Chemical analysis of oils, fats, waxes and of the commercial products derived therefrom : founded on Benedikt's second ed. of 'Analyse der fette,' / by Dr. J. Lewkowitsch.

  • Lewkowitsch, J. (Julius), 1857-1913.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Chemical analysis of oils, fats, waxes and of the commercial products derived therefrom : founded on Benedikt's second ed. of 'Analyse der fette,' / by Dr. J. Lewkowitsch. Source: Wellcome Collection.

    33/872 (page 5)
    TRIARACHIN—'TRIRICINOLEIN Triarachin, Arachin, C3H5(0 . C20H39O)35 prepared by Berthelot from diarachin and arachidic acid, is very slightly soluble in ether. Tricerotin, Cerotin, C3H5(0. C25H490)3, has been prepared by Marie1 from dicerotin. It crystallises in slender needles, melting at 76-5°-77° C. Trimelissin, Melissin, C3H5(0. C30H59O)3, was obtained from di- melissin by Marie.1 It resembles cerotin; its melting point is 89 C. Cerotin and melissin apparently do not occur in nature. Triolein, Olein, C3Hf)(0 . C1SH330)3. This glyceride2 3 has been ob- tained by heating glycerol with an excess of oleic acid at 240° C. Olein is a liquid substance which has not been obtained hitherto in the solid state ; it distils in vacuo without decomposition. Its specific gravity at 15° C. is 0-900. Olein dissolves easily in ether; in absolute alcohol it is more readily soluble than either palmitin or stearin; it is insoluble in dilute alcohol. Olein combines with concentrated sulphuric acid to form a saturated compound having the formula (C3H5)2(0 . C1SH340. S04. C18H340.0)3;s this substance is very unstable, and is partly dissociated on treatment with water or alcohol into H.,S04 and a-hydroxystearic acid. Just as oleic acid is converted by nitrous acid into elaidic acid (p. 57), so olein is converted under the same conditions into elaidin. Trielaidin, Elciidin, C3H5(0 . C18H330)3, crystallises in warts, melt- ing point 32° C. (Mayer), 38° C. (Duffy). It dissolves readily in ether, but is nearly insoluble in alcohol. Trierucin, Erucin, C3H.(0. C22H410)3, is prepared like olein. It is a crystalline mass, of the melting point 31° C. Nearly insoluble in alcohol, it dissolves very readily in ether, benzene, and petroleum ether. Nitrous acid converts trierucin into tribrassidin. Tribrassidin, Brassiclin, C3H5(0. C22H410)3, is a crystalline powder, melting point 47° C. When heated above its melting point it solidi- fies, on cooling, into another modification (?), melting at 36° C. Triricinolein, Bicinolein, C3H5(0 . C1SH330)3, has been synthetised by heating ricinoleic acid with glycerol at 120°-130°, unchanged glycerol and ricinoleic acid being removed by water and petroleum ether re- spectively.4 If Berthelot's method be employed, i.e. pressure and high temperature, condensation products of mono- and di-ricinolein are formed, the simplest of which is isomeric with triricinolein, and has the formula OH . C17H32. COO . Cl7H32. COO . C3H5(Cl7H32. COOH)2. When triricinolein is boiled with toluene, either alone or in presence of zinc chloride, it is condensed to various ethers, such as that repre- sented by the formula [(OH. C17H32. COO)2C3H5. C17H39. C0]20, which differ from triricinolein by their sparing solubility in alcohol and petroleum ether. H. Meyer5 describes triricinolein (prepared by heating ricinoleic 1 Jour. Chem. Soc. 1896, Abstr. i. 347. 2 Coula oil is stated to consist of almost pure olein [Jour. Soc. Chem. Ind. 1895, 493). 3 Cp. also Juillard, Jour. Soc. Chem. Ind. 1894, 820. 4 Juillard, Jour. Chem. Soc. 1895, Abstr. i. 500.