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1.
Three polyhydroxylated steroids were isolated from the Far-Eastern starfish Hippasteria phrygiana collected from the Sea of Okhotsk and were characterized as a new glycoside phrygioside A, viz., sodium (20R, 24S)-3,4,7,8,15,24-hexahydroxy-24-O-[3-O-methyl--D-xylopyranosyl-(12)--L-arabinofuranosyl]-5-cholestan-6-yl sulfate, its aglycone, and the already known marthasterone sulfate.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2526–2529, November, 2004.  相似文献   

2.
Administration of radiolabelled deprenyl to rats resulted in the urinary elimination of a 14C-labelled N-monomethyl-lysine. An increased level of N-monomethyl-lysine was found following an oral dose of another drug, also containing an N-methyl group. The urine sample was treated with 9-fluorenylmethoxycarbonyl chloride and then subjected to high-performance liquid chromatography (HPLC); the radioactive fraction was identified as N-monomethyl-lysine by using HPLC-MS in electrospray mode. Identification of N-monomethyl-lysine in the radioactive fraction gives experimental proof of transmethylation from a well-known drug to an endogenous compound.  相似文献   

3.
Complex formation of N-oxides of pyridine, 2- and 3-picolines, 4-nitropyridine, and 2,6-lutidine with iodine in benzene solutions and binary solid mixtures gives rise to equimolar complexes. In the solid phase, 1 : 2 and 2 : 1 complexes are also formed. Most solid complexes are polymorphous, and the enthalpies of intermolecular bonds in different crystal modifications are different. In solutions, external complexes pass into more stable internal complexes. The formation enthalpies of external and internal complexes with 2,6-lutidine N-oxides differ two times. Exposure of solid complexes to sun or UV light endows them with several types of coloration centers.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 2048–2055.Original Russian Text Copyright © 2004 by Ponomarenko, Borovikov, Sivachek, Makovetskii.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

4.
Summary. Protonation of the reactive 1:1 intermediate produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates with ethyl 2-(1-naphthylamino)-2-oxoacetate, leads to a vinylphosphonium salt, which undergoes intramolecular Wittig reaction to produce dialkyl 4-ethoxy-1-(1-naphthyl)-5-oxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates in excellent yields. A dynamic NMR effect is observed in the 1H NMR spectra of the title compounds as a result of restricted rotation around the single bond linking the naphthalene moiety and the heterocyclic system, which is attributed to the peri interaction between the pyrrole residue and the peri CH group. The free energy of activation (G ) for this process is 58±2kJmol–1.Received December 6, 2002; accepted December 11, 2002 Published online June 12, 2003  相似文献   

5.
Five triterpenoid saponins were isolated from the stems of Hedera colchica K. Koch, Araliaceae. Two of them are new natural substances. HCSt-A (1): 3-O--D-arabinopyranoside; 28-O--L-rhamnopyranosyl-(1 4)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl-arjunolic acid. HCSt-B (2): 3-O--D-xylopyranoside; 28-O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl-hederagenin. The derivative of arjunolic acid is described for the first time in Araliaceae family. The chemical structures of isolated compounds were established on the base of chemical and 1D and 2D NMR experiments.Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 461–463, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

6.
3-Aroyl- and 3-heteroyl-2,4-dihydro-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with 3-amino-5,5-dimethyl-2-cyclohexenone to give 3-aroyl-4-hydroxy-1-o-hydroxyphenyl-6,6-dimethyl-2,2,3,4,5,5,6,7-octahydro-1H-indole-3-spiro-2-pyrrole-2,4,5-triones. The structure of the products was proved by X-ray analysis.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1405–1409.Original Russian Text Copyright © 2004 by Mashevskaya, Duvalov, Tolmacheva, Aliev, Maslivets.This study was performed under financial support by the Russian Foundation for Basic Research (project nos. 01-03-32641 and 02-03-96411).For communication XLVII, see [1].  相似文献   

7.
Summary. Chemists have always defined the properties of materials on the basis of the changes observed when they reacted with other substances. Whereas this approach led chemists to relational concepts such as affinity, acid, and oxidant, physicists made measurements of objects they considered unchanged, determining their mass, charge, dipole moment, etc. In the middle of the 18th century, the Jesuit Josip Ruder Bocovi started thinking about the way in which atoms might be present in crystals, introducing a new concept according to which atoms in condensed phases represented punctual centres of attracting and repelling forces. Josef Loschmidt became aware of these ideas through the philosopher J. F. Herbart, and it is to Loschmidt that we owe the first representation of bonds as atomic spheres penetrating one another. The term quantum chemistry was first used by the physicist Arthur Erich Haas, who was born in Brno. However, Hans Hellmann (1903–1938) was the true founder of quantum chemistry. Hellmann, who was shot in Moscow in 1938, was the first person to realize the quantum-physical effect that leads to the chemical bond. In the 1960s K. Ruedenberg and others took theory a stage further when – thanks to the concept of the localized electron pair – they realized that the different approaches to the phenomenon of the chemical bond taken by chemists and physicists were largely comparable. This made it possible to bring the differing standpoints largely into line with one another.  相似文献   

8.
The complex of [Tb2(p-MOBA)6(PHEN)2] (p-MOBA=C8H7O3,p-methoxybenzoate; PHEN=C12H8N2, 1,10-phenanthroline) was prepared and characterized by elemental analysis and IR spectroscopy. The thermal behavior of Tb2(p-MOBA)6(PHEN)2 in a static air atmosphere was investigated by TG-DTG, DTA, SEM and IR techniques. By the kinetic method of processing thermal analysis data put forward by Malek et al., it is defined that the kinetic model for the first-step thermal decomposition is SB(m,n). The activation energy E for this step reaction is 140.92 kJ mol-1, the enthalpy of activation H is 136.06 kJ mol-1, the Gibbs free energy of activation G is 145.16 kJ mol-1, the entropy of activation S is -15.53 J mol-1, and the pre-exponential factor lnA is 29.26. The lifetime equation at mass loss of 10% was deduced as ln =-28.72+1.943·104/T by isothermal thermogravimetric analysis.  相似文献   

9.
Summary. The reaction of [RuCp(CH3CN)3]PF6 with 1 equiv of N-Me-imidazole results in the quantitative formation of [RuCp(1N-N-Me-imidazole)(CH3CN)2]PF6 (1) featuring a 1N rather than a 1C bound N-Me-imidazole ligand. According to DFT/B3LYP calculations, 1N coordination of N-Me-imidazole is preferred over 1C coordination by 25.5kJ/mol. Upon exposure to air 1 reacts with oxygen and water to afford the novel hydroxo-bridged dinuclear complex of [Ru2Cp2(1N-N-Me-imidazole)2(-OH)2](PF6)2 (2) featuring a metal-metal single bond. The dimeric nature of 2 was confirmed by a single-crystal X-ray structure analysis.  相似文献   

10.
We have developed new DNA extraction and purification procedures for investigation of mycorrhized seedlings and canned truffles. Use of these procedures on approximately 100 mg initial material enabled good sample representation. For mycorrhized seedlings, Taq polymerase inhibitors were discarded irrespective of tree species. In routine analysis we systematically used consensus primers ITS1/ITS4 to check the absence of Taq polymerase inhibitors and the presence of fungus DNA. Positive response with ITS validates other positive or negative PCR results. Absence of amplification with ITS prevents validation of other results. For canned truffles, DNA harvested from ascocarps sterilized for one and a half hours at 115°C was amplified with specific primers. We have developed consensus primers, named R12/F12, to check for the presence of amplifiable fungus DNA and the absence of Taq polymerase inhibitors. Here also, positive response with consensus R12/F12 validates other positive or negative PCR results. We have developed one primer pair specific for T. brumale and another specific for T. melanosporum. We can then characterize these two taxa, which enables the use of truffle or truffled French designations. We can also characterize T. indicum, the Asiatic black truffle that might fraudulently be sold as T. melanosporum and T. brumale. These three specific primer pairs were used independently of DNA extraction from tree seedlings or canned truffles. Our process is specific, sensitive, convenient, and quick.J.P. Douet and D. Mabru have contributed equally to this work  相似文献   

11.
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   

12.
Methyl 1-aryl-3-aroyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates react with N-substituted 3-amino-5,5-dimethyl-2-cyclohexenones to give 4-hydroxy-1-aryl-3-aroyl-6,6-dimethyl-1, 2,3,4,5,5,6,7-octahydro-1H,2H-indole-3-spiro-2-pyrrole-2,4,5-triones. The structure of the products was proved by the X-ray diffraction data for the 1-cyclohexyl derivative.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1840–1845.Original Russian Text Copyright © 2004 by Bannikova, Maslivets, Aliev.For communication XLVIII, see [1].  相似文献   

13.
The structure of a new dimeric indole alkaloid, arundarine, isolated from the roots of the plant Arundo donax L. (Poaceae) was determined. On the basis of spectroscopic data, arundarine was identified as 5-[3-(2-dimethylaminoethyl)indol-1-yl]-6-hydroxy-N 2-methyl-1,2,3,4-tetrahydro--carboline.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1697–1699, August, 2004.For Part 14, see Ref. 1.  相似文献   

14.
Reactions of octahedral and tetrahedral chalcocyanide cluster complexes of Re with Cu2+ cations and 1,2S,3S,4-tetraaminobutane (Threo-tab) were used to synthesize and study the structures of the following six novel chiral complexes: [{Cu2(NH3)(Threo-tab)3}Re6S8(CN)6] 3H2O (I) (where Threo is 1,2S,3S,4-tetraaminobutane), [{Cu2(NH3)(Threo-tab)3}Re6Se8(CN)6] 2H2O (II), [{Cu(Threo-tab)}2Re6Te8(CN)6] 13.5H2O (III), [{Cu(Threo-tab)}2Re4Te4(CN)12] 6.5H2O (IV), [{Cu2(NH3)(Threo-tab)2}Re4Te4(CN)12] 4H2O (V), and [{Cu(NH3)(Threo-tab)}]2[Re4S3.4Te0.6(CN)12] 1.25H2O (VI). The structures of complexes I–IV contain extended channels of sufficiently large size capable of including guest molecules.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 4, 2005, pp. 289–301.Original Russian Text Copyright © 2005 by Mironov, Naumov, Brylev, Efremova, Fedorov, Hegetschweiler.  相似文献   

15.
The Reformatskii reagents formed from alkyl esters of -bromoacetic, -bromopropanoic, and -bromoisobutyric acids and zinc react with N-arylamides of 2-oxochromene-3-carboxylic acid, yielding 3-R1-1-R2-1-R3-4a,10b-dihydro-1H-chromeno[3,4-c]pyridine-2,4,5-triones.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1516–1519.Original Russian Text Copyright © 2004 by Shchepin, Fotin, Vakhrin, Shurov.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

16.
The absolute configurations of the side chains of polyhydroxylated steroids from the starfish Henricia derjugini were determined by Moshers method using 1H NMR spectra of R-(+)- and S-(–)--methoxy--(trifluoromethyl)phenylacetates of these compounds. The chiral centers have the (24S) configuration in a steroidal hexaol and henricioside H1, the (24R,25S) configuration in henricioside H2, and the (24R, 25R) configuration in henricioside H3.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2530–2533, November, 2004.  相似文献   

17.
Acid-base and complexation properties of gem-disubstituted phosphorus acids, viz., methylenediphosphonic, 1-hydroxyethylidene-1,1-diphosphonic, P,P-diphenylmethylene-diphosphinic, and P, P-diphenyl-1-hydroxyethylidene-1, 1-diphosphinic acids, were studied in aqueous solutions and in the presence of biomimetics (micelles of ionic surfactants). The dissociation constants of the acids and stability constants of complexes with magnesium(II) and copper(II) ions were determined in aqueous solutions and microheterogeneous media containing sodium dodecyl sulfate, cetylpyridinium chloride, or cetylpyridinium nitrate (ionic strength 0.1 mol L–1, temperature 25°C).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1919–1925, September, 2004.  相似文献   

18.
Summary. (RS)-2-tert-Butyldimethylsilyl-1,2-thiazetidine-3-acetic acid 1,1-dioxide prepared from (RS)-S-benzyl--homocysteine was condensed via DCC/NHS with various L-amino acid esters or dipeptide esters yielding N-silylated -sultam peptides. A -sultam active ester was isolated as an intermediate. Desilylation with TBAF in THF yielded stable N-unsubstituted products, and deprotection of the benzyl esters was achieved by catalytic hydrogenation. (S)-S-Benzyl--homocysteine was obtained by fractional crystallization of the brucine salt of the racemate and transformed into benzyl (S)-1,2-thiazetidine-3-acetate, which was on the other hand synthesized by an enantiospecific route from -benzyl Boc-L-aspartate. Some -sultam peptides were prepared from the (S)-enantiomer, and finally some -sultam peptides containing D-Ala units were obtained.  相似文献   

19.
With the help of complete orthonormal sets of - ETOs, where = 1,0, – 1, – 2, ... a large number of series expansion formulas for the multicenter electronic attraction (EA), electric field (EF) and electric field gradient (EFG) integrals of integer and noninteger n Slater type orbitals (ISTOs and NISTOs) is established through the overlap integrals with the same screening constants and the new central and noncentral interaction potentials depending on the coordinates of the nuclei of a molecule are introduced. The convergence of the series is tested by calculating concrete cases for arbitrary quantum numbers, screening constants and location of ISTOs and NISTOs.  相似文献   

20.
The first double-decker sandwich complex of a sandwich was synthesized and fully characterized. The complex was prepared by the reaction of cyclic trimeric perfluoro-o-phenylene-mercury (o-C6F4Hg)3 (1) with ferrocene in an ethereal solution at 20 °C and has the composition {[(o-C6F4Hg)3]2(Cp2Fe)} (2). The ferrocene sandwich in 2 is located between the planes of two mercury-containing macrocycles and is coordinated to each of them through donation of the -electrons of the 5-Cp ligands to vacant orbitals of the mercury atoms of the adjacent molecule 1. It was concluded that all carbon atoms of the 5-Cp rings in complex 2 are involved in the bonding to the macrocycles. Complexation with 1 leads to considerable shifts of the (C-H) and (C-H) bands of ferrocene in the IR spectrum to high frequencies. The structure of complex 2 was determined by X-ray diffraction.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2754–2756, December, 2004.  相似文献   

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