Lipids
Hepatocytes isolated from rainbow trout fed on diets containing either fish oil or olive oil were incubated with individual odd-chain length unsaturated fatty acids (19∶1n−9, 19∶2n−6, 19∶3n−3, 21∶2n−6, 21∶3n−6, 21∶4n−6, 21∶3n−3, and 21∶5n−3) to examine whether these fatty acids were substrates for modification by desaturation and elongation. All odd-chain length fatty acids were readily assimilated...
The thermotropic phase behavior of lipids extracted either in vivo from inner forearm (SCLE) or plantar callus (PC) was investigated by differential scanning calorimetry and small angle X-ray diffraction. PC composition was chromatographically modified (MPC) by eliminating the more polar lipids in order to evaluate their role. Analysis of composition confirms the potential use of PC as a source of...
It was previously reported that a protein-free microemulsion (LDE) with structure roughly resembling that of the lipid portion of low density lipoprotein (LDL) was presumably taken up by LDL receptors when injected into the bloodstream. In contact with plasma, LDE acquires apolipoproteins (apo) including apo E that would be the ligand for receptor binding. Currently, apo were associated to LDE by...
The effect of oat bran-(OBD) and wheat bran-enriched diets (WBD) on fatty acid composition of neutral lipids and phospholipids of rat lymphocytes and macrophages was investigated. In neutral lipids of lymphocytes, OBD reduced the proportion of palmitoleic acid (48%), whereas WBD reduced by 43% palmitoleic acid and raised oleic (18%), linoleic (52%), and arachidonic (2.5-fold) acids. In neutral lipids...
A specimen of the sponge Callyspongia sp. collected off the coast of New South Wales, Australia, has yielded the novel lipid (6Z,9Z,12Z,15Z)-1,6,9,12,15-octadecapenten-3-one, together with (4Z,7Z,10Z,13Z)-4,7,10,13-hexadecatetraenoic acid.
Three different physical properties, the gel point (“solidification point”), the refractive index and the density, were determined and related to the structure of the branched triacylglycerols. A four-factor central composite face-centered design was constructed where the four variables were the length of the main chain, the branching position, the length of the side chain, and the number of branched...
Sesamol, a nonoil component of sesame seed oil, inhibited growth, fatty acid synthesis, and desaturation by Mucor circinelloides in vivo. Although sesamol also inhibited the growth of other fungi and yeasts, its effect on the lipid metabolism of M. circinelloides was exceptional. An enzymological study demonstrated that sesamol affected lipid synthesis primarily by the inhibition of malic enzyme activity,...
Postmenopausal hypercholesterolemic women are at risk for cardiovascular disease and are encouraged to follow low-fat (LF) (≤30% energy) diets. However, these diets may have undesirable effects on high density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apo A-I) and triglycerides, whereas diets high in monounsaturated fats do not. Twenty postmenopausal hypercholesterolemic women previously...
Rats were fed a diet supplemented with corn oil (n-3 deficient), soy oil, or a mixture containing 8% 22∶6n-3 ethyl ester for 6 wk. The hepatic capacities for the β-oxidation and synthesis of 22∶6n-3, in addition to the acylation of lysophosphatidate, were tested in vitro. In rats that were fed a 22∶6n-3-enriched diet, both the β-oxidation of 22∶6n-3 and elongation of 20∶5n-3 were enhanced compared...
The effects of n-3 fatty acid supplementation in the form of fresh fish, fish oil, and docosahexaenoic acid (DHA) oil on the fatty acid composition of plasma lipid fractions, and platelets and erythrocyte membranes of young healthy male students were examined. Altogether 59 subjects (aged 19–32 yr, body mass index 16.8–31.3 kg/m2) were randomized into the following diet groups: (i) control group;...
A simple and efficient method for the synthesis of taurine- and glycine-conjugated bile acids is described. The condensation reaction was achieved by the simple mixing of unconjugated bile acid (1.0 eq.), taurine (2.0 eq.) (or glycinate ester), diethyl phosphorocyanidate (1.2 eq.) in the presence of triethylamine at room temperature for 30–60 min. Sample clean-up was effected by the use of a prepacked...
A resistant cell line (HL-60R) was selected by incubating HL-60 cells with increasing concentrations of 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3) and used to examine the mechanism of resistance to the antineoplastic ether-linked lipid. The HL-60R cells exhibited a>10-fold increase in resistance when measured by [3H]-thymidine incorporation in comparison to the HL-60 cell...
A rapid and convenient chromogenic assay for phospholipase D from Streptomyces chromofuscus (PLDSc) has been developed that converts the choline generated from the enzyme-catalyzed hydrolysis of phospholipids into a chromogenic dye. By quenching the reaction with EDTA at defined times, an initial rate curve is produced from which a k cat and K m can be readily derived. This assay has been applied...
Several years ago, it was established that the Δ15 trans isomer of α-linolenic acid is converted in vivo into fatty acids containing 20 and 22 carbons (geometrical isomers of eicosapentaenoic and docosahexaenoic acids). The present study focused on the in vitro Δ6 desaturation, the first step of the biosynthesis of the n-3 long-chain polyunsaturated fatty acids from 18:3n-3. For that purpose, rat...
The effects of oleanolic acid (OA) and ursolic acid (UA) on the fluidity and stability of dipalmitoyl phosphatidylcholine (DPPC) liposomal membrane were monitored by measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene labeled in the liposomal membrane and the leakage of calcein from the probe-encapsulated liposomes. The experiments with the liposomes made of DPPC and OA or UA...
Several agents can alter biliary cholesterol secretion, critical for cholesterol excretion and gallstone formation. Although salicylate effects on bile formation and gallstones have been studied, biliary lipid secretion has not been measured during oral aspirin treatment. We examined whether oral acetylsalicylic acid affects bile lipid secretion. Three groups of young rats were fed chow for 3 wk....
A 10-hydroxy stearic acid-containing lipid from Cryptosporidium parvum was purified by thin-layer chromatography and analyzed by infrared spectroscopy, fast-atom bombardment mass spectrometry, 1H and 31P nuclear magnetic resonance spectroscopy, and was identified as phosphatidylethanolamine.
Recent work in our lab has shown that the chemoprotective fatty acid, conjugated linoleic acid (CLA), inhibits phorbol ester skin tumor promotion in mice. Because little is known about the deposition of CLA into tissues as well as its biological activity, this study compared the incorporation and biological activity of CLA to linoleic acid (LA; 18:2, c9, c12) and arachidonic acid (AA; 20:4 c5, c8,...
6,9,12,15,18-Heneicosapentaenoic acid (21:5n-3) (HPA), present in small amounts in fish oils, has been prepared by chemical elongation of eicosapentaenoic acid (EPA) and its biological properties compared with EPA and docosahexaenoic acid (DHA). All the double bonds of HPA are displaced one carbon away from the carboxyl group when compared to EPA. HPA is incorporated into phospholipids and into triacylglycerol...
4-Hydroxy-2-trans-nonenal, the most abundant and toxic unsaturated aldehyde generated during membrane lipid peroxidation, was synthesized starting from fumaraldehyde dimethyl acetal. In the first step of the synthesis, the fumaraldehyde dimethyl acetal was partially hydrolyzed using amberlyst catalyst to obtain the monoacetal. The 4-hydroxy-2-trans-nonenal was synthesized by the Grignard reaction...