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1.
A. Jordan I. Lamprecht T. Plesser B. Schaarschmidt 《Journal of Thermal Analysis and Calorimetry》1988,33(4):1013-1018
Microcalorimetric experiments on the periodic heat production in metabolizing cell free cytoplasmic extract from baker's yeast are described. The sugar substrates for glycolysis are supplied by two different techniques: (a) one-time addition of trehalose; (b) continuous infusion of glucose. For the first time the combination of calorimetry and substrate infusion technique is reported for oscillating biochemical reactions.
Zusammenfassung Mikrokalorimetrische Experimente über oszillierende Wärmeerzeugung in stoffwechselndem zellfreiem Hefeextrakt werden beschrieben. Die Zuckersubstrate für die Glykolyse werden nach zwei verschiedenen Methoden zugeführt: (1) einmalige Addition von Trehalose, (b) Kontinuierliche Infusion von Glukose. Erstmalig wird die Kombination von Kalorimetrie und Substratinfusion bei oszillierenden biochemischen Reaktionen beschrieben.
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2.
V. I. Grishkovets V. S. Strigunov A. S. Shashkov V. Ya. Chirva 《Chemistry of Natural Compounds》2001,37(2):167-172
Stem bark ofTetrapanax papyriferumC. Koch., Araliaceae, yielded new triterpene glycosides 28-O--L-rhamnopyranosyl-(14)-O-(6-O-acetyl--D-glucopyranosyl)-(16)-O--D-glucopyranosyl esters of the 3-O-[-D-glucopyranosyl-(13)-[-D-galactopyranosyl-(12)]-O--L-arabinopyranosides of oleanolic and echinocystic acids. The structures of these substances were established using chemical and physicochemical methods 相似文献
3.
A. A. Shashkov V. I. Grishkovets O. Ya. Tsvetkov V. Ya. Chirva 《Chemistry of Natural Compounds》1994,29(4):502-508
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. 相似文献
4.
3, 5-Dibromocomanic acid (3, 5-dibromo- -pyrone -2-carboxylic acid) VI and its ethyl ester, hitherto not described in the literature, are synthesized by the following route: diethyl acetonedioxalate (I) diethyl dibromochelidonate (III) (mono) ethyl dibromochelidonate (IV) diethyl 3, 5-dibromocomanate (V) VI. Direct bromination of diethyl bromochelidonate gives the ester III. 6-Bromocomenic acid and its ethyl ester are prepared, as well as 2-bromo-3-hydroxy - -pyrone. Bromocomanic acid (x-bromo--pyrone-2-carboxylic acid) XVI is synthesized by the following route: I (mono) ethyl chelidonate ethyl comanate comanic acid XVI. Oxonium salts are obtained: acid sulfates of comanic acid and ethyl comanate.For Part VII [1]. 相似文献
5.
The isomerization of the hetaryl analogs of unsymmetrical benzoins on heating in basic media is a convenient preparative method for the production of -hydroxyacyl derivatives of -excessive heterocycles. The motivating force here for the isomerization is the formation of a thermodynamically more stable product. It was established that isomerization is promoted by increase in the difference between the electron-donating characteristics of the (het)aryl residues 相似文献
6.
N. K. Kochetkov B. A. Dmitriev A. V. Nikolaev N. É. Bairamova 《Russian Chemical Bulletin》1977,26(7):1480-1483
Conclusions Trisaccharide-D-glucopyranosyl-(14)--L-rhamnopyranosyl-(1 3)-D-galactose was synthesized by using, 2-O-isopropylidene-4,6-O-ethylidene--D-galactopyranose for producing 1 3-rhamnosylgalactose, linkage.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1609–1613, July, 1977. 相似文献
7.
V. M. Potapov V. M. Dem'yanovich L. D. Solov'eva O. E. Vendrova 《Chemistry of Heterocyclic Compounds》1976,12(1):86-89
(+)-3-Methyl-3,4-dihydroisoquinoline-1-thione was obtained by sulfuration of (+)-3-methyl-3,4-dihydroisoquinolone with phosphorus pentasulfide or by cyclization of (+)--benzylethyl isothiocyante under the influence of polyphosphoric acid. Measurements of the rotatory dispersion and circular dichroism showed the presence of two positive Cotton effects due to n* and * transitions in the thioamide chromophore, as well as Cotton effects apparently due to * transitions in the aromatic chromophore.Communication XXXV from the series Stereochemical Investigations. See [11] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 94–97, January, 1976. 相似文献
8.
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 相似文献
9.
S. U. Sheikh 《Journal of Thermal Analysis and Calorimetry》1981,21(2):343-356
This paper contains a literature review on the mechanism of formation of applicable linear boron-nitrogen polymers.
Zusammenfassung Dieser Artikel enthält eine Literaturübersicht über den Bildungsmechanimus anwendbarer Bor-Stickstoffpolymerer.
Résumé Cet article contient une revue des publications sur le mécanisme de formation des polymères de bore-azote.
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10.
Summary FromAllium narcissiflorum Wells have been isolated for the first time trillin and a glycoside B, which proved to be 3-O-[-O-D-glucopyranosyl-(1 3)-O--D-glucopyranosyl-(1 6)-O--D-glucopyranosyl-(1 ]-26-O-[-D-glucopyranosyl-(1 ]-25R-furost-5-ene-3,22 , 26-triol.Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 55–58, January–February, 1976. 相似文献
11.
Shihab A. Kadum Nabeel A. Baker Tarik E. Al-Edanee 《Monatshefte für Chemie / Chemical Monthly》1991,122(5):349-358
Summary The virtual charge model (Tapia model) in conjunction with the CNDO/S-CI approximation in the frame of SCF-MO theory was employed to study the effects of solvent on the electronic structures and spectra of benzaldehyde and acetophenone molecules. The CNDO/S calculations in presence of solvation indicate a satisfactory interpretation of the medium effects on the electronic structures and spectra of the molecules investigated. The prediction of our MO calculations by means of the Tapia model concerning the solvochromic shifts of n * and * transitions are in accord with the observed trends which indicate a blue shift for the n * band and a red shift for the * band upon a change of solvent from non-polar to polar solvents.
Anwendung des Virtual Charge-Modells auf die Elektronenstrukturen und Spektren von Benzaldehyd und Acetophenon
Zusammenfassung Das Virtual-Charge-Modell (Tapia-Modell) im Zusammenhang mit der CNDO/S-CI-Näherung im Rahmen der SCF-MO-Theorie wurde zum Studium der Lösungsmitteleffekte auf die Elektronenstrukturen und Spektren von Benzaldehyd und Acetophenon herangezogen. Die CNDO/S-Rechnungen bei Anwesenheit von Solvens erlauben eine befriedigende Interpretation der Mediumeffekte auf Elektronenstrukturen und Spektren der untersuchten Verbindungen. Die aus MO-Rechnungen folgenden Voraussagen ergeben auf Basis des Tapia-Modells solvatochrome Verschiebungen für die n *- und *-Übergänge. Die vorausgesagten Effekte stehen im Einklang mit den experimentell beobachteten Trends: Blauverschiebung für die n *-Bande und Rotverschiebung für die *-Bande beim Wechsel von nichtpolarem zu polarem Lösungsmittel.相似文献
12.
A. Fargašová A. Bumbálová E. Havránek 《Journal of Radioanalytical and Nuclear Chemistry》1997,218(1):107-110
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). 相似文献
13.
Ya. Yu. Stepanskii N. P. Evmenenko G. S. Yablonskii V. I. Bykov 《Reaction Kinetics and Catalysis Letters》1980,14(3):335-339
Self-oscillation found experimentally in the cool-flame combustion of a model n-heptane-i-octane mixture has been studied in dependence on the composition of the reaction mixture. Calculations based on the CSTR model are in qualitative agreement with experimental data.
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14.
A volcano-shaped relationship was obtained between the temperature Tc, where a given conversion (per unit surface area of the catalyst) attained, and the heat of formation, Q, of metal oxide, suggesting that the mechanism of the reaction depended upon Q-value.
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15.
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. 相似文献
16.
A mordenite-containing rock from the Tokaj-mountains was investigated. The effect of the treatment with hydrochloric acid solutions of various molarity was established. From gas adsorption measurements, scanning electron microscopic investigations and measurements with a mercury porosimeter conclusions were drawn on the changes caused by acid treatment. Slight changes in the texture were found, but no damage in the crystal structure could be observed.
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17.
G. V. Khodakov Yu. A. Akimov A. S. Shashkov P. K. Kintya V. I. Grishkovets 《Chemistry of Natural Compounds》1995,30(6):704-708
Three new triterpene glycosides of the oleanane series — melilotosides A, B, and C — and the nonglycosylated soyasapogenol B have been isolated from the roots of the plant Melilotus albus Medik. (Leguminosae). The structures of the glycosides have been shown on the basis of chemical transformations and spectral results. Melilotoside A has the structure of soyasapogenol B 3-O--L-arabinopyranoside, melilotoside B that of soyasapogenol B 3-O-[O--D-galactopyranosyl-(12)--L-arabinopyranoside], and melilotoside C that of soyasapogenol B 3-O-[O--L-rhamnopyranosyl-(12)-O--D-galactopyranosyl-(12)--L-arabinopyranoside.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 756–762, November–December, 1994. 相似文献
18.
T. Kh. Shokhireva T. M. Yurieva G. K. Boreskov 《Reaction Kinetics and Catalysis Letters》1982,19(1-2):151-154
Catalytic properties of Ti–Mo oxide catalysts are shown to be determined to a great extent by the Ti–Mo heteropoly acid anchored to the TiO2 surface which is formed during the catalyst preparation.
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19.
4-O--D-Manopyranosyl-D-mannose, O--D-mannopyranosyl-(l4)-O--D-mannopyranosyl-(14)-D-mannose, and 0--D-mannopyranosyl-(14)-O--D-mannopyranosyl-(l4)-O--D-mannopyranosyl-(l4)-D-mannose have been isolated fron the products of the partial hydrolysis of ungeromannan-V, obtained fron the bulbs ofUngernia vvedneskyi, and have been identified. This set of oligosaccharides confirms the regular structure of the carbohydrate chain of ungeromannan-V, which consists of a linear sequence of -14-bound D-mannose residues.DeceasedTranslated from Khimiya Prirodnykh Soedineii, No. 4, pp. 434–436, July–August, 1981. 相似文献
20.
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. 相似文献