Xa, XIIa and XIVa were investigated pharmacologically for their central properties in mice. It was shown that only compound XIIa produced antinociceptive effects in mice.
