The Semi-ideal Solution Theory. 3. Extension to Viscosity of Multicomponent Aqueous Solutions

Viscosities were measured for the ternary aqueous systems NaCl–mannitol(C₆H₁₄O₆)–H₂O, NaBr–mannitol–H₂O, KCl–mannitol–H₂O, KCl–glycine(NH₂CH₂COOH)–H₂O, KCl–CdCl₂–H₂O, and their binary subsystems NaCl–H₂O, KCl–H₂O, NaBr–H₂O, CdCl₂–H₂O, mannitol–H₂O, and glycine–H₂O at 298.15 K. A powerful new approach is presented for theoretical modeling of the viscosity of multicomponent solutions in terms of the properties of their binary solutions. In this modeling, the semi-ideal solution theory was used to associate the solvation structure formed by each ion and its first solvation shell in a binary solution with the solvation structure of the same ion and its first solvation shell in multicomponent solutions. Then, the novel mechanism proposed by Omta et al. (Science, 301:347–349, 2003) for the effect of a single electrolyte on the viscosity of water was extended to describe the influence of solute mixtures on the viscosity of water, including electrolyte mixtures, nonelectrolyte mixtures, and mixtures of electrolytes with nonelectrolytes. The established simple equation was verified by comparison with measured viscosities and viscosities reported in literature. The agreements are very impressive. This formulation provides a powerful new approach for modeling this transport property in solutions. It can stimulate further research in establishing a dynamical analogue to that formulated for the thermodynamics of multicomponent solutions. It is also very important for the study of hydration of ions.     

Modified Coumarins. 19. Synthesis of Neoflavone D-Glycopyranosides

Neoflavone β-D-glucopyranosides, β-D-galactopyranosides, β-D-xylopyranosides, and α-D-arabinopyranosides were synthesized by Michael condensation of potassium salts of 7-hydroxy-4-arylcoumarins with acetobromosugars followed by deacetylation of the resulting peracetates. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 546–550, November–December, 2005.     

Triterpene glycosides ofHedera canariensis. V. Structure of glycosides from canary ivy stems

Triterpene glycosides from leaves of canary ivyHedera canariensis Willd. were previously isolated and characterized [1–4]. The glycosidic composition of the plant stems is reported in the present article. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 676–678, September–October, 1999.     

Triterpene glycosides from <Emphasis Type="Italic">Astragalus</Emphasis> and their genins. LXXXI. Chemical transformation of cycloartanes. VII. Synthesis of cyclosiversigenin lactone

The lactone 20R-25-norcycloartan-3β,6α,16β-triol-20,24-olide was synthesized from cyclosiversigenin. Presented at the 1st International Symposium on Edible Plant Resources and the Bioactive Ingredients, Xinjiang, China, July 25–27, 2008. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 324–327, May–June, 2009.     

Modified coumarins. 28. Synthesis of spirosubstituted pyranocoumarins

Spiropyranobenzopyrandiones were prepared, reduced, and dehydrated to form spirosubstituted pyranocoumarins. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 135–139, March–April, 2009.     

Modified coumarins. 20. Furocoumarin derivatives of cytisine

Cytisine derivatives modified by furocoumarins were synthesized using activated esters. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 230–232, May–June, 2006.     

Cardenolide glycosides ofCheiranthus allioni. XV. Glucocheiranthoside

Another new cardenolide glycoside has been isolated from the plantCheiranthus allioni Hort., and has been named glucocheiranthoside. Its chemical structure has been established as 3β-(4′-O-β-D-glucopyranosyl-β-D-gulmoethylpyranosyloxy)-14-hydroxy-19-oxo-5β,14β-card-20(22)-enolide. State Scientific Center for Drugs, Ukraine, 310085, Kharkov, USSR. ul. Astronomicheskaya, 33. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 269–271, March–April, 1994.     

Phytoecdysteroids of Rhaponticum carthamoides. II. Rhapisterone B

A new ecdysteroid (rhapisterone B) has been isolated from the seeds ofRhaponticum cathamoides (Willd.) Iljin. (familyCompositae). It has been shown that it is 2β, 3β, 11α, 14α, 20R, 24ξ-hexahydroxy-5β-cholest-7-en-6-one. Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 806–808, November–December, 1991.     

Triterpene glycosides of alfalfa. V. Medicoside H

A new triterpene glycoside — medicoside H — has been isolated from the roots ofMedicago sativa L. (Fabaceae), and on the basis of chemical transformations and spectral characteristics its structure has been established as medicagenic acid 3-O-β-D-glucopyranoside 28-O-[O-α-L-rhamnopyronosyl-(1 → 2)-β-L-arabino-pyranoside]. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 673–677, September–October, 1989.     

Components of plants of the family Empetraceae. II. Flavonoids of Empetrum nigrum

Tomsk Medical Institute. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 875–876, November–December, 1988.     

Modified coumarins. 22. Synthesis of N-coumarinyloxyacetyl derivatives of cytisine

N-Acetyl derivatives of cytisine modified by coumarins were synthesized. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 110–113, March–April, 2006.     

Simultaneous Determination of Triptolide and Tripdiolide in Extract of Tripterygium wilfordii Hook. f. by LC–APCI-MS

A novel method using liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry in the negative selected ion monitoring mode has been developed and validated for rapid simultaneous determination of triptolide and tripdiolide in the extract of Tripterygium wilfordii Hook. f. The molecular ions m/z [M–H]⁻ 359 and 375 were selected for the quantification in selected ion monitoring mode for triptolide and tripdiolide. Standard calibration curve was linear over the concentration range of 0.12–24 and 0.15–30 μg mL⁻¹ for triptolide and tripdiolide. The relative standard deviations of intra- and inter-day were in the range of 4.7–9.9 and 8.9–12.6%. The average recoveries were between 96.4 and 104.6%. The limits of quantitation were 2.0 × 10⁻³ and 2.5 × 10⁻³ μg mL⁻¹ for triptolide and tripdiolide.     

XRF Analysis of Microsamples of Semiconductor Type Multielement Materials by the Thin Layer Method. Determination of Cr, Co, Ni, Cu, Zn, Ga, Se, Sb, Yb

 A simple and quick method of durable samples preparation by the thin layer method through direct digesting of the analysed material on the substrate has been presented. Four- and three-component mono- and polycrystals have been analysed. Standards have been used in calibration containing: Cr, Co, Ni, Cu, Zn, Ga, Se, Sb, Yb. To improve the correlation between the concentration and the fluorescent radiation models of mathematical corrections have additionally been used: multiple linear regression, Lucas-Tooth-Pyne model (L. T. P.) and de Jongh model (d. J.). Statistical parameters: detection limits for 0.5 mg samples: Cr–0.041%, Co–0.034%, Ni–0.042%, Cu–0.053%, Zn–0.054%, Ga–0.057%, Se–0.057%, Sb–0.113%, Yb–0.077%. Correlation coefficients: simple regression 0.9946–0.9997, multiple regression 0.9974–1.0000, L. T. P. 0.9993–1.0000, d. J. 0.9995–1.0000. Received August, 1, 1998. Revision March 25, 1999.     

Lipids of Potomogeton sp.

Institute of the Ecology of the Volga Basin, Russian Academy of Sciences, Tol'yatti. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 850–852, November–December, 1991.     

Triterpene glycosides of Astragalus and their genins. XXIX. Cycloartanes of Astragalus kuhitangi

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 882–883, November–December, 1988.     

Triterpene glycosides of Astragalus and their genins. XXVIII. Cycloartanes of Astragalus babatagi

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 880–882, November–December, 1988.     

Hybrid organic/inorganic films of conducting polymers modified with phthalocyanines. II. EIS studies and film characterization

Conducting polymers were modified with Cu-phthalocyanine or Co-phthalocyanine embedded in a sol–gel matrix. The resulting films were characterized using electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. Electrochemical impedance spectroscopy data showed that the application of the sol–gel layer to the conductive polymer caused a noticeable increase in the impedance of the film across the frequency ranges studied. The hydrophobic character of the film was greatly influenced by the sol–gel and caused an increase in its capacitance. A modified ‘Randles’ equivalent cell was used to correlate the electrochemical parameters of the films. Elemental analysis and infrared data confirmed the presence of the phthalocyanine moieties in the film and the empirical formula of the film was estimated. The surface morphology of the sol–gel-modified conducting polymer was distinctly amorphous compared to the poly(3-methyl thiophene).     

The Role of Binary and Many-centre Molecular Interactions in Spin Crossover in the Solid State. Part II. Non-ideality Parameters Defined via Binary Molecular Potentials

Summary. Parameters of the formalism [1–6] describing spin crossover in the solid state have been defined via molecular potentials in model systems of neutral and ionic complexes. In the first instance Lennard-Jones and electric dipole–dipole potentials have been used whereas in ionic systems Lennard-Jones and electric point-charge potentials have been used. Electric dipole–dipole interaction of neutral complexes brings about a positive excess energy controlled by the difference of electric dipole moments of HS and LS molecules. Differences of the order of Δμ = 1–2 D cause an abrupt spin crossover in systems with T_1/2 = 100–150 K. Magnetic coupling contributes both to the excess energy and excess entropy, however the overall effect is equivalent to a modest positive excess energy. Ionic systems in the absence of specific interactions are characterised by very small excess energies corresponding to practically linear van’t Hoff plots. Detectable positive and negative excess energies in these systems may arise from interactions of ligands belonging to neighbouring complexes. The HOMO–LUMO overlap in HS–LS pairs can bring about a nontrivial variation of the shape of transition curves. Examples of regression analysis of experimental transition curves in terms of molecular potentials are given.     

Alkaloids ofAconitum kirinense. Structure of akiramidine

A new alkaloid called akiramidine is isolated from the aerial part ofAconitum kirinense. The structure 6β,14α,16β-trimethoxy-1α,4β,8β-trihydroxy-N-ethylaconitane is proposed based on spectral data and confirmed by chemical transformation from akiramine. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 774–776, November–December, 1999.     

Polysaccharides of Eremurus. XXIII. Carbohydrates from leaves of some species of Eremurus

Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 588–589, July–August, 1988.