An initial stage of infection mechanism of plant virus was explained from physicochemical point of view using model lipid membrane such as monolayer and/or liposome. Thus, the differences of self-assemble processes, secondary structures, penetration modes of plant virus coat proteins such as strong virus (tobacco mosaic virus, TMV) and its mutant, sensitive virus (cucumber green mottle mosaic virus, CGMMV) to lipid membrane were discussed. It was suggested that TMV protein having hydrophobic sites penetrated more to hydrophobic domains of lipid membrane. When we used the lipid membrane including a specific binding substance to TMV extracted from plasma membrane, TMV protein penetrated much more to membrane, but its structural change was small. The antiviral activity of polysaccharides on infectivity of virus was caused by blocking the decapsulation process of virus coat protein which occurs on the cell membrane in the initial stage of virus infection. These results suggest that it is possible to search a new and strong antiviral reagents from the biophysical-chemical view point.

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Z-Phenylalanine and Z-methionine ρ-nitrophenyl esters were hydrolyzed using a glycolipid hydrolase model at various pH. The glycolipid showed pH-dependence of hydrolyzing ability, as also noted for α-chymotrypsin, the profile being a mountain shaped curve peaking at pH 8, regardless of the presence or absence of a reaction field of phosphatidylcholine. The substrate-recognition ability of the glycolipid exhibits the reverse tendency to pH-dependence of the hydrolyzing ability. These findings are explained by increase in active species and decrease in vesicle membrane stability with pH.

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A highly sensitive method for the determination of phosphatidylcholine (PC) molecular species was established. PCs from soybean, mackerel (Scomber japonicus) muscle, saury (Cololabis saira) muscle and salmon (Oncorhynchus keta) roes were hydrolyzed with phospholipase C and the diacylglycerols thus obtained were converted to 2-anthrylurethanes, which were then subjected to reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection and on-line electrospray ionization mass spectrometry (ESI/MS). PC anthrylurethanes were found to be clearly separated into molecular species at the femtomole level by fluorescence examination. Positive ESI/MS of the derivatives gave prominent pseudomolecular [M+Na] ⁺ ions, by which individual molecular species could be identified.

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Base-catalyzed degradation (isomerization) of prostaglandin A2 (PGA2) to prostaglandin B2 (PGB2) was measured at pH 12 and 60°C, and the effect of micellization of PGA2 on the degradation was investigated. The rate of degradation was determined by measuring the rate of appearance of PGB2 with a spectrophotometer. The apparent rate constant, kapp, for degradation of free PGA2 was approximately constant below the critical micelle concentration (cmc), while kapp was decreased by the micellizatton of PGA2. This is considered to be due to the electrostatic repulsion between OH- and negatively charged PGA2 micelles. The value of kapp of PGA2 above the cmc was slightly increased by the addition of sodium chloride as an electrolyte. The apparent rate, μ, for degradation of PGA2 above the cmc could be explained in terms of the sum of two degradation rates, μf and μm, in the bulk and micellar phases, respectively : the increase in μ by the addition of NaCl was due to the decrease in μf and the increase in μm. For PGA2-nonionic surfactant mixed micellar systems, kapp was decreased as the mole fraction of PGA2 increased. These phenomena could be explained by the micellar surface potential in conformity with the Gouy-Chapman theory.

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The authors have synthesized the amphiphilic polymer, poly [2-methacryloyloxyethyl phosphorylcholine (MPC) -co-butylmethacrylate (BMA)], and its unique properties were clarified in comparison with commercial moisturizing agents. In skin care studies, measurement of water holding capacity showed 0.2wt% of the poly (MPC-co-BMA) to hold water equally or more than sodium hyaluronate. Using poly (MPC-co-BMA) lotion, 1.0wt% of the poly (MPC-co-BMA) prevented trans epidermal water loss for at least 7 days. Increase in visco-elasticity using 1.0wt% of the poly (MPC-co-BMA) was the same as that by sodium hyaluronate, and equall or greater than that of glycerol. Stratum corneum cells were significantly removed from elbow by tape stripping before treatment, in contrast to 1.0wt% poly (MPC-co-BMA) containing cream for 14 days. Poly (MPC-co-BMA) showed decreased surface electric resistance on using 1.0wt% of poly (MPC-co-BMA). Treatment of hair with poly (MPC-co-BMA) made it smooth and increased its strength and water content. This compound protects hair and skin from damage, rather than having curing effect.

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A surfactant is considered efficient when it possesses strong hydrophobicity (saturation concentration of singly dispersed solute in water is small) and also strong lipophobicity (saturation concentration of singly dispersed solute in hydrocarbon is small). Hydrophobicity is strongly dependent on alkyl chain length of the surfactant, while lipophobicity is mainly related to the length and type of hydrophile group. Lipophobicity, i.e., decrease in saturation concentration of singly dispersed solute in hydrocarbons in equilibrium with water phase, is an important property of amphiphiles. The method for measuring lipophobicity should be modified according to solution behavior of surfactant with particular attention to sample concentration when lipophobicity is quite high.
The characteristic properties of nonionic surfactants with hydroxyl groups as the hydrophilic moiety including alkyl glyceryl ethers and alkyl monoglycerides were studied and compared with those of nonionic surfactants having oxyethylene groups. The lipophobicity after introducing an oligo (oxyethylene) group into nonionic surfactants was found to increase by 2.5 times that of an oxyethylene group, or the secondary hydroxyl group, -CH (OH) -, and 4.6 times that of an oxyethylene group. Subsequent to transition from -O- (ether) to -COO- (ester), lipophobicity increased to 5 times as much. The lipophobicity of hexa (oxyethylene) dodecyl ether and monoglyceryl α-dodecyl ether were noted to be essentially the same; the former was water-soluble and the latter, oil-soluble at 25°C. Nonionic surfactants with hydroxyl groups thus not only have strong lipophobicity but are oil-soluble.
Highly lipophobic surfactants should thus be quite effective in a hydrocarbon-rich system or one with aromatic hydrocarbons. Glycolipids or polyglycerol nonionic amphiphiles should prove useful as solubilizers, emulsifiers and detergents owing to their high lipophobicity and insensitivity to temperature.

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Analysis was made of lipid classes and fatty acid compositions in four species of caprellid amphipods (Crustacea) from Otsuchi and Mutsu Bays in northern Japan. Total lipid content ranged from 1.42.3% wet weight with triacylglycerol (TG) and phosphatidylcholine (PC) as the lipids most abundantly present. Major fatty acid compositions of total lipids (TL) were in most cases 16 : 0, 18 : 1 (n-9), 20 : 5 (n-3), and 22 : 6 (n-3), constituting 4763% the whole. The amount of 20 : 5 (n-3), the most predominant polyunsaturated fatty acid, in TL was remarkably higher in the cool than warm temperature species (2932% in the former and 2122% in the latter). Differences in TL fatty acid compositions for the two groups were shown to arise from PC in the principal membranes, whereas fatty acid compositions of TG from either group were essentially the same.

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New fluoroalkylated end-capped oligomers containing hydroxy and dihydroxy segments were prepared by reactions of N- (2-hydroxypropyl) methacrylamide (HPMA) and N, N- (2, 2-dihydroxyethyl) acrylamide (DHEAA) with fluoroalkanoyl peroxides as key intermediates, respectively. Perfluorooxaalkylated end-capped HPMA oligomers thus obtained were soluble in organic polar solvents such as methanol, ethanol and tetrahydrofuran. Perfluoro-1-methyl-2-oxapentylated HPMA oligomer became slightly soluble in water as well as these organic polar solvents and GPC analysis of the HPMA oligomer indicated molecular aggregates to possibly form in water. Fluoroalkylated end-capped DHEAA oligomers were readily soluble not only in water but polar solvents such as methanol and ethanol. The fluorinated DHEAA oligomers were capable of reducing the surface tension of water effectively with a clear breakpoint resembling the critical micelle concentration and had an extremely high calcium ion binding power compared to traditional polymeric chelating agents [poly (acrylic acid)] and the corresponding nonfluorinated oligomer.

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After N-chlorobenzanilide (1) was had stood in ether solution containing iron (III) chloride-hydrogen chloride complex (FeCl3-HCl) at room temperature, 2-chloro and 4-chlorobenzanilides were obtained as the rearrangement products. Remarkable differences in reaction rates and product distribution were noted for the Orton rearrangenment of 4'-methylbenzanilide (2), 4', N-dichlorobenzanilide (3) and 4'-nitrobenzanilide (4) using FeCl3-HCl. The order of the reaction rates was as follows; 4>2>1>3, the yields of rearrangement products; 2>1>3>4, and yields of dechloronated products; 4>3>2=1=0. Reaction of 1 with iron (III) bromide-hydrogen bromide complex (FeBr3-HCl) gave 4-bromobenzanilide as the sole product. The Orton rearrangement of 1 apparently proceeds via an intermolecular pathway in para-position, while ortho-chlorination of 1 may occure via both inter- and intramolecular pathways.

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