Palmitic acid, labelled

A modified Wolff-Kishner reduction employing hydrazine in glycol has been used to prepare 10-phenyldecanoic acid from the 10-keto acid (70%) and palmitic acid labeled with C14 at carbon atom 6 from the corresponding 5-keto acid. As in the Clemmensen reduction, the thiophene nucleus is unaffected. ... 

Soap Draw the structure of the soap sodium palmitate (pahnitate is the conjugate base of the 16-carbon saturated fatty acid, palmitic acid). Label its polar and nonpolar ends. 

Figure 9. NMR spectra of the plasma membranes of Acholeplasma laidlawii enriched in palmitic acid labeled at the 13-position (I3-Ai 16 0) and in oleic acid labeled at the 12-position (12-d2 18 1). Spectra were obtained at the growth temperature, 37°C. The temperatures of optimal growth, To, and the calorimetric gel to liquid crystal phase transition of the lipids in the membranes, T, are indicated. Details of sample preparation and spectral acquisition are given in Ref. 23 and 24.

M. C. Williams, and M. F. Sorrels The transport and d5mamic state of exogenous glycerol and palmitic acid labelled tripalmitin. J. Lipid Res. 1, 241 (1960). 

A purified fatty acid is recommended for the preparation of a pure a-sulfo acid. Purified palmitic acid (m.p. 60.8-61.4°, neutralization equivalent 256.2) is prepared by twice recrystallizing a good commercial grade of palmitic acid from acetone at 0°, using a solvent ratio of 10 ml. to 1 g. However, the reaction may be applied to commercial saturated higher fatty acids, if the iodine number is sufficiently low. The checkers obtained similar results with recrystaUized Neo-Fat 1-56 (Armour and Company, Chicago, 111.) or Eastman white label palmitic acid. 

Macrolide aggregation pheromones produced by male cucujid beetles are derived from fatty acids. Feeding experiments with labeled oleic, linoleic, and palmitic acids indicate incorporation into the macrolide pheromone component [ 117 ]. The biosynthesis of another group of beetle pheromones, the lactones, involves fatty acid biosynthetic pathways. Japonilure and buibuilactone biosynthesized by the female scarab, Anomalajaponica, involves A9 desaturation of 16 and 18 carbon fatty acids to produce Z9-16 CoA and Z9-18 CoA,hydroxylation at carbon 8 followed by two rounds of limited chain shortening and cyclization to the lactone [118]. The hydroxylation step appears to be stereospecific [118]. 

Leaf discs from rapidly expanding V.faba leaves incorporated 14C-labeled palmitic acid into cutin. After removal of the soluble lipids and other materials, the insoluble residue was subjected to LiAlH4 hydrogenolysis and the labeled reduction products of cutin monomers were identified by chromatography as hexadecane-... 

B14. Blomstrand, R., A study on the intestinal absorption of fat in normal adults and in non-tropieal sprue with carbon-labelled oleic acid and palmitic acid. Acta Med. Scand. 152, 129-138 (1955). 

The main radiopharmaceuticals labelled with fluorine-18, routinely prepared ([2-i F] fluorodeoxyglucose [ F]FDG [26-28], [i F]fluoro-L-DOPA [29], [i F]altanserin [30, 31], [ F]setoperone [32]) are presented with their uses in Table 2. For comparison, the most common tracers labelled with carbon-11 (methionine [33], palmitic acid [34], flumazenil (RO 15.1788) [35], PK 11195 [36], raclopride [37], deprenyl [38], Way-100635 [39], McN-5652Z [40], CGP 12177 [41]) are shown in Table 3. By far, [ F]FDG is the most widely studied, particularly in oncology for the diagnosis of tumours, detection of sub-clinical diseases, assessment of therapy responses, and detection of recurrence. F-Steroids [42], F-proteins or peptides, or F-labelled tissue specific agents have also been synthesized for the detection and monitoring of various malignancies [43]. 

C-Carboxyl labeled palmitic acid is fed to a fasted rat. There is no increase in liver glycogen, but the glucose units of the glycogen contain 14C. 

The ketone palmiton CH3(CH2)14 - CO -(CH2)14CH3 is formed by mycobacteria. The carbon marked by an asterisk was found to be labeled after feeding of [l-14C]palmitic acid. Suggest a biosynthetic pathway. 

The other reactants, including the malonyl-CoA, were not radioactive. Where is the l4C-label found in palmitic acid ... 

Thus, the even-numbered carbons will be labeled with 14C when palmitic acid is biosynthesized from 14CH3C02H. 

Potassium octadecanoate was prepared in situ by neutralization of stearic acid (Hopkin Williams Ltd.) using a slight excess (2 cw of 0.1 M) potassium hydroxide solution to prevent hydrolysis. A concentration of 8.2 x 10 mol dm was used in all experiments. Although labelled Pure1, this sample of stearic acid was stated to contain a maximum of 6 % palmitic acid and 3 % oleic acid. Another sample (BDH Specially Pure ) was stated to be 99 % by gas-liquid chromatography. A... 

Analysis of the primary protein structure of the human 5-HT1B receptor reveals a putative site for palmitoylation, i.e., a cysteine residue located in the short carboxyl tail of the receptor (141). A recombinant c-myc epitope-tagged 5-HT1B receptor was expressed in Sf9 insect cells and palmitoylation of the receptor was demonstrated by metabolic labeling of the cells with [3H]palmitic acid. 

This type of modified lipopeptide cannot be deblocked under basic conditions because the labile palmitic acid thioester group would be preferentially hydrolyzed. The C-terminus of the peptide chain was selectively deprotected by removing the choline ester with choline esterase without affecting the palmitic acid thioester bond. The observed chemoselectivity here is exactly opposite to that found in nonenzymatic conversions. Some of the synthesized N-terminally deprotected lipopeptides, have been labeled with biotinand are expected to serve as anchors for a protein moiety in an artificial membrane. Butyrylcholine esterase mediated cleavage of the choline ester has been utilized l as the key step in the synthesis of S-palmitoylated peptides such as Myr-Gly-Cys(Plm)-Thr-Leu-Ser-Ala-OH, which represents the characteristic N-terminus of the a-subunit of human G o protein. 

Vitamin A, U5P. Vitamin A (Aquasol A) contains retinol (vitamin A alcohol) or its esters from edible fatty acids (chiefly acetic and palmitic acids), whose activity is not less than 9S% of the labeled amount a dosage of 0..T yrg of vitamin A alcohol (retinol) equals I USP unit. 

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