Lipid colorants

As a point of interest, it is possible to form very thin films or membranes in water, that is, to have the water-film-water system. Thus a solution of lipid can be stretched on an underwater wire frame and, on thinning, the film goes through a succession of interference colors and may end up as a black film of 60-90 A thickness [109]. The situation is reminiscent of soap films in air (see Section XIV-9) it also represents a potentially important modeling of biological membranes. A theoretical model has been discussed by Good [110]. 

Figure 2 Snapshot from an MD simulation of a multilamellar liquid crystalline phase DPPC bilayer. Water molecules are colored white, lipid polar groups gray, and lipid hydrocarbon chains black. The central simulation cell containing 64 DPPC and 1792 water molecules, outlined m the upper left portion of the figure, is shown along with seven replicas generated by the periodic boundary conditions. (From Ref. 55.)...

VMD is designed for the visualization and analysis of biological systems such as proteins, nucleic acids, and lipid bilayer assemblies. It may be used to view more general molecules, as VMD can read several different structural file formats and display the contained structure. VMD provides a wide variety of methods for rendering and coloring a molecule. VMD can be used to animate and analyze the trajectory of a molecular dynamics (MD) simulation. 

Methylanaline could be transnitrosated with nitrite and S-nitrosocysteine and also by a simulated protein bound nitrite. In the latter case, an important factor was the local concentration of nitrosothiol groups on the matrix. The effects of S-nitrosocysteine as an inhibitor of lipid oxidation, as a color developer, and as an anticlostridial, have been reported recently in a turkey product (31). The Molar concentration of RSNO equating to 25 ppm nitrite gave similar results for color and inhibition of lipid oxidation but had less anti-clostridial activity. Transnitrosation between RSNO and heme protein was demonstrated. 

Carotenoids are lipid-soluble pigments responsible for many of the brilliant red, orange, and yellow colors in edible fruits (lemons, peaches, apricots, oranges, strawberries, cherries, etc.), vegetables (carrots, tomatoes, etc.), fungi (chanterelles), flow-... 

Lipid-soluble food grade copper chlorophyll is manufactured similarly by extraction of adequate plant material, followed by replacement of magnesium by copper, and purihcation steps to remove carotenoids, waxes, sterols, oils, and other minor components that are co-extracted. Commercial copper chlorophylls may vary physically, ranging from viscous resins to fluid dilutions in edible oils as well as granulated forms and emulsions standardized with edible vegetable oil. Colors may vary... 

The red microalga Porphyridium aerugineum is a source of blue color. This species is different from other red microalgae in that it lacks red phycoerythrin and its phycocyanin is C-phycocyanin rather than the R-phycocyanin that accompanies phycoerythrin found in many red algae and in other Porphyridium species. However, the biochemicals produced by P. aerugineum are similar to those of other red microalgae, e.g., sulfated polysaccharides, carotenoids, and lipids. An alternative source of C-phycocyanin is Spirulina platensis. ... 

Figure 13.2 Fluorescence micrographs of DOPC multi-layer patterns fabricated by dip-pen nanolithography, (a) An array of 25 contiguous line features. Red color is from doped rhodamine-labeled lipid, (b) A higher magnification of the region highlighted by the white square in (a), (c) Two-component patterns containing two different dyes. Green color is from doped NBD-labeled lipid.

Beasley et al. developed a panel of immunoassays to monitor DDT, its metabolites, and structurally related compounds, but they found that milk has a severe effect on the assay performance. They found that when directly utilizing whole milk, color development was completely inhibited. Even when using 1 100 dilutions of whole milk, the assay sensitivity was reduced by 90% (based on the IC50 shift, not simply the dilution factor). A number of procedures were evaluated to eliminate the interferences from the fat-soluble analytes. However, many of the procedures that removed interferences also removed the analytes. Extraction with a mixture of solvents and the use of similarly processed blank milk to prepare the standards ultimately yielded more accurate results. This article demonstrates the difficulties encountered in analyzing lipid-soluble analytes. 

The sinusoids transport both portal and arterial blood to the hepatocytes. The systemic blood delivered to the liver contains nutrients, drugs, and ingested toxins. The liver processes the nutrients (carbohydrates, proteins, lipids, vitamins, and minerals) for either immediate use or for storage, while the drugs and toxins are metabolized through a variety of processes known as first-pass metabolism. The liver also processes metabolic waste products for excretion. In cirrhosis, bilirubin (from the enzymatic breakdown of heme) can accumulate this causes jaundice (yellowing of the skin), scleral icterus (yellowing of the sclera), and tea-colored urine (urinary bilirubin excretion). 

The other major class of extracellular LBPs of mammals is the lipocalins (Flower, 1996). These are approximately 20 kDa, P-sheet-rich proteins, performing functions such as the transport of retinol in plasma or milk, the capture of odorants in olfaction, invertebrate coloration, dispersal of pheromones, and solubilizing the lipids in tears (Flower, 1996). The retinol-binding protein (RBP) of human plasma is found in association with a larger protein, transthyretin, the complex being larger than the kidney threshold and thus not excreted, although the RBP itself may dissociate from the complex to interact with cell surface receptors in the delivery of retinol (Papiz et al., 1986 Sundaram et al., 1998). 

This test is used for both in vitro and in vivo determinations. It involves reacting thiobarbituric acid (TBA) with malondialdehyde (MDA), produced by lipid hydroperoxide decomposition, to form a red chromophore with peak absorbance at 532 nm (Fig. 10.1). The TBARS reaction is not specific. Many other substances, including other alkanals, proteins, sucrose, or urea, may react with TBA to form colored species that can interfere with this assay. 

Olive oil, cosmetically useful lipid, 7 833t Olivine, colorants for ceramics, 7 347t Olivine reserves, 75 322 Olmesartan, 5 18 7... 

Fig. 16.2 Schematic representation of cellular and artificial membrane nanotubes. (A) Two cells are connected by a tunneling nanotube (arrowhead) containing a bundle of filamentous actin (red line). N (grey), nucleus M (purple), mitochondrium ER (green), endoplasmic reticulum G (blue), Golgi apparatus. (B) Lipid nanotube connecting two lipid vesicles formed by pulling a membrane tether. (C) Membrane tether pulled from the plasma membrane of a cell (see Color Plates)...

Toxicologists classify hepatic toxicants according to the type of injuries they produce. Some cause accumulation of excessive and potentially dangerous amounts of lipids (fats). Others can kill liver cells they cause cell necrosis. Cholestasis, which is decreased secretion of bile leading to jaundice (accumulation of gruesome looking pigments that impart a yellowish color to the skin and eyes) can be... 

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