Lipids isolation

The synthesis of (65,7S,9i ,10i )-6,9-epoxy-nonadec-18-ene-7,10-diol 28, a marine epoxy lipid isolated from the brown algae Notheia anomala, by an oxiranyl anion strategy, was reported. One main step is the constmction of the furan ring <99TL731>. 

Figure D1.6.6 latroscan TLC-FID chromatograms of (A) a lipid fraction enriched with neutral lipids isolated from cod flesh and stored in ice (B) neutral lipids spiked with authentic 1 -0-palmityl-glyceryl ether dipalmitate (GE), coinciding in position with authentic highly unsaturated acids such as 22 6n-3 (C) hydrogenated neutral lipids spiked with GE. The solvent system was 97 3 1 (v/v/v) hexane/diethyl ether/formic acid for 40 min. Abbreviations O, origin SF, solvent front FFA, free fatty acid PL, phospholipids SE, steryl ester ST, free sterol TG, triglyceride. Reproduced from Ohshima et al. (1987) with permission from AOCS Press.

FIGURE 24.14 Structures of some representative lipids isolated from plant and animal tissue by extraction with nonpolar organic solvents. All have large hydrocarbon portions. 

Chen, G.Z. and Bennett, J.L. (1 993) Characterization of mevalonate-labeled lipids isolated from parasite proteins in Schistosoma mansoni. Molecular and Biochemical Parasitology 59, 287-292. 

Pilgram, G.S.K., et al. 2001. The influence of two azones and sebaceous lipids on the lateral organization of lipids isolated from human stratum corneum. Biochim Biophys Acta Biomembr 1511 244. 

Lemer RA, Siuzdak G, Prospero-Garcia O, Henriksen SJ, Boger DL, Cravatt BF. Cerebrodiene a brain lipid isolated from sleep-deprived cats. Proc Natl Acad Sci USA 1994 21 9505-9509. 

In any of the lipid isolation procedures described above, there is always the potential for inclusion of nonlipid components in the total lipid extract. These contaminants can include free amino acids, peptides, pigments, carbohydrates, inorganic salts, and other compounds. 

The lipids isolated from a cell preparation are separated on thin-layer chromatography, and the desired fractions are recovered by the extraction procedure described earlier in this chapter. In this instance, interest is centered on the phosphatidylcholine fraction, and it can be subjected to the protocol outlined in Scheme A (Figure 4-24). 

The lipids isolated from the membranes of 4.74 x 109 human red blood cells were spread as a monolayer with an area of 0.89 m2. Assuming the red blood cell approximates a disk 7 jun in diameter and 1 jun thick, show that the membrane covering the red blood cell must be two lipid molecules thick. 

Figure 6 Average CH2 symmetric stretching frequency of stratum comeum lipids, isolated by chloroform methanol extraction, plotted as a function of temperature (closed square, first heat open square, second heat) at constant hydration (95% RH). Error bars, SD. (From Ref. 40.)...

Golden, G. M. et al. Comparison of skin permeability and thin layer chromatographic analysis of lipids isolated from various stratum comeum. Journal of Investigative Dermatology 98 642,1992. 

The Suzuki reaction in the synthesis of bombykol, the sex pheromone of the female silkworm moth, and humulene, a lipid isolated from hops (Section 26.2B)... 

The Suzuki reaction was a key step in the synthesis of bombykol, the sex pheromone of the female silkworm moth, and humulene, a lipid isolated from hops, as shown in Figure 26.1. The synthesis of humulene illustrates that an intramolecular Suzuki reaction can form a ring. Sample Problem 26.2 shows how a conjugated diene can be prepared from an alkyne and vinyl halide using a Suzuki reaction. 

DRMs do not correspond directly to pre-existing lipid rafts in cell membranes. Because detergents can cause reorganization of membrane lipids, isolated DRMs do not strictly measure... 

A toxic lipid isolated by Spitznagel and Dubos by extraction of Mycobacteria with monochlorobenzene has been shown to contain cord factor as the only active compound. ... 

Lipids analysis has benefited from nanoESI with the ESI Chip.24 27 Lipids isolated from cells using liquid-liquid extraction can be quantified and separated using MS-MS scans such as multiple precursor and neutral loss scanning to identify head groups and side chain information.26... 

These results and those now discussed which show the ability of resorcinolic lipids to incorporate and modulate phospholipid bilayer properties, suggest a possible similar role in biological membrane-related enzymatic activities. It has been demonstrated that at a concentration of 10 5 M, long-chain resorcinolic lipids, caused a decrease of apparent acetylocholinesterase activity in the erythrocyte membrane while simultaneously stimulating the activity of Ca2+-dependent ATPase [348]. The inhibition of erythrocyte acetylcholinesterase has been also observed for other phenolic lipids (Stasiuk and Kozubek - unpublished work) and a similar effect of one of the homologues, namely tridecylresorcinol shown towards Na+-K+ ATPase [157]. a-Glucosidase and aldolase were also inhibited by resorcinolic lipids isolated from cashew [283]. 

Numerous applications are now encountered where FA chromatographic profiles of a human physiological fluid or tissue are correlated to certain pathological conditions. A few representative examples will now be mentioned that include both free (non-esterified) FA and the saponified lipids. The identification of a methyl-branched FA (phytanic acid) in plasma of the patients with Refsum s disease [360] is now a widely known example of the power of GC in studying various metabolic defects. The profiles of FA from brain ti.ssue lipids were investigated for various neurological disorders [361,362] and in experimental animals [363]. Tichy et al. [364] determined FA in different lipids isolated from the cerebrospinal fluid while the FA profiles in cerebrospinal fluid differ from those in blood serum, no obvious correlations between the FA composition and human neurological complications were established at this time. 

Product of the enzymic oxidation of potato lipids. Isol. as the Me ester by glc. 

Methylation is usually performed on lipids isolated from the matrix by several classical methodologies, but it... 

Originally assigned a branched chain nonitol struct. Correct struct established by synthesis in 1999. Degradation prod, of a complex of macrocyclic tetraether lipids isol. from membranes of thermo-acidophilic archaebacteria of the Cal-dariella group and Methanospirillum species, e.g. Sulfolobus solfataricus, Also found in Methanobacteria spp. 

Among the polar lipids isolated from group B Streptococci was a novel glyco-phospholipid containing residues of D-glucose, glycerol, fatty acids, and phosphate (molar proportions 1 3 4 2). The products obtained from acid and alkaline... 

Composition of Lipids Isolated from the Aorta, Coronary Arteries and Circulus Willisii of Atherosclerotic Individuals... 

Lipids constitute the largest group of natural rubber non-rubbers by weight. Depending on the clonal origin, the amount of lipids isolated from different latices has been found to vary from 1.3 to 3.5% w/w, as shown in Table 3.2. 

The fatty acid desaturase system was one of the first microsomal enzymes for which a lipid requirement was established. Using Fleischer s procedure of aqueous acetone extraction (Lester Fleischer, 1961) we were able to reduce the desaturase activity of hen liver microsomes to very low levels and restore activity completely with a mixture of lipids isolated from the microsomes (Holloway Peluffo, 1964 Jones at al., 1969). Shortly after this observation cytochrome bs was implicated in the desaturation process (Oshino et al., 1966). Progress in the isolation and purification of the stearyl CoA desaturase has been slow and it is only in the last two years that the complete resolution and reconstitution of the stearyl CoA desaturase has been achieved by Strittmatter and co-workers (Strittmatter et al., 1974). 

Figure 5. Formation of PBN spin adducts in lipid isolated from butter at 80 °C. The method is described in ref. (3), and the induction time is indicated. Unpublished results.

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