首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 156 毫秒
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.
Cyclization of esters of butane-1,1,4,4- and pentane-1,1,5,5-tetracarboxylic acids during electrolysis in methanol in the presence of Nal produces, with a yield of 95%, the esters of cyclobutane-1,1,2,2- and cyclopentane-1,1,2,2-tetracarboxylic acids. Under similar conditions, esters of the highest ,,,-alkanetetracarboxylic acids undergo iodation and hydroxymethylation due to electrical oxidation of methanol to formaldehyde. During electrolysis in methanol in the presence of NaOAc, the esters of ,,,-alkanetetracarboxylic acids undergo effective hydroxymethylation, followed by cyclization into substituted five- and six-member lactones, or tetrahydrofurans when structurally possible.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2332–2339, October, 1992.  相似文献   

3.
Zusammenfassung Beim Versuch zur Darstellung von 4-Vinyltriarylmethylradikalen durch Umsetzung von 4-Vinyltriarylmethylchloriden mit Metallen entstehen intermediär Radikale, die jedoch sofort in einer mesomeren Form weiterreagieren, wobei Polymere mit Chinodimethan-Strukturen entstehen. Als Modell hierfür dient das gelbe 1,4-,-Diphenylchinodimethan, das aus 4-Methyltriphenylmethylchlorid und Pyridin in Lösung erhalten werden kann; es ist nicht in fester Form isolierbar und polymerisiert sich leicht zu Poly-1,4-,-diphenylxylylen, das durch IR- und NMR-Spektren identifiziert wird.
The attempted preparation of 4- vinyltriarylmethyl radicals
The attempted preparation of 4-vinyltriarylmethyl radicals by interaction of 4-vinyltriarylmethylchlorides with metals yielded unstable radical intermediates immediately undergoing further reaction to give polymers of a quinodimethane structuretype. 1,4-,-Diphenylquinodimethane, obtained from 4-methyltriphenylmethyl chloride and pyridine in solution, was used as a model compound. It cannot be isolated and readily polymerizes to give poly-1,4-,-diphenylxylylene identified by IR and NMR spectra.


Mit 2 Abbildungen  相似文献   

4.
Conclusions Some,-bisdialkylphosphonoisopropylnitroxyl radicals were obtained by the thermolysis of dialkyl -nitrosoisopropylphosphonates and isolated in the pure state.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1867–1868, August, 1979.  相似文献   

5.
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   

6.
Circular dichroism (CD) and visible spectra of inclusion compounds between Methyl Orange (MO) analogues and -, -, -cyclodextrin (cdx), 2,6-dimethyl-and 2,3,6-trimethyl--cdx, water soluble -, -, -cdx polymer products were investigated. In the CD-spectroscopic investigation, the complex with -cdx epichlorohydrin condensate showed a large amplitude and splitting of the induced * band. Fractions of glyceryl ether of less than 2000 and polymer of more than 10000 dalton molecular mass were separated. Complexes of above two fractions and MO showed the same splitting spectral pattern. Job's plots from visible spectra showed the formation of the 11 complex and CD-data suggested the co-existence of the 21 MO-cdx complex. This splitting pattern showed the reversal of the signs when -cdx-ethyleneglycol-bis(epoxypropyl) ether was used and disappeared when larger host molecules and azo dyes were used. The splitting was explained by exciton interaction.  相似文献   

7.
Summary 1. The synthesis of L-(+)--oleoyl--linoleoyl--glycerylphosphorylethanolamine has been effected.2. During the investigations the following substances were isolated and characterized: L--oleoyl--glycerylphosphoryl-N-phthaloylethanolamine and L---linoleoyl--glycerylphosphoryl-N-phthanoylethanolamine.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 80–83, 1966  相似文献   

8.
Summary 1. The synthesis of the following neutral plasmalogens has been effected: -O-(octadec-1-enyl)-, distearoylglycerol, -O-(octadec-1-enyl)-, -dipalmitoylglycerol, -O-(hexadec-1-enyl)-, -distearoylglycerol, and -O-(pentadec-1-enyl)-, -dipalmitoylglycerol.2. During the synthesis, the following compounds were isolated and characterized by their physicochemical constants: the -octadec-1-enyl ether of glycerol, -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, the tosylate of -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, and -O-(2-tosyloxyoctadecyl) glycerol.3. The IR spectra of the -octadec-1-enyl ether of glycerol and the neutral plasmalogens have been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 367–371, 1966  相似文献   

9.
Experimentally determined partition coefficients for DMMP between NaCl-saturated water and 20 solvents were correlated using the solvatochromic parameters , , and *. An inverted LSER was then used to predict for 7 additional solvents. The new cohesion parameters and *2 were found to be more representative of cavity formation than H 2 . Most importantly, it was essential to include either or H 2 in the LSER. The partition method appears to be a useful adjunct to solvatochromic techniques in refining and extending the scale of solvent acidity and could be used to rationalize solvent selection in extraction processes.  相似文献   

10.
Conclusions The ethyl esters of- and'-oxodehydrodesthiobiotin when reacted with thioacetic acid in the presence of BF3 etherate respectively give the ethyl esters of-thiooxo- and, -diacetytmercaptodehydrodesthiobiotin.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 954–956, April, 1978.  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