An attempt was made to synthesize dipeptide-type surfactants analogs from glutamic acid and aspartic acid, which are naturally occurring and renewable amino acids. N-Lauroylglutamic anhydride was used as a raw material for the synthesis. In this study N-lauroylglutamyl aspartic acid (LGA) and N-lauroylglutamyl glutamic acid (LGG) were prepared. Physicochemical properties such as the solubility, the lowering surface tensions, the foaming ability, the emulsification potential, and the higher order structure of the surfactant aggregates were discussed with changing the neutralization of the tri-basic carboxylic acid in the surfactants. These surfactants showed an outstanding surface tension lowering ability. Surface tension and cmc of the aqueous solution of LGA increased as the neutralization of three carboxylic acids increased. On the other hand, those of LGG didn’t show the similar behavior. This difference would result from the inequality in the hydrophobicity produced by one more methylene groups between LGA and LGG. It should bring about some changes such as electrostatic repulsion between two negatively charged carboxylate anions, the inter- and intrahydrophobic interactions and the hydrogen bonds. It was confirmed that these surfactants possessed an excellent biodegradability, a high stability for the hydrolysis, high calcium ion stability. Introduction of the peptide linkage that bonds the two amino acids did not affect the hydrolysis stability of the surfactant. Neither LGG nor LGA were hydrolyzed in basic (pH=10) aqueous solution for one month. At the same time, they showed a high moisturizing effect in addition to a low protein denaturation potential.
A facile method for the preparation of a polymer surfactant (P-Cn-Chitosan) derived from chitosan was proposed. Chitosan was dissolved into water with lactic acid or pyrrolidone-2-carboxilic acid (PCA), then was partially acylated with acid anhydrides possessing long alkyl chains. P-Cn-Chitosan showed a strong emulsifying activity on the 1:1 mixture of squalane and water. The structure of this emulsion was o/w type and the role of the alkyl chains for emulsification was clarified by the spin probe method, showing that P-Cn-Chitosan acts as a cationic surfactant and covers the surface of the oil droplet by anchoring its alkyl chains. DSC study revealed that the lipid bilayer of liposome prepared from dipalmitoylphosphatidylcholine was stabilized by the surface adsorption of P-Cn-Chitosan. P-Cn-Chitosan did not show acute toxicity to a fish, Orizias Latipes, and was degraded by microorganisms in a river water. These results suggested that P-Cn-Chitosan is usable as a surfactant for medicines, cosmetics and foods.
In our continuous research directed towards the chemical characterization of seed oils, of seed oils from some rapeseed (canola) cultivars (canola Tobin, canola Impulse, rape Cubansky, rape Chinese Cultivars I, II., rape Yakshi and rape Khanna) introduced in different parts of the Mongolia were analyzed for their fatty acid composition and tocopherols, sterols content. The oil content in the seeds was 31.4-42.4%. The seed oils from both canola cultivars are mainly composed of oleic (60-12%), linoleic (to 22%) acids and some linolenic acid (8.4-11.9%). The rapeseed Cubansky was found to have a small amount of erucic acid (0.6%) in addition to oleic and linoleic acids as predominant acids. The rapeseed cultivar Yakschi contained an equal amount of eicosenoic (3.1%) and erucic (3.7%) acids. The rapeseed Chinese cultivars I, II and Khanna were found to be high in 20: 1n-9 (10.8 and 7.5%) and 22: 1n-9 (25.6 and 13.5%). Major tocopherol was γ-tocopherol (328.9-641.8 ppm) accompanied by a low level of α- and δ-tocopherol. Canola Impulse seed oil contained 33.8 mg/kg of β-tocopherol in addition to other isomers. Seed oil sterols are mainly composed of β-sitosterol, campesterol and brassicasterol.
5α-cholestan-3β-ol (II) is similar to 5-cholesten-3β-ol (cholesterol) (I) except the absence of the Δ5 double bond, whereas 5β-cholestan-3α-ol (III) is remarkably different from I in its skeletal structure and in the direction of its OH moiety. Two-dimensional thermodynamic properties such as surface pressure-molecular area (π-A) relationship, equilibrium spreading pressure (ESP) and enthalpy of compression of monolayer at air-water interface were studied for these sterols. II shows similar π-A relationships to I, whereas III gives the different ones. ESP value, increasing with increasing temperature, followed the order of II>I>III. Enthalpy of elution, ΔHESP, from the crystals onto water surface at ESP and also enthalpy of compression, ΔHcomp, of the monolayers from π=0 to ESP were obtained from the temperature dependence of ESP and of π-A relationship, respectively. The sum of ΔHESP and −ΔHcomp, which means the two-dimensional enthalpy of fusion, is approximately proportional to the ordinary enthalpy of fusion. II and III molecules gave a 1:1 compound in the mixed monolayer on water surface as well as in solid state. The ESP value for the 1:1 compound was also determined.
A fish oil diet affected the metabolism of essential fatty acids in both serum and egg yolk, and lowered the serum cholesterol level. The blood samples and eggs were obtained from hens fed diets containing either fish oil (21 g/kg diet) or a blend of vegetable oils for 2 months after 6-month-feeding with regular commercial diets. The concentrations of n-3 polyunsaturated fatty acids, eicosapentaenoic acid (20:5 n-3, EPA), docosapentaenoic acid (22:5 n-3, DPA) and docosahexaenoic acid (22:6 n-3, DHA), increased significantly in the sera and eggs from hens fed the fish oil diet (p<0.001, respectively). On the other hand, a significant reduction in arachidonic acid (20:4 n-6, AA) was found in the sera and eggs compared to those of controls (p<0.001, respectively). The ratios of AA (20:4 n-6)/DHA (22:6 n-3) were 0.21 in the sera and 0.12 in the egg yolks compared with those of 1.88 and 1.77 in controls, respectively. The variation in fatty acid composition in egg yolks was found in the acyl groups of phospholipids, phosphatidylcholine and phosphatidylethanolamine, rather than in those of triacylglycerol. The findings show that supplementing the diet for hen with fish oil alters essential fatty acid composition, in particular by increasing DHA and decreasing AA in egg yolk phospholipids. In conclusion, hens fed a diet containing fish oil (2.1%), a relatively lower level of fish oil content than the control, gives lower priced commercial eggs which are an ideal food with a recommended n-6/n-3 essential fatty acid balance for human health and nutrition.
(−)-Hydroxycitric acid (HCA), an active ingredient extracted from the rind of the Indian fruit Garcinia cambogia inhibits ATP-citrate lyase and is used for anti-obesity treatment. This study was conducted to examine the long-term effects of G. cambogia extracts on body fat accumulation in humans who are preobese or obese class 1 (body mass index from 25 to 35 kg/m2). A total of 40 subjects were randomized to either a G. cambogia (n=20, 1000 mg of HCA per day) or a placebo (n=20) group. The treatment period was 8 weeks. Each was subjected to computed tomography (CT) scan at the umbilical level before and after the treatment period, and blood samples taken to measure the clinical laboratory data every 4 weeks. As for a higher visceral fat area (VFA) in the subjects (with an initial VFA over 90 cm2), both the VFA and VFA/SFA (subcutaneous fat area) ratio in the G. cambogia group significantly decreased, compared to the placebo group (p<0.01 and p<0.05, respectively). Triacylglycerol was also reduced significantly in higher VFA subjects in the G. cambogia group, compared to the initial levels (p=0.05), but there were no significant difference between the groups in loss of body weight and the waist-hip ratio. No adverse effect was observed through out the test period. In conclusion, G. cambogia extract is useful for reducing body fat accumulation, especially visceral fat accumulation.
Crossed aldol condensation was effectively carried out in the presence of an anion exchange resin as solid catalyst. For this condensation, the basic strength of the anion exchange resin was adjusted by substituting the Cl- constituent of the resin with OH- for an appropriate quantity of the resin. This anion exchange resin, having taken on the proper basicity, was found to quite effectively catalyze the crossed aldol condensation reaction of benzaldehyde, saturated and unsaturated aliphatic aldehyde and terpenoid aldehyde with acetone. In view of this favorable finding, this anion exchange resin was applied to and found quite effective for the synthesis of 5,5-dimethyl-3-styryl-2-cyclohexen-1-one (12), 5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-3-penten-2-one (15), and pseudoionone (17).
Alkali and alkali earth metals and triethanolamine are used as counter-ions of fatty acid soaps. Basic amino acids such as lysine and arginine have also come to be used in recent years. It is well known that fatty acid salts each have distinctive properties. However, until the present, compounds used as counter-ions of fatty acid have all been alkaline. In this study, examination was made of the effects of amphoteric compounds such as N-methyltaurine on sodium laurate using 13C-NMR spectra and phase equilibrium diagrams. With 13C-NMR spectra, chemical shifts of carboxyl groups in lauric acid were measured in the course of their neutralization by sodium hydroxide and sodium N-methyltaurine respectively. These shift values in lauric acid neutralized completely by sodium N-methyltaurine differed from those when using sodium hydroxide. From this fact it is thought that the environments around the carboxyl groups when neutralized by sodium N-methyltaurine and when neutralized by sodium hydroxide differ from each other. It is suggested that N-methyltaurine is adsorbed by carboxyl groups in lauric acid as counter-ions. It was also found that a considerable amount of free lauric acid becomes separated from sodium N-methyltaurate laurate soap solution at higher temperature or lower concentration. Surface tension of sodium N-methyltaurate laurate solution and its interfacial tension with silicone oil are low compared to sodium laurate solution. The c.m.c. of sodium N-methyltaurate laurate is higher than that of sodium laurate. N-methyltaurine would thus appear to function as a fatty acid counter-ion.
Examination was made of the effects of polyglycerol fatty acid esters (PGFE) each comprised of three different fatty acids on hindering the crystallization of palm olein. PGFE which inhibited this crystallization was found to have long chain fatty acids (myristic, palmitic and stearic acids) and particularly those with long chain fatty acids/middle chain fatty acids (octanoic and decanoic acids) or long chain fatty acids/unsaturated fatty acids (oleic and linoleic acids) at 5°C, 20°C. At strage temperature, fatty acids of PGFE were essentially the same but present in different amounts. Fatty acid compositions of PGFE would not be the same as that of palm olein and were shown in this study to inhibit the crystallization of palm olein.
The effects of ingestion of α-linolenic acid-rich diacylglycerol (ALA-DAG) on the oxidation of dietary fat were investigated. Rats were fed ALA-DAG for 3 wk, deprived of food for 6 h, and then administered lipids containing [1-13C]-tripalmitin. All of the gas expired by the rats was collected at 2-h intervals for 6 h after administering the [1-13C]-tripalmitin. Rats fed triacylglycerol (TAG) for 3 wk were used as controls. The 13C content in the carbon dioxide expired from the ALA-DAG-fed rats was significantly greater (p<0.05) compared to that from the TAG-fed rats until 4-h after [1-13C]-tripalmitin administration. This result indicates that the long-term ingestion of ALA-DAG, as compared to TAG, induces an accelerated oxidation rate of dietary fat in rats.