The Highly Unsaturated Fatty Acids of Fish Oils

Abstract

UNSATURATED FATTY ACIDS OF FISH OILS 1289 tetraphenyl-succinonitrile. Each of these substances was identified by its melting point and the melting point of a mixture with samples of known structure. Benzoyl-phenyl-nitrocyclopropaneFive and three-tenths g. of the cyclopropane derivative was reduced in 50 cc. of methyl alcohol in the presence of 0.25 g. of platinum black. The reduction was stopped when 740 cc. of hydrogen had been absorbed. The platinum was removed after boiling the suspension to redissolvc a white solid which had separated during the reduction. On cooling the clear solution, it deposited 1.9 g. of a colorless solid which crystallized in needles and melted at 98-99°. A mixed melting point showed that this was /3-phenyl-7-nitro-butyrophenone. Summary 1. This paper gives an account of the results obtained by reducing a series of ,ß-unsaturated nitro compounds with hydrogen and platinum.2. In a discussion of the results it is shown that the behavior of ,ßunsaturated nitro compounds on catalytic reduction is essentially the same as that of ,/3-unsaturated ketones. The resulting saturated nitro compounds, however, generally undergo further reduction; the successive steps are RCH: CHN02 -> RCH2CH2N02 -[RCH2CH2NO] -RCH2CH: NOH -> RCH2CH: NH -> RCH2CH2NH2.3. The primary reduction product of a cyclopropane derivative which has a nitro group in direct union with one of the ring carbon atoms is likewise a saturated nitro compound.Cambridge 38, Massachusetts

The discovery and early structural studies of arachidonic acid

“…Brown (Ohio State University) and the other in Great Britain, Ida Smedley-Maclean (Lister Institute, London), became interested in a more complete structural characterization of arachidonic acid. Brown had been working with unsaturated fatty acids since his thesis work at the University of Illinois (17). Smedley-Maclean was already a respected lipid biochemist and was, in fact, the first female to be Chairman of the Biochemical Society (Fig.…”

Distillation of Natural Fatty Acids and Their Chemical Derivatives

“…Fractional distillation has been performed for some time on a variety of saturated and highly unsaturated fatty acid ester mixtures at reduced pressures on the laboratory scale as a method to purify fatty acid esters. Early reports examined the separation of various fatty acid methyl esters of corn (Baughman & Jamieson, 1921), sunflower (Baughman & Jamieson, 1922b), soybean (Baughman & Jamieson, 1922a), and menhaden oils (Brown & Beal, 1923) by fractional distillation into their various components. Later spinning band columns improved distillation fractionation; for example, Weitkamp (1945) reported the isolation of 32 compounds into four main compound classes (fatty acids, 2-hydroxy acids, and two types of branched iso and anteiso acids) from wool wax by distilling fatty acid methyl esters.…”

The Principal Chemical Researches on Cod Liver Oil.

“…Hexadecatrienoic acid, Clupanodonic (octodecatetrenoic) acid, CisH2s02; Arachidonic acid, 02 3202; Docosapentenoic acid, C22HS102; Docosahexenoic acid, C22H2202. Brown and Beal (1923), in their study of the unsaturated fatty acids of menhaden oil, had occasion to examine also salmon, herring, and sardine body oils, and cod liver oil.3 The saponification numbers, iodine numbers, and refractive indices of all five oils were very similar. Each oil was esterified by the methyl alcoholhydrogen chloride method, and the esters were fractionally distilled at 15 mm.…”