Cardiac glycosides ofAcokanthera venenata

Six cardenolides have been isolated from the leaves ofAcokanthera venenata G. Don: AV-1, mp 252–255°C, [] _D ²⁰ +39.4° (MeOH); AV-2, mp 199–208°C, [] _D ²⁰ -59.3° (MeOH); AV-3, mp 269–275°C/300–304°C, [] _D ²¹ –69.8° (MeOH); AV-4, mp 279–289°C; AV-5, mp 222–225°, [] _D ²⁰ -64.3° (MeOH); and AV-6, mp 193–196°C [] _D ²⁰ –23.8° (MeOH — CHCl₃). AV-5 has been identified as acovenoside A. AV-3 is a new cardiac glycoside: it is 1-acetoxy-3-(4-O--D-glucosyl-3-O-methyl--L-talomethylosyloxy)-14-hydroxy-5, 14-card-20(22)-enolide (glucoacovenoside B).Khar'kov State Pharmaceutical Institute. All-Union Scientific Research Institute of Drug, Chemistry and Technology, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 372–376, May–June, 1987.     

Triterpene glycosides of alfalfa. III. Medicoside I

On the basis of chemical transformations and with the aid of physicochemical results, the structure of glycoside I isolated from the roots of the plantMedicago sativa has been established as hederagin 3-O-[O--L-arabinopyranosyl-(1 2)--D-glucopyranosyl-(1 2)--L-arabinopyranoside] 28-O--D-glucopyranoside. Compound (I), C₅₂H₈₄O₂₂, mp 210–212°C, [] _D ²¹ +38.4° (c 1.48; methanol). Acid hydrolysis of (I) led to hederogenin (II) — C₃₀H₄₈O₄, mp 326–330°C, [] _D ²³ +84.2° (c 0.19; pyridine. The Hakomorimethylation of glycoside (I) yielded the permethylate (IV) — C₆₅H₁₁O₂₂ [] _D ²³ +41.6° (c 1.79; methanol). The GLC analysis of the products of the methanolysis of compound (IV) showed the presence of 3,4,6-tri-O-methyl-D-glucopyranose, 2,3,4,6-tetra-O-methyl-D-glucopyranose, 3,4-di-O-methyl-L-O-arabinopyranose, and 2,3,4-tri-o-methyl-L-arabinopyranose. The alkaline hydrolysis of glycoside I gave compound (III) with mp 230–233°C, [] _D ²¹ +35.2° (c 0.21; methanol), which was identified as medicoside C. Details of the PMR spectrum are given for compound (IV) and of the IR spectrum for compound (I).Institute of the Chemistry of Plant Substances of the Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–610, September–October, 1986.     

Glycosylation of triterpenoids of the dammarane series I. 20(S),24(R)-epoxydammarane-3α-12β,25-triol 25-O-β-D-glucopyranoside

The glycosylation of 3,12-diacetoxy-20(S),24(R)-epoxydammaran-25-ol with -acetobromoglucose under the conditions of Helferich's modification and with D-glucose tert-butyl orthoacetate under the conditions of the orthoester method gives a high yield (60–64%) of the hexacetate of the -D-glucoside at the tertiary hydroxy group of 20(S),24(R)-epoxydammarane-3,12,25-triol (III) with mp 207–209°C (ethanol), [] _D ²⁰ -20.9 (c 1.0, CHCl₃). Saponification with 10% KOH in methanol gives the free 20(S),24(R)-epoxydammarane-3,12,25-triol 25-O--D-glucoside (V) (yield 90%) with mp 275–279°C (methanol), [] _D ²⁰ +11.4° (c, 1.0, C₅H₅). The results of IR and¹H and¹³C NMR spectroscopy and of elementary analysis are given.Pacific Ocean Institute of Bioorganic Chemistry of the Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 205–208, March–April, 1980.     

First and second thermodynamic mixing properties of ethylbenzene +n-alkanes: Experimental and theory

Isobaric expansibilities _P and isothermal compressibilities _T have been determined at 25 and 45°C for binary mixtures of ethylbenzene + n-tetradecane and + n-hexadecane and the corresponding excess functions (V ^E /T)_P and (V ^E /P)_T have also been obtained. With these data and supplementary literature values, the following second order mixing properties are also reported at 25°C: _S ^E , (V ^E /P)_T, C_V and (VT). All mixing quantities have been compared with the results obtained at 25°C by using the Prigogine-Flory-Patterson theory of liquid mixtures. The predicted values suggest that the ability of ethylbenzene as a breaker of the pure n-C_n orientations is similar to what we found for toluene and higher than for p-xylene.     

Influence of temperature on the micellization of sodium dodecylsulfate in water from speed of sound measurements

Speed of sound measurements for aqueous solutions of sodium dodecylsulfate (NaDS) have been carried out from 20 to 45°C at intervals of 5°C. The critical micellar concentrations (cmc) were determined and their change with temperature is discussed. A second change in the speed of sound has been found between 15 to 20mM for temperatures above 20°C. Values for G _m ^o , H _m ^o and S _m ^o for the micellization process have been determined and compared with data previously obtained from other experimental properties. These results confirm that the micellization process of NaDS in water is mainly entropically driven.     

Determination of monomeric ethylene oxide in pharmaceutical raw materials

Summary A GC headspace test procedure has been developed for the determination of ethylene oxide (EO) in raw materials produced totally or partly from ethylene oxide. This procedure described is a limit test for EO within the concentration range 0.5–2.5 g/g. The determination is based on the standard addition method and is suitable for testing whether an upper limit of 1 g/g of EO is exceeded in pharmaceutical raw materials.

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Bestimmung von monomerem Ethylenoxid in pharmazeutischen Rohmaterialien

     

Triterpene glycosides ofSilphium perfoliatum. IV. Structure of siliphioside C

The epigeal part ofSilphium perfoliatum has a yielded a new triterpene glycoside, silphioside C — C₅₀H₈₀O₁₉, mp 207–210°C (from aqueous methanol), []_D ²⁵ +19.3 ± 2°C (c 0.88; methanol). On the basis of acid hydrolysis, mild alkaline saponification, and the results of GLC and of IR, mass, and¹H and¹³C spectroscopy the structure of silphioside C had been established as 28--D-glucopyranosyl 3-O-[O--D-glucopyranosyl-(12)-(6-O-acetyl--D-glucopyranosyl)oleanolate.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii. No. 4, pp. 519–522, July–August, 1985.     

Phytoecdysones ofSilene praemixta. II. Premixisterone

The structure of premixisterone (I) — a new ecdysteroid fromS. praemixta M. Pop. (Caryophyllaceae) — has been established. Compound (I) has the composition C₂₇H₄₄O₅, mp 110–112°C (from C₂H₅OH + H₂O), [] _D ²⁴ 0 ± 4° (c 0.85; MeOH), 202 nm (log 3.35), _max ^KBr 3415 cm^–1 (OH), 1710 cm^–1 (C=0), and does not contain the ⁷-6-keto grouping that is characteristic of natural ecdysteroids. The acetylation of (I) with (CH₃CO)₂ in Py gave the amorphous 3,22-diacetylpremixisterone (II), C₂₁H₄₈O₇. Compound (I) has the structure of 3,14,22R,25-tetrahydroxy-5-cholest-8-en-6-one. The IR, PMR, and mass spectra of (I) and (II) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 797–799, November–December, 1979.     

Crystal Structure of 1,3-Alternate 25,26,27,28-Tetra(tert-butoxyethoxy)calix[4]arene: a Selective Ag+ Extractant

Alkylation of calix[4]arene by 2-tert-butoxyethyl bromide led to the tetraalkylatedcalix[4]arene in the 1,3-alternate, the conformation of which has been established byX-ray crystallography. This spatial structure included a cavity potentially useful forhost–guest complexes achieved with metal cations, especially with Ag⁺. The titlecompound crystallizes in the monoclinic space group Cc with cell constants a = 29.901(2),b = 8.139(1), c = 22.264(3) Å, = 90°, = 117.08(1)°and = 90°. This conformer represents an example for Ag⁺-tunnelingacross an aromatic cavity. This behaviour could lead to important implications with regardto the metal cation- interaction expected for metal transport through ion channels,metal inclusion in fullerenes, intercalation of metal cations into graphites, etc.     

Polymorphism of (+)N-tosyl-L-glutamic acid

It has been shown that polymorphism is the reason for the occurrence of (+)N-tosyl-L-glutamic acid 1 with various melting points. 1 occurs in two crystalline forms: and . Form -1 (prisms) having a melting point of 145–147°C is chemically pure and stable. Form -1, however, is unstable and is formed as a result of the stabilizing effect of an organic solvent not introduced into the structure of the crystal. At about 125°C the forms is transformed to the form. The melting point of the form depends on the amount and type of solvent contained in the crystal, which, during measurement cannot leave the system.     

On the reduction of Pd2+ forms in Pd/γ-Al2O3 catalysts

The influence of the preparation method (i.e., Pd precursor and heat treatments) on the reduction pattern of Pd/-Al₂O₃ catalysts has been investigated by TPR. The role of the Cl^– ions and the effect of metal dispersity on the stability of Pd catalysts reduced at different T_r (400T_r800°C) have been discussed. Reoxidation of Pd^o occurs during exposure to the atmosphere and the formation both of easily reducible PdO forms and Cl-containign Pd²⁺ oxo-complexes, strongly interacting with alumina surface, has been pointed out.     

Monomeric copper(II) and nickel(II) complexes of N,N,N′,N′-tetrakis [(2-benzimidazolyl)methyl]-1,2-cyclohexanediamine], a chelating ligand containing imidazole groups

Summary Cu^II and Ni^II coordination compounds with N,N,N,N-tetrakis[(2-benzimidazolyl)methyl]-1,2-cyclohexanediamine (CDTB) have been prepared and characterized. The crystal structure of [Cu(CDTB)](ClO₄)₂ has been determined. The geometry around the Cu atom is highly irregular and can best be described as a cis-distorted octahedron, with four short CuN bond distances of 1.988(3) Å and 2.028(3) Å, and two very long CuN bond lengths of 2.543(4) A. The cis NCuN chelate angles in the complex range from 68.8(2) for N(1)CuN(1) to 141.03° for N(4)CuN(1). The cyclic voltammogram of the complex shows a fully reversible one-electron redox wave at E _1/2 = 0.162V versus standard calomel electrode, corresponding to the Cu^I/II redox couple. The structure of [Ni(CDTB)](NO₃)₂ ·EtOH has also been determined. The geometry around the Ni atom in this compound can be described as distorted octahedral, with N(4), N(4), N(1), N(1) as the ligating atoms in the basal plane, with cis chelate angles ranging from 79.37(10) to 120.9(2)° with the trans N(2)NiN(2) angle at 175.1(2)°. The structural differences in these two compounds are undoubtedly electronic rather than steric.     

Analysis of organobromine compounds and HBr in motor car exhaust gases with a GC/microwave plasma system

Summary In this investigation an analytical procedure for the determination of different organobromine compounds in motor car exhaust gases is developed in order to obtain a total balance of these compounds in this type of exhaust gas. For this purpose, adsorption sampling on Tenax GC combined with thermal desorption and a fast cold trap injection into the GC column system is used. A special capillary cold trap/thermodesorption system for a fast injection within 1 s is developed. The chromatographically separated fractions are identified by their retention times and elementspecific detection with a microwave plasma detector. Methyl bromide, 1,2-dibromoethane, and vinyl bromide are analysed in exhaust gases in cases where the gasoline contains 1,2-dibromoethane as an additive (leaded gasoline). The analysed bromine contents, which correspond to these organobromine compounds, are in the range of 90–190 g/m³, 15–85 g/m³, and 5–20 g/m³, respectively. The portion of the organobromine compounds is 22–44% of the total bromine which is emitted by the exhaust gases. The other portion contains mainly inorganic particulate bromide, which can be separated by filters. The concentration of the organobromine compounds decreases with increasing motor temperature. After conversion into 2-bromocyclohexanol and after gas chromatographic separation HBr is detected to be 5.8 g bromine per m³ exhaust gas, which corresponds to approximately 1% of the total bromine emission. 1,2-Dichloroethane is analysed in the range of 5–35 g Cl/m³, whereas the concentration of tetraalkyl lead in the exhaust gases is less than the detection limit of 6.7 g Pb/m³. The average bromine/lead ratio found in the filterable portion of the exhaust gases is 0.30 (by weight); the same ratio calculated for total bromine emission including the organobromine compounds is 0.47. Compared with the bromine/ lead ratio in gasoline of 0.39 this means that at least 17% of the total lead in the gasoline is not directly emitted with the motor car exhaust gases.

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Analyse von bromorganischen Verbindungen und HBr in Autoabgasen mit einem GC/Mikrowellenplasma-System

     

Studies on styrene phosphonic acid

Some properties of styrene phosphonic acid (SPA) were studied. The crystals were triclinic, witha=0.6434 nm,b=0.5842 nm,c=2.0338 nm, =96.17°, =97.33°, =79.65° andZ=4. SPA underwent a change in crystal structure at 78.8°C, the hydrocarbon network became disordered (liquid-like) at 138.5°C. Crystals melted at 148.6°C giving a cubic mesophase, then changed to an isotropic liquid at 155.6°C and at 162.13°C SPA underwent decomposition. Values for pK₁=2.15 and pK₂=7.66 were obtained at 25°C. The water solubility of SPA at several temperatures, and its interaction with surfactant micelles were determined.     

Strain Energies of α-Alkylsubstituted Styrenes, 1,1-Di-phenyl-ethene,Tri-, and Tetra-phenyl-ethene

The standard (p° = 0.1 MPa) molar enthalpies of formation _fH°_m (1 or cr) at the temperature T = 298.15 K were determined by using combustion calorimetry for -ethyl-styrene (A), -iso-propyl-styrene (B), -tert-butyl-styrene (C), 1,1-di-phenyl-ethene (D), tri-phenyl-ethene (E), and tetra-phenyl-ethene (F). The standard molar enthalpies of vaporization _l ^g H°_m or sublimation _cr ^g H°_m of compounds A to F were obtained from the temperature variation of the vapor pressure measured in a flow system. Molar enthalpies of fusion _cr ^l H°_m of solid compounds were measured by d.s.c. Resulting values of _fH°_m (g) were obtained at the temperature T = 298.15 K and used to derive strain enthalpies of phenylalkenes. The interactions of the substituents are discussed in terms of deviations of _fH°_m (g)from the group additivity rules. These values provide a further improvement on the group-contribution methodology for estimation of the thermodynamic properties of organic compounds.     

Potentiometric Studies on Binary and Ternary Complexes of Di- and Trivalent Metal Ions Involving Some Hydroxamic Acids, Amino Acids, and Nucleic Acid Components

Summary. Formation of binary and ternary complexes of Cu^II, Co^II, Ni^II, Zn^II, Fe^III, Al^III, and Cr^III metal ions with some selected aliphatic and aromatic hydroxamic acids and some biologically important amino acids or nucleic acid components was investigated using the potentiometric technique at 25°C and I=0.10moldm^–3 NaNO₃. The acid-base properties of the ligands were investigated and discussed. The acidity constants of the ligands were determined and used for determining the stability constants of the complexes formed in aqueous medium under the experimental conditions. The ternary complex formation was found to occur in a stepwise manner. The stability constants of these binary and ternary systems were calculated. The order of stability of the ternary complexes in terms of the nature of hydroxamic acid, amino acid, nucleic acid component and metal ions was investigated and discussed as well as the values of log K and log X for the ternary systems. The concentration distribution of the various complex species in solution was evaluated. In addition, evaluation of the effect of temperature of the medium on the stability of the ternary system M^III – benzohydroxamic acid – L-histidine or adenine (M^III=Fe^III, Al^III, and Cr^III) has been studied. The thermodynamic parameters were calculated and discussed.     

A new terpenoid coumarin trans-diversin fromFerula litwinowiana

The results are presented of investigations into the structure of a new terpenoid coumarin with the composition C₁₉H₂₀O₄ with mp 96–98°C (from aqueous ethanol), differing from diversion by the trans position of one bond. On the basis of spectroscopic (IR and¹H NMR) results, the structure of 7-(3,7-dimethyl-5-oxoocta-3E,6-dienyloxy)coumarin is proposed for this substance.V. L. Komarov Institute of Botany, Academy of Sciences of the Azerbaidzhan SSR, Baku. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 360–362, May–June, 1987.     

Study of thermal properties of endellite clay compound

The temperature dependence of the thermal properties (specific heat,C _p, thermal diffusivity,a, and thermal conductivity,K) of endellite clay has been investigated over the temperature rangeR·TT/280 °C using the plane temperature wave technique. The experimental results showed that in the initial stage of temperature rise botha andK diminish exponentially with increasing temperature up to 100 °C. Above 100 °C, the thermal parameters are found to reach stable values, namely,C _p=0.22±0.008 cal g^–1 deg^–1,a=(5.0±0.18)–10^–4 cm² sec^{– 1} andK=(2.2±0.16) · 10^–4 cal cm^–1 sec^–1 deg^–1. The explanation of the results was supported by using DTA and TG analysis.

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Zusammenfassung In einem Temperaturbereich zwischen Raumtemperatur und 280 °C wurde die Temperaturabhängigkeit der thermischen Eigenschaften (spezifische WärmeC _p, Temperaturleitfähigkeita, WärmeleitfähigkeitK) von Endellittonerde untersucht. Die Ergebnisse zeigen, daß sowohla als suchK im ersten Abschnitt der Temperaturzunahme mit steigender Temperatur bis 100 °C exponentiell abnehmen. Oberhalb 100 °C erreichen die Parameter stabile Werte:C _p=0,22 ±0,008 cal g^–1 deg^–1,a=(5,0±0,18)·10^–4 cm² sec^–1 undK=(2,2±0,16)·10^–4 cal cm^–1 sec^–1 deg^–1. Die Erklärung der Ergebnisse wurde unter Zuhilfenahme von DTA und TG durchgeführt.

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( _p, ) T280°. , 100° K . 100° _n=,22 ±0,008 · ^–1· ^–1, =5,0±0,18·10^{–4 2}· ^–1 K=2,2±0,16· 10^–4 · ^–1· ^–1· ^–1. .

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We wish to thank Dr. N. Afify, Phys. Dept. Assiut University, for his assistance during DTA and TGA analysis.     

Flavonoids of inflorescences of Calendula officinalis

By column chromatography on polyamide sorbent, the inflorescences of pot marigold calendula have yielded eight substances of flavonoid nature: two aglycons — quercetin (C₁₅H₁₀O₇, mp 309–311°C) and isorhamnetin (C₁₆H₁₂O₇, mp 314–316°C); six glycosides, of which three have been identified as isoquercetin (C₂₁H₂₀O₁₂, [] _D ²⁰ –36° in methanol, mp 218–220°C), isorhamnetin 3-O--D-glucoside (C₂₂H₂₂O₁₂, [] _D ²⁰ –59° in dimethylformamide, mp 193–195°C), narcissin (C₂₈H₃₂O₁₆, [] _D ²¹ –28° in dimethylformamide, mp 180–182°C), and three substances that have proved to be new and have been called calendoflaside (C₂₈H₃₂O₁₅, [] _D ²¹ –85° in methanol, mp 192–195°C; calendoflavoside (C₂₈H₃₂O₁₆, [] _D ²⁰ –106° in methanol, mp 189–192°C), and calendoflavobioside (c₂₇H₃₀O₁₆, [] _D ²⁰ –105° in methanol, mp 194–197°C).All-Union Scientific-Research Institute of Drug Chemistry, Khar'kov. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 795–801, November–December, 1988.     

Gel Chromatographic Fractionation and Partial Physicochemical Characterization of Gelatins

Summary Gel chromatography on Sephacryl S-400 HR was used to fractionate a type A and a type B gelatin on a semi-preparative scale. Fractionation was performed at 40 °C in 50 mM ammonium acetate, 0.02% (w/v) sodium azide. Five fractions, enriched in microgels, -chains, -chains, -chains and subfragments, were isolated. Their molar mass distribution was controlled by FPLC on Superose 6 and SDS-PAGE. No significant differences in amino-acid composition and hexose content were observed between the original gelatins and their fractions. The specific absorption coefficient at 230 nm was found to be the same for both type A and type B gelatin and the chromatographic fractions (2.0 L·g^–1·cm^–1).Presented at: International Symposium on Separation and Characterization of Natural and Synthetic Macromolecules, Amsterdam, The Netherlands, February 5–7, 2003