Stearic acid esterified

Unlike many fats and oils, the cocoa butter used to make chocolate is remarkably uniform in composition. All triacylglycerols contain oleic acid esterified to the 2° OH group of glycerol, and either palmitic acid or stearic acid esterified to the 1 ° OH groups. Draw the structures of two possible triacylglycerols that compose cocoa butter. 

Another class of carboxylic acid-derived surfactant is the sodium or calcium salts of fatty acid esters. Commercial examples include metal salts of stearic acid esterified with a dimer of lactic acid (sodium stearoyl lactylate) or maleic anhydride (sodium stearoyl fumarate), which are used as emulsifiers in bread making and in bread preservation due to their properties of preventing starch crystallization and dispersing fats [12, 13]. 

FIGURE 8.15 An example of a wax. Oleoyl alcohol is esterified to stearic acid in this case. 

Seed oil triglycerides consist of three fatty acids esterified to glycerin. Although most plants produce at least some Cie fatty acids, the majority of the triglycerides are comprised of Cig fatty acids. The balance of the fatty acids is quite specific to the plant from which the oil is derived, but the most prominent fatty acids among all plant species consist of a series of 18-carbon fatty acids containing zero, one, two, or three sites of unsaturation. These fatty acids are stearic, oleic, linoleic, and linolenic acids, respectively. These are the main fatty acids found in most seed oils and are illustrated in Fig. 5. 

The extract produced an inhibition of 5-aRl and 5-aR2 activities in the presence of free fatty (oleic, lauric, linoleic, and myris-tic) acids only. Esterified fatty acids, alcohols, and sterols assayed were inactive. A specificity of the fatty acids in 5-aRl or 5-aR2 inhibition has been found. Palmitic and stearic acids were inactive on the two isoforms. Lauric acid was active on 5-aRl (lC5o= 17 + 3 iig/mL) and5-aR2 (lC5o= 19 + 9 p,g/mL). The inhibitory activity of myristic acid was evaluated on 5-aR2 only and found active on this isoform (IC50 = 4 2 p,g/mL) ° . LSESr markedly inhibited both isozymes (Kj [type 1] = 8.4 nM and 7.2 p,g/mL, respectively Kj [type 2] = 7.4 nM and 4.9 iig/mL, respectively). Results indicated that LSESr displayed non-competitive inhibition of the type 1 isozyme and uncompetitive inhibition of the type 2 isozyme . 

Schweiz Sprengstoff-Fabrik AG, SwissP 226852(1943) CA 43, 2438(1949) (Highly brisant expl of low sensitivity to shock consists of PETN desensitized by a mixture of paraffin and nitropentaerythritol in which at least 3 OH groups are esterified with stearic acid) 9a) A.H. Blatt, "Compilation of Data on Organic Explosives , OSRD Rept 2014... 

Sodium, potassium, and calcium salts of ascorbic acids are called ascorbates and are used as food preservatives. These salts are also used as vitamin supplements. Ascorbic acid is water-soluble and sensitive to light, heat, and air. It passes out of the body readily. To make ascorbic acid fat-soluble, it can be esterified. Esters of ascorbic acid and acids, such as palmitic acid to form ascorbyl palmitate and stearic acid to form ascorbic stearate, are used as antioxidants in food, pharmaceuticals, and cosmetics. 

Concentrate the remaining volume to near dryness by nitrogen blowdown at room temperature. Add several milliliters of distilled ether, concentrate to near dryness in a water bath, and repeat four or five more times to remove HC1. Esterify with diazomethane (2) and analyze by capillary GC-FID for stearic acid and 2,4-dichlorophenol (5-chlorouracil also gave a derivative with diazomethane). Retain all concentrate after GC-FID analysis for possible HPLC analysis. 

The structures of common lipids, (a) The structures of saturated and unsaturated fatty acids, represented here by stearic acid and oleic acid, (b) Three fatty acids covalently linked to glycerol by ester bonds form a triacylglycerol. (c) The general structure for a phospholipid consists of two fatty acids esterified to glycerol, which is linked through phosphate to a polar head group. The polar head group may be any one of several different compounds—for example, choline, serine, or ethanolamine. 

Triacylglycerols are named in various ways. For example, unsaturated fatty acids sometimes are indicated as U and the saturated as S. If glycerol is completely esterified with stearic acid, the resulting monoacid TAG may be designated as SSS, or, more descriptively as StStSt, tristearin, tristearoylglycerol, or glycerol tristearate. 

The fatty acid distribution in esterified sterols differs from that found for canola oil. In the sterol esters, higher levels of palmitic and stearic acids were observed. All three major sterols were equally distributed in esterified and free sterol fractions in canola oil. Twice the amount of brassicasterol was found in free sterols than in esterified sterols. The total amount of sterols in rapeseed and canola oils ranges from 0.7% to 1.0%. The composition of major sterols in common vegetable oils is presented in Table 8. 

IViglycerides consist of a backbone of glycerol esterified — that is, covalently connected via an ester bond — with three molecules of fatty acid. The fatty acids may be alkane-like with no double bonds (e.g, palmitic or stearic acid) or alkene-like with one or more double bonds (c-g-, palmitoleic, oleic, or Jinoleic acid). 

Polysorbates are prepared from sorbitol in a three-step process. Water is initially removed from the sorbitol to form a sorbitan (a cyclic sorbitol anhydride). The sorbitan is then partially esterified with a fatty acid, such as oleic or stearic acid, to yield a hexitan ester. Finally, ethylene oxide is chemically added in the presence of a catalyst to yield the polysorbate. 

Fig. 4 Separation of dipalmitoyl phosphatidylcholine and distearoyl phosphatidylcholine. The solvent system used for the TC-CCC was hexane/ethyl acetate/ethanol/1% trifluoroacetic acid (5 5 5 4). The upper phase (organic phase) was mobile. The rotational speed was maintained at 1500-700 rpm. The highest column pressure was 360 psi. Amounts (100 pg each) of phosphatidylcholine dipalmitoyl and phosphatidylcholine distearoyl were loaded. Each fraction was spotted and developed on the HPTLC using chloroform/methanol/ 0.2% CaCl2 (60 32 4). Distearoyl phosphatidylcholine contains 2 mol of esterified stearic acids and dipalmitoyl phosphatidylcholine contains 2 mol of esterified palmitic acids. PC C16 0, dipalmitoyl phosphatidylcholine PC C18 0, distearoyl phosphatidylcholine. SF, solvent front.

To assess the ability of the TC-CCC molecular species, two molecular species of phosphatidylcholine, which were synthesized, were subjected to TC-CCC. Dipalmi-toyl phosphatidylcholine (PC C16 0) and distearoyl phosphatidylcholine (PC C18 0), two of the major molecular species of phosphatidylcholine, were completely separated as shown in Fig. 4. Distearoyl phosphatidylcholine contains 2 mol of esterified stearic acids and dipal-mitoyl phosphatidylcholine contains 2 mol of esterified palmitic acid. The structures of these compounds are shown in Fig. 4. These two compounds were completely separated. This result indicates that the TC-CCC system can separate molecular species in both phospholipids and glycolipids categories. 

Dietary lipids are composed mainly of triglycerides with only small amounts of phospholipids, cholesterol, and other sterols. Chemically, triglycerides are the triacylglycerols or a glycerol molecule esterified with three FAs. Saturated FAs have no double bonds in their carbon chain examples include palmitic (16 0) and stearic acid (18 0). Unsaturated FAs have one (monoun-saturated) or more (polyunsaturated) double bonds in the carbon chain. Depending on the position of the first double bond from the methyl end, these FAs are divided into n-9, n-6, or n-3 (also called co-9, co-6, or co-3) series, with the first double bonds being between carbon 9 and 10, carbon 6 and 7, and carbon 3 and 4, respectively. Common sources of different dietary FAs are shown in Table I. Animal fats are a rich source of saturated... 

Determine the number of moles of ATP that can be generated from the fatty acids in 1 mol of tristearin. (Tristearin is a tri-acylglycerol composed of glycerol esterified to three stearic acid molecules.) What is the fate of the glycerol ... 

Propoxylated derivatives of sorbitol are used as the polyols in the formation of rigid polyurethane foams. Sorbitol can be dehydrated and esterified with stearic acid to give sorbitol mono- or tristearate. The ester then can be ethoxylated with about 20 ethylene oxide units to give an ethoxylated surfactant. Hydrolysis of sorbitol results with glycerin, which is used in the pharmaceutical and personal care products field [108,109],... 

The lipid membrane is made up of a variety of fat-derived chemicals, the most important of which are the phospholipids (or lecithins) and ceramides. Phosphatidylcholine (13.7) is a typical phospholipid. The molecular structure is based on glycerol, propan-1,2,3-triol. Two of the alcohol functions are esterified with fatty acids, stearic acid in this case, and the third (one of the primary alcohol functions) with phosphoric... 

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