- Hydroxy fatty acids for the delivery of dideoxynucleosides as anti-HIV agents
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A series of α- and β-carboxylated phospholipid prodrugs of dideoxy nucleosides have been synthesized and evaluated against HIV. An increase in biological effect with a factor of 500 has only been observed for the adenine nucleoside, which suggests that this prodrug approach is base specific.
- Gangadhara, Kishore Lingam,Lescrinier, Eveline,Pannecouque, Christophe,Herdewijn, Piet
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- New GM1 ganglioside derivatives for selective single and double labelling of the natural glycosphingolipid skeleton
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Selective single and double labelling of the natural ganglioside GM1. enables one to introduce various markers into different parts of the glycosphingolipid molecule without changing the natural skeleton. To that end, N-Fmoc-2amino-, N-Fmoc-18-amino- and S-(ethoxythiocarbonyl)-18mercaptostearic acids have been prepared, and. coupled with the primary amino group in the sphingosine part of lyso-GM1 and. deAc-deAcyl-GM1. gangliosides. The products of these coupling reactions - building blocks 16a, 16b, 16c, 26 and 27 - may be used for the synthesis of GM1 derivatives with one or two fluorescent dye moieties or other labels of various polarities. Examples of various labelling strategies, using hydrophilic and lipophilic photostable fluorescent dyes, have been made available. The GM1. derivatives 17a, 22a and 23c labelled with the fluorescent dye ATTO 647N or the doubly labelled derivative 25b can be used as probes in fluorescence correlation spectroscopy (in conventional, microscopy or stimulated emission depletion nanoscopy) to study the diffusion of lipid analogues in model or live cell membranes.
- Polyakova, Svetlana M.,Belov, Vladimir N.,Yan, Sergey F.,Eggeling, Christian,Ringemann, Christian,Schwarzmann, Guenter,De Meijere, Armin,Hell, Stefan W.
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- Mesoionic 5-alkyl-1,3-dithiolium-4-thiolates: Synthesis and brine shrimp toxicity
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A series of twelve 1,3-dithiolium-4-thiolate mesoionic compounds were synthesized and characterized. The synthetical approach starting from α-bromoalkanoic acids to obtain the corresponding 2-N-morpholino-dithiocarbamoyl-carboxylic acids that by on-pot reaction with carbon disulfide and acetic anhydride in triethylamine formed not isolate intermediates, 1,3-dithiolium-4-olates. After, the 2-N-morpholino-5-alkyl-1,3-dithiolium-4-thiolates were obtained by retro 1,3-dipolar addition reactions. The alkyl moiety linked to C-5 of heterocyclic ring permitted the increase of the hydrophobic character and this effect was evaluated on Artemia salina lethality. The results indicated a bell-shaped relationship between the number of carbon of side chain in mesoionic derivatives and LD50 in brine shrimp toxicity assays.
- De Almeida, Paulo Afonso,Da Silva, Tania Maria Sarmento,Echevarria, Aurea
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p. 593 - 600
(2007/10/03)
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- Adsorption of Metal Ions to Surface-Template Resins Prepared with Amphiphilic Styrene Monomers Bearing Amino Carboxylic Acid
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Monomer-type functional surfactants, 2-(p-vinylbenzylamino)alkanoic acid (RnAc) and N,N-dialkyl derivatives (RRnNAc), have been used as both a ligand and an emulsifier for the preparation of surface-template resins. The surfactants adsorbed at the toluene-water interface and emulsified divinylbenzene-styrene in a Cu2+ or Zn2+ solution. Emulsion polymerization using a K2S2O8 initiator (80 °C) or by irradiation with γ-rays gave fine particles of 200-800 nm in diameter. Metal-imprinted resins prepared with RnNAc and RRnNAc showed a high adsorptive capacity for the metal ion (surface-template effect). Cu-imprinted resins prepared with R8NAc were 2.69-times as effective for Cu2+ in competitive sorption from a Cu2+-Zn2+ mixture and Zn-imprinted resins were 1.84-times as effective for Zn2+, compared with unimprinted resins. Because of the great emulsifying power, metal-imprinted resins prepared with R8NAc showed the most metal-selective adsorption and the largest capacity among resins prepared with RnNAc and RRnNAc.
- Koide, Yoshifumi,Tsujimoto, Keigo,Shosenji, Hideto,Maeda, Mizuo,Takagi, Makoto
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p. 789 - 796
(2007/10/03)
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- Synthesis of (2S,2'R,3R,4E,8E)-N-2'-Hydroxyoctadecanoyl-1-O-(β-D-glucopyranosyl)-9-methyl-4,8-sphingadienine (Pen III), a Cerebroside Isolated from Penicillium funiculosum as the Fruiting Inducer against Schizophyllum commune
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(2S,2'R,3R,4E,8E)-N-2'-Hydroxyoctadecanoyl-1-O-(β-D-glucopyranosyl)-9-methyl-4,8-sphingadienine (Pen III), a cerebroside isolated from Penicillium funiculosum A-1 as the fruiting inducer against Basidiomycete Schizophyllum commune, was synthesized by starting from D-glucose, L-serine, homoprenyl acetate and stearic acid.
- Abe, Tatsuichirou,Mori, Kenji
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p. 1671 - 1674
(2007/10/02)
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- Syntheses of 2-(2-Hydroxyethylamino) Fatty Acids
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Eight 2-(2-hydroxyethylamino) fatty acids, 2-(2-hydroxyethylamino)decanoic, -undecanoic, -dodecanoic, -tetradecanoic, -hexadecanoic, -octadecanoic, -nonadecanoic, and docosanoic acid, were synthesized by reacting 2-bromo fatty acids with more than 3 mol of 2-aminoethanol.The surface tension and the critical micelle concentration were determined for these compounds.
- Xianxian, Du
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p. 123 - 124
(2007/10/02)
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- DERIVATIZATION OF KETO FATTY ACIDS, VIII. SYNTHESIS OF SUBSTITUTED OXATHIOLANE AND DIOXOLANE
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Substituted oxathiolane and dioxolane derivatives have been synthesized from oxo fatty acids.The reaction of 3-mercaptopropan-1,2-diol with 10-oxoundecanoic (1) and 9-oxooctadecanoic (2a) acids affords the corresponding oxathiolanes and dioxolane in good yields.A similar reaction with 2-oxoundecanoic acid does not take place.Mass spectral fragmentation patterns of long-chain oxathiolanes and dioxolane derivatives are detailed.
- Husain, Syed Rafat,Ahmad, Fasih,Ahmad, Mashood
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- Short Syntheses of Furan and Catechol Derivatives. A Synthesis of Hydrourushiol
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The copper-catalyzed decomposition of ethyl diazopyruvate in enol ethers is shown to yield alkoxydihydrofuroates, whose exposure to acid leads to ethyl α-furoates.The latter are also the products of the copper-induced interaction of ethyl diazopyruvate with acetylenes.The conversion of one furoate into a furan and another into a furanoid terpene system is described.The Fetizon oxidation of primary β-alkoxycyclopropylcarbinols is shown to give alkoxydihydrofurans.The formation of a masked, 1,2,5-triketo system by the copper-assisted decomposition of 1-diazo-3,3-dimethoxy-2-butanone in n-butyl vinyl ether and subsequent acid-catalyzed unraveling of the resultant β-alkoxycyclopropyl ketone are portrayed.Ring scission of the intermediate in methanolic acid at elevated temperature yields veratrole.Utilization of this method of synthesis of aromatic compounds of the catehol type in the synthesis of hydrourushiol is illustrated.
- Wenkert, Ernest,Alonso, Miguel E.,Buckwalter, Brian L.,Sanchez, Eduardo L.
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p. 2021 - 2029
(2007/10/02)
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