The essential oils from aerial parts of Elatostema laetevirens and Elatostema umbellatum var. majus were investigated by capillary GC and GC-MS. The important aroma-active compounds were also detected in the oil using GC-MS/O and aroma extraction dilution analysis (AEDA). As a result, 79 compounds of E. laetevirens and 80 compounds of E. umbellatum var. majus, accounting for 95.41% and 98.37%, were identified, respectively. The major components of E. laetevirens oil were phytol (667.4 μg/100 g fresh samples), neophytadiene (335.2 μg) and γ-himachalene (49.8 μg). On the other hand, E. umbellatum var. majus oil contained phytol (402.3 μg), linoleic acid (289.4 μg) and palmitic acid (241.4 μg) as the major components. GC-MS/O and AEDA showed that (2E)-hexenal and (2E, 4E)-nonadienal were most aroma compounds of E. laetevirens oil. It seems that these components make the green-floral odor. On the other hands, it seems that (2E)-hexenal, (3Z)-hexenol and 1-octen-3-ol make the green-oily odor of E. umbellatum var. majus oil.
The effect of linoleic acid-menthyl ester (LAME) on lipid metabolism were assessed in HepG2 cells. It is well known that high level of apolipoprotein (apo) B100 in the serum is risk for atherosclerosis. Although linoleic acid (LA) treatment and LA plus L-mentol treatment increased apo B100 secretion, LAME treatment significantly decreased apo B100 secretion in HepG2 cells compared with control medium. The hypolipidemic effect of LAME was attributable to the suppression of triglyceride synthesis in HepG2 cells. It is also known that the risk of coronary heart disease is negatively related to the concentration of serum apo A-1. In the present study, LAME treatment increased apo A-1 secretion as compared with LA treatment in HepG2 cells. These results suggest that mentyl-esterification of fatty acids may be beneficial in anti-atherogenic dietary therapy.
The partition coefficients of 1-alkanols between water and didodecyldimethylammonium bromide (DDAB) vesicle membrane, and the change of the degree of counter-ion dissociation on DDAB vesicle caused by the solubilization of 1-alkanols were determined from electric conductivity measurements. A good linear relationship was obtained between logarithmic value of the partition coefficient and carbon number of alkyl chain in 1-alkanols. The standard transfer free energy change per methylene group was evaluated from the slope of this straight line. On the other hand, the effect of 1-alkanols on the degree of counter-ion dissociation was independent of carbon number of 1-alkanols. Comparing the results of the present system with those of sodium dodecylsulfate (SDS) micelle/1-alkanol system, it was found that the interior of DDAB vesicle membrane is more hydrophobic than that of SDS micelles. Furthermore, the increase in counter-ion dissociation caused by solubilized 1-alkanols was much lesser for DDAB vesicles than SDS micelles.
The protonation behavior and the stability of micelles of N-lauroylaminopropyl-N’,N’- dimethylamine oxide (C12AmCn; n=3) were studied by the hydrogen ion titration and the equilibrium surface tension measurement. The surface potential of C12AmC3 micelles estimated from the results of hydrogen ion titration was lower than that of dodecyldimethylamine oxide micelles at added NaCl concentration, CS, of 0.1M. The critical micelle concentration (cmc) estimated from surface tension measurements revealed that a reversal of the stability of the cationic and the nonionic micelles of C12AmC3 takes place in the range of CS higher than about 0.2M, that is, the cationic micelles become more stable than the nonionic ones in the range CS ≥ 0.2M. In addition, the surface tension measurements were carried out for C12AmCn with different spacer length, n, ranging from 2 to 6 methylene units at CS = 0.1M. The cmc values of nonionic species were kept at almost constant for n ≤ 4, while they decreased with n for n ≥ 4. The cmc values of cationic species also tended to decrease with n for n ≥ 4. These results were compared with those obtained for alkyldimethylamine oxides, and the effect of amide group and spacer groups introduced into amine oxide surfactants was discussed.
Phase behavior in a water/lysophospholipid system was investigated. A hydrated solid phase is observed at low temperature. Above the melting temperature of the hydrated solid a micellar phase at low surfactant concentration and a liquid crystalline phase at high surfactant concentration were observed. Similarly to poly(oxyethylene)-type nonionic surfactant systems, clouding behavior takes place at high temprature. The concentration of micelle-liquid crystal transition shifts to higher surfactant concentration in acidic or basic condition, but polyhydric alcohol addition does not affect very much on this transition point. The effect of added inorganic salts on the phase behavior was also studied, and the change in melting temperature of the hydrated solid and the cloud point shows a trend of the order of Hofmeister series. At room temperature a solid phase and an aqueous phase are equilibrated and one can obtain rather stable froth by shaking the sample that may be stabilized by the adsorption of solid dispersions on the air-water interface. The effect of inorganic salts on the froth stability in the water/lysophospholipid system was studied. The inorganic salts with salting-out effect improved froth stability.
TiO2 and TiO2/MoO3 particulate films were successfully prepared using a Langmuir-Blodgett technique. The as-deposited films were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and electron probe microanalysis (EPMA). The results indicate that the TiO2 and TiO2/MoO3 films are composed of separate layers of TiO2 and MoO3 particles. Furthermore, the photocatalytic activity of the films was evaluated from the decomposition of a stearic acid film under ultraviolet and visible light irradiation. It was found that photocatalytic activity is significantly enhanced by the layer structure of the TiO2/MoO3 film, compared to the single layer TiO2 film.
Persimmon peels (Diospyros kaki THUNB.) are discarded during the production of dried fruit. The 2-methoxy-4-vinylphenol (8) which is component of persimmon peel had high antioxidant activity on the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay and SOD (superoxide dismutase) assay. And (8) had higher tyrosinase inhibiting activity than that of arbutin using both L-tyrosine and L-DOPA as substrates. In addition, tyrosinase inhibiting activity of synthesized 2-methoxy-4-vinylphenol glycoside (8a) was studied. (8a) had tyrosinase inhibiting activity, suggesting that (8a) has possibilities for ingredient of cosmetics that are possessed of whitening effect.