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1.
A radiochemical charged particle activation procedure for the simultaneous production of carrier-free radioisotopes of more than one element in a single target and their subsequent separation through LLX has been demonstrated. The carrier free isotopes,95,96Nb,93,94,95,96,99mTc and94,95,97,103Ru formed through Mo(,pxn), Mo(,pxn) and Mo(,xn) nuclear reactions with 40 MeV -particle as detected by nondestructive -ray spectroscopy, have been effectively separated through LLX using TOA as an anionic extractant. Separation of the bulk matrix of molybdenum from the carrier free products has been monitored radiometrically using isotopic93,99mMo formed through the Mo(,xn) reaction, as radioindicators for the target element. Purity of the separated carrier free radionuclide has been verified by -ray spectrometry.  相似文献   

2.
A new glycoside (cyclofoetoside B) (I) has been isolated from the epigeal part of the plantThalictrum foetidum L. (Ranunculaceae). On the basis of chemical transformations and with the aid of physicochemical characteristics it has been established that cyclofoetoside B is 24S-cycloartane-3, 16, 24, 25, 29-pentaol 3-O--L-arabinopyranoside 16-O-[O--L-rhamnopyranoside-(1 6)--D-glucopyranoside], C47-H80O17, mp 194–197°C (methanol); [] D 24 +15.7 ± 2° (c 0.88; pyridine). The enzymatic hydrolysis of (I) has yielded cyclofoetigenin B (III), 24S-cycloartane-3,16,24,25,29-pentaol 16-O--D-glucopyranoside, (IV), C36H62O10, mp 223–225°C (acetone), [] D 24 +37 ± 2° (c 0.97; methanol) and 24S-cycloartane-3,16,24,25,29-pentaol 16-O-[O--L-rhamnopyranosyl-(1 6)--D-glucopyranoside, C42H72O14, mp 229–231°C (methanol), [] D 30 +41 ± 2° (c 0.7; methanol). Details of the IR and1H and13C NMR spectra of the compounds are given.Irkutsk Institute of Organic Chemistry, Academy of Sciences of the USSR. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Trashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 341–345, May–June, 1986.  相似文献   

3.
From the leaves of Algerian ivyHedera canariensis Willd. (fam. Aralaceae) we have isolated 13 triterpene glycosides: the 3-O--L-arabinopyranosides of oleanolic acid (A), of echinocystic acid (B1), and of hederagenin (B2); the 3-O-[O--L-rhamnopyranosyl-(2)--L-arabinopyranoside]s of oleanolic acid (C), of echinocystic acid (D), and of hederagenin (E1); the 3-O--L-rhamnopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside of hederagenin (G1); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O--gentiobioside of hederagenin (G3); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside]s of oleanolic acid (G2), of echinocystic acid (H1), and of hederagenin (H2); the 3-O-[O--L-rhanmopyranosyl-(12)--D-glucopyranoside] 28-O-(O--L-rhamno-pyranosyl-(14)--gentiobioside] of hederagenin (H2); and the 3-O-(O--L-rhamnopyranosyl-(12)-O-gentiobiosyl)-O-(14)--L-rhamnopyranosyl-(12)-a-L-arabinopyranoside] of hederagenin (G4). The structures of the substances isolated have been established on the basis of chemical transformations and13C NMR spectroscopy.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 377–383, May–June, 1996. Original article submitted December 3, 1995.  相似文献   

4.
Summary Two triterpene glycosides — caulosides b and c — have been isolated from a methanolic extract of the leaves ofCaulophyllum robustum maxim. Cauloside b has been identified as hederagenin 3--L-rhamnopyranosyl-(12)--L-arabinopyranoside, while cauloside c has the structure of hederagenin 3-0--L-arabinopyranosyl(13)--L-pyranosyl-(12)--L-arabinopyranoside.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 174–176, March–April, 1979.  相似文献   

5.
Zusammenfassung An Grundzuständen ,-ungesättigter Carbonylverbindungen sind polare Grenzstrukturen stark beteiligt, vgl. z. B.1011. Die bathochrome Verschiebung der Carbonylabsorption in IR- und der Einfluß auf chemische Verschiebungen und Kopplungskonstanten in NMR-Spektren wird untersucht.
The influence of mesomerism in IR and NMR spectra of ,-unsaturated carbonyl compounds
Polar resonance structures have a great share in the ground level of ,-unsaturated carbonyl compounds, compare1011. The bathochrome displacement of carbonyl absorption in IR spectra and the influence on shift and coupling constants in NMR spectra are investigated.
  相似文献   

6.
Heats of dilution of aqueous solutions of the following di-and tripeptides were determined at 25°C over a wide concentration range: -alanyl-glycine, -alanyl--alanine, DL--alanyl-glycine, glycyl-DL--alanine, L--alanyl-L-alanine, DL--alanyl-DL--alanine, DL--alanyl-DL-valine, DL--alanyl--alanine, glycyl--aminobutyric acid, glycyl-L-leucine and DL--alanyl-glycylglycine. The excess enthalpies Hex and partial molar relative enthalpies L2 were calculated and enthalpy coefficients of intermolecular interaction were analysed using the additivity principle of Savage and Wood. The concentration dependence of the enthalpic characteristics of peptide-peptide interactions is discussed based on of their hydrophobicity and hydrophilicity. The three-stage model of peptide association is described using enthalpic coefficients of intermolecular interactions.  相似文献   

7.
Conclusions In the reaction of some 2-mercapto-4,6-disubstituted pyrimidines with different,-dihaloalkanes, thiazolepyrimidine and pyrimidothiazine salts, 2-(-haloalkylthio)-4,6-disubstituted pyrimidines, and,-bis (4,6-disubstituted pyrimidinyl-2-thio) alkanes are formed. The structure of the products of the reactions is a function of the nature of the substituents in the pyrimidine ring, the number of methylene groups in the,-dihaloalkanes, and the ratio of the reagents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1396–1402, June, 1984.  相似文献   

8.
Phase transition of metastable -FeOOH into -FeOOH and its chemical transformation into -Fe2O3 upon hydrothermal treatment in 0-5 M NaOH solutions at 100-230°C were studied. The regions of formation of the above phases were specified. The probable composition of the crystallizing complexes formed in the solutions and the reactions occurring at their incorporation into various atomically smooth faces of -FeOOH and -Fe2O3 were considered.  相似文献   

9.
Effects of polymeric additives with different degrees of polymerization (DP) or substitution (DS) on the crystallization of celluloses I and I have been examined at an early stage of the incubation of Acetobactor xylinum by using newly developed FT-IR spectroscopy. It was found that the mass fraction of cellulose I is greatly decreased with increasing concentrations of carboxymethyl cellulose sodium salt (CMC) or xyloglucan (XG) in the incubation medium. Such a decrease in the mass fraction of cellulose I, which corresponds to the enhanced crystallization of cellulose I, is more prominent for CMC or XG with lower DPs, but the additives with too low DPs are not so effective probably due to higher solubility and the lower adhesion on the surface of microfibrils. Moreover, the mass fractions of celluloses I and I are highly correlated with the crystallite size of microfibrils, indicating that I is crystallized in larger-size microfibrils while I is produced in smaller-size microfibrils. On the basis of these experimental results, the mechanism of the crystallization of celluloses I and I is discussed in the Acetobactor xylinum system.  相似文献   

10.
Homogeneous hydrogenation studies of (NO2)1–2–C6H3–4–L nitro compounds (where L=–H,–NH2,–COOH,–CHO,–OH,–CH3 and –CH=CH–COOH) catalyzed by Re2S6TThio3Cl2 in dimethylformamide solutions at and T=343 K, have revealed that the reaction is enhanced by electron-acceptor substitutents and hindered by electron-donor ones.
(NO2)1–2–C6H3–4–L, L=–H,–NH2,–COOH,–CHO,–OH,–CH3,–CH=CH–COOH, Re2S6Thio3Cl2 343 . , .
  相似文献   

11.
Zusammenfassung Durch Umsetzung von ,-Dichloracetophenon mit überschüss. prim. Amin und Schwefel in äther. Lösung unter Zusatz von K2CO3 (Reaktionszeit 140 Stdn., Reaktionstemp. max. 20°) können N,N-disubstituierte -Iminophenylglyoxylsäurethionamide (1–3) in guten Ausbeuten synthetisiert werden.-Iminoglyoxylsäurethionamide (4–6), die am Imin- bzw. Aminstickstoff auch unterschiedlich substituiert sein können (4, 6), erhält man aus den entsprechenden Phenylglyoxylsäurethionamiden durch Umsetzung mit überschüss. primären Aminen.Die -Iminophenylglyoxylsäurethionamide können bereits bei Raumtemp. glatt durch H2S zu den entsprechenden Phenylessigsäurethionamiden reduziert werden.
Synthesis of N,N-disubstituted -iminophenyl-thioglyoxylic amides, and their reduction by means of H2S to phenyl-thioacetic amides (Willgerodt—Kindler reaction, V.)
N,N-Disubstituted -iminophenylthioglyoxylamides (1–3) can be synthesized in good yields by the reaction of ,-dichloroacetophenone with excess primary amine and sulphur in eth. solution in the presence of potassium carbonate (reaction period 140 hours, reaction temperature max. 20°C).-Iminothioglyoxylamides (4–6), which may be differently substituted at the imine and amine nitrogen atoms (4, 6), may be obtained from the corresponding phenylthioglyoxylamides by reaction with an excess of primary amines.The -iminophenylthioglyoxylamides can be reduced smoothly at room temperature by hydrogen sulphide to the corresponding phenylthioacetamides.


4. Mitt.:F. Asinger, A. Saus undA. Mayer, Mh. Chem.98, 825 (1967).

Vgl. auchF. Asinger undH. Offermanns, Angew. Chem.79, 953 (1967).  相似文献   

12.
Monosubstituted - and -alkylthiophans and -, -, and -alkylthiacyclohexanes were subjected to a comparative mass spectrometric study. The stability of the M+ ion increases on passing from - to -alkylthiophans and from - to - and -alkylthiacyclohexanes. In the case of -alkylthiophans and - and -alkylthia-cyclohexanes the principal process is associated with ejection of the substituent as a whole, whereas a portion of the alkyl substituent, with retention of one CH2 group in the composition of the charged fragment, is eliminated from the molecular ions of -alkylthiophans and -alkylthiacyclohexanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 176–181, February, 1978.  相似文献   

13.
A number of N1-(-butyrolactono) derivatives of 5-substituted uracils have been synthesized by condensing the sodium derivatives of the corresponding bases with -bromobutyrolactone or by the halogenation of N1-(-butyrolactono)uracil.For part I, see [1].  相似文献   

14.
The thermal behaviour of mechanically activated-PbO2 was studied. Dry grinding led to the mechanochemical decomposition of this phase into a-PbO2 and Pb3O4 mixture. In contrast, wet grinding prior to the mechanochemical decomposition caused significant changes in the thermal decomposition temperature and an increase in the intensity of the exothermic effect at ca. 200 C, which is associated with structural changes and a partial reduction of Pb(IV) to Pb(II). Throughout the exotherm, the crystallinity of-PbO2 increased and the cell dimensionb decreased.
Zusammenfassung Es wurde das thermische Verhalten von mechanisch aktiviertem-PbO2 untersucht. Trockenmahlen fürt bei der mechanochemischen Zersetzung dieser Phase zu einem Gemisch von Pb3O4 und-Pb3O4. Im Gegensatz dazu führt ein der mechanochemischen Zersetzung vorangehendes Feuchtmahlen zu Veränderungen der Zersetzungstemperatur und zu einer Verstärkung der Intensität des exothermen Effektes bei ca. 200 C, der von strukturellen Veränderungen und einer teilweisen Reduktion von Pb(IV) zu Pb(II) begleitet wird. Beim Anwachsen der Kristallinität von-PbO2 verringert sich die Gitterkonstanteb.

-PbO2. -PbOx Pb3O4. , , - , 200, . -PbO2 b.
  相似文献   

15.
Summary The identification of small amounts of sugars by their X-ray powder diagrams is suggested as a most simple and practical method in routine analysis.It is especially valuable in working with minute amounts of material, and has proved very useful for the final identification of chromatographically-separated sugars.The characteristics of the powder diagrams of a number of monosaccharides of special interest to the physiological chemist are reported in detail. The substances thus investigated are- and-D-glucose and-glucose monohydrate,- and-D-galactose,- and-D-mannose,D-fructose,D-glucuronolactone,- and-D-glucosamine hydrochloride,- and-D-galactosamine (chondrosamine) hydrochloride,-L-fucose, andD-ribose. For various reasons arabinose, lyxose, and xylose have also been included.It is clear from the powder diagrams of the galactoses that the crystalstructure earlier ascribed to-galactose is that of-galactose.A single-crystal study of-glucosamine hydrochloride was carried out by theWeissenberg technique. The crystal-dimensions obtained agree with those earlier found byCox et al5, 7.The optical rotation of chondrosamine hydrochloride was found to be [] D 20° = - 135° - 93° - 39°, the first value being considerably higher than that given for the-form byLevene. A method for the preparation of-mannose is described.
Zusammenfassung Die Identifizierung kleiner Mengen verschiedener Zuckerarten mit Hilfe ihrer Röntgen-Pulverdiagramme wird als einfache und praktische Routinemethode vorgeschlagen.Diese Methode ist besonders wertvoll, wenn nur kleine Substanzmengen zur Verfügung stehen, und hat sich für die endgültige Identifizierung von chromatographisch getrennten Zuckern als sehr geeignet erwiesen.Die Einzelheiten der Pulverdiagramme folgender physiologisch-chemisch bedeutungsvoller Monosaccharide werden mitgeteilt:- und-D-Glukose und Glukosehydrat,- und-D-Galaktose,- und-D-Mannose,D-Fruktose,D-Glukuronolakton,- und-D-Glukosaminhydrochlorid,- und-D-Galaktosamin-(Chondrosamin)-hydrochlorid,-L-Fukose, dieD-Pentosen Arabinose, Lyxose, Ribose und Xylose.Aus den Pulverdiagrammen der Galaktosen geht deutlich hervor, daß die Krystallstruktur, die früher der-Galaktose zugeschrieben wurde, tatsächlich diejenige der-Form ist.Die Untersuchung eines Einzelkristalles von-Glukosaminhydrochlorid wurde nach derWeissenberg-Technik ausgeführt. Die erhaltenen Werte stimmen mit den früher vonCox und Mitarbeitern gefundenen überein.Die optische Drehung des Chondrosaminhydrochlorids wurde zu [] D 20° = + 135° + 93° + 39° gefunden. Der erstgenannte Wert ist größer als der entsprechende, vonLevene angegebene Drehungswert.Eine Methode zur Darstellung von-Mannose wird beschrieben.

Résumé On propose une méthode de routine simple et pratique pour l'identification de petites quantités de divers sucres au moyen de leur diagramme de poudres aux rayons X. Cette méthode est particulièrement précieuse quand on n'a que de petites quantités de matière à sa disposition et elle s'est montrée très convenable pour l'identification finale de sucres séparés par chromatographie. Des particularités des diagrammes de poudres des monosaccharides suivants intéressent le chimiste physiologiste: et-D-glucose et hydrate de glucose, et-D-galactose, et-D-mannose, D-fructose,D-glucuronolactone, chlorhydrate d' et-D-glucosamine, chlorhydrate d' et-D-galactosamine (chondrosamine), l'-L-fucose, lesD-pentoses, l'arabinose, le lyxose, le ribose, le xylose. Des diagrammes de poudres des galactoses découle clairement le fait que la structure cristalline qui fut attribuée précédemment à l'-galactose est celle de la forme. L'expérience sur un cristal unique de chlorhydrate d'-glucosamine a été effectuée d'après la technique deWeissenberg. Les valeurs obtenues concordent avec celles trouvées précédemment parCox et ses collaborateurs. Le pouvoir rotatoire du chlorhydrate de chondrosamine a été trouvé égal à D 20 = + 135° + 93° + 39°. La première valeur est plus grande que celle donnée parLevene. On décrit une préparation de l'-mannose.


With 3 figures.  相似文献   

16.
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   

17.
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  相似文献   

18.
Summary It was shown that In contrast to the Meerwein-Koelsch reaction, the decomposition of benzenediazonlum fluoborate In esters of ,-unsaturated acids proceeds by a heterolytlc mechanism with the phenyl attacking the -carbon and the carbalkoxyl group of these esters. The reaction with ethyl crotonate gave -methylatropic acid (after hydrolysis) and a small amount of a dibasic acid, C14H16O4 (or C14H14O4). With methyl acrylate it gave atropic acid, phenyl acrylate, and a smaller amount of -methyl--phenylglutaric acid. With methyl methacrylate It formed benzylacrylic acid and the product of further conversions of phenyl methacrylate, namely the keto phenol 2-methyl-5-hydroxyindan-1-one.  相似文献   

19.
Conclusions The reaction of pentafluoro-N-(2,3,4,5,6-pentafluorobenzylidene) aniline with peracetlc acid or 90% hydrogen peroxide in CH2Cl2 at 20°C yields -pentafluoroanilino-2,3,4,5,6-pentafluorobenzylhydroperoxide. Its capability for thermal and photolytic transformation into bis (-pentafluoroanilino-2,3,4,5,6-pentafluorobenzyl) peroxide was shown.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 665–668, March, 1985.  相似文献   

20.
Conclusions A culture ofActinomyces roseochromogenus ATCC 3347 reduces 17-hydroxy- and 16, 17-epoxy-20-oxopregnenes to the corresponding 20-alcohols, but is incapable of reducing 17-acetoxy-, 17-methyl-, and 16-methylprogesterones or 17-unsubstituted 20-oxopregnenes. The results obtained show that the presence of the side chain in a conformation favorable for the formation of 20-alcohols in the reduction of 20-oxosteroids with complex metal hydrides is in itself insufficient for the reduction of the 20-oxosteroids by a culture ofActinomyces roseochromogenus, which also reduces the 20-oxo group of 17-pregnenes.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 38–47, 1970  相似文献   

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