The effects of phospholipids on the oxidative dimerization of dl-α-tocopherol (α-Toc) and d-δ-tocopherol (δ-Toc) during the thermal oxidation of trilaurin (Tri-La) and of trilinolein (Tri-Li) were examined. Experimental procedures were the same as those described in the previous papers of this series. α-Toc was oxidized with air at 180°C for 10h, and δ-Toc for 5h. A little influence of phospholipids on the oxidative stability of tocopherols was observed at the oxidation in Tri-La. (Tables-1 and 2) When tocopherols were oxidized in Tri-Li, the stability of tocopherols increased greatly by the addition of small amount of phosphatidyl choline or phosphatidyl ethanolamine. (Figs.-1 and 4) Similar effect was observed at the addition of tri-n-butyl phosphate (TBP), while tri-n-octylamine (TOA) gives no influence on the oxidative dimerization of tocopherols. (Figs.-2 and 4) This phenomenon is similar to that observed at the oxidation of γ-Toc, which was shown in the Part IV of this series. This fact shows that phosphate ester linkage supresses the oxidation of tocopherols in Tri-Li. The formation of 1, 2-bis (γ-tocopherol-5-yl) ethane (α-TED) was scarcely influenced by the addition of phospholipids, TBP and TOA. (Fig.-3) On the other hand, the amount of 5- (δ-tocopheroxy) -δ-tocopherol (δ-TED) formed from δ-Toc decreased remarkably;but the amounts of 5- (δ-tocopherol-5-yl) -δ-tocopherol and its atropisomer [δ-TBD (H) and δ-TBD (L)] were slightly influenced by the addition of phospholipids or TBP in Tri-Li. (Figs.-5, 6 and 7)
Yeast was cultured on mediums containing glucose or a fatty acid ester as carbon sources, and the effects of these carbon sources, and of culture conditions such as temperature, aeration and C/N ratio on the dry weight of the yeast, lipid content and fatty acid composition of the lipid were examined. Where the carbon source was glucose, the concentration of palmitic acid increased with exposure of the yeast to lower temperatures, the concentration of linoleic acid rose with increased aeration, and the concentration of stearic acid rose with a higher C/N ratio. Where the carbon source was a fatty acid ester, the dry weight of the yeast increased, and the fatty acid composition of yeast lipid varied greatly according to the kind of ester used. For example, when ethyl stearate, butyl stearate or ethyl oleate was used as carbon source, the composition differed greatly ; where butyl stearate was used, the activity of substrate-incorporating enzymes was low ; and where ethyl stearate was used, there was a low hexadecenoic acid content, although this was present in significant quantities when other ethyl esters were used.
It has been found that the dissolved water (141560 ppm) in safflower oil promoted the autoxidation of the oil in air at 20 and 50°C during the long time storage (45014, 000h). When those oils were stored for 450h at 20 and 50°C, there was no difference in the degree of the autoxidation of the oil dissolved the water (141560 ppm). During the long time (100014000 h), the oil contained 14 ppm H2O was little autoxidized owing to the formation of the hydrogen bond among the dissolved water and the hydroperoxide and peroxy group (HPO and PO group). At the same conditions, the autoxidation of the oils contained 2201560 ppm H2O was accelerated by the dissolved free water. In case of the equal amount of the dissolved water in these oils at 20 and 50°C, a plot of the POV (peroxide value) vs. the equivalent number of the HPO and PO group Per the mole aumber of the dissolved water gave one straight line. Therefore, when safflower oils containing water were stored at 20 and 50°C for the long time, it is thought that the mechanism of the action of the dissolved water in these oils an the autoxidation are identical.
2-Ethylhexyl 2, 3-dihydroxypropyl phthalate (GOP) and bis (2, 3-dihydroxypropyl) phthlate (DGP) were prepared to examine the synergetic effect on the thermal stabilization of PVC with synergetic metal soaps (Zn stearate/Ca stearate). 1) GOP and DGP were both colorless and transparent liquid. GOP was soluble in bis (2-ethylhexyl) phthlate (DOP) but insoluble in water. On the other hand, DGP was insoluble in DOP. 2) GOP and DGP slow down the appearance of zinc burning and prolonged the good initial color of PVC films compounded with synergetic soaps. 3) The good synergetic effect of GOP and DGP should be due to the masking effect of their polyol segment, and phenyl and 2-ethylhexyl benzoate segments involved the ability to disperse GOP and DGP into PVC, but phthalic acid and phthalic anhydride accelerated the appearance of zinc burning.
Some kinds of fluorinated surfactants have been prepared from perfluorooctanesulfonyl fluoride (1) and their surface active properties determined. Intermediate aminoamides (2 and 3) were obtained via reactions of (1) with alkylamines (C2-C4) or N, N-dimethylamine. (2) was reacted with ethyl chloroacetate to convert into sulfonamidocardoxylic ester which was then hydrolized to the corresponding alkali metal salt as anionic surfactant. (3) was quaternarized by methyl iodide or dimethyl sulfate and two kinds of quaternary salts were obtained as cationic surfactants. At the same time (3) was reacted with 1, 3-propanesultone to prepare sulfobetaine-type amphoteric surfactant. Surface active properties of the above surfactants have been investigated regarding surface tension, critical micelle concentration and emulsifying power.
Dichlorocyclopropane compounds, prepared from olefins or unsaturated carboxylic acids with chloroform, react with lithium naphthalenide to give alkylcyclopropanes, and/or unsaturated compounds as dechlorinated products. For example, a mixture of octylcyclopropane and 1-undecyne was obtained from the reaction of 1, 1-dichloro-2-octylcyclopropane and lithium naphthalenide. 9, 10-Nonadecadienoic acid was obtained as a main product from the reaction of 9, 10- (dichloromethylene) octadecanoic acid and lithium naphthalenide.
In measuring separatively contents of tocopherols in oil by high performance liquid chromatography (HPLC), measurement conditions such as packing agent and mobile phase were investigated. Then, a collaborative study was conducted with 6 laboratories, using distributed standard solution of tocopherols and specified packing agent and mobile phase. Results obtained were as follows : 1) It was found that fatty components were eluted together with α-tocopherol fraction by using some of mobile phase which could separate tocopherols one another, consequently lowering measurement values. 2) The response of fluorescent detector for each tocopherol was found to change with time when this detector was contenuously used for long time. 3) There was no difference in the precision of separation and detection of tocopherols when different brands of silica gel packing agent were used. 4) In measuring oils by HPLC without pretreatment, a measurement error was up to ±3% for individual tocopherol content of 10 mg/100 g or more, but over ±10% for smaller amounts.
The model triglyceride mixture was analalysed by GC-MS (Gas chromatography-Mass spectrometry) with lower ionization voltage (20 eV) than previous studies. Lowering the ionization voltage was favorable for the ion intensity of RCO+ and [M-RCO2]+. As for the fatty acid composition in each triglyceride group with same total carbon number of three acyl chains, GC-MS method was compared with the calculation from total fatty acid composition. The fatty acid compositions by two methods were in good agreement.
Aiming at the preparation of fluorine-containing surfactant an amidoamine (3) was synthesized from perfluorooctanoic acid (1) and N, N-dimethylaminopropylamine. (3) was reacted with methyl iodide or dimethyl sulfate to prepare quaternary salt (4 or 5) and also with propanesultone to obtaine sulfobetaine-type surfactant (6). Surface active properties of these surfactants were determined regarding surface tension, critical micelle concentration, solubilization and oil-repellency.