Triacylglycerides

Synthesis and characterization of fatty hydroxamic acids from triacylglycerides, Journal of Oleo Science 59,15-19. 

Compound lipids (phospholipids, sphingolipids, glycolipids, and cholesterol and its esters) that make part of the biomembrane are subject to a less active renew-al as compared with triacylglycerides. Their renewal is associated either with the restoration of an impaired portion of the membrane, or with the replacement of a defective molecule by a new one. 

Hydrolysis of triacylglycerides in tissues is effected by a tissue enzyme, tri-acylglyceride lipase, which hydrolyzes triacylglycerides to glycerol and free fatty acids. There are a variety of tissue lipases that differ primarily in their optimum pH and their location in the cell. The acidic lipase is contained in lysosomes the basic lipase, in microsomes and the neutral lipase, in cytoplasm. A specific feature of the tissue lipase is its sensitivity to hormones which, by activating adenylate cyclase, elicit the transition of the inactive tissue lipase to its active... 

The fatty acids, as produced by intracellular hydrolysis of triacylglycerides or supplied to the cell from the blood, must be brought into a state of activation. Their activation is effected in the cytoplasm with the participation of acyl-CoA synthetase according to the scheme ... 

In the organism tissues, fatty acids are continually renewed in order to provide not only for the energy requirements, but also for the synthesis of multicomponent lipids (triacylglycerides, phospholipids, etc.). In the organism cells, fatty acids are resynthetized from simpler compounds through the aid of a supramolecular multienzyme complex referred to as fatty acid synthetase. At the Lynen laboratory, this synthetase was first isolated from yeast and then from the liver of birds and mammals. Since in mammals palmitic acid in this process is a major product, this multienzyme complex is also called palmitate synthetase. 

The triacylglyceride thus synthetized is stored as fat inclusions in the cell cyto-plasm. 

Mitchell RJ, Earl L, Bray P, Fripp YJ, Williams J. DNA polymorphisms at the lipoprotein lipase gene and their association with quantitative variation in plasma high-density lipoproteins and triacylglycerides. Human Biology 1994 66 38397. 

Atmospheric Pressure Chemical Ionization (APCI)/MS APCI/MS is used to analyze compounds of intermediate molecular weight (100-1,500 da) and intermediate polarity and is particularly useful for the analysis of biochemicals such as triacylglycerides, carotenoids, and lipids (Byrdwell, 2001). For volatile, nonpolar compounds of low molecular weight, GC/MS is preferred to APCl/MS whereas APl-electrospray/ MS provides better results for larger, more polar materials. The selection of APCl/MS over GC/MS or APl-electrospray/MS depends on the compounds to be analyzed. Many LC/MS instruments can be easily switched between APCl/MS and APl-electrospray/MS so that it can be rapidly determined which ionization process is more suitable to a given chemical. Additional manipulations such as pre and postcolumn derivatization reactions (Nagy et al., 2004 Peters et al., 2004) or coulometric oxidation (Diehl et al., 2001) can make the chemicals of interest more amenable to detection by APCI. 

The elution factors in normal-phase TLC and RP-HPLC, using a fixed set of chromatographic parameters, were determined for a series of saturated triacylglycerides with TCN from C30 to Ceo, serving as reference compounds and various oxidation derivatives of analogous unsaturated triglycerides, including hydroperoxides, peroxides, epoxides, core aldehydes and their DNP derivatives. From these measurements, a series of incremental... 

Transport of dangerous goods (TDG), 745-6 Trauma, plasma oxidation level, 631 Triacetone triperoxide explosive, 707-8 Triacylglycerides, mass spectrometry, 689 Triarylgermyl hydroperoxide, formation, 822 Triarylphosphine, hydroperoxide determination, 679... 

Table 10.2 Organic Phase-Water Partition Coefficients of Some Organic Compounds for Various Organic Phases Octanol (o), Triacylglycerides (tag), Liposomes (lips), Proteins (prot), Cutin (cut), and Lignin (lig). (All values except Kiow in L kg"1 org. phase for 20-25°C if not otherwise stated. Note that the densities of the organic phases are close to 1 kg org. phase L 1 org. phase.)...

This unit defines three different tests that are used to evaluate lipid systems. The first two, i.e., iodine value (IV see Basic Protocol I) and saponification value (SV see Basic Protocol 2), are used to determine the level of unsaturation and the relative size (chain length) of the fatty acids in the system, respectively. The free fatty acid (FFA) analysis (see Basic Protocol 3) is self-explanatory. Each of these analyses provides a specific set of information about the lipid system. The IV and SV provide relative information this means that the data obtained are compared to the same data from other, defined lipid systems. In mixed triacylglyceride systems there is no absolute IV that indicates the exact number of double bonds or SV that indicates the exact chain length. The data from the FFA analysis is an absolute value however, the meaning of the value is not absolute. As a quality indicator, ranges of FFA content are used and the amount that can be tolerated is product and/or process dependent. 

The iodine value is reported as the number of grams of iodine that bind to 100 g of sample. As such, the IV can only be used as an index of unsaturation, especially in a mixed triacyl-glyceride system. This means that it can be compared to the same data from other mixed triacylglyceride systems, i.e., comparing to a competitor oil/fat. The other possible use is to reflect changes in the value based on treatment effects occurring in the system in question, e.g., to monitor hydrogenation. 

Data collected from a mixed triacylglyceride system can only be used as a relative index of chain length. This means that it can be compared to the same data from other mixed triacylglyceride systems. 

As previously mentioned, flaxseed is a rich source of dietary fiber (28%). Dietary fiber has been widely viewed as a component essential to lowering the risk of colon cancer. The flaxseed protein is similar to soy thus may be beneficial to health. Bhathena et al. (2002) first reported that flaxseed protein was effective in lowering plasma cholesterol and triacylglycerides (TAG) compared to soy and casein protein in male F344 and obese SHR/N-cp rats. The role of protein in disease prevention warrants further investigation. Components, such as PAs and flavonoids, may also contribute to the health benefits of flaxseed. 

Carotids from rat Carotid artery ligation — MALDI-MSI Triacylglycerides accumulation in response to cilostazol (33)... 

Gastric lipase and pancreatic lipase are the two major triacylglyceride ester hydrolases (EC 3,1.1.3) in mammals, but they probably have no effect on the recently introduced synthetic poly glycerol esters used as emulsifiers in food and as dietetic aids (Fig, 1),... 

A I is a phosphate (PO4) linked to a sugar and an amine a nucleotide. II has the formula CnH2nOn, indicative of a sugar. Ill contains three amino acids linked with peptide bonds. It is a tripeptide. IV is a triacylglyceride, a fat molecule. 

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