Oil-in-water (O/W) emulsions were prepared using a new amino acid-type emulsifier (surfactant), N-[3-lauryloxy-2-hydroxypropyl]-L-arginine L-glutamate (C12HEA-Glu), and the emulsifying potency of C12HEA-Glu was examined in terms of dispersibility, droplet size, interfacial tension, viscosity and hydrophilic microenvironment of droplet surface, whose emulsifying potency was compared with that of general amphoteric and nonionic surfactants. The effects of the constituent oils on the stability of emulsions were also examined. The emulsifying potency of C12HEA-Glu was greater than that of amphoteric N-lauryl-N, N-dimethyl-α-betaine and nonionic polyoxyethylene(10) laurylether, especially, the stability of emulsions containing oleic acid (OA), (C12HEA-Glu/OA/water system), was greatest, while the stability of emulsions containing octane (OC), (C12HEA-Glu/OC/water system), was inferior. OA possesses a hydrophilic carboxyl group and the viscosity of OA is higher than that of OC. The higher visco-elasticity of OA droplet surface and the formation of hydration layer on the droplet contributed to the greater stability of OA emulsions, thereby raising the stability of emulsions for the system C12HEA-Glu/OA/water in spite of the small | zeta-potential | (insufficiently electrostatic repulsion) of droplets.
1H NMR spin-lattice relaxation time of ethylenediammonium dioctanoate (EDADO), a model dispersant (MD) for phthalocyanine blue (PhB) pigment, was examined with a high-resolution magic angle spinning (MAS) 1H NMR probe (1H Nano·nmrTM Probe). The adsorption mechanism of EDADO onto PhB was discussed on the basis of the spin-lattice relaxation time obtained by changing the polarity of the solvent and the temperature in the 1H NMR measurement. In addition to the deduction shown in our previous report that the adsorption of the MD molecule onto the pigment is induced by the coordination of a lone electron pair of a nitrogen atom of the amino group onto Cu(II) of PhB, it became clear that equilibrium among a diammonium salt, a half-salt, and diamine (ethylenediamine, EDA) is an important factor in the adsorption behavior. A comparison of measurements in chloroform-d and in methanol-d4 suggests that the complex of PhB and a half-salt composed of EDA and octanoic acid still has interaction with a carboxylic acid molecule through proton-transfer from the carboxylic acid to PhB (PhB of the complex and/or free PhB) and successive hydrogen bonding which may effect the dispersion of pigment in a nonpolar medium. The results obtained in this model system may afford a basis for explaining the good dispersing ability of poly(ammonium carboxylate), that is, polymeric dispersants in practical use.
An efficient method for synthesizing unsaturated urushiol components in urushi sap, was established, Wittig reaction of ylides derived from alkyl-and alkenyltriphenylphosphonium iodides, as side chain parts of urushiol, with 3-(8-oxo-1-octyl) catechol diacetate or 3-(10-oxo-1-decyl) catechol diacetate, as aromatic part of urushiol. Quantitative analysis of urushiol components in the urushi sap was done using GC for comparison with synthesized urushiol components as reference. In this manner, we proved the structures of most urushiol components and established percentage compositions of urushiols in the sap of Rhus vernicifera of Japan, Korea and China. (approximately 95%), by quantitative analysis of urushiol derived from Rhus vernicifera, the most abundant constituent was triene urushiol (approximately 71%) and the next abundant were mono (14-16%) and diene (5-8%) urushiol. Content was found to depend on growth conditions of the Rhus vernicifera tree and on the particular season for obtaining sap.
To assess the thermal stability of phthalates a flow reactor with a jet nozzle was developed by the authors. Thermal decomposition reactions of phthalates, each having a high boiling point and viscosity, were conducted with this reactor for a short period from 2.4∼8.4 s. The phthalate were found from the results to decompose by cis elimination into the usual esters at 250∼500°C. Assuming first order reactions, activation energy determined when using a fixed quantity of unreacted phthalate was found to be as follows; dibutyl phthalate, 22.4; dihexyl phthalate, 38.4; dioctyl phthalate, 45.0; di(2-ethylhexyl) phthalate, 40.6; didecyl phthalate, 35.4; and dilaulyl phthalate, 24.2 kcal/mol.
Conjugated linoleic acid (CLA) is reported to display anti-diabetic activity in Zucker diabetic fatty fa/fa rats, but to induce insulin resistance in various other animal species. CLA was administered to diabetic C57BLKS-Leprdb/leprdb (db/db) mice long-term and its influence on diabetic symptoms was examined in this animal model. In addition, triacylglycerol CLA (TG-CLA), enzymatically prepared to provide organoleptic satisfaction, was used. Mice were fed for 23 weeks one of three diets supplemented with 1.2% safflower oil (control), 0.53% TG-CLA and 0.67% safflower oil (TG-CLA (L)) or 1.2% TG-CLA (TG-CLA (H)). During the administration, food intake did not differ between the groups. Body weight was significantly lower in the TG-CLA (H) group than in the control group (P<0.001). The body weight of the TG-CLA (L) group was between those of the other two groups. The abdominal and epididymal fat pad weight of the TG-CLA (H) group was reduced compared to the control (P<0.05). Plasma glucose and insulin levels were not affected by the TG-CLA supplementation. Serum triglyceride levels were noticeably reduced in mice fed TG-CLA compared to those fed the control diet (P<0.01) at certain stages of the administration (from 10 to 14-weeks of age). The serum GPT level of the TG-CLA (H) group was much higher than that of the control (P<0.05). The histopathological evaluation of the liver, the kidney and the pancreas revealed no effect of TG-CLA administration on these tissues. Consequently, long-term administration of TG-CLA has no adverse effect on the diabetic status in diabetic db/db mice.
Although dietary conjugated linoleic acid (CLA) has been shown to have anti-diabetic activity in Zucker diabetic fatty fa/fa rats, the long-term administration of glycerides rich in CLA (TG-CLA) had no effect on diabetic status in C57BLKS-Leprdb/leprdb(db/db) mice. In the present study, the effect of TG-CLA on blood glucose control in diabetic db/db mice was examined. Mice were fed a diet supplemented with either 1.2% safflower oil (control) or 1.2% TG-CLA. Oral glucose tolerance tests (OGTTs) were performed after 5 and 11 weeks of TG-CLA treatment. The body weight, fat pad weight and amounts of food consumed were lower in the TG-CLA fed mice than in the control. The administration of TG-CLA for 5 and 11 weeks suppressed the blood glucose increase after oral glucose ingestion. Furthermore, the insulin level during OGTTs had increased after 5 weeks of treatment, but it was suppressed after 11 weeks. These results that revealed beneficial effects of TG-CLA on blood glucose control in diabetic db/db mice, in addition to improved insulin sensitivity after a transient increase in insulin secretion, indicate the need for further study in human subjects.
It has been suggested that resveratrol (RT) has a protective effect against cardiovascular diseases. We analyzed the concentration of RT in must and wine samples made from nine varieties of red and two of white grapes grown in Hokkaido, Japan, by a combination of normal and reverse phase high-performance liquid chromatography. The sum of trans-and cis-RT concentrations in the must differed significantly among the grapes, ranging from 0.04 to 0.41 mg/L. After alcoholic fermentation, the RT concentrations in the red wines increased to 0.50∼2.76 mg/L due to maceration with skin, but those in the white ones scarcely changed. The ratios of trans-RT to the cis-form in the must samples were in the range of 3.0 to 12.0, but an increasing level of cis-RT was usually observed in the wine samples. In red wine samples, after malolactic fermentation, the RT concentrations were found to be increased 1.1-to 1.9-fold compared with those measured at the end of alcoholic fermentation. In contrast, the amounts of piceid (RT glucoside), quantified as the RT equivalent after β-glucosidase digestion, decreased in the wines. It was therefore assumed that the increase in RT might have resulted from the hydrolysis of piceid during malolactic fermentation.
The heat decomposition of soybean lecithin was studied using saturated hydrocarbon. On heating with isooctane for 18 hrs, phospholipid composition did not change, but solution color went to yellowish brown. The main coloring substances were separated by silica gel column chromatography and were found to be negative to Dittmer-Lester’s reagent. These substances were mixed polyene compounds possessing a small amount of carbonyl compounds. No exact determination was made of their structures. These substances were also found present in pre-heated soybean lecithin and their amounts increase on heating. The coloring of soybean lecithin on heating under 100°C is thus not due to decomposition of phospholipids, but the presence of polyene substances. On heating with octane for 9 hrs, the phospholipids decomposed but each at a different rate with residual amounts as follows : phosphatidylcholine (PC), 98% ; phosphatidylinositol (PI), 80% ; phosphatidic acid (PA), 65% ; phosphatidylethanolamine (PE), 0%. By heating with decane, PI, PA, and PE decomposed within 1 hr, while PC did so slowly, with 3.5% remaining at 9 hrs. With octane solution color quickly became deep brown. In the isolation of these browning substances, attention was directed to substances having absorption maxima at 350 nm. On heating soybean lecithin, substances having absorption maxima at 240 nm and 280 nm have previously been noted but not those with absorption maxima at 350 nm. The separation and purification of these new products will appear in a future paper.
Sterols in the fruit of Kochia scoparia (L.) Schrad. have been investigated. Based on both direct GC-MS comparison with authentic samples and mass spectral data, two 4,4-dimethylsterols, nine 4-monomethylsterols and nine 4-desmethylsterols were detected for the first time in the fruit, along with three terpene alcohols, and the amount of each was computed. The fruit was found to be unique in sterol composition, because it contained not only cholesterol and its several possible biosynthetic precursor sterols, but also some Δ7-sterols such as 24-ethyllathosterol as a major group. The amounts of nine 4-desmethylsterols in the fruit were also determined by GC.
Gangliosides participate in cellular interactions and signal transductions. An initial step in those processes is glycolipid interaction. We observed the conformational change of ganglioside GM1 (GM1) at the membrane surface by means of atomic force microscopy (AFM), and revealed the following changes of GM1 with increasing surface pressure : a uniform pattern at 29 mN/m, a swelling pattern at 33 mN/m, and a return to a uniform pattern at 40 mN/m. This behavior is thought to be related to specific cell recognition or signal transduction, and may prove useful for elucidating the functions of glycolipid microdomains in biological membranes.