Investigations in the field of complex lipids

Summary 1. The synthesis of L-(+)--oleoyl--linoleoyl--glycerylphosphorylethanolamine has been effected.2. During the investigations the following substances were isolated and characterized: L--oleoyl--glycerylphosphoryl-N-phthaloylethanolamine and L---linoleoyl--glycerylphosphoryl-N-phthanoylethanolamine.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 80–83, 1966     

Investigations in the field of lipids

Summary 1. The synthesis of the following neutral plasmalogens has been effected: -O-(octadec-1-enyl)-, distearoylglycerol, -O-(octadec-1-enyl)-, -dipalmitoylglycerol, -O-(hexadec-1-enyl)-, -distearoylglycerol, and -O-(pentadec-1-enyl)-, -dipalmitoylglycerol.2. During the synthesis, the following compounds were isolated and characterized by their physicochemical constants: the -octadec-1-enyl ether of glycerol, -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, the tosylate of -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, and -O-(2-tosyloxyoctadecyl) glycerol.3. The IR spectra of the -octadec-1-enyl ether of glycerol and the neutral plasmalogens have been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 367–371, 1966     

Thermodynamics of Binding of α:-Cyclodextrin to Straight-Chain Alkyl Derivatives in Aqueous Solution

Apparent standard Gibbs energy, enthalpy, entropy, and heatcapacity data of the interactions of -cyclodextrin (CD) to some n-carboxylatesH(CH₂)_nCOO^- (n = 4–6), are determined by isothermal titration microcalorimetryat different temperatures in phosphate buffer, pH 9.0, assuming a 1 : 1 model indilute solution. Modelling of contributions of the thermodynamic properties of the solutionindicates that CD undergoes conformational change upon binding to homologousseries of n-carboxylates, n-alcohols, ,-alkane dicarboxylates and ,-alkane diols.     

<Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR spectra of some drimanic sesquiterpenoids

One- and two-dimensional homo- and heteronuclear correlation proton, carbon, proton—proton, and proton—carbon NMR spectra of fifteen drimanic sesquiterpenoids: 11,12-dibromodrima-5,8-dien-7-one, drim-8-en-7-one, 11-hydroxydrim-8-en-7-one, 11,12-dihydroxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 8,9-epoxydriman-7-one, 8,9-epoxydriman-7-ol, 11,12-diacetoxydrim-8-en-7-ol, drimane-7,8,11-triol, 7,8-isopropylidenedioxydriman-11-al, 9, 11-dihydroxydrim-7-en-6-one, drimane-7,8,9-triol, drimane-7,8,11-triol, and drim-8-ene-7,11,12-triol were studied. The proton and carbon chemical shifts were assigned.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2589–2594, December, 2004.     

Transformed steroids. 160. Reaction of 20,20-dimethoxy-16α,17α-epoxypregn-5-ene-3β, 21-diol-20-one with pyridine thiocyanate and carbethoxyhydrazine

Conclusion The reaction of 20,20-dimethoxy-16,17-epoxypregn-5-ene-3,21-diol-20-one with pyridine thiocyanate in the presence of carbethoxyhydrazine proceeds by two competing paths: cisopening of the oxide ring by a -SCN ion at the C¹⁷ atom, and substitution of one of the methoxyl groups by -NCS ion. As a result 2,20-dicarbethoxyhydrazones of pregn-5-ene-3,21-diol-20-one-[17,16-d]-1,3-oxathiolan-2-one and 20-methoxy-16,17-epoxypregn-5-ene-3-ol-[20,21-d]-1,3-oxazolidine-2-thione are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 911–914, April, 1987.     

Kinetic analysis of consecutive reactions using TG and DSC techniques

A complex mechanism of thermal degradation processes was postulated for the reaction type , and a theoretical analysis of DTG and DSC curves was followed by corresponding mathematical simulation. In this scheme, compoundS represents a volatile product (e.g. gas and/or vapor), which is a necessary assumption in order to explain the differences in results which can arise after the kinetic analysis of DTG and DSC experimental data.Mathematical simulation was performed with different values of the Arrhenius parameter for both reaction rate constants (k ₁, andk ₂) in the range 83.1–291.0 kJ/mol for the activation energy and with corresponding values for the frequency factor (10⁵–10¹⁹ min^–1). The influence of endothermic heat effects (50–200 kJ/mol) in the reactionsAE andRS was also investigated. The calculated rates of mass and heat change (DTG and DSC), for different heating rates, showed that the maximum values of the two curves are reached at different temperatures. The non-uniformity of the DTG and DSC maxima depends on the difference between the values of the reaction rate constants and their temperature sensitivities (E ₁ andE ₂) and also on the heating rate.The theoretical analysis performed demonstrated the possibility of determining the reaction rate parameters (k ₁ andk ₂) in the case of consecutive first-order reactions, by using simultaneous TG and DSC analysis.The proposed theoretical analysis is supported by experimental DTG/DSC data concerning the pyrolysis of oil shale, which were interpreted in terms of consecutive reactions.

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Zusammenfassung Unter Annahme eines komplexen Mechanismus für thermische Abbauprozesse wurde für den Reaktionstyp eine theoretische analyse von DTG- und DSC-Kurven, gefolgt von einer entsprechenden mathematischen Simulation durchgeführt. Hier stellt die VerbindungS ein flüchtiges Produkt dar (lias oder Dampf), was eine notwendige Bedingung zur Erklärung von unterschiedlichen Ergebnissen nach der kinetischen Analyse der experimentellen DTG- und DSC-Daten ist. Bei der mathematischen Simulation wurden unterschiedliche Arrheniusparameterwerte benutzt, für beide Reaktionsgeschwindigkeitskonstanten (k₁ und k₂) in einem Intervall von 83,1–291,0 kJ/mol für die Aktivierungsenergie sowie unter Anwendung entsprechender Frequenzfaktoren (10⁵–10¹⁹ min^–1). Für die ReaktionenA R undR S wurde auch der Einfluß von endothermen Wärmeeffekten (50–200 kJ/mol) untersucht. Die berechneten Geschwindigkeiten für die Veränderung von Masse und Wärme (DTG und DSC) bei verschiedenen Aufheizgeschwindigkeiten zeigen, daß beide Kurven ihr Maximum bei unterschiedlichen Temperaturen erreichen. Die Ungleichmäßigkeit der DTG- und DSC-Maxima basiert auf den unterschiedlichen Werten der Reaktionsgeschwindigkeitskonstanten, deren Temperaturempfindlichkeit (E ₁ undE ₂ und hängt auch von der Aufheizgeschwindigkeit ab. Die durchgeführte theoretische Analyse zeigt, daß es mit Hilfe simultaner DTG- und DSC-Untersuchungen möglich ist, im Falle konsekutiver Reaktionen erster Ordnung die Reaktionsgeschwindigkeitsparameter (k ₁ undk ₂) zu bestimmen. Das vorgeschlagene theoretische Analysenverfahren wird am Beispiel der experimentellen DTG/DSC-Daten der Pyrolyse von Ölschiefer und Anwendung konsekutiver Reaktionen illustriert.

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. S (. ), , . ( _{1 2}) 83,1–291,0 · ^–1 (10⁵–10^{19 –1}). (50–200 ·^–1) AR RS. ( ) , . (E ₁ E ₂), . , ₁, ₂ . / , .

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The authors are greatful for financial support to the KFA International Bureau D-5170 Jülich on the German side, and to the Research Fund of the Belgrade Region Business Association for the Exploration, Production and Exploitation of Oil Shales, Belgrade, and SOUR Jugopetrol, Belgrade on the Yugoslavian side.     

Approaches to the synthesis of 9α,21-dihydroxy-16α,17α-epoxypregn-4-ene-3,20-diones

Various approaches to the synthesis of 16,17-epoxypregn-4-ene-9,21-diol-3,20-dione were studied. A preparative method was found for the synthesis of this compound by the microbiological transformations of 20,20-dimethoxy-16,17-epoxypregn-5-ene-3,21-diol using Rhodococcus sp. with subsequent removal of the dimethyl acetal protection in 20,20-dimethoxy-16,17-epoxypregn-4-ene-9,21-dio-1-3-one.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 690–693, March, 1990.     

Thermoanalytical studies on the preparation of industrial crystalline aluminium sulphate

Changes in the water content of aluminium sulphate hydrate were investigated gravimetrically at room temperature in air with different relative humidities. The samples conditioned in this way were characterized by thermoanalytical (TG, DTG, DSC) and X-ray diffraction measurements. Industrial aluminium sulphate hydrate obtained by freezing the melt has a partly crystalline structure. After grinding, this material crystallizes during storage. This process requires a humid atmosphere; increasing relative humidity brings about more intensive crystallization.It was found that the crystallization of aluminium sulphate from the melt is facilitated by a higher water content of the melt.

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Zusammenfassung VerÄnderungen des Wassergehalts von Aluminiumsulfat-Hydrat bei Zimmertemperatur in Luft unterschiedlicher relativer Feuchtigkeit wurden gravimetrisch untersucht. Die auf diese Weise konditionierten Proben wurden durch thermoanalytische (TG, DTG, DSC) und röntgendiffraktometrische Messungen charakterisiert. Durch Erstarren der Schmelze erhaltenes industrielles Aluminiumsulfat-Hydrat ist teilweise kristallin. Nach dem Mahlen kristallisiert dieses Material wÄhrend der Lagerung. Dieser Proze\ erfordert eine feuchte AtmosphÄre, wobei sich der Kristallisationsgrad mit steigender relativer Feuchtigkeit erhöht. Es wurde festgestellt, da\ die Kristallisation des Aluminiumsulfats durch einen höheren Wassergehalt der Schmelze gefördert wird.

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. , , . , , . . , . , .

     

Über halogen- und stickstoffhaltige Derivate aliphatischer Carbonsäuren, 6. Mitt.: Über die Gewinnung von α-Oximino- und α-Nitrodicarbonsäureestern

Zusammenfassung Aus den entsprechenden -Bromestern werden durch Umsetzung mit Natriumnitrit die -Oximinodicarbonsäuredimethylester C₇ und C₉ und der , -Dioximinoazelainsäuredimethylester erhalten. -Methyladipinsäure wird zum Gemisch aus -Bromund -Bromester umgesetzt. Mit Natriumnitrit wird -Nitro-und -Oximino--methyladipinsäuredimethylester erhalten.

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The -oximino dicarboxylic dimethyl esters of C₇ and C₉ and the , -dioximino azelaic acid dimethyl ester are received from the corresponding -bromo esters by reaction with sodium nitrite. -Methyladipic acid is reacted with bromine to a mixture of the -bromo and -bromo ester. Reaction with sodium nitrite gives the -nitro ester and the -oximino ester of -methyl adipic acid.

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5. Mitt.:H. Reinheckel, Mh. Chem.98, 1217 (1967).     

Charge-transfer Interaction: A Driving Force for Cyclodextrin Inclusion Complexation

PM3 calculations were performed on the complexation of -cyclodextrin (-CD) with nitrobenzene, benzoic acid, benzoate anion, 4-nitrophenol, and 4-nitrophenolate anion. The results, in agreement with the experimental observations, indicated that the complex -CD-benzoic acid was more stable than -CD-nitrobenzene, and -CD-4-nitrophenolate was more stable than -CD-4-nitrophenol. Frontier orbital analysis suggested that charge-transfer interaction led to such behaviors, and hence constituted a nontrivial driving force in the molecular recognition of -CD.     

Synthesen von 2-Anilinocyclopentanonen

The syntheses of the 2-anilinocyclopentanones2 a–2 e in yields about 50% by reaction of 2-chlorocyclopentanone with 4-chloroaniline, N-methyl-4-chloroaniline, ,,-trifluoro-3-toluidine, N-methyl-,,-trifluoro-3-toluidine and 3,4,5-trimethoxyaniline, are described.     

Hydrolysis of 4-acetyl-3α, 4α-epoxycarane

Conclusions The acid hydrolysis of 4-acetyl-3,4-epoxycarane proceeds with opening of the oxide ring at the carbon atom not attached to an electronegative substituent to give the diol 4-acetyl-3, 4-caranediol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1052–1054, May, 1980.     

Transformed steroids. 189. Synthesis and transformations of 21-hydroxy-5α-H-pregnane 2′,2′-dimethyl-[16α,17α-d]-thioxalanes

In a continuation of the research on use of 20-keto-16,17-epoxysteroid 20-hydrazones for synthesis of 17-thio analogs of 20-ketosteroid 16,17-acetonides [2, 3], we synthesized 5-H-pregnane-3,16,21-trihydroxy-17-thiol-20-one 16,17-acetonide and found methods for its microbiological dehydrogenation and hydroxylation into ⁴-3-keto-and 9-hydroxy-⁴-3-keto derivatives.See [1] for Communication 188.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1182–1186, May, 1992.     

Triterpene glycosides ofHedera taurica. XI. Structures of taurosides St-G1, St-H1, and St-H2 from the stems of Crimean ivy

The previously known glycosides 3-O--L-arabinopyranosyl-28-O-[-L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl]hederagenin and 3-O-[-L-rhamnopyranosyl-(12)-O--L-arabinopyranosyl]-28-O-[-L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl]hederagenin and the new triterpene glycoside tauroside St-H₁ — 3-O--D-glucopyransyl-28-O-[-L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl]hederagenin — have been isolated from the stems ofHedera taurica Carr.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 571–579, July–August, 1993.     

Polyhydroxylated steroids from the starfishPatiria pectinifera

By chromatography on Polikhrom-1, silica gel, and Florisil, an ethanolic extract of the digestive organs of the starfishPatiria pectinifera has yielded the steroid polyols 5-cholestan-3,6,8,15,16,26-hexaol and 5-cholestan-3,4,6,7,8,15,16,26-octaol 6-(sodium sulfate). The structures of the compounds have been shown by spectral characteristics and chemical transformations.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 738–741, November–December, 1984.     

Mechanism of the Low-Temperature Interaction of Hydrogen with α-Oxygen on FeZSM-5 Zeolite

The mechanism of a low-temperature reaction of hydrogen with the radical anion surface oxygen species (-oxygen, ) formed by decomposing N₂O over FeZSM-5 zeolite was studied using kinetic and isotope techniques. It was found that the reaction is of first order with respect to hydrogen and the rate of the reaction is proportional to the concentration of . The activation energy of the reaction, which was measured for ₂ or D₂ over a temperature range from +20 to –;;100°, is equal to 3.2 or 5.3 kcal/mol, respectively. The reaction occurs with a considerable kinetic isotope effect (k /k _D), which varies over the range of 3.4–;;41 depending on the temperature. This fact indicates that the rate-limiting step of the reaction includes the dissociation of the hydrogen molecule. The temperature dependence of the isotope effect gave a value of 2.1 kcal/mol, which is close to the difference between the zero bond energies in the molecules of ₂ and D₂; this fact suggests that a tunnel effect does not significantly contribute to the reaction. The dissociative mechanism is consistent with data obtained by in situ IR spectroscopy. The interaction of hydrogen with -oxygen is accompanied by the formation of new hydroxyl groups (absorption bands at 3635 and 3674 cm^–;;1) at the surface of the zeolite. The identification of these groups was supported by an isotope shift either on the replacement of ₂ by D₂ or on the replacement of ¹⁶ by ¹⁸. The stoichiometric ratio ₂ : is consistent with the previously drawn conclusion on the paired arrangement of -sites.     

Transformed steroids. 121. Synthesis of the δ-lactone of 3β-acetoxy-16α-hydroxy-6-oxo-24-nor-5α-chol-17(20)-en-23-oic acid

The synthesis of the ¹⁷⁽²⁰⁾-16 analog of natural chiogralactone is described. Attempts to introduce a 6-oxo group directly into the -lactone proved unsuccessful, since the first stage — saponification — took place with the formation of three products: the 3-hydroxy--lactone, the 3-hydroxy-²⁰⁽²²⁾-lactone, and the 15,17(20)-dienoic acid. The synthesis of the desired compound was effected from the ethyl ester of the 5,16-dienoic acid by the scheme 3-acetate3-tosylate6-hydroxy-3,5-cyclosteroid6-oxo-3,5-cyclosteroid6-oxo-5H--lactone. It has been shown that the cyclopropane ring in the 3,5-cyclosteroid -lactone is extremely stable under the conditions of acid treatments.N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 184–187, March–April, 1981.     

Polyhydroxysteroids from the Far-Eastern starfishCtenodiscus crispatus

Four new polyhydroxysteroids, 5-cholesta-3,5,6,15,16,25,26-heptaol, 24-ethyl-5-cholesta-3,5,6,15,28,29-heptaol-29-sulfate, (22E)-24-methyl-5-cholest-22-ene-3,5,6,15,25,26-hexaol-26-sulfate, 24-propyl-5-cholesta-3,5,6,8,15,28,29-heptaol, and the known 5-cholesta-3,5,6,15,16,26-hexaol, have been isolated from the starfishCtenodiscus crispatus.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1821–1825, October, 1994.     

Possible conformations and relative stability of the 7-membered ring in 1α,5β,6,7α(H)-and 1β,5α,6,7α(H)-guai-11(13)-en-6,12-olides

Stereoisomers of 1,5,6,7(H)- and 1,5,6,7(H)-guai-11(13)-en-6,12-olides are calculated using molecular mechanics. The possibility of forming various conformations in the 7-membered ring is examined as a function of the fusion to the 5-membered C-ring. The effect of the methyl orientation on the conformation of the 7-membered ring and the relative stability of the conformers are discussed.Insitute of Phytochemistry, Karaganda, fax (3212)-43-37-73. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 54–56, January–February, 2000.