The aqueous properties of an anionic gemini surfactant, (CH2)2[NCO(C11H23)C2H4CO2Na]2, 212, and 212/sodium dodecanoate(soap) mixtures, were studied in the presence of solubilizate of Orange OT, 1-(o-tolylazo)-2-naphthol. The following parameters were measured:critical micelle concentration(cmc), micelle composition, and solubilization capacity for Orange OT. For the sake of comparison, the properties of SDSa (SDSa=sodium N-dodecanoylsarcosinate, the monomer corresponding to the 212), and mixtures of SDSa/soap, were also investigated. The cmc value of 212 in the solubilizing system obtained, 1.0mM, approximately corresponds to the second cmc value, 1.6mM, obtained in the non-solubilizing system. This second cmc value is much higher than the first cmc value, 0.04mM, determined by the surface tension method. Whereas, the cmc value of SDSa in the solubilizing system is 10.0mM, and close to that, 10.2mM, determined by the surface tension method in the nonsolubilizing system. The solubilization capacity of 212 for Orange OT is 3.0 times that of SDSa. The micelle compositions of the mixtures of 212/soap and SDSa/soap are 2:1 and 1:1, respectively. The solubilization capacity of the 212/soap mixture is 1.8 times that of the SDSa/soap mixture in the region of lower soap molar ratio. The mixed cmc values, 1.9-5mM, of 212/soap mixture in the solubilizing system are markedly lower than those, 12-16mM, in the non-solubilizing system. These behaviors of 212 may reflect the greater tendency of 212 to release Na+ into the bulk phase, permitting larger solubilized amount of Orange OT.
Effect of additives (inorganic salts and polyols) on the cloud point of water-polyglycerol didodecanoate ((C11)2Gn) system was investigated as a function of the weight fraction of polyglycerol chain in whole surfactant, WH/WS, which is directly related to Griffin’s HLB number (=20×WH/WS). The average number of dodecanoic acid residues attached to polyglycerol, m, is in the range of 1.6-2.3. Unlike an ordinary commercial polyglycerol surfactant, the surfactants used in this study contain a very small amount of unreacted polyglycerol. Compared with poly(oxyethylene)-type nonionic surfactant aqueous solutions, NaCl and Na2SO4 largely decrease the cloud point, whereas NaSCN and 1,3-butanediol abruptly increase it with increasing the salt concentration at a fixed WH/WS. However, in the absence of additive, the cloud point drastically increases with a small increase in the hydrophilic chain length or WH/WS. It means that the solubility of polyglycerol surfactant in water is not largely influenced by temperature but is highly dependent on WH/WS. The apparent large effect of additive on the cloud point is mainly attributed to the temperature-insensitiveness of the phase behavior of (C11)2Gn. Single-phase or three-phase microemulsions are formed at the water/oil ratio=1 in water/(C11)2Gn/hydrocarbon(heptane, decane, hexadecane, and m-xylene) systems. As well as the cloud point, the three-phase temperature or HLB temperature is abruptly increased with a small increase in WH/WS. However, both WH/WS for the HLB temperatures are coincident around 25°C, since the hydrophilicity of polyglycerol chain per weight is almost similar to that of poly (oxyethylene) chain at room temperature.
The effcts of deamidation of fragmentation on the antioxidative activity of α-zein were investigated individually. Heat treatment at 70°C in 70% ethanol-0.05M HCl caused deamidation of α-zein without fragmentation. Antioxidative activity of α-zein was improved by this deamidation. α-Zein with deamidation treatment for 12 hours protected 80% of docosahexaenoic acid ethyl ester from autoxidation until 7 days. Model peptide of α-zein had a lower antioxidative activity than α-zein. Fragmentation by N-btromosuccinimide decreased the antioxidative activity of α-zein.
It has been shown that a wide variety of antioxidants inhibits macrophage scavenger and polylactosamine receptor activities. The activity of macrophage scavenger receptors to take up oxidized low density liporprotein is also inhibited by protein kinase inhibitors but enhanced by protein phosphatase inhibitors. We studied whether the antioxidants including lipid-soluble phenolic, water-soluble phenolic, glutathione-related and ascorbic acid-related antioxidants were effective to inhibit protein phosphorylation of macrophages. Lower than 100 μM of α-tocopherol, probucol, propyl gallate, nordihydroguaiaretic acid, curcumin, quercetin and Trolox inhibited total protein phosphorylation of thioglycollate-induced mouse macrophages as assessed by H332PO4 incorporation. Lower than 1 mM of α-tocopherol, probucol, butylated hydroxytoluene, curcumin, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, glutathione, glutathione isopropyl ester, N-acetylcysteine, ascorbic acid, erythorbic acid and dehydroascorbic acid inhibited protein tyrosine phosphorylation of macrophages in the presence of vanadate, a protein tyrosine phosphatase inhibitor, as assessed by Western-blot analysis using anti-phosphotyrosine IgG monoclonal antibody. Most of the antioxidants inhibited protein tyrosine phosphorylation of epidermal growth factor (EGF) receptor of A431 cells in a cell-free system. Oxidative satus of macrophages examined by using dihydrorhodamine 123, and all the catechins reduced their oxidative status. Above results suggest that oxidative stress in macrophages maintain or enhance protein phosphorylation, and that antioxidants reduce protein phosphorylation and the receptor activities by reducing oxidative status.
We have reported that high exogenous vitamin E (0.1-1 mM) inhibits thioglycollate-induced mouse peritoneal macrophages from binding and uptake of oxidized low density lipoprotein (oxLDL). However, in the present study, we found the amount of oxLDL bound to mouse macrophages increased with increasing levels of endogenous vitamin E in macrophages. Different vitamin E levels in macrophages were obtained by feeding mice with vitamin E deficient-, adequate- or rich-diet for 3 weeks;0.02, 0.12 and 0.14 μg/mg protein, respectively. Exogenous vitamin E dose-dependently (up to 1 μM) increased the amount of oxLDL bound to macrophages from mice fed vitamin E adequate-diet and the numbers of lipid droplet positive macrophages. An increase of oxLDL binding with increasing of exogenous vitamin E was also observed in macrophages from mice fed vitamin E deficient-diet. Above results suggest that vitamin E at physiological levels enhances macrophages to bind and incorporate oxLDL.
Modified glycerophospholipids with expected novel physiological functions were prepared by introducing different acyl groups into soybean phospholipids. The method was based on the enzymatic transesterification of phospholipids with monoacylglycerol (MG) or diacylglycerol (DG). The transacylation ratios reached 46-59% and nearly quantitative recovery of phospholipids was obtained in the case of transacylation of phospholipids with MGs having C12 to C18 saturated and monounsaturated acyl groups. With C18:2-MG or C18:3-MG, however, transacylation ratios were less than ca. 20% MGs with C4 to C8 saturated acyl groups also gave very low transacylation ratios, but the ratios were moderately improved by using DGs with C6 and C8 acyl groups. It is considered from a series of the results that higher transacylated phospholipids might be obtained y repeating transacylations owing to be able to recover the phospholipids quantitatively after the reaction because MG with longer acyl groups than C10 or DG with C8 acyl groups acted as acyl donors and replacement for essential water, to suppress the simultaneous hydrolysis, in an enzymatic reaction.
A new compound, egonol β-primeveroside (EGX) was isolated from immature seeds of Styrax obassia Sieb. et Zucc., along with three known egonol glycosides and its structure was determined as 3''-O-[6-O-(β-D-xylopyranosyl)-β-D-glucopyranosyl]egonol based on spectroscopic and chemical findings. The major glycoside EGX changed to egonol β-gentiobioside (EG2) in the maturing season of seeds.
A series of symmetrical and unsymmetrical 1,4,5,8-naphthalenetetracarboxydiimide (NDIM) derivatives were characterized by UV-visible and fluorescence spectral analyses in order to understand the relationships between their structures and physical properties. The UV-visible spectral analyses showed the intermolecular interactions on phenyl group of 3,3-diphenylpropyl derivatives, and the fluorescence spectra suggested the weak intermolecular interactions for 2,5-di-tert-butylphenyl derivatives. These results revealed that 3,5-di-tert-butylphenyl group is one of the best substituents for disturbing the intermolecular interaction. The redox potentials of reduction for NDIM derivatives were slightly shifted to the negative region by the introduction of electron-donating substituents.
Four esters of docosahexaenoic acid, methyl (DHA-ME), ethyl (DHA-EE), propyl (DHA-PE) and isopropyl docosahexaenoate (DHA-IE), were synthesized and autoxidized at 25°C to determine how the ester structure provides stability to highly unsaturated fatty acid (HUFA) against oxidation. Stability was assessed based on oxygen absorption during autoxidation. Monohydroperoxide (MHPO) isomers were examined by high-performance liquid chromatography (HPLC). DHA-ME was found to undergo oxidation most rapidly, whereas DHA-IE was most stable toward this process. Induction period of DHA esters was longer with greater alcohol chain length. HPLC demonstrated the presence of ten MHPO positional isomers (4-,7-,8-,10-,11-,13-,14-,16-,17-and 20-MHPO) during autoxidation of the DHA esters. 20-MHPO was the main constituent of any one of these isomers, constituting 20% of total MHPO regardless of the DHA esters. Peroxide had virtually no effect on MHPO isomer compostion. 4-MHPO was produced in the least amount from autoxidized DHA-ME (8%), though more so from autoxidized DHA-IE (17%). More 4-MHPO was obtained from total MHPO with increase in alcohol chain length. MHPO produced from during autoxidation of DHA-EE, DHA-PE and DHA-IE was stable, during its incubation at 25°C, whereas only 4-MHPO of DHA-ME was unstable. Ester structure is thus shown to provide stability toward oxidation and products obtained from the oxidation of DHA.