Steroids of the spirostan and furostan series from Nolina microcarpa IV. Structures of nolinogenin,nolinospiroside B,and nolinofuroside B

A glycoside has been isolated from the plantNolina microcarpa S. Wats. (family Dracaenaceae) which has been called nolinofuroside B and has the structure of 6-methoxy-3,5-cyclo-(25S)-furostan-1,22,26-triol 1-O--D-fucopyranoside 26-O--D-glucopyranoside (I). Enzymatic hydrolysis of the bioside (I) yielded nolinospiroside B (III) and nolinogenin (IV). The latter is 6-methoxy-3,5-cyclo-(25S)-spirostan-6-ol, and glycoside (III) is its 1-O--D-fucopyranoside.M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 218–224, March–April, 1992.     

Triterpene glycosides ofFatsia japonica. I. Isolation and structure of glycosides fromFatsia japonica seeds

The known triterpene glycosides hederagenin 3-O--L-arabinopyranoside, hederagenin 3-O-\-D-glucopyranoside, oleanolic acid 3-O--sophoroside, hederagenin 3-O--sophoroside, and their 28-O--gentiobiosyl esters, respectively, in addition to the new triterpene glycoside 3-O--sophorosyl-28-O--L-rhamnopyranosyl-(14)-O--gentiobiosyl hederagenin are isolated fromFatsia japonica (Araliaceae) seeds. The structures of these glycosides are established using chemical and spectral methods.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 131–133, March–April, 2000.     

Ionic Mobility, Phase Transitions, and Superionic Conduction in Solid Solutions (100 ? x)PbF2-xZrF4 and Crystals K2ZrF6, (NH4)2ZrF6, KSnZrF7, and M(NH4)6Zr4F23 (M = Li, Na)

Methods of (¹⁹F, ¹H) NMR and impedance spectroscopy are used to investigate the internal mobility and ionic conduction in solid solutions arising in the system PbF₂-ZrF₄ and polycrystals KSnZrF₇, Li(Na)(NH₄)₆Zr₄F₂₃, and M₂ZrF₆ (M = K, NH₄). Factors responsible for the form of ionic motions and their energetics at 170–550 K are considered. It is established that the phase transitions in these compounds are connected with the crystal transition to a superionic state and that the high ionic (superionic) conductivity of beta phases is due to the diffusion of fluoride ions, ammonium cations, and possibly alkali metal cations. The obtained data testify to a substantial role of chainlike aggregation of anionic groupings and a variableness of structural mechanisms of formation of such chains in fluorozirconates for the development of translational diffusion in these compounds.__________Translated from Elektrokhimiya, Vol. 41, No. 5, 2005, pp. 573–582.Original Russian Text Copyright © 2005 by Kavun, Uvarov, Slobodyuk, Goncharuk, Kotenkov, Tkachenko, Gerasimenko, Sergienko.     

Secondary-ion mass spectra of pennogenin glycosides

LSIMS mass spectra of pennogenin glycosides have been studied; the most characteristic ions are (M+H–H₂O)⁺ (with glycerol as the liquid matrix) and (M+Na)⁺ (with glycerol +NaCl as matrix). In both cases the peaks of ions formed as the result of the successive elimination of the carbohydrate units, the breakdown of the bonds of the terminal pyranoses, the cleavage of the bonds of the rings D and E, and the peaks of the ions Agl⁺ and (Agl–H₂O)⁺ were observed.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. All-Union Scientific-Research Institute for Agricultural Biotechnology, All-Union Academy of Agricultural Sciences, Moscow. Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 523–525, July–August, 1991.     

Formation of MoS2 inorganic fullerenes (IFs) by the reaction of MoO3 nanobelts and S

The reaction of MoO3 and S at temperatures higher than 300 degrees C in an argon atmosphere provides a convenient and effective method for the synthesis of MoS2 nanocrystalline substances. MoS2 nanotubes and fullerene-like nanoparticles have been obtained by the reaction at 850 degrees C under well-controlled conditions. The influences of reaction temperature and duration were carefully investigated in this paper. All of the nanostructures were characterized by Xray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). A stepwise reaction model and rolling mechanism were proposed based on the experimental results.     

Catalysis by titanium (IV) ions of reactions forming chlorohydrins from olefins

A study was made of reactions forming chlorohydrins from cyclohexane and other olefins acted upon by H₂O₂ and HCl or H₂O₂ and TiCl₄ in alcoholic solutions. The catalyzing action of titanium (1V) was established, and possible reaction mechanisms are discussed.L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prosp. Nauki, 252039, Kiev, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 5, pp. 295—299, September–October, 1996. Original article submitted February 9, 1996.     

Fragmentation of some 1,2-epoxyguaianolides

The mass spectra of four guaianolides with epoxy groups of C₁–C₂ have been studied. A mechanism is proposed for the formation of the main ions. The origin of the secondary fragments has been confirmed by measurements of elementary compositions.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 796–800, November–December, 1980.     

Synthesis of the p-toluenesulfonate of oleyl acohol under conditions of phase-transfer catalysis

The tosylation of oleyl alcohol under the conditions of phase-transfer catalysis has been studied. In this process oleyl p-toluenesulfonate of formed with a yield of up to 80%.Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, 443–445, May–June, 1988.     

Spectroscopic study of compounds possessing a bond of an element of group IVB with hydrogen

Conclusions The frequencies of the valence vibrations of the Si-H bond in trisubstituted silanes depends not only on the inductive effect of substituents, but also on the effects of d-p interaction, ,- and p,-conjugation. An analysis was made of the relative contributions of these effects, depending on the nature of the substituent.For the preceding communications, see [1, 2].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 544–550, March, 1971.     

Ionizing-Radiation Ignition of a Hydrogen–Air Mixture

The behavior of a hydrogen–air mixture under the action of ionizing radiation was studied. A kinetic model for radiation-chemical processes in the H₂–O₂–N₂ system was constructed, and the effects of the main parameters of radiolysis on shifting its flammability limits were analyzed. It was found that, under normal conditions (p = 0.1 MPa, T ₀ = 300 K), the ignition of the stoichiometric mixture began at a radiation intensity of about 0.1 kGy/s. The induction period of the chain H₂ oxidation reaction shortened with increasing radiation dose rate and pressure.