Triglyceride compositions of beef fat, lard and palm oil were studied by oxidation-fraction-GLC. 1) Saturated and unsaturated fatty acids were randomly distributed in beef fat and lard, but non-randomly in palm oil. Most fatty acids of S3, S2U, SU2 and U3 were randomly distributed in each triglyceride fraction. 2) Lauric acid and myristic acid content was high in S3. Palmitic acid content of beef fat and lard increased, but stearic acid content decreased with unsaturated fatty acyl group as S3<S2U<SU2. But palmitic acid content of palm oil was constantly high level about 87% among the glycerides. 3) C44 to C50 triglyceride were mainly composed of S3 and S2U, and so they would appear solid fats. C52 were composed of S2U and SU2, and so they would appear plastic fats. Finally, C54 were composed of SU2 and U3, and so they would appear liquid oils. 4) Triglyceride compositions of these fats were calculated without the glyceride distribution theory, and the data agreed with the values found in literatures.
Phase transition phenomena in the water-potassium stearate-polyol (glycerol, propylene glycol, 1, 3-butanediol) systems were studied by differential scanning calorimetry and X-ray diffraction. In the absence of polyols, suitable annealing treatment for the samples was necessary to the gel-to-coagel transition. In the presence of polyols, in the temperature range where the coagel phase is stable state, the gel phase was transformed into the coagel phase without annealing. With increasing polyol content, the transition temperature for the gel-isotropic solution or liquid crystal (Tc) decreased and that for the coagel-gel (Tgel) increased. Therefore, Tc and Tgel coincided with each other at a certain polyol content, and above this content the stable gel phase disappeared and the coagel phase was directly transformed into the isotropic solution. The order of reducing the area of the gel region in the phase diagram was following; 1, 3-butanediol> propylene glycol> glycerol.
Supercritical fluid chromatography (SFC) is a new method for analysis, separation and purification. It has the merits of both gas chromatography and liquid chromatography. In the present study, this method was used to separate esterified fatty acids containing lipids in fungi. The characteristics of SFC were compared with those of HPLC in the analysis of the fatty acid. The elution order of each ester was not found to obey the partition number of HPLC, but to depend on the modified partition number defined as (carbon number-2/3 x number of double bond). Further, this relation was affected by temperature, pressure and the addition of methanol. γ-Linolenic acid was present at about 58% in the lipids in the fungi. Operation conditions of SFC were studied for separating γ-linolenic acid from other fatty acids. The former was concentrated from 6% to 9799% by SFC at 35°C and pressures of 100 and 120 kg/cm2.
The solution behavior in water of some alkyl diglyceryl ethers with different structures (DGE-OMe, IDGE-OMe and IDGE-OH) was investigated through the determination of their binary phase diagrams. Though each alkyl diglyceryl ether formed a lamellar liquid crystalline phase even at low concentrations, their solution behavior was different. In low concentration range, DGE-OMe gave a two-phase region composed of a liquid crystalline phase and a water phase, whereas IDGE-OMe, which is an isomer of DGE-OMe, formed a homogeneous liquid crystalline phase. IDGE-OH with one more hydroxyl group than IDGE-OMe exhibited a solution behavior similar to that of IDGE-OMe. Fluorescent probe study and thermal analysis on these liquid crystalline phases showed that the planar structure of lamellar liquid crystal of DGE-OMe changed to somewhat a disordered one with increase in water content, while that of IDGE-OMe remained unchanged. The residual area per molecule of DGE-OMe obtained from the surface tension-concentration curve was larger than that of IDGE-OMe. These facts indicated that this type of surfactants was so less hydrophilic that readily aggregated to form a liquid crystalline phase, and therefore the property of liquid crystal and solution behavior was strongly affected by slight differences in the molecular shape rather than the number of hydroxyl groups.
Crown ethers (5 a, b) with a pyrrolidine ring and long alkyl chain were synthesized from 4-hydroxyl-L-proline via the five steps shown in Scheme-1. Some physical and aqueous solution properties of (5 a, b) and complexing stability constants (log K1') of these compounds with Na+ and K+ in methanol were examined. The obtained crown compounds were optically active, [α] 25D : -23.8 and -37.2 (c=1, CH3OH) for (5 a) and (5 b) respectively. Cloud points and the critical micelle concentrations (cmc) of (5 a, b) were lower than those of the reference compounds (6 and 7). The stability constants of (5 a) were less than those for the reference compound (6). The results can be explained on the basis of lipophilicity and steric hindrance of a pyrrolidine unit introduced into the crown ring.