Rosemary extract was added to tuna orbital oil (fish oil) to restrain oxidation, and both the peroxide value (PV) and the fatty acid composition of the fish oil were determined under autoxidation conditions. The oxidative stability of fish oil added with rosemary at levels of 0.02% or 1.0% of rosemary extract (w/w) was more effective compared to the original fish oil under autoxidation for 8 days at 20°C, which thus demonstrated the antioxidative ability of rosemary. Further, rosemary extract was added to the diet of rats and the influence of the oxidized fish oil on the liver lipids and fatty acid was examined. The lipid content and PV of the liver lipid of rats administered oxidized fish oil and rosemary did not show much difference among experimental groups. The changes in the fatty acid composition in rat liver lipid were considered to reflect the metabolism of unsaturated fatty acids in vivo.
Two novel phosphonoglycolipids, named PnGC1 and PnGC2 were isolated from the marine crab, Erimacrus isenbeckii by successive column chromatography on ion exchange Sephadex (DEAE- and QAE-Sephadex) and silicic acid (Iatrobeads). Their chemical structures were characterized as phosphonocerebrosides, 4’-O-(2-aminoethylphosphonyl) Glcpβ1-1 ceramide for PnGC1 and 4’-O-(N-methyl-2-aminoethylphosphonyl) Glcpβ1-1 ceramide for PnGC2 by IR, MALDI-TOF MS, 1H-NMR, GC and GC-MS analyses of the water-soluble products after acid hydrolysis, and methylation of the product of hydrogen fluoride degradation. In both phosphonocerebrosides, the ceramide moieties were composed of tetradeca-4-sphingenine as the sole sphingoid, and stearic, arachidic, behenic and docosamonoenoic acids as the major fatty acids.
Determination was made of α-and γ-tocopherol, vitamin K1 and 2',3'-dihydrovitamin K1 in vegetable oil during the course of hydrogenation under various conditions. Iodine value(IV) was found to decrease from 80 to 60 with hydrogenation, with consequently considerable reduction in vitamin K1. At IV 50 or less, vitamin K1was virtually essentially absent (0.1 mg/kg or less). 2',3'-dihydrovitamin K1 increased with decrease in vitamin K1. 2',3'-dihydrovitamin K1 peaked at 2.9 mg/kg at IV 50, and then decreased. α-and γ-Tocopherol content remained basically the same under all conditions. Subsequent to oil hydrogenation and then deodorization at 260°C for 120 minutes, α-tocopherol showed the highest residual ratio (80%) of all the vitamins, followed by 2',3'-dihydrovitamin K1 (66%) and vitamin K1 (60%).
Two types of sesamol oligomers, ortho methylene-bridged and direct-linked oligomers, were prepared and their antioxidant effects on the autoxidation of lard and tetralin were evaluated. The methylene-bridged oligomers were prepared by the reaction of sesamol, a major antioxidative compound in sesame seed, with ethylmagnesium bromide and subsequent oligomerization with paraformaldehyde. During the reaction, methylidenedioxy moieties of the sesamol oligomers were partially cleaved and the addition of hydroxyl groups was observed. The methylene-bridged oligomers had much stronger antioxidant effects on the autoxidation of lard than the sesamol monomer. And the oligomers, having a larger average number of hydroxyl groups per sesamol unit, were a more efficient antioxidant for lard. Direct-linked oligomers were synthesized by an oxidative coupling of sesamol by hydrogen peroxide using horseradish peroxidase as a catalyst. Molecular structures of the direct-linked oligomers were influenced by the pH of the buffer solution in which the oxidations were carried out. Oligomers having a larger number of hydroxyl groups were prepared under more acidic conditions. The direct-linked oligomers prepared in acidic conditions were better antioxidants of lard than the sesamol, whereas oligomers prepared under neutral and alkaline conditions did not improve the antioxidant effect. Both methylene-bridged and direct-linked oligomers inhibited the autoxidation of tetralin; but, in contrast to the lard results, almost all of the oligomers were less effective antioxidants for tetralin than the sesamol monomer.
The apparent molar volume and the apparent molar adiabatic compression of aqueous solutions of n-alkylammonium bromide (CnH2n+1NH3Br; n=1-8, 10) and n-alkyltrimethylammonium bromide (CnH2n+1N(CH3)3Br; n=1, 8, 10) were measured using a vibration-tube density meter and a sing-around ultrasound velocity meter at 5°C, and the partial molar volume and the partial molar adiabatic compression at infinite dilution (φV0 and φK0) were evaluated. It was confirmed that φK0 linearly decreased with increasing alkyl chain length while φV0 linearly increased. Differences of φK0 between CnH2n+1NH3Br and CnH2n+1N(CH3)3Br with the same alkyl chain were negligibly small, which was in good agreement with the fact that the successive N-methylation of ammonium cation had only a little effect on compression. These results could be interpreted in terms of the compensation between the increase of hydrophobic hydration and the decrease of electrostriction of water around the ammonium group, leading the net compression being almost constant. When the amphiphiles with an octyl or a decyl group form micelles above their critical micelle concentration, on the contrary, the adiabatic compression of CnH2n+1NH3Br was distinctly larger than that of CnH2n+1N(CH3)3Br. The reason for the difference in compression of these micelles was discussed concerning the counter ion binding and the aggregation number.
A-B-type silicone copolymer (or surfactant), Me3SiO(Me2SiO)12-Me2SiCH2CH2CH2-O-(CH2CH2O)33.1H(Si14C3EO33.1), forms lamellar liquid crystal (Lα) in a pure state. In a binary water-Si14C3EO33.1 system, the Lα phase coexists with excess water in a dilute region, whereas the Lα phase changes to an isotropic solution (Wm) by replacing water with ethylene glycol. Although water enhances the segregation between hydrophilic and lipophilic chains of copolymer, it does not change the layer curvature of long lipophilic-chain copolymer to be positive. Since ethylene glycol is more soluble in the hydrophilic chain than water, it changes the curvature from zero to positive, where positive curvature means the copolymer-layer curvature is convex toward water or polar solvent. When ethylene glycol is replaced with PEG 300 (polyethylene glycol, Mn ca=300), the Lα-H1(normal hexagonal phase)-Wm transition takes place. With the further increase in the molecular weight of PEG, the Lα phase coexists with an excess PEG as well as the water-copolymer system and the solubilization of PEG in the Lα phase decreases. This change in the phase behavior may be attributed to the solubilization part of PEG in the hydrophilic chain of the silicone copolymer. On the other hand, non-polar solvent, octamethylcyclotetrasiloxane, D4, is soluble in the lipophilic chain, and the Lα phase changes to a reverse micellar solution (Om) via reverse hexagonal (H2) phase. With the increase in the molecular weight of oil, the Lα phase retreats to the concentrated region and the solubilization of oil (poly(dimethylsiloxane)) in the Lα phase becomes very low. As a result, PEG and silicone oil change the surfactant (or copolymer) layer curvature in the opposite way, but, the swelling of high-molecular-weight solvents or homopolymers in the Lα phase is very restricted. In ternary water/ Si14C3EO33.1/D4, ethylene glycol/ Si14C3EO33.1/D4, and PEG/Si14C3EO33.1/poly (dimethylsiloxane) systems, isotropic microemulsions are formed at an equal polar/non-polar solvent ratio. The relationship between microemulsions with water and oil or with hydrophilic and lipophilic homopolymers is also discussed.
In order to determine the characteristics of a mixed system of an anionic gemini surfactant with N, N-dialkylamide and carboxylate groups and a conventional anionic surfactant, aqueous solutions of (CH2)2[NCO(C11H23)C2H4CO2Na]2 (212)/sodium dodecanoate (soap) mixture were studied. The following parameters were measured: critical micelle concentration (cmc), micelle composition, surface tension, foaming power, degree of micelle ionization, and pH values. For the sake of comparison, mixtures of SDSa/soap (SDSa=sodium N-dodecanoylsarcosinate, the corresponding monomer of 212) were also investigated. The cmc values of the SDSa/soap mixture monotonously increase with increasing molar fraction of soap at 30°C. In contrast, the cmc values of the 212/soap mixture are intermediate between those for the pure surfactants over a broad region at 30°C. The composition of 212/soap mixture in micelles is kept at a 2:1 molar ratio in the plateau region. With increase in temperature of 212/soap mixture, cmc values reach a maximum at a soap molar fraction of 0.6. This is obvious at 50°C. The surface tension of 212/soap mixture is minimal at a soap molar fraction of 0.6 at 30°C, at which the surface tension is the lowest among those of the pure surfactants. The foaming power of the 212/soap mixture is maximal at the soap molar fraction of 0.6, at which the foaming power is the largest among those of the pure surfactants. Greater degree of micelle ionization for 212/soap mixture than for SDSa/soap mixture was observed over a broad region. The reason for this is the larger proton uptake by the carboxylate group of 212 than that of SDSa, which releases Na+ into the bulk phase in the mixed micellization process. The evidence for this is the larger increase in pH in the mixed cmc solutions for 212/soap mixture than for SDSa/soap mixture. The unexpected synergistic interaction between 212 and soap molecules is due to stronger reduction of the mutual repulsion between the anionic head groups in the 212 molecule in the presence of a soap molecule.
The aggregation behavior of molecular assemblies formed between oppositely charged surfactants in water was investigated through measurements of the electrochemical behavior of the cationic component, 11-ferrocenylundecyltrimethylammonium bromide (FTMA), in mixtures with the anionic component, sodium dodecylbenzenesulfonate (SDBS). FTMA/SDBS mixture was found to form various types of molecular assemblies such as micelles and vesicles in aqueous solutions depending on the mixing ratio. Cyclic voltammogram on FTMA in the molecular assemblies showed that the peak of oxidation current due to FTMA/SDBS complexes consisting of vesicles is observed on the anodic side of that due to FTMA moleculs consisting of mixed micelles. Moreover, electrochemical measurements on the total surfactant concentration dependence of the phase behavior in solutions of 1:0.4 molar ratio of FTMA and SDBS revealed that vesicles begin to form at a concentration (critical aggregation concentration; cac) much lower than the critical micelle concentration (cmc) of FTMA alone and a phase containing both vesicles and micelles appears at a concentration higher than the cmc.
We examined whether brewer’s yeast cell wall (BYC) is able to reduce serum lipid levels in rats fed a high cholesterol and fat (HCF) diet. Male Sprague-Dawley rats were fed a standard diet, an HCF diet or an HCF diet containing 2.5% or 5.0% BYC for 14days. The addition of 5.0% BYC to the HCF diet significantly reduced the increment of serum total cholesterol levels. On the basis of the results obtained, BYC may be utilized as a cholesterol-lowering foodstuff.
Phospholipid liposomes were prepared using deep sea water and the liposomes obtained were used to solubilize oil-soluble medicines. In addition, the dispersion stability of the liposomes was examined. Deep sea water treated with reverse osmosis membrane (RO water) gave liposomes, whereas 100% deep sea water failed to yield liposmes. Soybean lecithin liposomes solubilizing oil-soluble medicine dispersed in RO water was more stable than those dispersed in distilled water. The time needed for the liposome-medicine system to attain solubilization equilibrium was shorter in RO water than in distilled water. Moreover, a better stability was suggested for easily oxidizable vitamin A when it was solubilized in liposomes dispersed in RO water.