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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.
An x-ray structural analysis has been made with the aim of reliably determining the spatial structure of the sesquiterpene lactone ajafinin. It has been established that it has the structure and configuration of 1,2--epoxy-3,4,10-trihydroxy-5,6(H),7(H)-guai-11(13)-en-6,12-olide.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 291–295, May–June, 1986.  相似文献   

3.
248Cm and249Bk metals were prepared by thermal reduction of their oxides with thorium and metallic249Cf with metallic lanthanum. These rare actinide samples of 1.0 mg in mass were thin layers on a flat substrate and were investigated by X-ray technique. Dhcp lattice parameters of -Cm, -Bk and -Cf as main phases in X-ray diagrams are presented. The effect of impurities on the -Cm lattice parameters is shown. Fcc lattices for the high temperature form of Cm metal (-Cm) with a=0.4933 nm, and of Cm and Bk monoxides (a=0.502–0.504 nm and a=0.5002 nm, respectively) have been observed. Thermal expansion coefficients for -Cm and -Bk at 80–300 K were calculated. Identification problems of fcc lattices and oxidation features of metals prepared are discussed.  相似文献   

4.
As -cyclodextrin (-CD) was added to D2Osolutions of 2-methylnaphthalene, its proton signals shifted to lower fieldsat low concentrations of -CD. At 2.0 × 10-2 moldm-3 of -CD, however, a reverse, higher-field shift wasobserved for the H-8 signal, indicating the formation of 1 : 1 and 2 : 1-CD–2-methylnaphthalene inclusion complexes. Intrinsic chemicalshift differences of all the protons in 2-methylnaphthalene have beenevaluated for both the 1 : 1 and the 2 : 1-CD–2-methylnaphthalene inclusion complexes. These intrinsicchemical shift differences suggest that the first -CD molecule has noselectivity in accommodating one end of uncomplexed 2-methylnaphthalene;-CD binds to a methyl group, as well as a naphthalene ring-end havingno methyl group, to form the 1 : 1 inclusion complex, resulting in theformation of two kinds of 1 : 1 complexes.  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.
The kinetics and intermediates of the permanganate oxidation of trans-crotonic acid have been investigated in the pH range of 0.5–5.0 using the stoppedflow technique. The formation of manganese(III) as a short-lived intermediate has been established. The reaction is first order with respect to both MnO 4 and crotonic acid (crotonate). The resolved rate constants at 25°C are 730 and 410 M–1 sec–1 for the acid and the anion, respectively. The reaction mechanism is discussed.
pH=0,5–5,0, . (III) . MnO 4 , (). 25°C 730 410 M–1 –1 , . .
  相似文献   

7.
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   

8.
Conclusions Replacement of the 20-oxo group in 17,21-epoxypregn-5-en-3-ol-20-one by the hydrazono-group affects the cleavage of the oxetane ring by thiocyanic acid, reaction occurring preferentially by introduction ofNCS at C17 with consequent expansion of the four-membered ring to a six-membered ring with the formation of the [17; 21]-1,3-tetrahydrooxazine-2-thione.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1393–1396, June, 1987.  相似文献   

9.
2-(-Oximinoethyl)-2-methylthiirane was obtained by the reaction of 3,4-dibromo-3-methyl-2-butanone oxime with sodium sulfide. At the same time, the O-carbamoyl derivative of the ,-dibromo oxime was converted to the corresponding substituted ,-unsaturated oxime under the same conditions. Thiirane oxime, like its O-carbamoyl derivative, underwent the desulfuration that is characteristic for thirranes under the influence of tributylphosphine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 751–753, June, 1982.  相似文献   

10.
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   

11.
A preparative method for 9a-hydroxylation of 5-3-hydroxysteroids using the fungi ofCircinella sp. 10Kh-1220 not capable of modifying theA ring has been developed. It is established that the yields of the main and the side products greatly depend on the transformation conditions, mycelium age, and the structure of the steroid substrate. Under the optimal transformation conditions novel 9-hydroxysubstituted derivatives of androstenolone, pregnenolone, 16-dehydro-16,17-epoxy-, and-16-methoxypregnenolone have been obtained in 36–80 % yields.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 737–743, April, 1994.  相似文献   

12.
Conclusions An efficient method for the synthesis of ,,-trihydropolyfluoroalkyl chlorophosphates is by reacting ,,-trihydropolyfluoroalkyl dichlorophosphites and bis-(,,-trihydropolyfluoroalkyl) phosphites with sulfuryl chloride. It has been found that in three-coordinated polyfluoroalkyl phosphites, the high electronegativity of the polyfluoroalkyl groups hinders cleavage of the latter on reaction with sulfuryl chloride, thereby facilitating the formation of oxidation products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 146–149, January, 1988.  相似文献   

13.
The cyclization of the di(phenylhydrazone) of methyl -phenyl-,-dioxobutyrate with hydrazines has given phenylhydrazones of methyl indol-2-ylglyoxylates, which have been reduced to methyl -aminoindol-2-ylacetates. Some reactions of these compounds have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1040–1042, August, 1973.  相似文献   

14.
Triterpene glycosides from Pulsatilla chinensis   总被引:1,自引:0,他引:1  
Four triterpene glycosides were isolated from the roots of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae). Two new glycosides, chinensiosides A (1a) and B (2), were identified as 3-O-[-L-rhamnopyranosyl-(12)--L-arabinopyranosyl]-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid and 3-O-{-L-rhamnopyranosyl-(12)-[-D-glucopyranosyl-(14)]--L-arabinopyranosyl}-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid. The other two glycosides were identified as previously known hederasaponin C (3) from Hedera helix and glycoside III (4) from Pulsatilla cernua.  相似文献   

15.
Apparent standard Gibbs energy, enthalpy, entropy, and heatcapacity data of the interactions of -cyclodextrin (CD) to some n-carboxylatesH(CH2)nCOO- (n = 4–6), are determined by isothermal titration microcalorimetryat different temperatures in phosphate buffer, pH 9.0, assuming a 1 : 1 model indilute solution. Modelling of contributions of the thermodynamic properties of the solutionindicates that CD undergoes conformational change upon binding to homologousseries of n-carboxylates, n-alcohols, ,-alkane dicarboxylates and ,-alkane diols.  相似文献   

16.
The new ester, fertidin, has been isolated from the phenolic fraction ofFerula tenuisecta, and on the basis of chemical transformations and spectral characteristics its structure and stereochemistry have been established as 10-angeloyloxy-4-hydroxy-6-p-hydroxybenzoyloxycarot-(9)-ene.Institute of the Chemistry of Plant Substances, Uzbek., Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinii, No. 6, pp. 795–797, November–December, 1991.  相似文献   

17.
The influence of chelating agents on the separation factor, , of lithium isotopes separation was studied by ion exchange elution chromatography. Eluents contained the chelating agent having different number of coordination sites. The chelating agents used in eluent were Na-glycine (Na–Gly), 2Na-iminodiacetic acid (2Na-IDA), 3Na-nitrilotriacetic acid (3Na-NTA), and 4Na-ethylenediaminetetraacetic acid (4Na-EDTA). The ion exchanger was Dowex 50W-X8, sulfonic acid type, sodium form. As a result,6Li was enriched in resin phase, and7Li was in solution phase. The separation factor, , was gradually increased with increasing number of coordination site (=1.0022–1.0038) at the same distribution coefficient and with increasing distribution coefficients (=1.0017–1.0026) at the same concentration of chelating agents.  相似文献   

18.
The structure of a new cycloartane glycoside, cycloaraloside B, isolated from the roots ofAstragalus amarus Pall. (Leguminosae) has been established on the basis of chemical transformations and spectral characteristics: it is 20R,24S-epoxycycloartane-3,6,16,25-tetraol 3-O-[O--L-rhamnopyranosyl-(12)-(6-O-acetyl--D-glucopyranoside)].Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 528–531, September–October, 1992.  相似文献   

19.
This work reports the use of and -cyclodextrin-modified carbon paste electrodes (CPE-CD and CPE-CD) to determine simultaneously Pb(II) and Cd(II) by means of the electrochemical technique known as anodic stripping voltammetry (ASV). Both modified electrodes displayed good resolution of the oxidation peaks of the said metals. Statistic analysis of the results strongly suggests that the CPE-CD exhibited a better analytical response that the CPE-CD, while the detection limits obtained for Pb(II) were 6.3×10–7 M for the CPE-CD and 7.14×10–7 M for the CPE-CD, whereas for Cd(II) they were 2.51×10–6 M for the CPE-CD and 2.03×10–6 M for the CPE-CD.  相似文献   

20.
2,4-di-tert-butyl-6-methylpyrilium and -thiopyrilium salts were synthesized. From them were obtained symmetrical tetra-tert-butyl substituted -pyrilocarbo- and dicarbocyanines and their sulfur analogs. The -pyrilocyanines were converted to symmetrical -pyridocyanines. The effects of heteroresidue structure, length of polymethine chain, and solvent on the location and shape of the absorption bands of these dyes were studied. Their experimental spectral properties were compared with the results of quantum chemical calculations of average band locations, second-power changes of bond order upon excitation, and theoretical electron donor capabilities.For Communication 23, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 760–765, June, 1987.  相似文献   

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