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1.
Five new sulfated derivatives of sokotrasterol and halistanol have been obtained: 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate); 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate) 23-palmitate; 24,25-dimethyl-5-cholestane-2,3,6-triol 3-(sodium sulfate); 24,25-dimethyl-5-cholestane-2,3,6-triol 6-(sodium sulfate); and 24,25-dimethyl-5-cholestane-2,3,6-triol 2,6-di(sodium sulfate). The inhibiting and membranolytic properties of the polysulfated steroids from sponges and their derivatives have been studied. It has been shown that physiological activity in this series of compounds depends on biphilicity.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 441–445, July–August, 1986.  相似文献   

2.
Conclusions The reaction of hypophosphorus acid esters with chloral es studied. A series of esters of bis(-oxy-, , -trichloroethyl) phosphonic acid esters is obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1633–1634, July, 1968.  相似文献   

3.
Aqueous solutions of -cyclodextrin (-CD) or 2,6-di-o-methyl--cyclodextrin (DM--CD) and dodecylethyldimethylammonium bromide (D12EDMAB) have been studied from speed of sound (u) data at 298.15 K, using a pulse-echo-overlap technique. The molecular encapsulation process of the surfactant monomer into the cyclodextrin cavity and its effect in the micellization process of the surfactant have been analyzed from theu measurements: I) as a function of [D12EDMAB] in the presence of several initial cyclodextrin concentrations (-CD or.DM--CD); II) as a function of [cyclodextrin] (-CD or DM--CD), for an initial micellar solution of D12EDMAB and; III) as a function of the [cyclodextrin]/[surfactant] stoichiometric concentrations. Both inclusion complexes formed (-CDD12EDMAB) and (DM--CDD12EDMAB) have stoichiometries of 11, and their association constantK have been determined using a model proposed in this work, based on the additivity of the different contributions of the involved species to the speed of sound. The apparent critical micellar concentration, cmc*, of D12EDMAB is found to increase linearly upon the addition of cyclodextrin (-CD or DM--CD). The free surfactant concentration in the micellar region, [D12EDMAB]f, decreases in the presence of -CD and slightly increases in the presence of DM--CD. The influence of the parcial methylation of the -cyclodextrin (-CDDM--CD) and of the polar head of the surfactant (D12TAB D12EDMAB) on the complextion and micellar parameters are also discussed.Supplementary material available: Tables of speed of sound (14 pages) are available from the authors.  相似文献   

4.
It was found that opening of the isoxazolidine ring of 6a-isopropenyl-1/-trimethylsilyloxy-3, 3a,4,5,6,6a-hexahydro-(1H)-cyclopent[c]isoxazoles by the F ion initially gives an intermediate, a tertiary nitrosocompound detected by UV and NMR spectroscopy. Its transformation, finally, into ,-unsaturated aldoximes probably involves an unprecedented allylic migration of the nitroso group.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 461–464, March, 1994.  相似文献   

5.
The epithermal reactor neutron spectrum shape-factor, and the associated effective resonance energy for a given nuclide, are examined theoretically in great detail. First the necessity, meaning and importance of the choice of a reference neutron energy in a non-ideal spectrum (0) are explained. Next, the definition and practical calculation of are discussed, showing that the relation between the reasonance integrals in ideal and non-ideal spectra cannot be described adequately by two independent parameters and . The exact meaning of the logarithmic expression defining an independent of is clarified, its limits of validity are established as a function of and, as a result, it follows that relatively large systematic errors on can be introduced by its use. It is shown that is dominated by the first lowest resonance energies for a given nuclide, making its vulnerability to literature updates of resonance parameters almost equal to those of individual resonances. The effect, on the epithermal and total activation of specific nuclides, of large systematic and statistical errors on and, is calculated for a series of nuclides (different I0/0 and ) and irradiation facilities (different and the), and represented graphically.Finally, the effect of important errors on and is calculated for final NAA results in terms of concentrations, botained by a comparator technique based on the197Au reference nuclide. Conclusions are drawn concerning the impact of the foregoing on the usefulness of comparator type reactor NAA as an alternative to classical NAA using multi-element standards.  相似文献   

6.
A study of the extraction of polonium from aqueous solutions containing -hydroxyisobutyric acid (-HIBA) was performed with four different extractants, di-n-octyl sulphide (DOS), Cyanex 272, Cyanex 301 and Cyanex 302, dissolved in toluene. The extracted complex for DOS at low -HIBA concentrations is most likely PoO(-HIB)2·2DOS, while at higher -HIBA concentrations there seems to be a solvating effect implicating an extracted complex of the type PoO(-HIB)2(-HIBA)2·2DOS. For the extraction of polonium with Cyanex 272 the results are inconclusive. The extracted complex is either PoOA2 or PoO(-HIB)2·2HA. For extraction with Cyanex 301 or Cyanex 302 the major extracted species does not contain any -HIBA molecules. The neutral species in both cases is PoOA2, extracted at low extractant concentrations, while at higher extractant concentrations a complex of the type PoOA2·xHA is extracted. The extraction of polonium increases in the order Cyanex 272 < DOS < Cyanex 302 < Cyanex 301.  相似文献   

7.
The effect of representing dielectric properties in terms of the complex polarizability c = – i is examined. Loss curves ( and tan ) are shifted towards higher frequencies, revealing the existence of new relaxations and allowing the clarifications of ones already known. We have calculated the shift ratios (at maximum or tan )/ (at maximum or tan ) from the more conventional empirical equations representing the dielectric behavior. Some examples are given.  相似文献   

8.
    
Summary N, N, N, N-Tetramethyllysine hydrazide, its derivatives with oxidized nucleosides, and their 5-phosphates have been synthesized. The stabilities of the modification products and the influence of the introduction of the hydrazide on the chromatographic properties of model compounds have been characterized. The possibility is discussed of using N, N, N, N-tetramethyllysine hydrazide as a specific 3-terminal modifying agent for RNA.Institute of Organic Synthesis, Academy of Sciences of the Latvian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 210–213, March–April, 1973.  相似文献   

9.
The dipole (), quadrupole (C), and dipole-quadrupole (B) polarizabilities and the dipole hyperpolarizability () of the chloride ion have been calculated by using the many-body perturbation theory approach and a series of large polarized GTO/CGTO basis sets. The complete fourth-order treatment of the electron correlation effects with a basis set comprising the s, p, d, f, and g functions gives: =38.01 a.u., C=211.5 a.u., B=–5.14×103 a.u., and =128. 5×103 a.u. as compared to the corresponding SCF values (=31.49 a.u., C=158.9 a.u., B=–2.92×103 a.u., =57.7×103 a.u.). The quenching of polarizabilities of the Cl ion in solutions and ionic crystals is discussed.  相似文献   

10.
Several halomethyl-arylcarbinols were prepared, and the influence of substituents on enantiomer selectivity in the acetalisation reaction with [2S-(2,3a,4,7,7a)]-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-ol was examined.
Unserem sehr verehrten Lehrer, Herrn Prof. Dr.Otto Hromatka, mit den besten Wünschen zum 80. Geburtstag gewidmet.  相似文献   

11.
Zusammenfassung 2,5-gleichsubstituierte, C-peralkylierte 4-Selenoxoimidazolidine (1–5) lassen sich glatt aus Ketoncyanhydrinen, NH3, H2Se und den den Cyanhydrinen zugrunde liegenden Ketonen darstellen.Durch Umsetzung von -Aminonitrilen (-Aminoacetonitril, -Aminoisobutyronitril und -Aminobenzylcyanid) mit Aldehyden oder Ketonen und H2Se können auch in 2- und 5-Stellung unterschiedlich substituierte 4-Selenoxoimidazolidine (1, 7–17) synthetisiert werden. Es werden die Salzbildung (Ag+, Cd++), die saure Hydrolyse, die Hydrierung mit LiAlH4 und die Oxydation mit H2O2/NaOH am Beispiel von C-peralkylierten 4-Selenoxoimidazolidinen beschrieben.Die aminkatalysierte Einwirkung von Schwefel auf ein 2,2-dialkyliertes 5-Phenyl-4-selenoxoimidazolidin führt zum entsprechenden Imidazolin-3-thion-(5).
Identically 2.5-substituted, C-peralkylated 4-selenoxoimidazolidines (1–5) may be obtained readily from ketone cyanohydrins, ammonia, selenium hydride and the ketones corresponding to the cyanohydrins.4-Selenoxoimidazolines, differently substituted in 2- and 5-positions may also be synthesised by the reaction of -aminonitriles, e.g. -aminoacetonitrile, -aminoisobutyronitrile or -aminobenzylcyanide, with aldehydes or ketones. Salt formation (Ag+, Cd++), acid hydrolysis, reduction with LiAlH4 as well as oxidation with NaOH/H2O2 have been described in the case of C-peralkylated 4-selenoxomidazolidines.


65. Mitt.:F. Asinger, H. Offermanns, P. Müller undH. Andree, Mh. Chem.99, 2059 (1968).

Teil der Dissertation vonH. Berding, Techn. Hochschule Aachen, 1966.  相似文献   

12.
The title metallocenium salts form crystalline 2:1 host:guest inclusion compounds with-cyclodextrin, [(5-C5H5)2M]PF6 · 2-CD · 8H2O (1, M = Fe;2, M = Co;3, M = Rh). The X-ray crystal structures of1 and3, and the lattice constants, crystal system and space group of2 have been determined. Crystal data: triclinic, space groupP1 (No. 1),Z = 1;1,a = 13.865 (2) Å,b = 13.839 (2) Å,c = 15.520 (2) Å, = 91.43 (2)°, = 85.81 (2)°, = 120.22 (2)°, andR F = 0.089 for 4257 observed MoK reflections [I > 3(I)];2,a = 13.810 (2) Å,b = 13.872 (2) Å,c = 15.560 (2) Å, = 93.99 (2)°, = 87.06 (2)°, = 120.04 (2)°;3,a = 13.756 (1) Å,b = 13.863 (1) Å,c = 15.561 (2) Å, =94.39 (1)°, = 86.92 (1)°, = 119.89 (1)°, andR F = 0.061 for 11142 observed MoK reflections [I > 3(I)]. In the crystals of1 and3, two -cyclodextrin molecules are arranged head-to-head to form a dimer by means of intermolecular hydrogen bonding across the secondary hydroxyl faces of adjacent -CD monomers. The dimers are stacked along the crystallographicc axis to form a channel-type structure. The metallocenium cation is encapsulated within the cavity of the dimer, while the PF 6 anion is located outside the cavity, being centered between the primary hydroxyl faces of adjacent dimers. Eight water molecules of hydration per asymmetric unit reside in the spaces between the -CD columns. In view of the almost identical crystal data for2 a similar structure can be assumed for the cobaltocenium adduct.  相似文献   

13.
Three minor partially acetylated glycosides have been isolated from the leaves of Algerian ivy, Hedera canariensis Willd. (Araliaceae) — the previously known {3-O-[-L-rhamnopyranosyl-(12)-O--L-arabinopyranoside] 28-O-[-L-rhamnopyranosyl-(14)-O-(6-acetyl--D-glucopyranosyl)-(16)-O--D-glucopyranoside}s of oleanolic acid and of hederagenin (ciwujianoside C4 and kizuta saponin K11) and the new 3-O-[-L-rhamnopyranosyl-(12)--O-L-arabinopyranoside] 28-O-[-L-rhamnopyranosyl-(14)-O-(6-O-acetyl--D-glucopyranosyl)-(16)-O--D-glucopyranoside of echinocystic acid (glycoside L-G0). The structures of the glycosides isolated have been established on the basis of chemical transformations and1H and13C NMR spectroscopy.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 81–86, January–February, 1999.  相似文献   

14.
Conclusions The complex ions of iron with,-dipyridyl and 1,10-phenanthroline can serve as catalysts for the autooscillating oxidation of malonic acid and its analogs with bromate. It is postulated that ions of variable valency with a single electron transition and a standard redox potential in the region 0.9–1.6 V can act as catalysts for this autooscillating reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2618–2619, November, 1969.  相似文献   

15.
The seeds ofCheiranthus allioni hort. have yielded three new cardenolides the structures of which have been established and which have been named as 4-dehydrosarmentogenin (II), 4-dehydrosarmentogenin rhamnoside (I), and 4-dehydrosarmentogenin rhamnoglucoside (IV). (II) — C23H32O5. m.p. 296–302°, [] D 20 +26.2±3° (in pyridine) is 3,11,14-trihydroxy-14-card-4,20(22)-dienolide. (I) C29-H42O9, m.p. 268–275°, [] D 20 –38.2±3° (chloroform-ethanol) is 11,14-dihydroxy-3--L-rhamnopyranosyloxy-14-card-4,20(22)-dienolide.(IV) C35H52O14, [] D 20D –44.1±3° (methanol), is 3-(4-O--D-glucopyranosyl--L-rhamnopyranosyloxy)-14-card-4, 20(22)-dienolide. An independent synthesis of 4-dehydrosarmentogenin (II) has been carried out, starting from 3,5,11,14-tetrahydroxy-5,14-card-20(22)-enolide, which has confirmed its structure.For Communication XI, see [1].All-Union Scientific-Research Drug Institute, Kharkov. Kharkov State Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 119–125, January–February, 1987.  相似文献   

16.
Reaction of methyl -D-galactopyranoside (1) with two equivalents oft-butyldimethylchlorosilane yields methyl 2,6-bis-O-(tBDMSi)--D-galactopyranoside (1 b), methyl 3,6-bis-O-(tBDMSi)--D-galactopyranoside (1 c) and methyl 4,6-bis-O-(tBDMSi)--D-galactopyranoside (1 d). Likewise methyl -D-mannopyranoside (6) affords methyl 2,6-bis-O-(tBDMSi)--D-mannopyranoside (6 d) and methyl 3,6-bis-O-(tBDMSi)--D-mannopyranoside (6 b), which can be isomerised withTPP/DEAD to methyl 4,6-bis-O-(tBDMSi)--D-mannopyranoside (6 f). Methyl 6-O-(tBDMSi)--D-galactopyranoside (1 a) and methyl 6-O-(tBDMSi)--D-mannopyranoside (6 a) can be prepared from1 or6 with one equivalent oft-butyldimethylchlorosilane.Without an external nucleophile the sugar derivatives1 a and1 b react withTPP/DEAD to form the 3,4-carbonato--D-galactopyranosides1 h and1 i and the 3,4-carbonato-2-O-ethoxycarbonyl--D-galactoside (1 j). In contrast to the formation of the compound1 i by means ofTPP/DEAD the reaction of1 a withTPP and Di-t-butyl-azodicarboxylate (DTBAD) yields the 2,3-anhydro--D-taloside (4 b) and only a small amount of1 i. The epoxide4 b can be cleaved withp-nitrobenzoylchloride/pyridine to the 3-chloro-3-deoxy-2,6-di-O-p-nitrobenzoyl--D-idoside (5). Reaction of1 c and1 d withTPP/DEAD yields the 2,3-anhydro--D-gulopyranoside (2), which can be transformed with NaN3/NH4Cl to the 2-azido-2-deoxy--D-idopyranoside (3).Likewise6 a and6 d can be converted to the 3,4-anhydro--D-talosides (7 a and7 b). Reaction of7 b or6 d withTPP/DEAD/NH3 leads to 3,4-anhydro-2-azido-2-deoxy--D-galactopyranoside (8) and 3-azido-3-deoxy--D-altropyranoside (10), resp.The epoxide7 b is opened with NaN3/NH4Cl to the 4-azido-4-deoxymannosides (11 a and11 c) and the 3-azido-3-deoxy--D-idopyranoside (12), while the epoxide8 affords the 2,4-di-azido-2,4-dideoxy--D-glucopyranoside (9).Structures were elucidated by1H-NMR-analysis of the corresponding acetates.
H. H. Brandstetter undE. Zbiral, Helv., im Druck.  相似文献   

17.
The previously known triterpenoid 3-O--L-arabinopyranosides of oleanolic and echinocystic acids and hederagenin, 3-O--D-glucopyranosyl-(12)-O--L-arabinopyranosides of oleanolic acid and hederagenin, in addition to 28-O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl ethers of the 3-O--L-arabinopyranoside of hederagenin, and 3-O--D-glucopyranosyl-(12)-O--L-arabinopyranosides of oleanolic acid and hederagenin, respectively, are isolated from leaves ofFatsia japonica(Araliaceae). The structures of the glycosides are confirmed by chemical methods and 13 C NMR spectroscopy  相似文献   

18.
New 1,3-dioxanes, which are derivatives of 2-nitro-2-ethylpropane-1,3-diol and aldehydes of the furan series, were synthesized. The nitrodioxanes were reduced by means of sodium amalgam to the corresponding amines. The kinetics of the formation of the nitrodioxanes was studied. The accelerating action of the electron-acceptor diol substituent on the reaction rate was established. The rate constants in the aldehyde series increase on passing from-methylfurfural to-nitrofurfural, and they correlate satisfactorily with Brown's p + constants.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1159–1162, September, 1972  相似文献   

19.
Summary 6,6-Methylenebisdeoxyvacisinone and its homologs have been synthesized by the reaction of methylenebisanthranilic acid with lactams (-butyrolactam, -valerolactam, -caprolactam, and -chloro- and ,-dichloro--caprolactams). The condensation of anthranilic acid and its derivatives (4-nitro-, 5-bromo-, 5-iodo-, and 5-nitroanthranilic acids) with ,-dichloro--caprolactam has given seven-membered analogs of deoxyvasicinone containing two chlorine atoms in the polymethylene ring.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 544–547, July–August, 1977.  相似文献   

20.
Zusammenfassung Für die Elemente Neon, Natrium, Magnesium, Aluminium und Silizium werden mit einem quantenmechanischen Variationsverfahren unter Verwendung einer minimalen STF-Funktionenbasis Röntgenübergänge vom Typ K 1L1L2 berechnet und den K -Satellit-Linien , , 3, 3 and 4 zugeordnet.
Relation between K -Satellits and X-ray-transitions of the type K 1 L 1L 2 for Ne, Na, Mg, Al and Si
STF-Calculations are reported for X-ray-transitions of the type K 1L1L2 for Ne, Na, Mg, Al and Si. It is shown that these transitions are correlated with the K -satellits , , 3, 3 and 4.


Die Wellenfunktionen können auf Anfrage zur Verfügung gestellt werden.  相似文献   

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