Lipids, structured

HEAD GROUP STRUCTURE LIPID NAME ABBRE- VIATION... 

Myelin components exhibit great heterogeneity of metabolic turnover. One of the novel characteristics of myelin demonstrated in early biochemical studies was that its overall rate of metabolic turnover is substantially slower than that of other neural membranes [1]. A standard type of experiment was to evaluate lipid or protein turnover by injecting rat brains with a radioactive metabolic precursor and then follow loss of radioactivity from individual components as a function of time. Structural lipid components of myelin, notably cholesterol, cerebro-side and sulfatide, as well as proteins of compact myelin, are relatively stable, with half-lives of the order of many months. One complication in interpreting these studies is that the metabolic turnover of individual myelin components is multiphasic - consisting of an initial rapid loss of radioactivity followed by a much longer slower loss. 

Lipid nanodispersions (SLN and NLC) are complex, thermodynamically unstable systems. The colloidal size of the particles alters physical features (e.g., increasing solubihty and the tendency to form supercooled melts). The complex structured lipid matrix may include hquid phases and various lipid modifications that differ in the capacity to incorporate drugs. Lipid molecules of variant modifications may differ in their mobility. Moreover, the high amount of emulsifier used may result in liposome or micelle formation in addition to the nanoparticles. 

Antilipidemic activity. Triglycerides structured lipids from coconut oil, administered to rats at a dose of 10% of diet for 60 days, produced a 15% decrease in total cholesterol and a 23% decrease in LDL cholesterol levels in the serum compared to coconut oil-fed rats. Total and free cholesterol levels in the liver of structured lipid-fed rats were lowered by 31 and 36%, respectively. The triglycerides in the serum and liver were decreased by 14 and 30%, respectively " . Anti-nociceptive activity. Aqueous extract of the husk fiber, administered orally to mice at doses of 200 or 400 mg/kg, produced an inhibition of the acetic acid-induced writhing response . 

CN143 Rao, R., and B. R. Lokesh. Nutritional evaluation of structured lipid containing omega 6 fatty acid synthesized from coconut oil in rats. Mol Cell Biochem 2003 248(1-2) 25-33. 

The most superficial layer of skin is the stratum comeum (SC), which consists of terminally differentiated keratinocytes (comeocytes) that originate from actively proliferating keratinocytes in lower epidermis (basale, spinosum, and granulosum cells), and contain a lamellar lipid layer secreted from lamellar bodies (Fig. 7a). Flydration of the SC is an important determinant of skin appearance and physical properties, and depends on a number of factors including the external humidity, and its structure, lipid/protein composition, barrier properties, and concentration of water-retaining osmolytes (natural moisturizing factors, NMFs) including free amino acids, ions, and other small solutes. 

Bacteria also contain a very rich variety of glycolipids with unusual structures. Lipid A13 is the site of attachement of the 0-specific chain of Gram (-) bacteria, which constitutes the antigenic lipopolysaccharide [87]. Other members of this family can be quoted, for example glycosyl glycerophospholipids in which the carbohydrate and glycerol moieties are linked by a phosphodiester bond (e.g. GPI anchor 14) [88] or carbohydrate esters (e.g. cord-factor of mycobacteria 15). 

Sterols are structural lipids present in the membranes of most eukaryotic cells. The characteristic structure of this fifth group of membrane lipids is the steroid nu-... 

Structural lipids and triacylglycerols contain primarily fatty acids of at least sixteen carbons. 

In the Liver, Regulation Gives Priority to Formation of Structural Lipids Over Energy-Storage Lipids... 

The sphingolipids are important structural lipids found in eukaryotic membranes. The acylation of sphin-genine produces ceramide, which reacts with phos-... 

Alternatively, nanosized drug delivery particles, such as lipid-based nanoparticles or the nano-structured lipid dispersions can be produced by dispersing water-insoluble drug in lipid-based... 

The bllayer lipid membrane (BLM) has become one artificial membrane model which has permitted extensive investigation of the chemistry associated with the structural lipids present in natural membranes.(1 -2)... 

Rawlings, A.Y., et al. 1994. Abnormalities in stratum corneum structure, lipid composition, and desmosome degradation in soap-induced winter xerosis. J Soc Cosmet Chem 45 203. 

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