Fatty acids, recently reported as constitutents of certain fish lipids, were identified to be derivatives of furan (furanoid fish fatty acids). 12,15-Epoxy-13,14-dimethyleicosa-12,14-dienoic acid is predominant among the furan acids and is associated withbis-homologs in regard to chain length. Monomethyl acids, such as 12,15-epoxy-13-methyleicosa-12,14-dienoic, are present in appreciable amounts. The structures were concluded from oxidative degradations, from mass spectrometry of methyl esters of the novel acids and fatty acids derived from them by opening the ring, and from nuclear magnetic resonance, infrared, and Raman spectra. The results from chemical procedures and from spectrometric methods were in aggreement with those obtained with authentic methyl 9,12-epoxyoctadeca-9,11-dienoate. The number of substituents at the furan ring greatly influences hydrogenation, hydrogenolysis, and hydrolysis reactions of the ring.

Furanoid fatty acids from fish lipids.

High-chain fatty acid esters of myristyl alcohol with even carbon number: Novel organic phase change materials for thermal energy storage—1

Convenient one-pot synthesis of novel 2-substituted benzimidazoles, tetrahydrobenzimidazoles and imidazoles and evaluation of their in vitro antibacterial and antifungal activities

Although animal studies have shown that the chemical reactions occurring in fats during frying do not make them unsuited for food use, questions continue to arise about the products of these reactions and their significance. The purpose of this work was to identify as many as possible of the monomeric products that form when fats are heated in the air. Cottonseed oil was kept at 182 C for six 8 hr days; then it was converted to methyl esters. The distillable, non-urea-adductable fraction (DNUA) of the esters was separated into 96 fractions by gradient elution chromatography on silica gel. Each fraction was analyzed by gas liquid chromatography (GLC). One hundred thirty-six components were observed, corresponding to 0.42% of the fat. Many of the components were isolated by preparative GLC. Fifty-one were partially or completely characterized. The most abundant components of the DNUA were octadecenoate and octadecadienoate which had not been removed completely by urea adduction. Esters of alicyclic fatty acids made up 34% of the characterized material. These cyclic materials are probably responsible for the toxic effects that have been seen when DNUA was isolated and fed to rats at high dietary levels. Many of the other components appear to be of little biological interest. No components present in substantial amounts remain uncharacterized.

Systematic isolation and identification of minor components in heated and unheated fat

The many nonsubstrate effects of iodide in the thyroid appear to be due to at least four mechanisms: 1) a possible anion effect of iodide for which the supporting data are conflicting; 2) an inhibition of organic iodine formation (the so-called Wolff-Chaikoff effect); 3) the iodination of critical enzymes in the thyroid gland; and 4) the inhibition of cellular processes by iodinated products such as oxidized iodine itself, or an oxidation reaction involving iodine. The separation into these categories is not firm, but circumstantial evidence suggests that the mechanisms are different. In addition, high levels of iodide will saturate the iodide pump (Ki ≈3×10−5M) (1). In this case, however, the amounts of iodide which enter the thyroid cell remain large, despite transport saturation and are replaced by diffused iodide. Hence this subject will not be discussed here.

Excess iodide inhibits the thyroid by multiple mechanisms

Fatty acids, part 27: The formation of 1,4-epoxides from methyl linoleate and related esters by reaction with toluene-p-sulphonic acid and an appropriate solvent☆

S.D. Hoyes

Papers

Fatty acids, part 27: The formation of 1,4-epoxides from methyl linoleate and related esters by reaction with toluene-p-sulphonic acid and an appropriate solvent☆