Palmitic and stearic acids

Distillation. Most fatty acids are distilled to produce high quaHty products having exceUent color and a low level of impurities. Distillation removes odor bodies and low boiling unsaponifiable material in a light ends or heads fraction, and higher boiling material such as polymerized material, triglycerides, color bodies, and heavy decomposition products are removed as a bottoms or pitch fraction. The middle fractions sometimes can be used as is, or they can be fractionated (separated) into relatively pure materials such as lauric, myristic, palmitic, and stearic acids. 

The mixed oxidation products are fed to a stiU where the pelargonic and other low boiling acids are removed as overhead while the heavy material, esters and dimer acids, are removed as residue. The side-stream contains predominately azelaic acid along with minor amounts of other dibasic acids and palmitic and stearic acids. The side-stream is then washed with hot water that dissolves the azelaic acid, and separation can then be made from the water-insoluble acids, palmitic and stearic acids. Water is removed from the aqueous solution by evaporators or through crystallization (44,45). 

Palmitic and stearic acids aflatoxins Bi and Bi 15 to 35% unseparated fatty acids intensified the fluorescence when investigating com extracts [224]... 

Guidon, P.T.J. Hightower, L.E. (1986). The 73 kD heat shock cognate protein purified from rat brain contains nonesterified palmitic and stearic acids. J. Cell. Physiol. 128,239-245. 

Another painting by Cuno Amiet ( Standard Rose , 1913, private collection) showed a whitish bloom. GALDI-MS readily revealed palmitic acid (m/z 279 [M+Na]+) as the main component, while efflorescence on several other paintings of the twentieth century (e.g. by Alfred J. Jensen, 1903 1981) showed signals of a mixture of palmitic and stearic acid. 

Egg yolk TMAH Palmitic and stearic acids methyl esters (>60%) azelaic acid methyl esters (<10%) and pyrrole (<50%) 1... 

The presence of characteristic peaks from palmitic and stearic acids is consistent with the hypothesis of the use of oil as binding media. The lack of any characteristic ions issued from egg tempera means that ToF-SIMS does not allow detection of egg tempera in this sample. However, it could be present but is not detected due to high degradation occurring in very old egg tempera. The presence of short chain fatty acids, which are not detected in the new reference sample, is attributed to oil ageing. The distribution of fatty acid ions in the cross-section is well correlated with the distribution of lead. The ions are not detected in the ground layer (Figure 15.9). 

Hydroxide ions react to split ( hydrolyse ) natural esters in the skin to form glycerol (II) and palmitic or stearic acid - a reaction called saponification. Palmitic and stearic acids subsequently react with the base to form the respective long-chain carboxylate anions - which is soap. 

Fatty acids, saturated (palmitic and stearic acids) Silicalite-1 Acetone [180]... 

The common fatty acids have a linear chain containing an even number of carbon atoms, which reflects that the fatty acid chain is built up two carbon atoms at a time during biosynthesis. The structures and common names for several common fatty acids are provided in table 18.1. Fatty acids such as palmitic and stearic acids contain only carbon-carbon single bonds and are termed saturated. Other fatty acids such as oleic acid contain a single carbon-carbon double bond and are termed monounsaturated. Note that the geometry around this bond is cis, not trans. Oleic acid is found in high concentration in olive oil, which is low in saturated fatty acids. In fact, about 83% of all fatty acids in olive oil is oleic acid. Another 7% is linoleic acid. The remainder, only 10%, is saturated fatty acids. Butter, in contrast, contains about 25% oleic acid and more than 35% saturated fatty acids. 

The table lists the full series of aliphatic carboxylic acids that are found in plants and animals. In higher plants and animals, unbranched, longchain fatty acids with either 16 or 18 carbon atoms are the most common— e.g., palmitic and stearic acid. The number of carbon atoms in the longer, natural fatty acids is always even. This is because they are biosynthesized from C2 building blocks (see p.168). 

Both and nmR showed the presence of aromatic and aliphatic components. In l C-NMR, resonances at =58 ppm indicate the presence of many OCH3 groups, such as those occurring in syringic, vanillic, and ferulic acids. Spectra clearly show the presence of palmitic and stearic acids by GC/MS, IR, and NMR data. The fulvic and humic acids are predominantly made up of phenolic and fatty acid units. These are highly aromatic because lignin residues have been incorporated in the humification process. 

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 . 

N.A. Linoleic, oleic, palmitic, and stearic acids, flavonoids, malic acid, anthocyanins, tartaric, tannins, monoterpene glycosides.99182 Antioxidant, internally for varicose veins, excessive menstruation, menopausal syndrome, hemorrhage, and hypertension. 

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. 

The caprylic, capric, lauric, myristic, palmitic, and stearic acids purchased from die Hormel Institute were of high purity (-—99% ) as determined by gas chromatographic analysis (GLC). Eastman caprylic, lauric, myristic, palmitic, and stearic acids of equivalent purity (GLC) were also used. The butyric, valeric, and caproic acids were obtained from T. T. Baker Chemical Co. analysis (GLC) showed them to be of 99, 97/4, and 99.3% purity, respectively. 

The calculations for (W0 — Wc) obtained by comparing the desorption rate constants of Ci6 and Ci8 sulfates and phosphonates and palmitic and stearic acids are summarized in Table II. 

The calculation of surface viscosity by this method had a maximum sensitivity and precision of 3 X 10 5 and 1 X 10 4 surface poise, respectively, in the low viscosity range, and 1 X 10 3 and 1 X 10 - surface poise, respectively, in the high viscosity region. The method offers extreme simplicity in construction and operation, and is more adaptable to high viscosity films (greater than 10 2 surface poise) than the canal or slit viscometer. Recent work (31) with the canal viscometer indicates an inability to measure film viscosities of palmitic and stearic acid mono-layers over pH 9.0 to 9.5 KOH substrates. 

I roponions shown are approximate actual compositions can vary greatly. b Palmitic and stearic acids. 

The vegetable oil used was rapeseed oil (Nacalai Tesque Kyoto, Japan) without further treatment. The fatty acid content of the rapeseed oil mainly consisted of unsaturated fatty acids (93 wt%), with the saturated fatty acids of palmitic and stearic acids accounting for only a small amount (7 wt%). Various fatty acids of oleic (C181), linoleic (C18 2), linolenic (C18 3), and palmitic (C16 0) acids as well as their methyl esters were purchased from Nacalai Tesque. Anhydrous methanol and distilled water were also supplied by the same company. 

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