Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesize... more Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesized from vernonia oil, a natural epoxydized triglyceride. The presence of a 12,13-epoxy group on the C18 unsaturated fatty acid, vernolic acid, which is the main constituent of vernonia oil, permitted the synthesis of novel amphiphilic derivatives with a hydrogen-bonding hydroxyl and a cationic headgroup moiety on adjacent carbon atoms. The amphiphiles were prepared in a two-stage synthesis that comprised opening of the epoxy groups with a haloacetic acid, followed by quaternization of the halo group with a tertiary amine containing a C12 aliphatic chain. Intact vernonia oil as the starting material gave a triple-headed cationic amphiphile, containing three vernolic acid derived moieties connected through a glycerol backbone. A single-headed amphiphile with two alkyl chains and a single quaternary ammonium headgroup was synthesized from the methyl ester of vernolic acid as the starting material. The triple-headed derivative could form nonencapsulating structures. Cholesterol was required in the formulation (1:1) to make spherical vesicles that could encapsulate a water-soluble marker. The single-headed derivative, however, formed spherical encapsulating vesicles without cholesterol. TEM, NMR, and FT-IR were used to characterize the vesicles, and molecular structure vs morphology relationships were postulated on the basis of these data. The triple-headed amphiphile also formed a DNA complex that was highly resistant to hydrolysis by DNase. This amphiphile-DNA complex was used as vector for gene transfer in cell culture demonstrating efficient DNA transfection.
Journal of The American Oil Chemists Society, 1984
Jojoba wax was thermally isomerized over a range of temperatures. The equilibrium constant and th... more Jojoba wax was thermally isomerized over a range of temperatures. The equilibrium constant and the rates ofcis-trans andtrans-cis conversions were measured. Activation energy (∼ 24 kcal/m) and enthalpy were calculated.
Journal of The American Oil Chemists Society, 1984
Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensit... more Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensitizers, at room temperature.Cis-trans isomerization took place only with sensitizers with triplet energy greater than 68 kcal/mol. Quantum yields were low and a conversion of up to 25% of thetrans isomer was achieved at the photostationary state.
Journal of The American Oil Chemists Society, 1984
Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensit... more Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensitizers, at room temperature.Cis-trans isomerization took place only with sensitizers with triplet energy greater than 68 kcal/mol. Quantum yields were low and a conversion of up to 25% of thetrans isomer was achieved at the photostationary state.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Journal of The American Oil Chemists Society, 1984
The oxidation with hydrogen peroxide and permanganate and the allylic bromination, chlorination a... more The oxidation with hydrogen peroxide and permanganate and the allylic bromination, chlorination and chloro-etherification of the olefinic bonds of the liquid wax extracted from beans of jojoba (Simmondsia chinensis) were studied. Hydrolytic splitting of the wax into its carboxylic and alcoholic components competed with most reactions carried out in aqueous systems. The use of a suitable phase-transfer catalyst enabled the oxidation of the double bonds to carboxyls using permanganate in aqueous systems. Reaction of the wax with hydrogen peroxide in formic acid yielded formates, which were then hydrolyzed to vicinal glycols. The diglycols obtained by hydrogen peroxide oxidation were benzoylated. Allylic chlorination of jojoba wax with t-butyl hypochlorite in organic solvents was carried out. Conditions were found for the allylic bromination of the wax, yielding mono-, di-, tetra-, or octabromo derivatives.
Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesize... more Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesized from vernonia oil, a natural epoxydized triglyceride. The presence of a 12,13-epoxy group on the C18 unsaturated fatty acid, vernolic acid, which is the main constituent of vernonia oil, permitted the synthesis of novel amphiphilic derivatives with a hydrogen-bonding hydroxyl and a cationic headgroup moiety on adjacent carbon atoms. The amphiphiles were prepared in a two-stage synthesis that comprised opening of the epoxy groups with a haloacetic acid, followed by quaternization of the halo group with a tertiary amine containing a C12 aliphatic chain. Intact vernonia oil as the starting material gave a triple-headed cationic amphiphile, containing three vernolic acid derived moieties connected through a glycerol backbone. A single-headed amphiphile with two alkyl chains and a single quaternary ammonium headgroup was synthesized from the methyl ester of vernolic acid as the starting material. The triple-headed derivative could form nonencapsulating structures. Cholesterol was required in the formulation (1:1) to make spherical vesicles that could encapsulate a water-soluble marker. The single-headed derivative, however, formed spherical encapsulating vesicles without cholesterol. TEM, NMR, and FT-IR were used to characterize the vesicles, and molecular structure vs morphology relationships were postulated on the basis of these data. The triple-headed amphiphile also formed a DNA complex that was highly resistant to hydrolysis by DNase. This amphiphile-DNA complex was used as vector for gene transfer in cell culture demonstrating efficient DNA transfection.
Journal of The American Oil Chemists Society, 1984
Jojoba wax was thermally isomerized over a range of temperatures. The equilibrium constant and th... more Jojoba wax was thermally isomerized over a range of temperatures. The equilibrium constant and the rates ofcis-trans andtrans-cis conversions were measured. Activation energy (∼ 24 kcal/m) and enthalpy were calculated.
Journal of The American Oil Chemists Society, 1984
Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensit... more Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensitizers, at room temperature.Cis-trans isomerization took place only with sensitizers with triplet energy greater than 68 kcal/mol. Quantum yields were low and a conversion of up to 25% of thetrans isomer was achieved at the photostationary state.
Journal of The American Oil Chemists Society, 1984
Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensit... more Jojoba wax solutions were irradiated at wavelengths longer than 366 nm, in the presence of sensitizers, at room temperature.Cis-trans isomerization took place only with sensitizers with triplet energy greater than 68 kcal/mol. Quantum yields were low and a conversion of up to 25% of thetrans isomer was achieved at the photostationary state.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Journal of The American Oil Chemists Society, 1984
The oxidation with hydrogen peroxide and permanganate and the allylic bromination, chlorination a... more The oxidation with hydrogen peroxide and permanganate and the allylic bromination, chlorination and chloro-etherification of the olefinic bonds of the liquid wax extracted from beans of jojoba (Simmondsia chinensis) were studied. Hydrolytic splitting of the wax into its carboxylic and alcoholic components competed with most reactions carried out in aqueous systems. The use of a suitable phase-transfer catalyst enabled the oxidation of the double bonds to carboxyls using permanganate in aqueous systems. Reaction of the wax with hydrogen peroxide in formic acid yielded formates, which were then hydrolyzed to vicinal glycols. The diglycols obtained by hydrogen peroxide oxidation were benzoylated. Allylic chlorination of jojoba wax with t-butyl hypochlorite in organic solvents was carried out. Conditions were found for the allylic bromination of the wax, yielding mono-, di-, tetra-, or octabromo derivatives.
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