Influence of complexation by metal cations on solvophobic retention of crown compounds in reverse-phase high-performance liquid chromatography

The retention of crown compounds in reverse-phase HPLC is determined by their ability to bind to cations present in the eluent. The dependence of the retention of crown compounds on concentration of the binding cation has a break. This enables the stability constant of the crown-compound-cation complex to be calculated. The retention of the antitumor antibiotic actinomycin D in 75% MeOH is demonstrated to depend on [Na⁺] and not on [K⁺] for concentrations of the latter from 10^–6 to 10^–1 M.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2265–2269, October, 1991.     

Zinc(II) Complexes with Azomethines of 2,4,6-Trimethylaniline and Halogen-Substituted Salicylaldehyde

Russian Journal of General Chemistry - Azomethines were synthesized from 2,4,6-trimethylaniline, salicylaldehyde, and its 3(5)-halogen derivatives, as well as their complexes with zinc(II) (ZnL2)....     

Interplay between the Ribosomal Tunnel,Nascent Chain,and Macrolides Influences Drug Inhibition

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Highlights? Macrolides exhibit nascent polypeptide chain–dependent inhibition ? Peptides can form specific interactions with the ribosomal tunnel ? A covalent bond between tylosin and the ribosome is necessary for inhibitory activity     

Chemical and Electrochemical Synthesis,Structure, and Properties of Metal Chelates of Tridentate N,S-Containing Azomethinazo Ligands

Novel Cu(II), Co(II), Ni(II), and Zn(II) complexes of 5-methyl-2-phenyl-4-[(4-phenylazo)anilinemethylylidene]- 2,4-dihydro-3H-pyrazole-3-thione and 5-methyl-4-[4-methyl-2-(4-methylphenylazo)anilinemethylylidene]- 2-phenyl-2,4-dihydro-3H-pyrazole-3-thione, i.e. ligands containing the phenylazo group in the ortho and para positions of the aniline fragment, were synthesized by the chemical and electrochemical methods. The complexes and ligands were characterized by IR, ¹H NMR, X-ray absorption spectroscopy and magnetochemistry. The azo group of the ligands is not involved in coordination to the metal.     

Effect of heating on the spall fracture of a composite based on SKTN rubber

Russian Research Institute of Experimental Physics, Arzamas-16. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 36, No. 3, pp 167–169, May–June, 1995.     

Catalytic activity of rare earth oxides in flameless methane combustion

The following rare earth oxides, which were prepared by the precipitation of hydroxides, were studied as catalysts for the reaction of complete methane oxidation: CeO₂, a hydrated phase of La₂O₃, Pr₆O₁₁, Tb₄O₇, and Gd₂O₃. The catalytic activities of the oxides were compared in terms of first-order reaction rate constants per unit surface area of the catalyst. With consideration for data on the reduction of CeO₂, Pr₆O₁₁, and Tb₄O₇, the previously proposed redox reaction mechanism on transition metal oxides was supported. The high activity of hydrated La₂O₃ was found, and it was hypothesized that, in this case, the process occurred by the mechanism of oxidative methane condensation followed by the rapid oxidation of the resulting intermediate products.     

The chemical nature of the products of the microbiological transformation of lathyrine

The chemical nature of the compounds formed in the microbiological transformation of -amino--(2-amino-4-pyrimidyl)propionic acid (lathyrine) under the action of soil microorganisms capable of using pyrimidine bases as sources of carbon and nitrogen has been studied.