Reversed phase high performance liquid chromatography (HPLC) with an RI detector was used to separate and determine hydroperoxides of autoxidized ethyl oleate, linoleate and linolenate. Ethyl oleate hydroperoxide appeared as a single peak apart from unoxidized ethyl oleate on the chromatogram. The hydroperoxide isomers formed by autoxidation of ethyl linoleate were resolved into two components which were geometrical isomers having cis-trans and trans-trans conjugated diene structures. Autoxidized ethyl linolenate gave two peaks of conjugated diene monohydroperoxides and conjugated triene dihydroperoxides, respectively. Under the HPLC conditions used here, the hydroperoxides could be separated according to the number of their double bonds and hydroperoxy groups, and the configuration of the conjugated double bonds (cis-trans and trans-trans), but not on the basis of the difference in the location of hydroperoxy groups. When autoxidized esters were subjected to HPLC analysis directly, a good linear relationship was observed between the ratio of the peak area of hydroperoxides to that of all peaks on the chromatogram and POV of the sample ester in the range of 303, 000meq/kg. POV determined by this procedure agreed quite well with those measured by the official titration method.
The high resolution gas chromatography of fatty acid methyl esters obtained from seven samples of domestic soft type margarines for home use was carried out using glass capillary columns. The content of the cis and trans isomers of linoleic and linolenic acids was determined. The content of the geometrical and positional isomers of oleic acid was obtained by gas-liquid chromatography of the ozonolysis products of the cis and trans monoenoate fractions separated with silver nitrate-impregnated silicic acid thin-layer chromatography. The specific features of the fatty acid composition of the margarines are discussed.
6-Methyl-5-hepten-2-one (1) had been synthesized from 1-chloro-3-methyl-2-butene (3) and acetone (5) in anhydrous systems by using flaky alkali hydroxide with troublesome handlings. Much improvement in handlings, such as recovery of the catalyst or separation of sodium hydroxide and sodium chloride, was obtained by using phase transfer catalysts in aqueous systems. Various amines, quaternary ammonium salts, quaternary phosphonium salts, and tertiary sulfonium salts were investigated as catalsyts. Quaternary ammonium salts of long alkyl or benzyl derivatives and tricyclohexyl phosphonium salts were effective for industrial usage. Effects of solvents or sodium iodide and application to other ketones were also studied. It was suggested that the affinity of the catalyst to both organic and aqueous phase was quite important to obtain monoalkylated ketones. The reaction of (3) and (5) with aqueous sodium hydroxide in the presence of trimethyl (n-octadecyl) ammonium chloride (7) was investigated under various conditions from the viewpoint of conversion-selectivity of (3) to obtain (1) in an optimum yield. The reaction was dependent upon the concentration of sodium hydroxide as depicted in Figs.-6A, 7B, and 6C. Reactions of (3) and (5) in anhydrous systems by using flaky sodium hydroxide were also examined to compare with aqueous systems. Industrial profits of phase transfer reactions were discussed in consideration of a continuous process.
The effect of pH on coagulation (particle-particle, particle-fabric) was studied so as to find some substitute for a phosphate builder, using ferric oxide (Fe2O3) as a model of particulate soil. The ζ-potentials of Fe2O3 particles and nylon fabrics were mesured in a solution of various pH with HCl or NaOH adjusted to 5×10-3 ionic strength with NaCl. Fe2O3 deposited on the nylon fabrics was also measured in the same solution. The particle size distribution of Fe2O3 in the solution was measured and interpreted in terms of the potential energy of the interaction between particles. Fe2O3 deposited on nylon fabrics is discussed on the basis of the heterocoagulation theory for a sphere and an infinite flat plate. The increase in the ζ-potential of Fe2O3 in a highly acidic or alkaline solution promoted the dispersion stability of particles, and corresponded to the potential energy curves. It was difficult to express Fe2O3-deposition on nylon fabrics in terms of potential energy. However, deposition was found to depend on dispersion stability in aqueous solution. Consequently, the redeposition of particulate soil may possibly be prevented by enhancing the ζ-potential so as to promote dispersion stability.
This paper reports a rapid quantitative analysis of polyunsaturated fatty acids (PUFA) of human plasma, platelet and erythrocyte lipids by short capillary column gaschromatography. Determination of biologically important fatty acids such as linoleate, di-homo-γ-linolenate, arachidonate, icosapentanoate, docosahexanoate, within 5 minutes was carried out. Unknown or unclassified components were found in the lipids of platelets and erythrocytes in the vicinity of palmitate and stearate peaks. For quantification of the weight content of fatty acids, tricosanoic acid, which dose not overlap any biologically important PUFA mentioned above, can be used as the internal standard.
Methyl jasmonate and γ-jasmolactone, as important perfumery constituents, were synthesized from a readily available starting material, 3-cyano-1, 1-dimethoxypropane (1). The synthetic route is shown in Scheme-1. The reaction of (1) with cis-3-hexenylmagnesium bromide gave 1, 1-dimethoxy-cis-7-decen-4-one (4) in 54% yield. Deacetalization of (4) followed by cyclization afforded 2-(cis-2-pentenyl)-2-cyclopenten-1-one (6) in 48.6% yield. Methyl jasmonate (7) was obtained from (6) in 65% yield. γ-Jasmolactone (8) was synthesized by an one-pot reaction of methyl 4-oxobutyrate (3) with cis-3-hexenylmagnesium bromide in 69% yield.