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1.
Zusammenfassung Die Synthese von 3, 16-Diacetoxy-5 -pregnan-20-on (VI) aus 3-Acetoxy-5 -pregn-16-en-20-on und eine verbesserte Darstellung von 3, 16-Diacetoxy-5 -pregnan-20-on (III) aus 3-Acetoxy-pregna-5, 16-dien-20-on werden beschrieben.  相似文献   

2.
The13C NMR spectra of acetylated derivatives of the following hederagenin glycosides have been studied hederagenin 3-0--L-arabinopyranoside, hederagenin 3-0-[0--L-rhamnopyanosyl-(12)--L-arabinopyranoside], hederagenin 3-0-[0--D-glucopyranosyl-(12)--L-arabinopyranoside], hederagenin 28-0--D-glucopyranoside, and hederagenin 28-0-[0--L-rhamnopyranosyl-(14)-0--D-glucopyranosyl-(16)--D-glucopyranoside]. The spectra give information about the monosaccharide composition, the position of attachment of the carbohydrate chain, and the configurations of the glycosidic bonds, and, in some cases, the orders of the bonds.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. 3, pp. 359–362, May–June, 1980.  相似文献   

3.
The epoxide ring opening of 16,17-epoxy-17-ethynylandrost-4-en-3-one and its dicobalt hexacarbonyl complex on reacting with Py·HF, Py·HCl, and Py·HSCN was studied. The results of these reactions and the structure of the end products depend not only on the complexation of the acetylene bond, but also on the nucleophilic reagent used. On the basis of the reaction of a Co-coordinated 16,17-epoxy-17-ethynylandrost-4-en-3-one there has been developed a preparative method for the synthesis of pregn-4-ene-3,20-dione-[17,16-d]-1,3-oxazolidin-2-one.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2661–2666, November, 1992.  相似文献   

4.
    
The kinetics of carbohydrate binding to dimeric concanavalin A have been studied by the fluorescence temperature-jump method at 24°C in the range of 1–600 atm. From the pressure dependence of the reaction rate parameters, a positive activation volume for association and a small negative activation volume for dissociation have been obtained
24°C 1–600 . , .
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5.
Conclusions 1. A. new route for the synthesis of optically active ,-diglycerides has been developed.2. D- and L-, -Distearins and D-, -dilinolenin have been synthesized from the readily accessible L- and D--O-tritylglycerols.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 210–214, 1969  相似文献   

6.
The composition of the mono- and sesquiterpenoids from the oleoresin of the Khingan fir has been studied. Thirteen monoterpenoids have been identified — bornyl acetate, -terpenyl acetate, geranyl acetate, citronellyl acetate, -fenchyl acetate, linalool, geraniol, terpineol-4, -terpineol, -fenchol, borneol, sabinene hydrate and thymol methyl ether; and 19 sesquiterpenoids — -longipinene, longicyclene, longifolene, -copaene, -ylangene, sibirene, -and -selinenes, - and -cadinenes, -muurolene, caryophyllene, -humulene, - and -bisabolenes, ar-curcumene, nerolidol, bisabolol, and -cedrol. The crystal structure of -cedrol has been investigated by x-ray structural analysis.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 41–45, January–February, 1985.  相似文献   

7.
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.  相似文献   

8.
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.  相似文献   

9.
By using reactive atmospheres, the area of application of thermal analysis is expanded considerably to cover many aspects of high temperature research into fuels, extractive metallurgy, materials and catalysts. This article reviews the design of apparatus and its application in kinetic and thermodynamic studies involving atmospheres such as H2, CO, N2, NH3, CO2, H2O, SO2or3, H2S, S2, Cl2, HO, F2 and HF at low or high pressures and as low pressure plasmas. Apart from gas-solid reactions, the important influence of a controlled product gas atmosphere on decomposition reactions is discussed also. Gas-solid adsorption and solubility studies are not included.
Zusammenfassung Das Anwendungsgebiet der thermischen Analyse wird durch Arbeiten in reaktiver Atmosphäre beträchtlich erweitert, so dass Hochtemperaturuntersuchungen auf solchen Gebieten wie Brennstoffe, extraktive Metallurgie, Material- und Katalyseforschung möglich werden. Dieser Übersichtsartikel behandelt die Konstruktion der Geräte und ihre Anwendungen bei kinetischen und thermo-dynamischen Untersuchungen in solchen Gasphasen wie H2, CO, N2, NH3, CO2, SO2o der 3, H2S, S2, Cl2, HCl, F2 und HF sowie im Niederdruckplasma. Ausser Gas-Festkörperumsetzungen wird auch der Einfluss einer geregelten Produktgas-Atmosphäre auf Zersetzungsreaktionen diskutiert. Auf die Adsorption von Gasen an Festkörpern und Löslichkeitsuntersuchungen wird nicht eingegangen.

, , , . , , , , , , , - , , , , . — , . - .
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10.
Cyclosiversigenin 6-O--L-rhamnopyranoside and 6-O--D-glucopyranoside were isolated fromAstragalus coluteocarpusBoiss. (Leguminosae) andAstragalus dissectusB. Fedtsch. et N. Ivanova, respectively. Cyclosiversigenin 5-O--L-rhamnopyranoside was shown to be an artifact forAstragalus coluteocarpus.Thus, the cyclosiversigenin 6-O--D-glucopyranoside that was isolated from certainAstragalusspecies is hypothesized also to be an artifact. Glycosylation of the 6 -hydroxyl group of cycloartanes by D-glucose and D-xylose, in contrast with other substituents, does not change the low-field position of the PMR signal of the 4-CH 3 group (1.65 2.01 ppm) that is caused by the influence of deuteropyridine directly on the 6 -hydroxyl. Obviously one of the hydroxyls of the -D-glucopyranoside or -D-xylopyranoside residues has the same effect in this instance.  相似文献   

11.
The reaction of ketoximes with hypophosphorous acid resulted in previously unknown -substituted--aminophosphinic acids, which were oxidized into the corresponding -substituted--aminophosphonic acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2729–2732, November, 1996.  相似文献   

12.
Conclusions An efficient method for the synthesis of ,,-trihydropolyfluoroalkyl chlorophosphates is by reacting ,,-trihydropolyfluoroalkyl dichlorophosphites and bis-(,,-trihydropolyfluoroalkyl) phosphites with sulfuryl chloride. It has been found that in three-coordinated polyfluoroalkyl phosphites, the high electronegativity of the polyfluoroalkyl groups hinders cleavage of the latter on reaction with sulfuryl chloride, thereby facilitating the formation of oxidation products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 146–149, January, 1988.  相似文献   

13.
The characteristics of crystallization, melting and spherulitic growth of a random propylene copolymer (PRC) containing small amount of ethylene were studied in the presence of a selective -nucleating agent (calcium pimelate). It was established that the products of isothermal and non-isothermal crystallization are very rich in -modification but have mixed polymorphic composition. The formation of -modification may be attributed to -transition on the surface of growing -spherulites resulting in -twin-spherulites. During melting of PRC of -modification, the characteristics observed with -nucleated propylene homopolymers, namely, a -recrystallization of recooled samples and separated melting of non-recooled samples (i.e. the melting memory effect), as well as a -recrystallization leading to a perfection of the structure within the -modification, are also demonstrated. The disturbance of regularity of the polymer chain highly reduces the tendency to -crystallization. In contrast to the observations with propylene homopolymers, the growth rate of -modification (G ) is higher than that of -modification (G ) and no critical crossover temperature can be found (T()=413 K) below whichG >G . The experimental results show that a partial disturbance of chain regularity by incorporation of comonomer units considerably reduces the tendency to -crystallization.This research was supported by the National Scientific Research Fund (OTKA), the author is grateful for it. Thanks are due to Professor Géza Bodor for his help in X-ray diffractometric investigations and to Ms. Tünde Lócska for her prudential technical assistance in the optical experiments.  相似文献   

14.
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.  相似文献   

15.
-Cyclodextrin having cinnamamide at 6- or 3-positions (6-CiNH--CD, 3-CiNH--CD) and -cyclodextrin with cinnamamide on 6-position (6-CiNH--CD) have been prepared. Supramolecular structures were formed in the solid state or aqueous solutions and characterized by measurements of NMR and vapor pressure osmometry (VPO). The results indicate that 6-CiNH--CD formed insoluble supramolecular polymers in the solid state, while 6-CiNH--CD and 3-CiNH--CD formed supramolecular complexes in aqueous solutions. 6-CiNH--CD was found to form a dimer in an aqueous solution. 3-CiNH--CD formed intermolecular complexes to give supramolecular polymers. The differences of the position of guest part on cyclodextrins caused to give a variety of supramolecular structures in aqueous solutions.  相似文献   

16.
CO2 undergoes cycloaddition to propyne on a cationic rhodium site with the assistance of O2–/OH of support or iron oxide over Rh4 and Fex Rhy carbonyl clusterderived catalysts.13CO12 labeling and FTIR studies suggest that monodentate carbonate formed on the catalyst surface is most likely a key species to offer an active CO2 to be converted into a carbonyl intermediate prior to the product 4,6-dimethyl-2-pyrone.
CO2 O2–/OH Rh4 Fex Rhy. 13CO2 , CO2 , 4,6--2-.
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17.
A new withasteroid — vamonolide — has been isolated from the epigeal part ofPhysalis angulata L. (Solanaceae). On the basis of spectral characteristics, its structure has been established as 5,14-dihydroxyl-l-oxo-6,7-epoxy-20R,22R-with-2-enolide.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 856–858, November–December, 1987.  相似文献   

18.
Two new steroid glycosides, which have been called echinasterosides B1 and B2 have been isolated from the starfishEchinaster sepositus. Using chemical transformations (methylation, hydrolysis) and also spectral methods (1H and13C NMR spectroscopy and GLC-MS) the complete chemical structure of B1 has been established as 15-acetoxy-5-cholestane-3,4,6,8,24-pentaol 24-O[O-(2)O÷ methyl--D-xylopyranosyl)-(13)--L-arabinofuranoside] (I) and that of glycoside B2 as 5-cholestane-3,4,6,8,15,24-hexaol 24-O-[O÷(2-O-methyl--D-xylopyranosyl)-(13)--L-arabinofuranoside] (II).Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Pirodnykh Soedinenii, No. 2, pp. 246–249, March–April, 1987.  相似文献   

19.
In the presence of catalytic amounts of FeCl3, alkanes (cyclohexane, n-hexane), toluene and ethylbenzene are oxidized by air oxygen to CH3CN, (CH3)2CO or CH2Cl2 under visible light irradiation to yield ketones and alcohols.
FeCl3 (, -), CH3CN, (CH3)2CO CH2Cl2 .
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20.
The thermal decomposition of rare earth oxysulfides (excluding Sc, Ce and Pm) has been studied in air. The oxysulfides are oxidized to oxysulfates between 600 and 900 and the oxysulfate phase, which is unstable at higher temperatures, decomposes to oxide. The stability of the oxysulfate and its decomposition temperature decreases with decreasing radius of the rare earth ion. For the heavier rare earths the oxidation to oxysulfate takes place only partially before the decomposition to oxide begins.
Zusammenfassung Die thermische Zersetzung der Oxysulfide der seltenen Erden (mit Ausnahme von Sc, Ce und Pm) wurde in Luft untersucht. Die Oxysulfide werden zwischen 600 und 900 zu Oxysulfaten oxidiert und die Oxysulfatphase, welche bei höheren Temperaturen instabil ist, wird zu Oxid zersetzt. Die Stabilität des Oxysulfats und seine Zersetzungstemperatur nehmen mit abnehmendem Radius des seltenen Erden-Ions ab. Bei den schwereren seltenen Erden erfolgt die Oxysulfatbildung nur teilweise vor den Einsetzen des Abbaus zu Oxid.

- , Sc, m. 600 900° , , . - . - , .
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