首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
In neutral and alkaline solutions, tetrakis(4-carboxyphenyl)porphyrin (TCPP) and tetrakis(4-sulfonatophenyl)porphyrin (TSPP) form 1:1 and 2:1 host–guest inclusion complexes with -cyclodextrin (-CD), -cyclodextrin (-CD), and 6-deoxy-6-diethylamino--CD (DEA--CD), except for DEA--CD in alkaline solution. On the other hand, TCPP and TSPP form only 1:1 inclusion complexes with 6-deoxy-6-dihexylamino--CD (DHA--CD). The limited solubilities of DEA--CD in alkaline solution and DHA--CD are likely responsible for no observation of the 2:1 inclusion complex containing DEA--CD in alkaline solution and that containing DHA--CD. The equilibrium constants (Ks) of TCPP and TSPP for the formation of the inclusion complexes have been estimated from the absorption and/or fluorescence intensity changes in neutral and alkaline solutions. The K2 values, which are the equilibrium constants for the formation of the 2:1 host–guest inclusion complex from the 1:1 inclusion complex, are about one tenth the corresponding K1 values, except for the -CD–TSPP system in alkaline solution. In neutral solution, where DEA--CD and DHA--CD are in protonated forms, the electrostatic force operates between DEA--CD (DHA--CD) and TCPP (TSPP), leading to the greater K values than those in alkaline solution, where DEA--CD and DHA--CD exist as neutral species.  相似文献   

2.
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   

3.
Summary FromAllium narcissiflorum Wells have been isolated for the first time trillin and a glycoside B, which proved to be 3-O-[-O-D-glucopyranosyl-(1 3)-O--D-glucopyranosyl-(1 6)-O--D-glucopyranosyl-(1 ]-26-O-[-D-glucopyranosyl-(1 ]-25R-furost-5-ene-3,22 , 26-triol.Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 55–58, January–February, 1976.  相似文献   

4.
Summary The results of a study of the mass spectra of syriogenin and its D-analog confirm that this cardiac aglycone has the structure of 3,12,14-trihydroxy-5,14-card-20(22)-enolide.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 615–617, September–October, 1974.  相似文献   

5.
60Co -ray radiolysis of cholesterol /3-hydroxy-5-cholestene/ /I/ in the two-phase system /water-ethyl acetate/ and in the presence of air has been studied using TLC and GC methods. The following products were observed in the irradiated mixture: 3, 7-dihydroxy-5-cholestene /II/, G O. 36, 3-hydroxy-7-keto-5-cholestene /III/, G 1.48, 3-hydroxy-7-keto-5-cholestane /IV/, G 0.22, 3,5,6-trihydroxy-5-cholestane /V/, G 0.83, 5,6-epoxy-3-hydroxy-5-cholestane /VIa/, G 0.26, 5,6-epoxy-3-hydroxy-5-cholestane /VIb/, G 0.24, and 2, 3-dihydroxy-5-cholestene /VII/, G 0.22. The dose dependence of the formation of these products shows that the cholesterol derivatives substituted in the position 7 /II–IV/ are formed from a common precursor — the radical Ia. On the other hand, the products of the 5–C=C double bond reactions /V and VI/ are formed independently. Also the product VII is formed independently. A reaction scheme that is in agreement with these results is proposed.  相似文献   

6.
Two new steroid glycosides of the spirostan series have been isolated from the fruit ofAllium cepa L. (family Liliaceae): alliospirosides C and D. On the basis of chemical transformations and spectral characteristics it has been established that the aglycon of both glycosides is a new steroid sapogenin — cepagenin — having the structure of (24S,25R)-spirost-5-ene-1,3,24-triol. Alliospirosides C and D are cepagenin 1-O-[O--L-rhamnopyranosyl-(12)-L-arabinopyranoside] and 1-O-[O--L-rhamnopyranosyl-(12)-O--D-galactopyranoside], respectively.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 843–849, November–December, 1987.  相似文献   

7.
The oxidation of vindoline with the Sarett reagent has given five lactams the structures of which have been established on the basis of the results of instrumental methods of analysis (the x-ray structural method, and the PMR, mass, and IR spectroscopy). Two of the vindoline derivatives — 4-acetoxy-7,8-dihydroxy-16-methoxy-3-methoxycarbonyl-3,6-epoxy-7,8,9,19-tetradehydrovincaminoreine 7,9-betaine and 4-acetoxy-16-methoxy-3-methoxycarbonyl-1-methyl-7,8-dioxo-3,6-epoxyaspidospermidine — have been obtained for the first time and are new compounds.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 551–556, July–August, 1988.  相似文献   

8.
Summary A new alkaloid buxaline-C has been isolated fromBuxus sempervirens cultivated in Tashkent.The results of a comparison of the physicochemical properties of the products of the hydrolysis of buxaline-C and those of cycloprotobuxine C have enabled the structure and configuration of buxaline-C to be determined as 3-acetylmethylamino-20-dimethylamino-4,4,14-trimethyl-9,19-cyclo-5-pregnane.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 776–778, November–December, 1975.  相似文献   

9.
The glycosylation of lupeol, allobetulin, 3-28-dihydroxy-18-lupene, 3-28-dihydroxy-18, 19-epoxylupane and of betulin monoacetates in acetonitrile with mercury cyanide has been studied. The 3- and 28-mono- and the 3,28-di-O--D-glucopyranosides of 3-28-dihydroxy-18-lupene and of 3-28-dihydroxy-18, 19-epoxylupane have been synthesized for the first time. Preparative methods for the synthesis of glucosides of lupeol, of allobetulin, and of betulin 3- and 28-monoacetates are proposed.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 212–217, March–April, 1988.  相似文献   

10.
Zusammenfassung N,N-Diphenyl--alanine mit Substituenten in einem oder in beiden Phenylresten wurden durch Umsetzung von entsprechenden Diphenylaminderivaten mit -Propiolacton erhalten. In ähnlicher Weise reagierte Diphenylamin mit -Butyrolacton zu -(N,N-Diphenylamino)-buttersäure. 4,4-Diäthyldiphenylamin und 2-Chlor-6-methyl-diphenylamin wurden als Ausgangsmaterialien für die entsprechenden -Alanine hergestellt.
N.N-Diphenyl--alanines with substituents in one or in both of the phenyl groups were synthesized by reactions of the corresponding diphenylamine derivatives with -propiolactone. Similarly diphenylamine reacted with -butyrolactone to give -(N.N-diphenylamino)-butyric acid. 4.4-Diethyldiphenylamine and 2-chloro-6-methyldiphenylamine were prepared as starting materials for the corresponding -alanines.
  相似文献   

11.
Summary Short-range segmental motions of the amorphous phase of polyamide 66 were studied by means of spin probe radicals. In a dry sample the relaxation in the temperature range 366–426 with an activation energy 27.6 kJ/mol was found. In a sample containing traces of water two processes, and relaxations, with activation energies 47.0 kJ/mol and 22.0 kJ/mol, respectively, were found. relaxation was dominant in the higher temperature range (410–460 K) while relaxation was active at lower temperatures (365–410 K).
Zusammenfassung Die inneren, lokalen Drehbewegungen in den amorphen Bereichen des Polyamid 66 wurden mit Hilfe der Paramagnersondenmethode untersucht. Wasserfreies Polyamid 66 zeigt den-Relaxations-prozeß (die Aktivierungsenergie 27.6 kJ/Mol) im Temperaturbereich von 366 K bis 426 K, wasserhaltiges Polyamid 66 zeigt zwei Prozesse,- und-Relaxationen, deren Aktivierungsenergien 47.0 kJ/Mol und 22.0 kJ/Mol sind. Die-Relaxation dominiert in dem höheren Temperaturbereich (von 410 K bis 460 K) und die-Relaxation in dem niederen Temperaturbereich (von 365 K bis 410 K).
  相似文献   

12.
Summary From the seends ofCheiranthus allioni hort. another three cardiac glycosides have been isolated. One of them has been identified as cheirotoxin. It has been established that in cheirotoxin the D-glucose is attached to C4 of the D-gulomethylose and this glycoside therefore has the structure of strophanthidin 3-O-[4-O--D-glucopyranosyl--D-gulomethylopyranoside]. The two other glycosides, which have been named sarmentogulomethyloside and gulosarmentoglucoside are new and are, respectively, sarmentogenin-3-O--D-gulomethylopyranoside and sarmentogenin 3-O-[4-O--D-glucopyranosyl--D-gulomethylopyranoside].For Communication VIII see [1].Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–611, September–October, 1974.  相似文献   

13.
Another six components ofAstragalus tragacantha Habl. have been identified on the basis of spectral characteristics and chemical transformations. We have previously described cyclocanthagenin and its 3-0--D-xylopyranoside — cyclocanthoside A — as products of the acid hydrolysis of cyclocanthoside D. Cyclocanthosides B, C, E, and G are here described for the first time and are (24S)-cycloartane-3,6,16,24,25-pentol 3-O-(4-O-acetyl--D-xylopyranoside) 6-O--D-glucopyranoside, (24S)-cycloartane-3,6,16,24,25-pentol 6-O-(6-O-acetyl--D-glucopyranoside) 3-O--D-xylopyranoside, (24S)-cycloartane-3,6, 16,24,25-pentol 6-O--D-glucopyranoside, and (24S)-cycloartane-3, 6, 16, 24, 25-pentol 6-O--D-glucopyranoside 3-O-[O--D-glucopyranosyl-(12)--D-xylopyranoside], respectively.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Institute of Ecological Genetics, Moldavian Academy of Sciences, Kishenev. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 360–367, May–August, 1992.  相似文献   

14.
Summary From the flower heads ofRhaponticum integrifolium we have isolated a new phytoecdysone — integristerone B. It has been shown that it is 1, 2, 3, 5, 14, 20R, 22R, 25-octahydroxy-5-cholest-7-en-6-one.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 457–463, July–August, 1978.  相似文献   

15.
Summary From the roots ofYucca filamentosa L. we have isolated a new sarsasapogenin glycoside, yuccoside E, which is 3-O-{[O--D-galactopyranosyl(1 2)]-[-O--D-galactopyranosyl(1 6)]-O--D-glucopyranosyl-(1 4)--D-glucopyranosyl}-(25S), 5 -spirostan-3-ol.Institute of Chemistry, Academy of Sciences of the Moldavian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 747–750, November–December, 1975.  相似文献   

16.
Summary Another three cardiac glycosides have been isolated from the seeds ofCheiranthus allioni hort. One of them has been identified as digifucocellobioside (digitoxigenin 3 -O-[O--D-glycopyranosyl(1 4)-O--D-glucopyranosyl(1 4)-O--D-fucopyranoside]). The two other glycosides, called digitoxigenin gulomethyloside and glucodigigulomethyloside are, respectively, digitoxigenin 3 -O--D-gulomethyloside and digitoxigenin 3 -O-(4-O--D-glucosyl--D-gulomethyloside).For Communication X, see [1].Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. All-Union Scientific-Research Institute of Medicinal Plants. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 754–758, November–December, 1975.  相似文献   

17.
Triaryl-substituted -aminoamidines were obtained by the reaction of ,-unsaturated N-arylimidoyl chlorides with arylamines. Acylation of the products gave the products from monosubstitution at the -amino group. Triaryl-substituted -aminoamidines react with phosgene and with oxalyl chloride to form 4-aryliminoperhydropyrimidin-2-ones and 5-aryliminoperhydro-1,4-diazepine-2,3-diones, respectively.For previous communication, see [1].A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2633–2642, November, 1992.  相似文献   

18.
The inclusion complexes of -CD with sodium octylsulfonate (C8As), sodium dodecyl sulfonate (C12As), andsodium hexadecyl sulfonate (C16As) in aqueous solutions havebeen studied by surface tension measurement at the air/water interfaceand 1H NMR spectroscopy at 323 K.At fixed concentrations of the surfactants, the surface tensions firstincrease with the increase of -CD concentrations,then they attain a maximum. The surface tension curves of the surfactantsin the presence of -CD are higher than those in the absence of-CD. The values increase with increasing -CD concentrations foreach surfactant. The apparent critical micelle concentrations (CMC) of thesurfactants vary linearly with -CD concentrations.A 1H NMR study shows that the signals of theinner H-3 and H-5 of -CDshift upfield upon addition of the surfactants.The magnitude of the chemicalshift changes (= CD obs)varies as a functionof the concentrations of the surfactants. From therelationships between the chemicalshift changes of H-3 or H-5 inside the -CD cavityand guest/host molar ratios, a 1:1 stoichiometry foreach inclusion complex is assumed. The associationconstants of the inclusion complexes have beendetermined by 1H NMR spectroscopy.  相似文献   

19.
    
Conclusions It has been established that stachyflaside, obtained from the herbStachys annua L. is a new flavonoglycoside which has the structure of scutellarein 7-[O--D-mannopyranosyl-(1 2)--D-glucopyranoside].Khar'kov Chemical and Pharmaceutical Scientific-Research Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 721–723, November–December, 1971.  相似文献   

20.
Summary From a methanolic extract of the skins of the bulbs ofAllium giganteum Rgl, a new steroid glycoside has been isolated — aginoside, which is (25R)-5-spirostan-2, 3, 6-triol 3-0-{[0--D-xylopyranosyl-(13)-]-[0--D-glucopyranosyl-(12)]-0--D-glucopyranosyl-(14)-0--D-galactopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–486, July–August, 1976.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号