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1.
    
A glycoside, holothurin A1 has been isolated from the polar glyosidic fractions of the holothuriansH. floridana andH. grisea. The complete structure of the glycoside has been established; it is: 3-[0-(3-0-methyl--D-glucopyranosyl)-(1 3)-0--D-glucopyranosyl-(1 4)-0--D-quinovopyranosyl-(1 2)-(4-sulfato--D-xylopyranosyl)oxy]holosta-9(11)-ene-12,17,22-triol. Details of the IR and1H and13C NMR spectra of the compounds obtained are given.For Communication XIV, see. p. 449.Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. National Institute of Oncology and Radiobiology, Ministry of Public Health of the Republic of Cuba, Havana. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 464–469, July–August, 1982.  相似文献   

2.
Summary 1. A new glycoside neorobinin has been isolated from the seeds ofCheiranthus allionii. On the basis of the results of chemical and spectroscopic investigations, the structure of kaempferol 7--L-rhamnofuranoside-3-(-D-galactofuranosyl-6--L-rhamnofuranoside) has been proposed for it.2. On partial hydrolysis, neorobinin is split into a series of intermediate substances, the following of which have been isolated and characterized: kaempferol 7--L-rhamnofuranoside (rhamnorobin), kaempferol 3--D-galactofuranoside (galactorobin), and kaempferol 3-(-D-galactofuranosyl-6--L-rhamnofuranoside) (biorobin).Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 388–394, 1966  相似文献   

3.
Chlorobis/-diketonato/ oxotechnetium/V/ complexes [TcOCl/-dik/2, -diketone=acetylacetone, benzoylacetone and dibenzoylmethane] were newly synthesized using macroamount of99Tc. These complexes were further separated into geometrical isomers. Furthermore, an improvement of the yields for the syntheses of tris/-dike-tonato/technetium/III/ complexes [Tc/-dik/3, -diketone=acetylacetone, benzoylacetone and 2-thenoyltrifluoroacetone] was examined using Tc/III/-thiourea complexes as a starting material.  相似文献   

4.
Effect of 3,5-dichlorophenol (DCP) on the extraction of Fe(III) with acetylacetone (Hacac) in nonpolar organic solvents has been studied. It is found that a mixture of Hacac and DCP in heptane gives much higher extraction of Fe(III) than Hacac alone. Such novel enhancement effect is ascribable to the association of tris(acetylacetonato)iron(III) [Fe(acac)3] with DCP in the organic phase by hydrogen bonding. Association of Hacac with DCP has also been investigated and the intrinsic extraction equilibrium of Fe(III) is analyzed by using the equilibrium concentration of free Hacac and DCP. The association complexes are found to be Fe(acac)3 · n DCP (n=1, 2, 3) in heptane, and the overall association constants (ass, n) are determined to be log ass, 1 = 3.41, log ass, 2, = 5.97 and log ass, 3, = 7.50.  相似文献   

5.
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   

6.
Summary The complex formation between iron(III) and oxalic acid (ethanedioic acid, H2ox) has been studied by potentiometry in dimethylsulphoxide (dmso) solution. H2ox behaves as a weak diprotic acid in such a solvent, with overall association constants: log j1=8.551(3) and log j2=14.242(3) at 25°C and 0.1 Mn-Bu4NClO4. A reliable set of overall stability constants for the iron(III)-oxalato complexes, log 11=13.16(4), log 12=23.66(4) and log 13=30.75(4), have been obtained for the first time under identical conditions. The electrochemical behaviour of such complexes was studied in dmso at a platinum electrode. The coordination ability of oxalate towards iron(III) in dmso and water media is compared and discussed in the light of thermodynamic and structural parameters.  相似文献   

7.
Zusammenfassung Die frühere Annahme, daß die beiden Modifikationen von-Naphthol den gleichen Schmelzpunkt besitzen und somit einen Grenzfall der Enantiotropie darstellen, wurde durch differentialthermoanalytische Untersuchungen widerlegt. Die beiden Modifikationen stehen zueinander im Verhältnis der Monotropie mit der allerdings nur geringen Schmelzpunktsdifferenz von 0,5°. Auch die IR-Spektren der beiden Kristallformen bestätigen das Vorliegen einer Monotropie.Für die Phasendiagramme der Naphthalingruppe, an denen-Naphthol beteiligt ist, ergeben sich Korrekturen. Da die instabile Mod. II die mit Naphthalin korrespondierende Kristallform ist, liegt in dem System Naphthalin--Naphthol keine lückenlose Mischkristallreihe vor (Typ. I, Roozeboom), sondern es wird eine Mischungslücke gebildet, denn das System besteht aus zwei Mischkristallphasen (Typ. IV). Auch im System-Naphthol--Naphthylamin tritt auf der-Naphtholseite eine bisher nicht erkannte Phasenüberschneidung auf und anstelle von Typ. III wird Typ. V (Roozeboom) gebildet.Schmelzdiagramme ohne Mischkristallbildung-Naphthol--Naphthol,-Naphthol--Naphthylamin) sind von einer Korrektur nur insofern betroffen, als die Kurvenäste der beiden Modifikationen des-Naphthols nicht von einem Punkt ausgehen und der stabile Kurvenast nicht als Mod. II, sondern als Mod. I bezeichnet werden muß.
New results on the polymorphism of-naphthol and its effects on the phase diagrams of the naphthalene group
Summary The earlier assumption that the two modifications of-naphthol have the same melting point and thus constitute a borderline case of enantiotropy was disproved by differential thermoanalytic investigations. The two modifications only have the slight difference in melting point of 0.5°. The IR spectra of the two crystal forms confirm the presence of monotropy.There are corrections for the phase diagrams of the naphthalene group in which-naphthol is involved. Since the unstable modification III is the crystal form corresponding to naphthalene, there is no unbroken series of mixed crystals in the naphthalene--naphthol system (Type I, Roozeboom), but a mixing gap is formed since the system consists of two mixed crystal phases (Type IV). A phase overlap which had not been previously recognized also occurs on the side of-naphthol in the-naphthol--naphthylamine system; the Roozeboom Type V is formed instead of Type III. The melting diagrams of a mixed crystal formation (-naphthol--naphthol,-naphthol--naphthylamine) are affected by a correction only to the extent that the curve branches of the two modifications of-naphthol do not begin at one point and the stable branch of the curve must be designated not as modification II but as modification I.
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8.
Fluoride and sulphate complexing of Np(VI) has been studied by controlled-potential coulometry at a constant ionic strength. The values of 1 * and 2 * for fluoride complexes were found to be 9.4 and 8.9, respectively, at an ionic strength =0.5. At an ionic strength =1.0, 1 * and 2 * obtained were 6.6 and 10.5, respectively. Sulphate complexing of Np(VI) was studied only at an ionic strength =0.5. The value of 1 * obtained was 5.6.  相似文献   

9.
The effect of 2-hydroxypropyl--cyclodextrin (HP--CyD) on the release of a water-soluble 1-selective adrenoreceptor antagonist, metoprolol (Met), from ternary Met/HP--CyD/ethylcellulose (EC) tablets was investigated. The release rate of Met from the ternary tablets was dependent on amounts of HP--CyD in the tablets, i.e., the rate decreased when small amounts of HP--CyD were added, while large amounts of HP--CyD accelerated the rate. The slowest rate was observed for the tablet consisted of a 30/10/60 weight ratio of Met/HP--CyD/EC. The analyses of the release rates by the Korsmeyer equation and their temperature dependence suggested that Met is released from the EC matrix containing HP--CyD according to the diffusion-controlled mechanism. The water penetration studies and the micro- and macroscopic observations suggested that the retarding effect of HP--CyD is attributable to a viscous gel formation in small pores on the surface of the tablets, where HP--CyD gels may work as a barrier for the water penetration into the tablets and the release of the drug from the tablets. The in-vitro release property of the ternary tablets was reflected in the in-vivo absorption profile in dogs. The results indicated that a combination of HP--CyD and EC is useful for the release control of water-soluble drugs such as Met.  相似文献   

10.
A cluster structure of the surface of a polypyromellitimide film was studied by the electron microscopy and ATR IR spectroscopy methods at different steps of consecutive treatment with aqueous solutions of an alkali and acid. The effective size and fractal dimension D of polyamidoacid clusters, as well as the degree s of the filling of the surface with the latter were calculated from the data of the electron microscopy as a function of the degree of imide group conversion into amidoacid units on the film surface. The s and D parameters were shown to increase with a rise in : s = 0.1–0.3 and D = 1.3–1.4 at < cr and s 0.6 and D 1.7 at > cr, where cr is a critical degree of conversion, which corresponds to the formation of a continuous physical network of polyamidoacid macromolecules or a percolation cluster. In a region close to cr (at < cr), the correlation length land the concentration C of the clusters vary according to the laws of the percolation theory for two-dimensional lattices: l (cr – ) and C (cr – ), where = 1.3 ± 0.1 and = 0.67 ± 0.05.  相似文献   

11.
Zusammenfassung Das feste -Carotin ist gegen -Strahlung ziemlich stabil. Bei Bestrahlung unter Sauerstoffbegasung treten deutliche -Carotin-Verluste erst bei der hohen Dosis von 12 Mrad auf; bei Bestrahlung an der Luft werden ähnliche Radiolyseerscheinungen erst durch wesentlich höhere Strahlendosen ausgelöst. Spaltungsprodukte, die bei 12 Mrad und Sauerstoffbegasung auftraten und dünnschichtchromatographisch aufgetrennt werden konnten, waren Isozeaxanthin, -Carotin-5,6-5, 6-diepoxid, -Carotin-5,8-5,8-diepoxid, -Apo-12-carotinal, -Apo-10-carotinal, 3,3,6-Trihydroxy--carotin-5,8-epoxid und Vitamin-A-Alkohol. Es ist bemerkenswert, daß ein Teil der Radiolyseprodukte (z. B. Vitamin-A1-Alkohol, -Apo-12-carotinal und -Apo-10-carotinal) Vitamin-A-Wirksamkeit besitzt.
The -Irradiation of synthetic -carotene. Some physico-chemical and thin-layer chromatographic studies of radiolysis products
Solid -carotene is remarkably stable to -irradiation. In an oxygen atmosphere doses as high as 12 Mrad were required to bring about significant losses of -carotene, whereas in air even larger doses had to be applied in order to effect a comparable degree of radiolysis. Cleavage products which arose in O2 at a dose of 12 Mrad and which could be separated from each other by thin-layer chromatography were isozeaxanthin, -carotene-5,5-5,6-diepoxide, -apo-12-carotenal, -apo-10-carotenal, 3, 3, 6-trihydroxy--carotene-5,8-epoxide and vitamin A1. It is notable that some of the radiolysis products (e.g., vitamin A1, -apo-12-carotenal and -apo-10-carotenal) possess vitamin A activity.


Herrn Prof. Dr.O. Hromatka zum 65. Geburtstag gewidmet.  相似文献   

12.
From the leaves of Crimean ivy we have isolated the previously known glycosides 3-O--L-Arap-28-O-[O--L-Rhap-(14)-O--D-Glcp-(16)--D-Glcp]hederagenin, 3-O-[O--L-Rhap-(12)--L-Arap]-28-O-[O--L-Rhap-(14)-O--D-Glcp-(16)--D-Glcp]oleanic acid and -hederagenin, and 3-O-[O--L-Rhap-(12)--L-Arap]-28-O-[O--D-Glcp-(16)--D-Glcp]hederagenin and a new one: tauroside H1 — 3-O-[O--L-Rhap-(12)-O--L-Arap]-28-O-[O--L-Rhap-(14)-O--D-Glcp-(16)--D-Glcp]echinocystic acid.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 522–528, September–October, 1992.  相似文献   

13.
Summary The composition and stability of copper(I) complexes with thioacetamide (TAA) have been evaluated with the help of square-wave voltammetry using the fast pulse technique. Two species, namely Cu(I) (TAA) and Cu(I) (TAA)2, have been identified having the formation constants log 1=16.85; log 2=18.03. The complex is stable in highly acidic medium (pH1). The application for the determination of copper is pointed out.  相似文献   

14.
Isostructural crystals of aluminum hexamolybdenocobaltate(III) and hexamolybdenocromate(III) Al[MMo6O18(OH)6] · 16H2O (M = Co(III) and Cr(III)) were studied using X-ray diffraction analysis. These compounds crystallize in the triclinic system: space group P , Z = 1, (calcd) = 2.665 and 2.611 g/cm3, respectively. The unit cell parameters were determined: for aluminum hexamolybdenocobaltate(III), a = 6.796(1) Å, b= 11.248(2) Å, c = 11.568(2) Å; = 101.36(2)°, = 96.95(2)°, = 102.23(2)°; for aluminum hexamolybdenocromate(III), a = 6.838(1) Å, b = 11.312(2) Å, c = 11.605(2) Å; = 101.29(3)°, = 97.13(3)°, = 102.15(3)°.  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.
Summary Equimolar quantities of CrCl3 · 3THF and-diketones, -dkH, react to yield CrCl2(-dk) · 2THF and CrCl2(-dk) · THF complexes in coordinating and noncoordinating solvents respectively. For 1 : 2 and 1 : 3 molar ratios of reactants, derivatives of general formulae CrCl(-dk)2 and Cr(-dk)3 (where-dkH = acerylacetrrnc, benzoylacetonc and dibenzoylmethane) have been isolated. All complexes have been characterized by elemental analysis, molecular weights and by i.r. spectra.  相似文献   

17.
Crystal structure refinement was performed of the metastable modification of glycine (space gr. P21, a = 5.092(2) , b = 6.273(3) , c = 5.384(3), = 113.17(4)°, Z = 2, R = 0.0274). The crystals were obtained by a new method (not described in the literature): they were precipitated from a water solution with the addition of glacial acetic acid. The crystal structure of the glycine modification [space gr. P21/n, a =5.106(1) , b = 11.979(5) , c = 5.463(2) , = 111.75(2)°:, Z =4] was refined for comparison. Transition from the to the modification in a damp atmosphere was revealed, resulting in the formation of a strongly strained crystal of a mosaic structure. The orientation of the crystallographic axes in the newly formed crystal of the modification relative to the axes in the initial crystal of the modification was determined. It is shown that as in glycine, the lengths of the intramolecular C—O bonds in the modification are fairly similar [1.248(2) and 1.253(2) ] and the previously found significant difference between them is most likely due to the errors of the photomethod. A comparative analysis of the crystal structures of the and glycine modifications (glycine zwitterion packings and structure of intermolecular hydrogen bond networks) was performed. Data of the analysis are used to discuss the properties of the glycine modifications, the possible reasons for the stability of the modification in dry air, the difficulties of crystal growth from solutions, and the ease of crystallization of the modification under various conditions.  相似文献   

18.
Three new glycosides, D1, D2, and D3, have been isolated from the Far Eastern starfishDistolasterias nipon. They have been identified by chemical and physicochemical methods as 5-cholestane÷3,6,8,15,24-pentaol 3,24-di-O--D-xylopyranoside, t-cholest-22-ene-3,6,8,15,24-pentaol 3,24-di-O--D-xylopyranoside (II), and 5-cholestane-3,6,8,15,24-pentaol 24-O--D-glucopyranoside 3-O--D-xylopyranoside (III).Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 250–255, March–April, 1987.  相似文献   

19.
Summary This article describes some complexes of cobalt(III) with -mercaptopropylamine,N, N-dimethyl--mercaptopropylamme andN,N-dimethyl--mercaptoethylamine. The compounds are of stoichiometry [Co(ligand)3], [Co3(ligand)6]X (X=Cl or Br) and [Co(ligand)3]X3 (X=Cl or ClO4). -Mercaptopropylamine yields both chelated and non-chelated compounds while theN,N-dimethyl derivatives yield only non-chelated complexes. This behaviour contrasts with the results obtained with nickel(II).  相似文献   

20.
Zusammenfassung Die thermische Zersetzung von Lithiumhexacyanoferrat (III) in Luft führt in drei Temperaturbereichen, d.h. zwischen 250 und 400°, 500 und 650° und 925 und 1000° zur Bildung ferromagnetischer Produkte. Durch Röntgendiffraktionsuntersuchung und magnetische Messungen wurde bewiesen, daß im ersten Temperaturbereich-Fe2O3 die für die ferromagnetischen Eigenschaften der Zersetzungsprodukte verantwortliche Phase ist, während in den anderen Bereichen diese Eigenschaften durch Lithiumferrit der Formel Li0.5Fe2.5O4 verursacht werden.
The thermal decomposition of lithium hexacyanoferrate (III) in air leads to the formation of ferromagnetic products in three temperature ranges, namely 250–400°, 500–650° and 925–1000°. By X-ray diffraction studies and magnetic measurements it has been proved that in the first temperature region-Fe2O3 is the phase responsible for the ferromagnetic properties of the decomposition products, whereas in the other regions these properties are due to the presence of the lithium ferrite Li0.5Fe2.5O4.

Résumé La décomposition thermique du ferricyanure de lithium dans l'air conduit à des produits ferromagnétiques dans trois intervalles de température: 250–400°, 500–650° et 925–1000°. Par diffraction des rayons X et mesures magnétiques, on montre que lors de la première étape de décomposition c'est l'oxyde-Fe2O3 qui est responsable des propriétés ferromagnétiques des produits de décomposition, tandis que pour les deux autres étapes, le ferromagnétisme est dû à la présence de ferrite de lithium de formule Li0.5Fe2.5O4.

-()- : 250–400°, 500–650° 925–1000°. - , , , , -Fe2O3. Li0.5Fe2.5O4.
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