Recommended intake of essential nutrient is usually estimated from the minimum requirement of the nutrient with margin of safety. However, the daily fat intake is usually over the requirement of essential fatty acids, and the over intake of fat is associated with coronary heart diseases. Recommended Daily Allowance of the Department of Health and Welfare in Japan indicates 2530 energy percent of fat intake for the children and youth and 2025 energy percent for the adult would be appropriate. Balance of intake of saturated fat, monounsaturated fat and polyunsaturated fat is important together with the balance of n-6 and n-3 fatty acids. Present status of fat intake in Japan is discussed based on the recent data of fatty acid composition table of Japanese foods, from the nutritional viewpoint.
The effects of marine and terrestrial humic substances on the K+-permeability of lipid bilayer of dimyristoyl phosphatidylcholine (DMPC) liposomes were investigated for their physiological activity on biological membranes. Commercial humic acid and humic and fulvic acids extracted from soil and marine sediment were used for the experiment. Potassium ions inside liposomes were released through the DMPC bilayer following the addition of humic acid. The effect of humic acid was conspicuous above the phase transition temperature of DMPC. Humic acids containing many carboxyl groups but few phenolic and alcoholic hydroxyl groups had little effect on the K+-permeability of the bilayer. From the relation between the K+-permeability and the degree of humification determined by optical spectroscopy, humic acids humified to a lesser extent were found to interact strongly with liposomes. The K+-permeability enhancing effect was stronger in the case of highly aliphatic marine humic acids than highly aromatic terrestrial acids. Hydrophilic fulvic acid exerted virtually no effect on K+-permeability. The hydrophobic chain of the acid would thus appear to be incorporated into the hydrophobic core of lipid bilayer, enhancing the fluidity of the lipid. The lower molecular weight fractions of marine humic acids promoted K+-release more than the original humic acids. The commercial humic acids with smaller molecular size affected strongly K+-permeability compared to marine humic acids having essentially the same humification and functional group content. This molecular size effect indicates the rates of adsorption of humic acid molecules onto and their incorporation into the lipid bilayer to possibly contribute to interactions with liposomes.
2-Alkyl 3-or 4-methyl furans and 2-alkylfurans, naturally occuring compounds, were synthesized from γ-oxoaldehydes or γ-oxoaldehyde acetals. 3-Methyl-4-oxoaldehydes were synthesized from aliphatic aldehyde and crotonaldehyde by radical addition reaction in 4860% yields. γ-Oxoaldehydes were treated with pyrophosphoric acid in benzene under reflux with the azeotropic removal of water to give alkylfurans in 342% yields. A furnace, consisting of silica-calsia or silica-almina beads packed into a Pyrex tube, was heated at 200°C. γ-Oxoaldehyde acetal was added dropwise under reduced pressure to the Pyrex tube at a rate of 0.5 mL/min. Alkylfurans were obtained in 3578% yields. Menthofurans, a minor but important olfactive ingredient of peppermint oil, was also obtained from 9, 10-epoxy-3, 3-ethylenedioxy-p-menthane in a 64% yield.
Water-in-oil (W/O) -type emulsification was studied using an inclusion compound consisting a nonionic surfactant and organophilic montmollironite (Or-Mon). This compound (S·Or-Mon) swelled in oils such as liquid paraffin, resulting in the formation of a gel. When water was added further to a rapidly stirred oil gel, a stable W/O-type emulsion was obtained. In this system, S. Or-Mon should function as a W/O-type emulsifier on the water/oil interface. The W/O-type emulsion containing 70 wt% water was quite stable and highly viscous without solid paraffin contained in the ordinary W/O-type emulsion to cause the system to be hard. The system containing considerable glycerol was easily emulsified by S. Or-Mon.
A method for determining double-bond positions in highly unsaturated fatty acids by GC-MS was developed and is conducted as follows : A highly unsaturated fatty acid methyl ester is partially reduced with hydrazine or deuterated hydrazine. After acidification, the resulting mixture containing several kinds of unsaturated esters along with one saturated ester is recovered by hexane extraction and then separated by argentation TLC according to the number of double bonds. The isolated methyl monoenoate fraction corresponding to standard methyl cis-monoenoates is subjected to I2-catalyzed reaction with dimethyl disulfide. The resulting dimethyl disulfide adducts of methyl monoenoates areanalyzed by GC-MS. The cleavage between the methylthio-substituted carbons yielded sets of key fragment ions showing the original double-bond positions in the monoenoate carbon chain. The GC-MS data on the structures of methyl monoenoates derived from the starting highly unsaturated ester confirmed the original double-bond positions in the molecule of the starting ester. Separately using hydrazine and deuterated hydrazine as reducing reagents for the simultaneous analysis of the same sample provided further useful data for identifying the sample structure owing to the resulting shift of key fragment ions with deuterium atoms. This method was applied to the analysis of polyenoic fatty acids in eel total lipid. The most highly unsaturated fatty acid in the lipids was found to be cis-4, cis-7, cis-10, cis-13, cis-16, cis-19-docosahexaenoic acid based on mass spectral data.
In the course of studies on the iodine-sensitized conjugation of 1, 4-diene compounds, the effects of iodine compounds on this reaction were investigated. A solution containing 10% methyl linoleate and iodine compound (0.1% : calcd. for I2) in petroleum ether was irradiated with a 100 W high-pressure mercury lamp for 8 h. Iodine compounds, especially CHI3, CH2I2, IBr, ICl, (CH3) 2CHI, ICl3 and C6H5I, were found effective for this sensitized reaction. Methyl linoleate was converted to conjugated dienoates in approximately 80% yields along with small quantities of methyl trans-octadecenoates and dimers. The ratio of cis, trans-, cis, cis- and trans, trans-forms was 8 : 1 : 24 in the conjugated dienes. Conjugation with CH3I was quite slow, the yield being 10% after 8 h. The activities of iodine compounds in this sensitized reaction decrease in the following order : CHI3 ≥ I2 ≥CH2I2 ≥ IBr ≥ ICl > (CH3) 2CHI ≥ ICl3 ≥ C6H5 I> p-CH3C6H4I >> CH3 (CH2) 3I > CH3 (CH2) 2I >> CH3CH2I > CH3I The rates of conjugation of methyl linoleate thus appear closely correlated to the dissociation energies of the I-X bonding (X=C, Cl, Br, I) and absorption spectra of iodine compounds. This isomerization proceeds fundamentally in the same way as noted in the previous paper. That is, an iodine compound first dissociates with light, and conjugation subsequently proceeds through a radical mechanism involving a bridged iodoalkyl radical.
Samples were extracted from igusa with acetone, ethanol and ethyl acetate and assessment was made of antioxidative and antimicrobial activity. Determination was also made of color, α-tocopherol content and absorption spectra. The following results were obtained ; α-tocopherol content was 340 mg in the acetone extract, 54 mg in the ethyl acetate extract and 8.9 mg in the ethanol extract from igusa of 100 g. Thin layer chromatography (solvent system, chloroform : ether : acetic acid at 97 : 2.3 : 0.5, vol/vol) indicated the presence of 9 components in the acetone and ethanol extracts and 7 components in the ethyl acetate extract. The strongest antioxidative activity from igusa was noted for the ethyl acetate extract. Among the fractions in the ethyl acetate extract the fractions 6 and 7 show strong activity. Antimicrobial activity from igusa was observed to have the order, ethyl acetate extracts>acetone extracts>ethanol extracts, the strongest antimicrobial activity being that for fraction 3 in the ethyl acetate extract.