Synthesis and Cytotoxic Activity of 4-Substituted 3-Cyano-6,6-dimethyl-5,6-dihydro-2-pyranones

The respective 4-(arylvinyl)lactones and compounds of the Michael adduct type were synthesized by the condensation of substituted benzaldehydes with 3-cyano-4,6,6-trimethyl-5,6-dihydro-2-pyranone in the presence of catalytic amounts of sodium hydroxide. It was shown by the semiempirical AM1 method that the indicated products can be formed through one and the same intermediate compound. Some of the synthesized phenylvinyl-5,6-dihydro-2-pyranones have a cytotoxic effect, and this corresponds to the prognosis of the OREX expert system.     

The structure of fullerene films and their metallocene doping

Hexagonal close-packed (HCP) C₆₀ and C₇₀ films have been prepared by the Langmuir method and examined by electron microscopy and electron-diffraction analysis. It has been shown that the vacuum deposition of a C₆₀+C₇₀ mixture results in the formation of a film with small sized grains and a distorted C₆₀-HCP structure. The simultaneous deposition of C₆₀ and ferrocene results in the formation of a film with a changed morphology and an electron-diffraction pattern that contains a variable amount of ferrocene depending on the experimental conditions. The electron-diffraction pattern corresponds to the presence of the known molecular complex C₆₀[(C₅H₅)₂Fe]₂. The analogous simultaneous deposition of fullerene C₆₀ and cobaltocene results in the formation of a C₆₀ film stable in air and water, which contains carbon and cobalt (from the data of X-ray fluorescence, electron microscopy and microdiffraction). It has a different morphology and different diffraction patterns than pure C₆₀ films and, depending on the cobaltocene content (relative to that of fullerene), appears to be a fullerite film doped with various amounts of cobaltocenium fullende, which is an ionic compound.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1379–1383, August, 1994.The work was financially supported by the Russian Foundation for Basic Research (Projects 93-03-4676 and 93-03-18368).     

Synthesis of penicillin derivatives and study of their cytotoxic properties

By the interaction of heterocyclic thiols with sulfoxides of 6,6-dihydro- and 6-chloropenicillanates, derivatives of 4-heteryldithio-2-azetidinones have been synthesized, as well as products of their cyclization to form 2-heterylthiomethyl-and 2-halomethyl-substituted penicillanates and an ester of 3-chloro-3-methyl-7-chlorocepham-4-carboxylic acid. Also, the desulfurization of 6-chloropenicillanate by Raney nickel has been accomplished. For the substances that have been synthesized, a direct relationship has been established between the intensity of their cytotoxic actionin vitro with respect to tumor cells and the influence of these compounds on the intracellular generation of nitric oxide radicals.Latvian Institute of Organic Synthesis, Riga LV-1006, Translated from Khimiya Geterosiklicheskikh Soedinenii, No. 11, pp. 1494–1503, November, 1998.     

Silyl Modification of Biologically Active Compounds. 8. Trimethylsilyl Ethers of Hydroxyl-containing Thiazole Derivatives

Trimethylsilyl ethers of various hydroxyl-containing thiazole derivatives have been synthesized. The psychotropic activity (in vivo) and the cytotoxicity (in vitro on tumor cell lines HT-1080 and MG-22A) of these ethers and of their unsilylated precursors have been studied. It was discovered that the obtained compounds possess a sedative action. A moderate cytotoxic effect was detected for piperidine-containing thiazoles, displayed most strongly in relation to MG-22A cells.     

Mössbauer study of the surface of core-shell type nanoparticles

The properties of the surface layer of core-shell nanoparticles incorporated into the matrix of macromolecules of 3,4-bis(decyloxybenzoyl) poly(propylene imine) derivative of the second generation are studied by Mössbauer spectroscopy at low temperatures. The spin states, the details of the phonon spectrum and the Debye temperature of surface layer atoms discussed.     

Synthesis and characterization of nanoparticles with an iron oxide magnetic core and a biologically active trialkylsilylated aliphatic alkanolamine shell

Water-soluble double-coated magnetic nanoparticles (NPs) containing cytotoxic decyldimethyl(β$\beta$-dimethylaminoethoxy)silane methiodide (AA) molecule sorbed at biocompatible magnetic particles, which consist of magnetite pre-coated with oleic acid (OA), have been prepared. X-ray line profile broadening analysis was used for crystallite size determination. The method of magnetogranulometry has been used for determination of diameter of iron oxide magnetic core and magnetic properties of NPs prepared. In vitro cytotoxicity on monolayer tumor cell lines HT-1080 (human fibrosarcoma), MG-22A (mouse hepatoma) and normal mouse fibroblasts (NIH 3T3) has been studied. It was revealed that all the water-based colloidal solutions obtained are non-toxic and possess high NO-induction ability.     

Correction to: Aziridine-2-Carboxylic Acid Derivatives and Its Open-Ring Isomers as a Novel PDIA1 Inhibitors

Chemistry of Heterocyclic Compounds -     

Synthesis and photochemical properties of 3,6-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-9<Emphasis Type="Italic">H</Emphasis>-carbazole derivatives

Method of synthesis has been developed for a series of 3,6-di-tert-butyl-9H-carbazole derivatives and their photochemical properties have been investigated. The dependence of the Steglich esterification reaction on the nature of the catalyst was studied. The synthesized compounds show fluorescent emission in the range 400–600 nm with a high quantum yield.     

Interaction of fullerenes with metallic lithium in the condensed state

The relative stability of exo-and endohedral lithium complexes with the C₆₀ fullerene was estimated using quantum chemistry and molecular-dynamics methods. Endohedral compounds were shown to have a higher stability. The possible maximum filling of the C₆₀ inner sphere by lithium was estimated theoretically. The interaction of metallic lithium with the C₆₀ fullerene and a C₆₀ + C₇₀ mixture was studied using DTA and EPR and established to proceed in several stages.