Human studies using deuterium-labeled fatty acids have answered many questions related to the metabolism and health effects of dietary fats. These studies also raised a number of unanswered questions and unresolved issues. For example, studies with cis and trans positional isomers dispelled concerns and allegations that the isomers in partially hydrogenated fats were poorly absorbed, accumulate in undesirable phospholipid acyl positions, mimic stearic acid and competed with oleic acid. Trans 18:1 isomers were metabolically intermediate between 16:0 and 18:0, so the unanswered question is why are the metabolic properties of trans fatty acids not consistent with their physiological effects? Results from ²H-18:0 studies address questions regarding stearic acid absorption and desaturation. Contrary to accepted dogma, stearic acid was well absorbed and less than 10% was desaturation to oleic acid. The still unanswered question is what is the metabolic basis for why 18:0 is less hypercholesterolemic than other saturated fatty acids? The question of whether humans convert 18:3n-3 to EPA and DHA was investigated by feeding male subjects a mixture of ²H-18:3n-3 and ²H-18:2n-6. The unequivocal answer was that 18:3n-3 is converted to EPA and DHA and the conversions for 18:3n-3 to 20:5n-3 and 18:2n-6 to 20:4n-6 were about equal. A major issue that remains unresolved is the wide variability between studies for the estimated conversion of 18:3n-3 to 20:5n-3 and 22:6n-3. The commercial availability of liquid oils hardened by interesterified with 18:0 has raised the question of whether fatty acids in the sn-2 and sn-1,3 TAG positions are metabolically equivalent. To answer this question, subjects were fed triglycerides containing ²H-16:0 and ²H-18:2n-6 at specific sn-1(3) and sn-2 acyl positions. The result was that dietary fatty acids at the sn-1(3) and sn-2 triacylglycerol positions are essentially metabolically equivalent.

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A semi empirical kinetic (SEK) method has been used to determine the ratio of cetyltrimethylammonium bromide (CTABr) micellar binding constants of counterion X^– and Br^– (a reference counterion), i.e. K_X/K_Br (=R_X^Br). The values of K_X and K_Br have been derived from the kinetic parameters obtained in the presence spherical/non-spherical and spherical micelles, respectively. This rather new method gives the respective mean values of R_X^Br as 45±2, 25±3, 4.7±0.6 and 119±10 for X=2,4-, 2,5-, 2,6- and 3,4-Cl₂C₆H₃CO₂^– (Cl2Bz’Na). Literature lacks the report on the values of R_X^Br for all X except for X=2,6-Cl₂C₆H₃CO₂^– (2,6-Cl₂Bz’^–) for which the reported value is 5.0. Rheological properties, such as shear thinning behavior, reveal indirectly the presence of wormlike micelles (WM) in the CTABr micellar solutions containing MX for all X except X=2,6-Cl₂Bz’^–. The micelles remain spherical within [2,6-Cl₂Bz’^–] range 0.01–0.34 M at 0.015 M CTABr. The maxima of the plots of zero shear viscosity, η₀, (obtained from the initial plateau region of flow curves, i.e. η vs. γ curve) vs. [MX] (MX=2,4-, 2,5- and 3,4-Cl₂Bz’Na) at 0.015 M CTABr also support indirectly the presence of linear, entangled and branched WM.

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A two-component Langmuir monolayer consisting of (perfluorobutyl)undecanol (F4H11OH) and dipalmitoylphosphatidylcholine (DPPC), a major component of pulmonary surfactants in mammals, has been investigated at the air-water interface. The binary monolayer has been systematically examined from both thermodynamic and morphological perspectives. The excess Gibbs free energy of mixing has been calculated from surface pressure (π)–molecular area (A) isotherms, and the results indicate that the miscibility of the two-component system shows a maximum in thermodynamical stability when the mole fraction (X_F4H11OH) is 0.3. Results from a two-dimensional phase diagram (π vs. X_F4H11OH) are consistent with these findings and depict the degree of miscibility resulting from the variation in the transition and collapse pressures relative to the concentration of X_F4H11OH. The miscibility is also supported by in situ Brewster angle microscopy and fluorescence microscopy, as well as ex situ atomic force microscopy for the system after transfer onto a mica substrate. Aside from temperature, a known driving force for the fluidization of DPPC monolayers is a change in surface composition caused by the addition of additive molecules. In the present study, however, the fluidization is driven by increasing surface pressures even at constant X_F4H11OH. Such a fluidization is a fascinating property when looked at in context of its potential implications for pulmonary replacement therapy, and hence, this study provides a fundamental insight into designing fluorinated materials for biomedical use.

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Hop (Humulus lupulus L.) pomace contains procyanidin-rich polyphenols, which are large oligomeric compounds of catechin. We studied the effect of high dose (1%) of dietary hop pomace polyphenols (HPs) in Otsuka Long-EvansTokushima Fatty (OLETF) rats, an animal model of type 2 diabetes. By 70 days, the rats fed HPs tended to have a lower body weight and reduced mesenteric white adipose tissue weight than the rats fed a control diet. Triglyceride levels in both plasma and liver tended to be lower in the HPs-fed group than in the control group. Dietary HPs substantially suppressed the activities of hepatic fatty acid synthetase, glucose-6-phosphate dehydrogenase, and malic enzyme, through the suppression of SREBP1c mRNA expression in OLETF rats. Moreover, in the HPs-fed group, monocyte chemotactic protein-1 (MCP-1) expression and fasting blood glucose levels at 40 days, and hemoglobin A1c (HbA1c) levels at 70 days were significantly lower than those in the control group. Thus, dietary HPs may exert an ameliorative function on hepatic fatty acid metabolism, glucose metabolism, and inflammatory response accompanying the increase of the adipose tissue mass in OLETF rats.

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In this study, biotransformation of (+)-fenchone (compound 1) by Salmonella typhimurium OY1002/2A6 expressing human CYP2A6 and NADPH-P450 reductase yielded two oxidized metabolites, namely, (+)-(1S,6R)-6-endo-hydroxyfenchone (compound 2) and (+)-(1S,6S)-6-exo-hydroxyfenchone (compound 3). The conversion rate of compound 1 to compound 2 and 3 was 2.4% and 5.2%, respectively. This is the first study that succeeded in metabolizing compound 1 to obtain large amounts of metabolite 2 and 3 by using S. typhimurium OY1002/2A6 expressing human CYP2A6 and NADPH-P450 reductase.

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Fungus isolate, Aspergillus sp. (RBD01), which was isolated from biocontaminated clarified butter was evaluated for its potential to transesterify used edible and non-edible oils for generation of alkyl esters, when used as biocatalyst as dry biomass. The work aimed at determining the potential of dry biomass of Aspergillus sp. (RBD01) to transesterify used cottonseed oil and non-edible oils viz., jatropha and karanj under various culture conditions. A conversion of oil (cotton seed) to ethyl ester to the extent of 84% was obtained at reaction temperature of 35°C, with 20% biomass and step-wise addition of ethanol at 1:5 molar ratio (oil to ethanol), within total reaction time of 36 h. Under similar conditions, transesterification of Jatropha and Karanj oils resulted in only 75 and 78.2% ethyl ester. Further, with reference to the effect of frying on transesterification, increase in frying time decreased the extent of transesterification from 84% to 30%.

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We have shown previously that jacaric acid (JA; 8c,10t,12c-18:3), which has a conjugated triene system, has a strong anti-tumor effect. However, the characteristics of absorption and metabolism of JA have yet to be determined in vivo, and the details of absorption and metabolism of JA in the small intestine are particularly unclear. This information is required for effective use of JA in humans. Therefore, in this study we examined absorption and metabolism of JA using cannulation of the thoracic duct in rats. Emulsions of two test oils, jacaranda seed oil and tung oil, which contain JA and α-eleostearic acid (α-ESA; 9c,11t,13t-18:3), respectively, were administered to rats and lymph from the thoracic duct was collected over 24 h. We examined the rate of absorption of JA and possible conversion to a conjugated linoleic acid (CLA)containing a conjugated diene system. The positional isomerism of the CLA produced by JA metabolism was determined using gas chromatography-electron impact/mass spectrometry. The rate of absorption and percentage conversion of JA were compared with those of α-ESA. We found that JA is rapidly absorbed and converted to a CLA in rats and that the percentage conversion of JA was lower than that of α-ESA. This is the first report on the absorption and metabolism of JA and this information may be important for application of JA as a functional food.

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Biotransformation of nerol by larvae of the common cutworm (Spodoptera litura) was investigated. The resulting major metabolites were (2Z,6E)-1-hydroxy-3,7-dimethyl-2,6-octadien-8-oic acid and 8-hydroxynerol, and the minor metabolites were 9-hydroxynerol and (2Z,6E)-1-hydroxy-3,7-dimethyl-2,6-octadien-8-al. (2Z,6E)-1-Hydroxy-3,7-dimethyl-2,6-octadien-8-oic acid is a novel compound. The results indicate that biotransformation of nerol by S. litura larvae involved 2 pathways; the main pathway involved oxidation at the methyl group of the geminal dimethyl at C-8 position followed by carboxylation, and the minor pathway involved oxidation at the methyl group of the geminal dimethyl at C-9 position.

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Biosurfactants are surface-active compounds produced by microorganisms. Mannosylerythritol lipids (MEL) are promising biosurfactants produced by Ustilaginomycetes, and their physicochemical and biochemical properties differ depending on the chemical structure of their hydrophilic and/or hydrophobic moieties. To further develop MEL derivatives and expand their potential applications, we focused our attention on the use of cuttlefish oil, which contains polyunsaturated fatty acids (e.g., docosahexaenoic acid, C_22:6, and eicosapentaenoic acid, C_20:5, as the sole carbon source. Among the microorganisms capable of producing MEL, only nine strains were able to produce them from cuttlefish oil. On gas chromatography-mass spectrometry (GC/MS) analysis, we observed that Pseudozyma churashimaensis OK96 was particularly suitable for the production of MEL-A, a MEL containing hexadecatetraenoic acid (C_16:4) (23.6% of the total unsaturated fatty acids and 7.7% of the total fatty acids). The observed critical micelle concentration (CMC) and surface tension at CMC of the new MEL-A were 5.7×10^–6 M and 29.5 mN/m, respectively, while those of MEL-A produced from soybean oil were 2.7×10^–6 M and 27.7 mN/m, respectively. With polarized optical and confocal laser scanning microscopies, the self-assembling properties of MEL-A were found to be different from those of conventional MEL. Furthermore, based on the DPPH radical-scavenging assay, the anti-oxidative activity of MEL-A was found to be 2.1-fold higher than that of MEL-A produced from soybean oil. Thus, the newly identified MEL-A is attractive as a new functional material with excellent surface-active and antioxidative properties.

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The essential oil from Gaillardia pulchella Foug. flowers was obtained by hydrodistillation and its chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-eight compounds representing 92.63% of the essential oil were identified, of which the most prominent were n-Hexadecanoic acid (26.90%), Phytol (7.58%) and Cyclopropaneoctanoic acid, 2-[[2-[(2-ethylcyclopropyl) methyl] cyclopropyl] methyl]-, methyl ester (6.73%). Meanwhile, antioxidant activity of the essential oil was tested. The essential oil showed certain antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) with an EC₅₀ of 70.95 μg/ml. This is the first report on the essential oil of this particular species. Its bioactivities warrant further studies.

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