Nonsaponifiable lipids

Collection of Nonsaponifiable Lipids. Two hundred ants from the 2-C14-acetate feeding were ground with sand and the resulting brei refluxed for 4 hours in 25 ml. of ethanol, ethanol-diethyl ether (3 to 1), and diethyl ether (twice). The extracts were pooled, the solvents were evaporated, and the residue was saponified by refluxing for 1 hour with 20 ml. of methanolic potassium hydroxide (10% potassium hydroxide in 60% aqueous methanol). An equal quantity of water was added and the aqueous solution extracted three... 

Chromatography of Nonsaponifiable Lipids. The nonsaponifiable residue plus 4.5 mg. of carrier cholesterol was applied to the top of a 7.5 X 1.7 cm. column containing 20 grams of Merck alumina (suitable for chromatographic adsorption) which had been previously deactivated by mixing with 7% aqueous acetic acid (10% glacial acetic acid in distilled water) (18). The column was packed in petroleum ether (redistilled, b.p. 60-70° C.) and 10 ml. fractions were collected. The eluting solvents are shown in Table II. 

The two major polymeric lipid components found in plant cuticles are cutin and cutan. Whereas cutin is the polyester biopolymer that is solubilized upon saponification treatment, cutan is a nonsaponifiable and nonextractable polymeric substance... 

The structures of lipids are quite varied triacylglycerols (fats and oils), waxes, phospholipids, sphingolipids, steroids, eicosanoids, fat soluble vitamins, and pigments. Some lipids are simple in structure while others are more complex. Among these molecules are those which are esters in nature and therefore saponifiable in aqueous base. Others are nonsaponifiable. Many are completely nonpolar while others are amphipathic, that is, they have a polar/nonpolar nature. 

A fused multiple-ring system is the structural framework for steroids. Cholesterol is the nonpolar, nonsaponifiable progenitor of the metabolic and gonadal hormones such as cortisol, testosterone and estrogen as well as the bile acids used for the intestinal absorption of fats and oils. Many toxins fit into this lipid subclass. 

Very early in the investigation of sterol biosynthesis it was estabUshed that acetate was the primary precursor. In 1942 Bloch and Rittenberg found that deutero-acetate could be converted to cholesterol in the intact animal in high yields [7]. This was in accord with the earlier observation of Sonderhoff and Thomas that the nonsaponifi-able lipids from yeast (primarily sterol) were heavily labeled by the same substrate [8]. Degradation of the sterol molecule in the laboratories of both Bloch and Popjak showed that all of the carbon atoms of cholesterol were derived from acetate and that the labeling pattern of methyl and carboxyl carbons originating from acetate indicated that the molecule was isoprenoid in nature [9]. It was apparent then that sterols have as their fundamental building block, acetate, a molecule that resides at the center of intermediary metabolism. 

Sterols and Cholesterol. Natural sterols are crystalline C. C steroid alcohols containing an aliphatic side chain at C17. Sterols were first isolated as nonsaponifiable fractions of lipids from various plant and animal sources and have been identified in almost all types of living organisms. By far, the most common sterol in vertebrates is cholesterol (2). The total cholesterol content measured in all mammalian species that have been examined is... 

The best quality oil, low in phosphatides, free fatty acids, nonsaponifiable matter and pigments, is extracted first, while poorer quality lipids are extracted with more exhaustive extraction. The industry, however, strives for the most complete extraction possible. Residual oil contents of finished solvent-extracted soybean meal range 0.5-1.5% (toasting defatted soybean meal liberates oil, and toasted meal will test higher in oil content than do drained untoasted extracted flakes). Some have advocated doing less complete oil extraction to reduce refining costs, but not ail extraction plants have capabilities to alkali refine and, thus, there is little incentive to extraction plants to minimize refining loss. 

Lipids - A loosely defined term for substances of biological origin that are soluble in nonpolar solvents. They consist of saponifiable lipids, such as glycerides (fats and oHs) and phospholipids, as well as nonsaponifiable lipids, principally steroids. [5]... 

Nonhydrolyzable lipids are not cleaved into smaller molecules by hydrolysis (including acid, saponification, and digestion) because of the absence of ester groups. Three classes of compounds comprise the nonsaponifiable lipids, as shown in the bottom of Fig. 19-1. Steroids contain a four-ring system of three 6-membered rings and one 5-membered ring ... 

Table 19-2 describes the biological functions of the various nonsaponifiable lipids. 

Route B does not strictly represent a fractionation protocol but is worthy of highlighting in the instances where an alternative rapid procedure is preferred for the analysis of total FA. Here, an acid-catalyzed transesterification can be undertaken, converting total ester-finked acyl residues directly to their methyl esters. As a byproduct, nonsaponifiable lipids are also retained in this fraction (hydrocarbons, isoprenoids) and analyzed simultaneously by chromatographic techniques. While more rapid, the technique yields a more complex sample for analysis. 

FIGURE 9.3 Partial capillary gas chromatograms of lipid fractions from blue whale Bal-aenoptera musculus) lipid samples, (a) Total FA (analyzed as methyl esters) derived from the solvent fractionation of lipid classes from a subcutaneous blubber lipid extract by the hydrolytic reaction of O-acyl ester lipids (b) the neutral hpid fraction, containing nonsaponifiable lipids (analyzed as bis(trimethylsilyl)trifluoroacetamide (OTMS) esters), derived from the solvent fractionation of lipid classes from a dorsal blubber hpid extract. In this case, FA have contaminated the neutral lipid fraction and have been detected as OTMS esters. 

Classify lipids as saponifiable or nonsaponifiable and list the major functions of lipids. 

What functional group is common to all saponifiable lipids 8.4 Classify the following as saponifiable or nonsaponifiable lipids 8.14 Ehaw the structure of a triglyceride that contains one myristic acid, one palmitoleic acid, and one Unoleic acid. Identify the ester bonds. 

KT21. Soapstock is recovered via the alkaline refinement process of oilseeds and contains phosphorus lipids, hydrateable and nonsaponifiable compounds, soaps of FFA, vitamins A and E, as well as carotenoid pigments. In their work, condensed corn-soluble basal medium was initially fed with biodiesel glycerol water but when the dissolved oxygen level rose above 10%, the medium was fed with sunflower soapstock. A shift in the monomer compositions from 3-hydroxydecanoate to 3-hydroxyoctanoate was observed when the medium was fed with sunflower soapstock. The final PHA also contained 3-hydroxytetradecanoate and 3-hydroxytetradecenoate monomers with a CDW and PHA content of 17 g/1 and 17%, respectively. 

Oils water-insoluble, liquid organic compounds. They are combustible, lighter than water, and soluble in ether, benzene and other organic solvents. Naturally occurring O. may be acylglycerols, e. g. the O. stored in certain seeds, or fish liver oils (see Fats) or they may be nonsaponifiable lipids, e.g. Essential oils (see). 

Nonsaponifiable lipids are nonpolar compounds that do not form soap. They include steroids, many vitamins, and bile acids. Cholesterol is a steroid present in animal cell membranes and is a precursor of many hormones. 

What is the difference between saponifiable and nonsaponifiable lipids ... 

Lipids are present as ingredients in most foods and play key nutritional roles, being crucial for many physiological functions, they also can be used as food quality markers. For these reasons, the characterization of the lipid fraction present in fats and oils is important for the food industry. Following a general lipid classification, triacylglycerols (mono- and diderivatives), phospholipids, glycolipids, waxes, and sterol esters are included in the saponifiable fraction, whereas the nonsaponifiable... 

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