Acidic Monosaccharides become Incorporated into Calcite Single Crystals**

Carbohydrates, along with proteins and peptides, are known to represent a major class of biomacromolecules involved in calcium carbonate biomineralization. However, in spite of multiple physical and biochemical characterizations, the explicit role of saccharide macromolecules (long chains of carbohydrate molecules) in mineral deposition is not yet understood. In this study, we investigated the influence of two common acidic monosaccharides (MSs), the two simplest forms of acidic carbohydrates, namely glucuronic and galacturonic acids, on the formation of calcite crystals in vitro. We show here that the size, morphology, and microstructure of calcite crystals are altered when they are grown in the presence of these MSs. More importantly, these MSs were found to become incorporated into the calcite crystalline lattice and induce anisotropic lattice distortions, a phenomenon widely studied for other biomolecules related to CaCO₃ biomineralization, but never before reported in the case of single MSs. Changes in the calcite lattice induced by MSs incorporation were precisely determined by high-resolution synchrotron powder X-ray diffraction. We believe that the results of this research may deepen our understanding of the interaction of saccharide polymers with an inorganic host and shed light on the implications of carbohydrates for biomineralization processes.     

Kinetic model of ethylene oxidation by p-benzoquinone in solutions of cationic palladium(ii) complexes in a binary acetonitrile—water solvent

Russian Chemical Bulletin - A kinetic model was developed for the reaction of ethylene oxidation to acetaldehyde by p-benzoquinone (Q) at 30 ℃ catalyzed by the cationic palladium(II)...     

The state of palladium and copper bromides in the PdBr2-CuBr2-THF-H2O system used in the conjugated process of cyclohexanecarboxylic acid production

The state of bromide complexes of palladium and copper in model solutions and under conditions of the conjugated catalytic synthesis of cyclohexanecarboxylic acid by the hydrocarboxylation of cyclohexene is studied by electron and infrared spectroscopy. It is found that during the conjugated process, copper exists in the form of copper(I) compounds, and palladium is present in the form of palladium(II) carbonyl complex.     

Sulfur-containing amino acids of the polyhedral protein of the silkworm yellows virus

Conclusions 1. The polyhedral protein of silkworm virus yellows isolated by the alkali method does not contain sulfhydryl groups.2. The content of sulfhydryl groups in the reduced polyhedral protein has been determined by titration with methylmercury nitrate and by means of Ellman's reagent (0.029–0.033 µmole of SH groups per mg of protein). The content of S-carboxymethylcysteine groups in acid hydrolysates of reduced and carboxymethylated polyhedral protein has been determined with an amino acid analyzer (0.03 µmol/mg).3. The content of cysteic acid in acid hydrolysates of oxidized polyhedral protein is 0.069 µmole/mg.Khimiya Prirodnykh Soedinenii, Vol. 4, No. 3, pp. 174–178, 1968