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1.
4-O--D-Manopyranosyl-D-mannose, O--D-mannopyranosyl-(l4)-O--D-mannopyranosyl-(14)-D-mannose, and 0--D-mannopyranosyl-(14)-O--D-mannopyranosyl-(l4)-O--D-mannopyranosyl-(l4)-D-mannose have been isolated fron the products of the partial hydrolysis of ungeromannan-V, obtained fron the bulbs ofUngernia vvedneskyi, and have been identified. This set of oligosaccharides confirms the regular structure of the carbohydrate chain of ungeromannan-V, which consists of a linear sequence of -14-bound D-mannose residues.DeceasedTranslated from Khimiya Prirodnykh Soedineii, No. 4, pp. 434–436, July–August, 1981.  相似文献   

2.
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   

3.
Oxidation of tricyclic sesquiterpenoids of the caryophyllene type with the HBr—DMSO system afforded ,-unsaturated -bromoketones. Since tricyclic derivatives, unlike simple alicyclic ketones, cannot undergo aromatization, all intermediate oxidation products can be isolated, which provide evidence that oxidation proceeds according to the following scheme: ketone-bromoketone,-dibromoketone,-unsaturated -bromoketone.  相似文献   

4.
    
Summary The structure of a new C-glycoside, cratenacin, has been established; it is 5,7,4-trihydroxyflavone 8C-[-D-glucopyranosyl-(1 4)-monoacetyl-O--L-rhamnopyranoside].Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 90–93, 1966  相似文献   

5.
Zusammenfassung 4-Hydroxy-2-alkenale verschiedener Kettenlänge (C5–C10) werden in einer mehrstufigen Synthese hergestellt: Alkanal 2-Bromalkanaldimethylacetal 2-Alkenaldimethylacetal 4-Brom-2-alkenaldimethylacetal 4-Hydroxy-2-alkenaldimethylacetal 4-Hydroxy-2-alkenal.  相似文献   

6.
Bioaccumulation of six metals (Cu2+, Cu+, Mo6+, Mn2+, V5+, Ni2+) and their combinations by algaScenedesmus quadricauda was determined by using radio nuclide X-ray fluorescence (RXFA). The metals were added into the cultivation medium in concentrations corresponding with EC50 value for each metal. The obtained results indicate that Ni2+, Cu2+ and Cu+ were accumulated in high amounts (20%, 17.5% and 15.19%) the Mo6+ ion (<0.2%) was accumulated in the lowest amount. For metal-metal interactions in accumulation of metal ions by algaS. quadricauda three types of answers were determined: inhibition (MoCu2+, Ni, Mn, V; VNi, Mn; MnNi, Cu2+, Cu+; Cu+Ni; Cu2+Ni; NiMn, V), enhancement (VCu+; Cu2+Mn;Cu+V, Mn; MnV; NiCu2+, Cu+) and neutral effect (VMo; Cu2+Mo; Cu+Mo; MuMo; NiMo).  相似文献   

7.
From the epigeal organs of the great march marigold (family Ranunculaceae) two triterpene glycosides, a tetra- and a pentaoside of hederagenin, have been isolated. Their chemical structures have been established by chemical methods of investigation and by1H and13C NMR spectroscopy. Glycoside G is hederagenin 3-O--L-arabinoside 28-O-[O--L-rhamnopyranosyl-(1 4)-O--D-glucopyranosyl-(1 6)--D-glucopyranoside]. Glycoside I is hederagenin 3-O-[O--D-glucopyranosyl-(1 2)--L-arabinoside 28-O-[O--L-rhamnopyranosyl-(1 4)-O--D-glucopyranosyl-(1 6)--D-glucopyranoside].I. G. Kutateladze Institute of Pharmacochemistry, Georgian SSR Academy of Sciences, Tbilisi, Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 229–236, March–April, 1988.  相似文献   

8.
We have isolated from Crimean ivy berries in addition previously known triterpene glycosides — 3-O--L-arabinopyranosyl-28-O-[O--L-rhamnopyranosyl-(1 4)-O--D-glycopyranosyl-(1 6)--D-glucopyranosyl]hederagenin, 3-O-[O--L-rhamnopyranosyl-(1 2)--L-arabinopyranosyl]-28-O-[O--L-rhamnopyranosyl-(1 4)-O--D-glucopyranosyl-(1 6)--D-glycopyranosyl]hederagenin, the new triterpene glycosides hederoside H2-3-O-[O--D-glycopyranosyl-(1 2)--D-glycopyranosyl-(1 2)--D-glucopyranosyl]-28-O-[O--D-glucopyranosyl-(1 6)--D-glucopyranosyl]oleanolic acid- and hederoside I-3-O-[O--D-glucopyranosyl-(1 2)--D-glucopyranosyl]-28-O-[O--D-glucopyranosyl-(1 6)--D-glucopyranosyl]hederagenin. Details of their13C NMR spectra are given.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 779–783, November–December, 1990.  相似文献   

9.
Zusammenfassung Wie beim Persistenzmodell vonPorod undKratky wird ein wurmförmiger Faden durch den Grenzübergangl0,0 erzeugt, ausgehend von einer Valenzwinkelkette mit der Bindungslängel und dem Valenzwinkel-. Jedoch wird der Rotationswinkel behindert und simultan einem Grenzübergang unterworfen. Auf diese Weise können wurmförmige Fäden mit Krümmungs- und Windungsparameter erhalten werden. Die Formel für den mittleren quadratischen Fadenendenabstand dieses Modells wird berechnet.
Summary Like the persistent thread ofPorod andKratky a wormlike chain is formed by the limiting processl0, 0 starting from a valence angle chain with bond lengthl and valence angle. But the angle of rotation is hindered simultaneously and underlies a limiting process too. Thus wormlike chains with parameters for curvature and torsion can be obtained. The formula for the mean square end-to-end distance of this model is given.


Herrn Professor Dr.G. V. Schulz zum 65. Geburtstag gewidmet.  相似文献   

10.
Conclusions The triterpene glycosides scabiosides D, E, F, and G have been isolated from the roots ofPatrinia scabiosofolia Fisch. et Link. It has been established that scabioside D is O--D-glucopyranosyl-(1 4)-O--L-arabopyranosyl-(1 3)-O-oleanoloyl-(28 1)--D-xylopyranose, and scabioside E is O--D-glucopyranosyl-(1 4)-O--L-arabopyranosyl-(1 3)-O-oleanoloyl-(28 1)-O--D-xylopyranosyl-(4 1)--L-rhamnopyranose.  相似文献   

11.
Stem bark ofTetrapanaxpapyriferum yielded the new triterpene glycosides 3-O-[-D-glucopyranosyl-(13)]--D-galactopyranosyl-(12)-O--L-arabinopyranosides of oleanolic and echinocystic acids and their 28-O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl esters. Their structures were established using chemical and physicochemical methods  相似文献   

12.
The electronic excitation spectra of pyridine and phosphabenzene have been studied using theoretical methods. The electronic states are described by wave functions derived from second-order perturbation theory based on multiconfigurational reference functions. The study includes singlet and triplet valences excited states as well as a number of Rydberg states. For both molecules the transition energies to the two lowest * excited singlet states are known from experiment and reproduced with an accuracy of 0.15 eV or better, while then * transition energies are predicted with a somewhat uncertain error of about 0.2 eV. The calculations suggest the lowestn * transition detected experimentally in pyridine corresponds to an adiabatic transition. 43 electronic states have been determined in each of the molecules.  相似文献   

13.
3, 5-Dibromocomanic acid (3, 5-dibromo- -pyrone -2-carboxylic acid) VI and its ethyl ester, hitherto not described in the literature, are synthesized by the following route: diethyl acetonedioxalate (I) diethyl dibromochelidonate (III) (mono) ethyl dibromochelidonate (IV) diethyl 3, 5-dibromocomanate (V) VI. Direct bromination of diethyl bromochelidonate gives the ester III. 6-Bromocomenic acid and its ethyl ester are prepared, as well as 2-bromo-3-hydroxy - -pyrone. Bromocomanic acid (x-bromo--pyrone-2-carboxylic acid) XVI is synthesized by the following route: I (mono) ethyl chelidonate ethyl comanate comanic acid XVI. Oxonium salts are obtained: acid sulfates of comanic acid and ethyl comanate.For Part VII [1].  相似文献   

14.
15.
Conclusions It has been established that patrinoside D1 is the -D-glucopyranosido(13) -D-xylopyranosido(12) -L-rhamnosido(14)--D-xylopyranoside (13) of oleanolic acidKhimiya Prirodnykh Soedinenii, Vol. 5, No. 2, pp. 84–89, 1969  相似文献   

16.
The 1 * and n1,3 * transitions of some suitable conjugated carbonyl compounds have been investigated by the molecules-in-molecules method. The results are compared with experiment and previously obtained P-method results. The results for the 1 * transitions agree well with experiment, but several unexplained features arise in the results for the n1,3 * transitions. In particular, doubts are cast on the assignment of the glyoxal band at approximately 4.5 eV.
Zusammenfassung Die 01 *- und 1,3 *-Übergänge einiger substituierter Carbonylverbindungen sind mittels des Verfahren der Moleküle in Molekülen untersucht und mit früheren theoretischen sowie experimentellen Werten verglichen worden. Die Übereinstimmung ist im Fall der 1 *-Übergänge gut; bei den anderen verbleiben jedoch einige Unklarheiten, insbesondere in bezug auf die um 4,5 eV liegende Glyoxal-Bande.

Résumé Les transitions »1 * et n1,3 * de certains composés conjuguées carbonyles appropriés ont été étudiées par la méthode des molécules dans les molécules. Les résultats sont comparés à l'expérience et aux résultats obtenus auparavant par la méthode P. Les résultats pour les transitions 1* sont en accord avec l'expérience, mais plusieurs particularités non expliquées apparaissent dans les résultats relatifs aux transitions n 1 3 *. En particulier, des doutes sont émis quant à l'attribution de la bande du glyoxal aux environs de 4,5 eV,
  相似文献   

17.
Five minor triterpenoids have been isolated from the chloroform-soluble fraction of a methanolic extract ofThalictrum minus by chromatography on silica gel: (I) — oleanolic acid; (II) — oleanolic acid 3-0--L-arabinopyranoside; (III) — oleanolic acid 3-0-[0--D-glucopyranosyl-(1 3)--L-arabinopyranoside]; (IV) — oleanolic acid 3-0-[0--L-rhamnopyranosyl(1 2)-0--D-glucopyranosyl-(1 3)--L-arabinopyranoside]; and (V) — oleanolic acid 28-0--D-glucopyranoside 3-0-[0--D-glucopyranosyl-(1 3)--L-arabinopyranoside]. This is the first time that any of the compounds isolated have been detected in plants of the genusThalictrum. The possibility has been shown of determining the structures of triterpene glycosides on the basis of13C NMR spectroscopy and FAB mass spectrometry without chemical transformations of the glycosides.Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 107–111, January–February, 1987.  相似文献   

18.
The vapor absorption spectrum of acrylonitrile CH2CHCN has been measured in the vacuum ultraviolet region. In addition, an all-valence-electron molecular orbital calculation has been used to calculate the electronic structure and spectrum of the molecule. On the basis of the MO calculation, as well as a vibrational analysis of the observed spectrum, several electronic transitions are assigned. The lowest energy absorption band (2107Å, = 150) is assigned as an n * transition. Absorption bands at 2030Å (=1600), 1725Å ( = 2100), and 1570Å ( = 1920) are assigned as 0–0 bands associated with transitions that are, respectively, *,*, and * in character.
Zusammenfassung Das UV-Absorptionsspektrum von dampfförmigen Acrylnitril wurde gemessen und eine CNDO/2-Rechnung für die Elektronenstruktur durchgeführt. Auf dieser Basis konnten unter Zuhilfenahme der Analyse der Schwingungsstruktur im beobachteten Spektrum mehrere Banden zugeordnet werden: die 2107-Å-Bande ( = 150) einem n*-Übergang, die drei Banden bei 2030Å ( = 1600), 1725Å ( = 2100) und 1570 Å ( = 1920)0-0-Übergängen von *-, *- bzw. *-Banden.

Résumé Mesure du spectre d'absorption en phase vapeur de l'acrilonitrile CH2CHCN dans la région de l'ultraviolet. Par ailleurs, la structure électronique et le spectre de la molécule ont été calculés à l'aide d'une méthode des orbitales moléculaires semi-empirique pour tous les électrons de valence. Sur cette base, ainsi que sur une analyse vibrationnelle du spectre expérimental, on procède à l'attribution de plusieurs transitions électroniques. La bande d'absorption de plus basse énergie (2107 Å, = 150) est attribuée à une transition n *. Les bandes d'absorption à 2030Å ( = 1600), 1275Å ( = 2100) et 1570Å ( = 1920) sont considérées comme des bandes 0 - 0 associées à des transitions *, * et * respectivement.
  相似文献   

19.
From the leaves of Algerian ivyHedera canariensis Willd. (fam. Aralaceae) we have isolated 13 triterpene glycosides: the 3-O--L-arabinopyranosides of oleanolic acid (A), of echinocystic acid (B1), and of hederagenin (B2); the 3-O-[O--L-rhamnopyranosyl-(2)--L-arabinopyranoside]s of oleanolic acid (C), of echinocystic acid (D), and of hederagenin (E1); the 3-O--L-rhamnopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside of hederagenin (G1); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O--gentiobioside of hederagenin (G3); the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--gentiobioside]s of oleanolic acid (G2), of echinocystic acid (H1), and of hederagenin (H2); the 3-O-[O--L-rhanmopyranosyl-(12)--D-glucopyranoside] 28-O-(O--L-rhamno-pyranosyl-(14)--gentiobioside] of hederagenin (H2); and the 3-O-(O--L-rhamnopyranosyl-(12)-O-gentiobiosyl)-O-(14)--L-rhamnopyranosyl-(12)-a-L-arabinopyranoside] of hederagenin (G4). The structures of the substances isolated have been established on the basis of chemical transformations and13C NMR spectroscopy.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 377–383, May–June, 1996. Original article submitted December 3, 1995.  相似文献   

20.
Mono- and disialogangliosides were isolated from gonads of the starfish Evasterias retifera. Their structures were elucidated using chemical methods, GC-MS analysis, and enzymatic hydrolysis with neuraminidase. The monosialoganglioside has the structure 8-O-Me-Neu5Gc-23-GalNAc-13-Gal-14-Glc-11-Cer, while the disialoganglioside contains an additional Neu5Ac residue which glycosylates GalNAc in position 6. The lipid moieties of both gangliosides contain phytosphingosine (mainly C18:0) and two types of fatty acids, unsubstituted (mainly C16:0 and C18:0) and -hydroxy acids (mainly -hydroxy-C16:0).  相似文献   

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