- Novel amphiphilic chitosan derivatives: Synthesis, characterization and micellar solubilization of rotenone
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Novel amphiphilic chitosan derivatives N-(octadecanol-1-glycidyl ether)-O-sulfate chitosan (NOSCS) with octadecanol glycidyl ether as hydrophobic groups and sulfate as hydrophilic groups were synthesized successfully. The NOSCS were characterized with 1H NMR, FT-IR, and their critical micellar concentrations (CMCs) were found to be 3.55 × 10-3 to 5.50 × 10-3 mg/mL. The degree of substitution (DS) of octadecanol glycidyl ether grafted on chitosan was ranging from 0.6% to 7.1%. NOSCS could form polymeric micelles with the size of 167.7-214.0 nm by self-assembly in aqueous solution. Rotenone, a water-insoluble botanical insecticide, was entrapped into NOSCS micelles solution by reverse micelle method. And the highest rotenone concentration was up to 26.0 mg/mL, which was much higher than that in water (0.002 mg/mL). Therefore, NOSCS nano micelles may be useful as a prospective carrier for control released agrochemical.
- Lao, Shui-Bing,Zhang, Zhi-Xiang,Xu, Han-Hong,Jiang, Gang-Biao
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- Synthesis and properties of mono or double long-chain alkanolamine surfactants
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Two types of N-substituted long-chain alkanolamine surfactants were prepared. Firstly, octadecyl glycidyl ether was synthesized from octadecanol and epichlorohydrin. Subsequently, a ring-opening reaction of the epoxide ring of octadecyl glycidyl ether was performed with monoethanolamine and diethanolamine to synthesize bis(octadecyloxy)-2- hydroxypropylmonoethanolamine (D-MEA)and octadecyloxy-2-hydroxypropyldiethanolamine(M-DEA) without catalyst at 60 °C, respectively. And their corresponding tertiary amine salts bis(octadecyloxy)-2- hydroxypropylmonoethanolamine hydrochloride (D-MEAS) and octadecyloxy-2- hydroxypropyldiethanolamine hydrochloride (M-DEAS) were attained by neutralization with hydrochloric acid. The study on these four surfactants included their surface active properties, foaming abilities, emulsifying properties, lime-soap dispersion abilities and wetting abilities. The results show that D-MEAS possesses the best surface active property and lime-soap dispersion ability. D-MEA has better foaming ability and foaming stability. The wetting ability of M-DEA and the emulsifying property of M-DEAS are prominent.
- Zhang, Ya,Xu, Yongshen,Qiu, Shouji,Yang, Lei
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- Synthesis of natural 1- O -alkylglycerols: A study on the chemoselective opening of the epoxide ring by onium quaternary salts (N and P) and ionic liquids
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A chemoselective route for the synthesis of 1-O-alkylglycerols chimyl (1), batyl (2), and selachyl (3) is reported. These compounds can be naturally isolated from shark liver oil and the skin of animals such as stingrays and chimeras and exhibit potential anti-fouling activity. The synthetic approach developed in this work included two distinct methods of preparation. The first was based on solvent-free reactions catalyzed by onium quaternary salts (N and P) and ionic liquids; the second methodology was based on a series of one-pot reactions.
- Nascimento, Thiana Santiago,Braga, Esther Faria,Casaes Gomes, Giselle Cristina,Batista, William Rom?o,Mazzei Albert, André Luís,Capella Lopes, Rosangela Sabbatini,Lopes, Claudio Cerqueira
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p. 1050 - 1054
(2020/01/23)
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- CATIONIC SURFACTANTS COMPRISING AN ETHER LINK
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A cationic surfactant and a method of making the cationic surfactant are described. The method comprises reacting a lipophilic bio-based material having at least one epoxy functional group and a hydrophilic organic compound having at least one cationic functional group and at least one hydroxyl functional group to form a reaction product containing a stable ether linkage connecting the lipophilic bio-based material to the organic compound. At least a portion of the cationic functional groups is neutralized or ion exchanged with an organic acid. Incorporation of the simple organic acid reduces the surfactant's aquatic toxicity and acts as a substrate to encourage co-digestion of the surfactant molecule, making the compound more biodegradable.
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Page/Page column 10-11
(2019/12/25)
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- Hydrophobically assisted switching phase synthesis: The flexible combination of solid-phase and solution-phase reactions employed for oligosaccharide preparation
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Hydrophobically assisted switching phase (HASP) synthesis is a concept that allows the choice between the advantages of solid-supported chemistry and those of solution-phase synthesis. Starting from the examination of adsorption and desorption properties of hydrophobic molecules to and from reversed-phase silica, we designed a dilipid as a quantitative and fully reversible HASP anchor, permitting final product release. The utility of this new tool in synthetic organic chemistry was demonstrated on oligosaccharide preparation. The synthesis of a pentarhamnoside was accomplished by repetitive glycosylation reactions. Glycosylations were conducted preferably in solution, whereas all protecting group manipulations were performed on solid support. Without the need for chromatographic purification of intermediates, the HASP system furnished the final product after 12 linear steps with average yields of 94% per step at a scale of 0.1 mmol, thus overcoming several of the limitations encountered in the solid-phase synthesis of complex carbohydrates. Copyright
- Bauer, Joerg,Rademann, Joerg
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p. 7296 - 7297
(2007/10/03)
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- Improvement of the phase-transfer catalysis method for synthesis of glycidyl ether
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A convenient procedure for the synthesis of aliphatic alkylglycidyl ether has been studied. It has been found that the improved preparation of the alkylglycidyl ether can be achieved by using fatty alcohol such as octanol and octadecanol with epichlorohydrin in the presence of phase-transfer catalyst (PTC) such as 1-alkyloxypropan-2-ol-3-trimethyl ammonium methylsulfate, 1-alkyloxypropan-2-ol-3-methyldiethanolammonium methylsulfate, alkyloxy-2-hydroxypropyldimethylamine and alkyloxy-2-hydroxypropyldiethanolamine, tetrabutylammonium bromide, etc. without water and other organic solvents. This method, carried out in solid phase/organic phase (reactants and product themselves), has the following merits: (i) producing the solid by-products such as sodium chloride and sodium hydroxide which are easily removed by simple filtration, (ii) saving the amount of reactants used such as sodium chloride and phase-transfer catalyst, and (iii) increasing the yields of glycidyl ethers. The yields of octylglycidyl ether and octadecylglycidyl ether are 92.0 and 91.7%, respectively. The amount of sodium hydroxide used can be saved by from 1.5 to 0.7 molar ratio with respect to octanol in comparison with those in the conventional method using PTC.
- Kang,Byung Min Lee,Yoon,Yoon
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p. 423 - 429
(2007/10/03)
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- Tetrazole is an effective sn-3 phosphate replacement in substrate analog inhibitors of 14 kDa phospholipase A2
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A series of substrate analog inhibitors of 14 kDa PLA2 possessing replacements for the sn-3 phosphate moeity was prepared and evaluated. Tetrazole 26 possessed similar in vitro inhibition potency to phosphate-containing substrate analog inhibitors, but demonstrated superior cell permeability as monitored by LTC4 release in monocytes.
- Lee, Dennis,Marshall, Lisa A.,Bolognese, Brian,Adams, Jerry L.
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p. 1427 - 1432
(2007/10/03)
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- 37. Synthesis of highly fluorinated di-O-alk(en)yl-glycerophospholipids and evaluation of their biological tolerance
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The syntheses of various fluorocarbon/fiuorocarbon and fluorocarbon/hydrocarbon rac-1,2- and 1,3-di-O-alk(en)ylglycerophosphocholines and rac-1,2-di-O-alkylglycerophosphoethanolamines (see Fig.2), which may be used as components for drug-carrier and delivery systems, are described together with some results concerning their biological tolerance. They were obtained by phosphorylation of perfluoroalkylated rac-di-O-alk(en)ylglycerols using POCl3, then condensation with choline tosylate or N-Boc-ethanolamine (2-[(tert-butoxy)carbonyl-amino]ethanol) followed by Boc-deprotection (Schemes 6-8). The fluorocarbon/fluorocarbon 1,2-di-O-alkylglycerols were prepared by O-alkylation of rac-1-O-benzylglycerol using perfluoroalkylated mesylates, then hydrogenolysis for benzyl deprotection (Scheme I). The two different hydrophobic chains in the mixed fluorocarbon/ fluorocarbon and fluorocarbon/hydrocarbon 1,2-di-O-alk(en)ylglycerols were introduced starting from 1,2-O-isopropylidene- then O-trityl-protected glycerols or from 1,3-O-benzylidene-glycerol (Schemes 3 and 4). The perfluoroalkylated O-alkenylglycerols were obtained by O-alkylation of a glycerol derivative using an ω-unsaturated alkenyl reagent, the perfluoroalkyl segment being connected onto the double bond in a subsequent step (Schemes 1 and 3) The perfluoroalkylated symmetrical and mixed 1,3-di-O-alkylglycerols were synthesized by displacement of the Cl-atom in epichlorohydrin by perfluoroalkylated alcohols, then catalytic (SnCl4) opening of the oxirane ring of the resulting alkyl glycidyl ethers in neat alcohols (Scheme 5). When injected intravenously into mice, acute maximum tolerated doses higher than 1500 and 2000 mg/kg body weight were observed for the fluorinated glycerophosphocholines, indicating a very promising in vivo tolerance.
- Ravily, Veronique,Gaentzler, Sylvie,Santaella, Catherine,Vierling, Pierre
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p. 405 - 425
(2007/10/03)
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- Synthesis of glycerol deuterated ether phospholipids
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1,3-Dialkyl glycerophosphocholines deuterated on the glycerol moiety were synthesized starting either from propiolic acid to yield a pentadeuterated compound, or from epibromohydrin to give a monodueterated substance.
- Nuss, Simone,Oudet, Pierre,Lebeau, Luc,Mioskowski, Charles
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p. 5705 - 5706
(2007/10/03)
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- Carboxylic acid derivatives
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A compound represented by the formula: STR1 wherein R represents a hydrogen atom or a lower alkyl group; R1 represents a higher alkyl group which may be substituted; R2 represents a hydrogen atom or a lower alkyl group, a lower alkanoyl group or a nitrogen-containing 5- to 7-membered heterocyclic group each of which may be substituted; X represents a divalent group represented by the formula: wherein p represents an integer of 1 to 5, a divalent group represented by the formula: wherein q represents an integer of 3 to 8, or a divalent group represented by the formula: wherein J represents an oxygen atom or a group represented by the formula: --S(O)r -- (wherein r represents 0, 1 or 2), and p and q are the same as defined above; Y represents a divalent group containing tertiary or quaternary nitrogen atom(s); and Z represents an alkylene group which may be substituted and/or interrupted, or a group represented by the formula: wherein Q and W represent an alkylene group which may be substituted, and T represents a phenhylene group, a naphthylene group, a cycloalkylene group; and a salt thereof exhibit excellent antitumor action including differentiation inducing action and are useful as pharmaceuticals.
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- Optically active oxiranes. Synthesis of PAF (Platelet Aggregating Factor)
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A number of epoxides bearing no function in the α-position have been converted into β-hydroxy sulfonium salts.Association with an otically active acid (dibenzoyltartaric) allowed the resolution.This method has been used to prepare the optically active glycidol octadecyl ether which was converted into (-) PAF. Key words: oxiranes / resolution / PAF synthesis
- Cimetiere, B,Jacob, L,Julia, M
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p. 926 - 938
(2007/10/02)
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- Synthesis of 1-O-alkyl-2-O-acetyl-Sn-3-glyceryl-3-phosphoryl choline the enantiomer of platelet activating factor (PAF)
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A novel sterospecific synthesis of biologically active ether-phospholipids (PAF) is reported, involving chemoenzymatic approach.
- Kumar,Shanker
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p. 1763 - 1768
(2007/10/02)
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- RESOLUTION OF OXIRANES. APPLICATION TO THE SYNTHESIS OF THE PLATELET AGGREGATION FACTOR
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Resolution of racemic oxiranes has been achieved through their conversion into hydroxy sulfonium salts of dibenzoyltartaric acid.Thus, resolution of n-octadecyl glycidyl ether followed by reaction with phosphorylcholine and acetylation led to C18-P.A.F.
- Cimetiere, Bernard,Jacob, Laurent,Julia, Marc
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p. 6329 - 6332
(2007/10/02)
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