The composition of the acetone-soluble lipids contained in Japanese Littleneck (Tapes japonica (Deshayes)) was studied from the view point of its seasonal variation. The lipids were extracted with ethanol-ether or methanol-chloroform, and acetone soluble lipids were obtained by means of acetone precipitation and Folch-washing method. The acetone soluble lipids were analyzed with counter-current distribution method (95% methanol-petroleum ether, 100- transfer). Sterols and phospholipids were separated, but glyceride and fatty ester of sterols were not separated. Fraction of the mixtures of glycerides and sterols esters were determined for the unsaponifiables, to calculate the per cent of glyceride, sterol ester, free sterol and phospholipid. The separation of these fractions were identified with thin-layer chromatography on silicic acid. The seasonal variation of the composition of acetone -soluble lipids was not prominent. The sterol was mainly 7- dehydrostigmasterol, but the presence of another sterol was indicated by the infrared absorption spectrum and by the thin-layer chromatography.
Authors studied the reactions of methyl crotonate and methyl vinylacetate with bromoacetonitrile at 120-150°C using di-tert-butylperoxide as initiator. Methyl - γ -bromocrotonate and methyl- α -bromo- β -methyl- γ -cyanobutyrate were the main products in the reaction of methyl crotonate. In case of the reaction of methyl vinylacetate, the corresponding compound (α -bromovinylacetate) was not obtained. The formation of γ -bromocrotonate in the latter case could be explained as the rearrangement of the intermediate radical CH2=CH-CHCO2CH3 into ·CH2-CH=CH-CO2CH3. Apparent activation energy of the hydrogen abstraction reaction from methyl crotonate calculated from the rate of formation of methyl- γ -bromocrotonate was lower than that from methyl vinylacetate, and apparent activation energy of the addition of bromoacetonitrile to the former was higher than that of the latter. Conjugative stabilization of intermediate radical plays an important role in theae reactions. The effect of addition of palladium chloride and of other heavy metal salts on the hydrogen ahstraction and on the addition reaction of BrCH2CN was also studied.
The aim of this study was to elucidate the mechanism of colour development in frying oils. Methyl linoleate was selected as the typical model component of frying oil. The sample was heated for 8 hr at 200°C and the time dependence of chromaticity and characteristic changes were determined. The severer changes were observed in methyl linoleate than in soybean oil. The highly coloured sample was divided into five fractions by the urea adduct method, then above mentioned measurements were made for each fraction. In addition to the above mentioned analyses, the composition and mean molecular weight of the compounds which did not give the urea adduct were determined and the presence of cyclic structure was identified. As a result it was found that isolated cis double bonds isomerizecl to trans double bonds by heating, and simultaneously the cis-trans and trans-trans conjugation of the isolated double bonds followed. In the highly coloured fractions, isolated trans and Irans-trans conjugated double bonds were predominantly observed. Dimerization and timerization occured accompanying the formation of carbonyl, hydroxyl and epoxy groups. The coloured materials which were composed of partly cyclic dimers and trimers were concentrated in the fraction which slid not give the urea adduct. It was surely established that the polar dimer, which contained oxvgens, exhibited deeper red colour.
Thin layer chromatography technique using sillica coated plate and the solvent system consisting of methylethylketone-benzene-ethanol-water was successfully applied to the analysis of both commercial liquid shampoos and liquid dish washing detergents with following results. 1) Essential constituents in those test-samples, namely, fatty acid alkylolamides, anionic and nonionic surfactants, urea, free fatty alcohols and amines were separated and identified. 2) Detecting of free triethanolamine or ammonium sulfate suggested the presence of anionic surfactants based on these amines or ammonium salts. 3) A suitable selection of indicating reagents made it possible to separate higher alcohol sulfate from its ether sulfate. 4) It was also demonstrated that this procedure is useful to detect various impurities in those test samples.
An atempt was made to prepare L-12-hydroxystearic acid (L-acid) from commercial D-12-hydroxystearic acid (D-acid) by the Walden inversion. D-Acid was converted to the methyl ester, and then to the tosylate by reaction with p -toluenesulfonyl chloride. The Walden inversion occured when the tosyl group was acetylated with sodium acetate in acetic acid containing acetic anhydrous. L-Acid was obtained by saponifying the acetate with potassium hydroxide. The yield of the crude product was about 61%, based on the D-acid. The metal soaps of D-acid and L-acid formed helical aggregates from mineral oil, exhibiting the enantiomorphic relationship for the direction of the twist.