Triterpene glycosides ofPatrinia scabiosofolia; II

Conclusions The triterpene glycosides scabiosides D, E, F, and G have been isolated from the roots ofPatrinia scabiosofolia Fisch. et Link. It has been established that scabioside D is O--D-glucopyranosyl-(1 4)-O--L-arabopyranosyl-(1 3)-O-oleanoloyl-(28 1)--D-xylopyranose, and scabioside E is O--D-glucopyranosyl-(1 4)-O--L-arabopyranosyl-(1 3)-O-oleanoloyl-(28 1)-O--D-xylopyranosyl-(4 1)--L-rhamnopyranose.     

Metal bioaccumulation by the freshwater algaScenedesmus quadricauda

Bioaccumulation of six metals (Cu²⁺, Cu⁺, Mo⁶⁺, Mn²⁺, V⁵⁺, Ni²⁺) and their combinations by algaScenedesmus quadricauda was determined by using radio nuclide X-ray fluorescence (RXFA). The metals were added into the cultivation medium in concentrations corresponding with EC₅₀ value for each metal. The obtained results indicate that Ni²⁺, Cu²⁺ and Cu⁺ were accumulated in high amounts (20%, 17.5% and 15.19%) the Mo⁶⁺ ion (<0.2%) was accumulated in the lowest amount. For metal-metal interactions in accumulation of metal ions by algaS. quadricauda three types of answers were determined: inhibition (MoCu²⁺, Ni, Mn, V; VNi, Mn; MnNi, Cu²⁺, Cu⁺; Cu⁺Ni; Cu²⁺Ni; NiMn, V), enhancement (VCu⁺; Cu²⁺Mn;Cu⁺V, Mn; MnV; NiCu²⁺, Cu⁺) and neutral effect (VMo; Cu²⁺Mo; Cu⁺Mo; MuMo; NiMo).     

Error of Atomic Charges Derived from Electrostatic Potential

The purpose of this article is to show that CHELP, CHELPG, and Merz and Kollman undergo error for the charge on atoms of HCOO^– (H₂O) _n for n = 1 6. We also demonstrate that the CHELP, CHELPG, and Merz and Kollman show error for the tendency toward change in the charges on carbons for CH₃NH⁺ ₃ (CH₃)₂NH⁺ ₂ (CH₃)₃NH⁺ (CH₃)₄N⁺.     

Triterpene glycosides of Gleditschia triacanthos IV. The structure of triacanthosides A1 and G

Summary The pericarps ofGleditschia triacanthos L. have yielded a new triterpene glycoside — triacanthoside A₁ — and it has been shown that it has the structure of echynocystic acid 3-O-[-D-xylopyranosyl-(14)--L-arabopyranosyl-(13)--D-glucopyranoside].It has been shown that the O-glycosidic moiety of triacanthoside G coincides in structure with triacanthoside A₁. The O-acyloside moiety of triacanthoside G contains the trisaccharide D-glucopyranosyl-(13)-O-L-arabopyranosyl-(14)-O-L-rhamnopyranose.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 314–316, May–June, 1973.     

Proanthocyanidins of Polygonum coriarium. I

Six proanthocyanidins have been isolated from the roots ofPolygonium coriarium. The structures of three oligomeric proanthocyanidins have been established: taranin, consisting of [epigallocatechin gallate]-(48)-[epigallocatechin gallate]-(48)-[epigallocatechin-(48)-epigallocatechin₂-(48)-epigallocatechin; taranoside A - [epigallocatechin gallate]-7-0-[-(16)--D-Glcp]₃-(48)-[epigallocatechin-(48)-epigallocatechin]₂-(48)-gallocatechin; and taranoside B - [epigallocatechin gallate]-7-O-[-(16)--D-Glcp]₄-(48)-[epigallocatechin-(48)-epigallocatechin]₂-(48)-epigallocatechin-(48)-[epigallocatechin gallate).Institute of the Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 59–67, January–February, 1992     

The scaled-particle theory and solvent isotope effects on the thermodynamic properties of inert solutes in water and methanol

The scaled-particle theory has been applied to the calculation of the thermodynamic changes associated with the formation of a cavity in several isotopic varieties of liquid water and methanol. From these results, the thermodynamic functions for the transfer of a cavity (or a hard-sphere solute) have been computed for the following solvent pairs: H₂OD₂O, H₂OH₂ ¹⁸O, H₂ ¹⁸OD₂ ¹⁸O, D₂OD₂ ¹⁸O, CH₃OHCH₃OD. For the last two of these solvents, density measurements required for the calculations were carried out as a function of temperature. The calculated deuterium solvent isotope effect on the heats and entropies of hard-sphere solutes in water is much greater than the¹⁸O isotope effect; the former also exhibits a more pronounced temperature dependence. The transfer functions computed for hard-sphere solutes are compared to experimental data on the transfer of various solutes from H₂O to D₂O and from CH₃OH to CH₃OD. In most of the cases examined, the cavity effect accounts for a large part of the transfer quantities measured for rare gases, hydrocarbons, and solutes containing a significant hydrocarbon substituent.     

The triterpene glycosides ofpatrinia intermedia roem et schult

Conclusions It has been established that patrinoside D₁ is the -D-glucopyranosido(13) -D-xylopyranosido(12) -L-rhamnosido(14)--D-xylopyranoside (13) of oleanolic acidKhimiya Prirodnykh Soedinenii, Vol. 5, No. 2, pp. 84–89, 1969     

Some peculiarities of metal exchange reactions in porphyrin and phthalocyanine complexes

Kinetics of metal exchange reaction Cd(II) Zn(II) and Cd(II) Cu(II) in Cd complexes with tetraphenylporphyrin in DMSO is studied. Reaction with Cu(II) nitrate occurs in both cases more vigorously as compared to that with Zn(II) nitrate. Conditions for metal exchange reactions are studied depending on the nature of metal porphyrinate, a salt (nitrates, acetates, and chlorides of Zn(II), Cu(II), and Co(II), and of organic solvent (DMSO, CH₃CN). It is shown that Zn(II) complexes with nonplanar porphyrins do not show metal exchange Zn(II) Cu(II) or Zn(II) Co(II) under mild conditions in DMSO and CH₃CN.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 2, 2005, pp. 104–109. Original Russian Text Copyright © 2005 by D. Berezin, Shukhto, Nikolskaya, B. Berezin.     

Triterpene glycosides of Hedera taurica. III. Structures of hederosides A3, B,E2 and F from the berries of Crimean ivy

Four triterpene glycosides — hederoside A₃, B, E₂, and F — have been isolated from the berries ofHedera taurica Carr. (Crimean ivy), family Araliaceae. On the basis of the results of acid hydrolysis and physiochemical methods of investigation the following structures have been suggested: A₃ — 3-O-(-L-arabinopyranosyl)hederagenin; B — 3-O-(-D-glucopyranosyl)hederagenin; E₂ — 3-O-[O--D-glucopyranosyl-(1 2)--D-glucopyranosyl]oleanolic acid; and F — 3-O-[O--D-glucopyranosyl-(1 2)--D-glucopuranosyl]hederagenin. Hederoside E₂ is a new glycoside of oleanolic aid.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 721–726, September–October, 1988.     

Über die Wirkungen von Aldehyden auf gesunde und maligne Zellen, 2. Mitt.: Synthese von homologen 4-Hydroxy-2-alkenalen,I

Zusammenfassung 4-Hydroxy-2-alkenale verschiedener Kettenlänge (C₅–C₁₀) werden in einer mehrstufigen Synthese hergestellt: Alkanal 2-Bromalkanaldimethylacetal 2-Alkenaldimethylacetal 4-Brom-2-alkenaldimethylacetal 4-Hydroxy-2-alkenaldimethylacetal 4-Hydroxy-2-alkenal.     

Excited Π states of divinyl chalcogenides and chalcophenes

Electron transitions in divinyl chalcogenides (CH₂=CHXCH=CH₂, where X is S, Se, or Te) have been analyzed using UV absorption spectra of dialkyl and alkyl vinyl chalcogenides. The following relations for the orbital energies are found: ^* < ^* < ^* < ^* for Te and ^* < ^* < ^* < ^* for S and Se. For chalcophenes, a correlation between the energy of the excited state (E ^*) of specific symmetry, the ionization potential (I) and the electron affinity (EA) is obtained:E ^*=const+(I+EA)/2. The electron affinity of divinyl chalcogenides is estimated. The correlation between the excited ^* states of divinyl chalcogenides and chalcophenes is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 831–835, May, 1994.     

MO LCAO calculations and the electronic spectra of the anions of cyclopent-4-ene-1,3-diones and indane-1,3-diones

The Hückel approximation in MO LCAO is used to show that the anion system of cyclopent-4-ene-1,3-dione should have two ^* transitions: a weak one at long wavelengths, NV₁, and a strong one at short wavelengths, C=C(1,3)V₁. An ethylene, phenyl, or acyl group at position 2 gives rise to a new strong band, NC=C(2), Nbenz, or NC=O (2). A p-nitrophenyl group at position 2 gives rise to a strong NNO₂ band, which overlaps the weak NV₁ band, while the Nbenz band becomes weak and is virtually lost from the spectrum.     

Triterpene glycosides ofHedera canariensis. I. Structures of glycosides L-A,L-B1, L-B2, L-C,L-D,L-E1 1, L-G1, L-G2, L-G3, L-G4, L-H1, L-H2, AND L-I1 from the leaves ofHedera canariensis

From the leaves of Algerian ivyHedera canariensis Willd. (fam. Aralaceae) we have isolated 13 triterpene glycosides: the 3-O--L-arabinopyranosides of oleanolic acid (A), of echinocystic acid (B₁), and of hederagenin (B₂); the 3-O-[O--L-rhamnopyranosyl-(2)--L-arabinopyranoside]s of oleanolic acid (C), of echinocystic acid (D), and of hederagenin (E₁); the 3-O--L-rhamnopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside of hederagenin (G₁); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O--gentiobioside of hederagenin (G3); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside]s of oleanolic acid (G₂), of echinocystic acid (H₁), and of hederagenin (H₂); the 3-O-[O--L-rhanmopyranosyl-(12)--D-glucopyranoside] 28-O-(O--L-rhamno-pyranosyl-(14)--gentiobioside] of hederagenin (H₂); and the 3-O-(O--L-rhamnopyranosyl-(12)-O-gentiobiosyl)-O-(14)--L-rhamnopyranosyl-(12)-a-L-arabinopyranoside] of hederagenin (G₄). The structures of the substances isolated have been established on the basis of chemical transformations and¹³C NMR spectroscopy.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 377–383, May–June, 1996. Original article submitted December 3, 1995.     

Ab initio calculations of potential energy surface for reaction of nucleophilic addition of H− ion to methylacetylene

Within the framework of the Hartree-Fock-Roothaan Method, using double- basis sets 3-21++G and (6-31-H-G//3-21++G), the minimum energy paths (MEPs) have been calculated for reactions of nucleophilic addition of the hydride ion H^– to the methylacetylene molecule: CH₃-CCH+H^–[CH₃-CH=CH]^– (1) CH₃-CCH+H^–[CH₃-C=CH₂]^– (2). It has been established that the activation energy for reaction (2) is 7.02 kJ/mole lower than for reaction (1). An analysis has been made of the character of electron density distribution along the MEP of each reaction. It has been shown that distortion of geometry of the reactants plays an important role in intensifying the interaction of the frontier orbitals. The reasons for nonfulfillment of Markownikoff's rule for these reactions have been determined. The results from the calculations are compared with calculations reported in the literature for the related reaction of nucleophilic addition of the hydride ion H^– to the acetylene molecule: HCCH+H^–[CH₂=CH]^–.Translated from Teoreticheskaya i Éxperimental'naya Khimiya, Vol. 21, No. 3, pp. 303–309, May–June, 1985.     

Theory of direct atom-molecule reactions. Part II

Processes that may be considered as sequences of pair collisions giving rise to the stable molecule AB are discussed on the basis of a general method of representing the cross-section of A+BC AB+ + in the impulse approximation via a mean over the initial state of BC. It is shown that such processes resemble the one-step processes considered in part I in not being purely classical in character (contrary to the assumptions of [2]) and in being substantially dependent on the mode of overlap of the wave functions_BC and _AB even at high collision energies. The reactions T+H₂HT+H, T+D₂ DT+D are considered on the basis of the general method.     

Structure of cucumarioside G1 — A new triterpene glycoside from the holothurianCucumaria fraudatrix

A new triterpene glycoside — cucamarioside G₁ — has been isolated from the Pacific Ocean holothurianCucumaria fraudatrix. On the basis of physicochemical characteristics and the results of chemical transformations, its structure has been established as 16-acetoxy-3-[O-(3-O-methyl--D-xylopyranosyl)-(1 3)-O--D-glucopyranosyl-(1 4)--D-quinovopyranosyl-(1 2)-(4-O-sulfato--D-xylopyranosyloxy)]-holosta-7,24-diene.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 244–248, March–April, 1985.     

Triterpene glycosides of Hedera taurica

From the leaves of Crimean ivy we have isolated the previously known glycosides 3-O--L-Ara_p-28-O-[O--L-Rha_p-(14)-O--D-Glc_p-(16)--D-Glc_p]hederagenin, 3-O-[O--L-Rha_p-(12)--L-Ara_p]-28-O-[O--L-Rha_p-(14)-O--D-Glc_p-(16)--D-Glc_p]oleanic acid and -hederagenin, and 3-O-[O--L-Rha_p-(12)--L-Ara_p]-28-O-[O--D-Glc_p-(16)--D-Glc_p]hederagenin and a new one: tauroside H₁ — 3-O-[O--L-Rha_p-(12)-O--L-Ara_p]-28-O-[O--L-Rha_p-(14)-O--D-Glc_p-(16)--D-Glc_p]echinocystic acid.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 522–528, September–October, 1992.     

Mechanisms of Heterogeneous Processes in the System SiO2 + CH4: III. Products of >Si

Permenov  D. G.  Radzig  V. A. 《Kinetics and Catalysis》2004,45(2):273-278

The UV spectra of arsines and arsine selenides

Short-wavelength n_Se ^* and long-wavelength n_Se ^* bands are observed in the UV spectra of saturated trialkylarsine selenides in the near-UV region. The n_x ^* band in going from arsine selenides to arsine sulfide and then to arsine oxides is shifted hypsochromically, as in the corresponding phosphorus compounds. The n_x ^* band is only slightly sensitive to the chalcogen. Saturated trialkylarsines, in contrast to alkylphosphines, absorb in the near UV region (the n_As ^* band is at 208 nm).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 940–942, April, 1990.