共查询到20条相似文献,搜索用时 15 毫秒
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Five ellagic acid glycosides were isolated from Aphananthe aspera and their structures were identified as 3-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (1), 3-O-methylellagic acid-4′-O-β-D-xylopyranoside (2), 3,3′-di-O-methylellagic acid-4′-O-β-D-xylopyranoside (3), 3,3′, 4-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (4), and 3,3′-di-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (5) on the basis of spectroscopic analysis. Compound 1 is new, and all the compounds were isolated for the first time from the title plant.
Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 458–459, September–October, 2007. 相似文献
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Xingzeng Zhao Xu Feng Xiaodong Jia Ming Wang Yu Shan Yunfa Dong 《Chemistry of Natural Compounds》2007,43(4):399-401
A new linear furanocoumarin glycoside named dahurin B (1) was isolated from the fresh roots and rhizomes of Angelica dahurica. The structure of the new compound was elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, and COSY.
Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 330–331, July–August, 2007. 相似文献
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Rolf W. Berg 《Monatshefte für Chemie / Chemical Monthly》2007,138(11):1045-1075
Summary. A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate
picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical
results combined with vibrational spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C4
mim][X]) salts. The rotational isomerism of the [C4
mim]+ cation is described: the presence of anti and gauche conformers that has been elucidated in remarkable papers by Hamaguchi et al. Such presence of a conformational equilibrium seems to be a general feature of the room temperature liquids. Then the “localized
structure features” that apparently exist in ionic liquids are described. It is hoped that the structural resolving power
of Raman spectroscopy will be appreciated by the reader. It is of remarkable use on crystals of known different conformations and
on the corresponding liquids, especially in combination with modern quantum mechanics calculations. It is hoped that these
interdisciplinary methods will be applied to many more systems in the future. A few examples will be discussed. 相似文献
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M. Grin’ko V. Kulcitki N. Ungur A. Barba K. Delyanu P. F. Vlad 《Chemistry of Natural Compounds》2007,43(3):277-281
Several α,ω-bifunctional derivatives of E,E,E-geranylgeraniol were prepared via convergent synthesis starting with geraniol (8), which was converted in three steps into the tetrahydropyranyl ether of 8-chlorogeraniol (9) and 8-hydroxygeranylphenylsulfone (10). Combination of synthons 9 and 10 with subsequent reductive removal of the phenylsulfonyl group produced the tetrahydropyranyl ether of ω-hydroxygeranylgeraniol (5), hydrolysis of which gave exclusively trans-ω-hydroxygeranylgeraniol (1). Derivatives 5–7 of geranylgeraniol were synthesized using standard methods.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 231–234, May–June, 2007. 相似文献
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Wanxing Wei Yuanjiang Pan Yaozu Chen Cuiwu Lin Tengyou Wei Shukai Zhao 《Chemistry of Natural Compounds》2005,41(1):17-21
Five compounds, terephthalic acid mono-[2-(4-carboxy-phenoxycarbonyl)-vinyl] ester (1), (E)-3-(5′-hydroperoxy-2,2′-dihydroxy[1,1′-biphenyl]-4-yl)-2-propenoic acid (2), 3,4,5-trihydroxybenzoic acid (3), succinic acid (or butanedioic acid) (4), and 2,3,4,5,6-pentahydroxybenzoic acid (5), were isolated from Phyllanthus urinaria. The structures of these compounds were elucidated by means of spectral techniques including IR, MS, and 1D/2D NMR. 1 and 2 are new compounds.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 14–17, January–February, 2005. 相似文献
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Anita Kovács I. Csóka Magdolna Kónya E. Csányi A. Fehér I. Erős 《Journal of Thermal Analysis and Calorimetry》2005,82(2):491-497
Summary The properties of the inner and the external aqueous phases, were studied in w/o/w multiple emulsions with light microscopic image analysis and differential scanning calorimetry (DSC). The importance of multiple
emulsions lies in the presence of these aqueous phases, making them available for sustained, controlled drug delivery systems.
Differentiation of these two aqueous phases, studying the effect of manufacturing technology on droplet structure, quantitative
determination of phase volumes and any changes occurring during storage are essential when planning w/o/w emulsions. The present study uses microscopic observations combined with DSC measurements in order to identify the formed
structure, at developmental stage in case of different components, preparation methods, and stirring rates. These tools are
beneficial during manufacturing as in process controls, or to ensure product quality. 相似文献
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K. Turdumambetov Z. Bekmuratov D. A. Rakhimov M. Kh. Malikova 《Chemistry of Natural Compounds》2007,43(1):1-4
Structures of glucofructans isolated from Cousinii radians roots were studied by methylation, periodate oxidation, and IR and 13C NMR spectroscopies. It was found that fructofuranose units were bonded to each other by inulin-type β-(2→1)-gylcoside bonds.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–5, January–February, 2007. 相似文献
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