Volume 1

Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch.

  • Julius Lewkowitsch
Date:
1904
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch. Source: Wellcome Collection.

    52/454 (page 32)
    CHAP. CLASSIFICATION OF OILS, FATS, AND WAXES Cetyl Stearate, C1GH33.0 . CO . C17H35, forms large scales resembling those of spermaceti. Its melting point is 55°-60° C. Ceryl Cerotate, C20H51. O . CO . C25H64, occurs in Chinese wax, which consists almost exclusively of this ester. It has also been found in opium wax, and very likely occurs in wool fat. Ceryl cerotate forms snow-white, lustrous scales (from chloroform), melting at 82-5° C. Cocceryl Coccerate, Coccerin, C30H6G(O.C31H61O2)2, has been found in the wax from cochineal. It is obtained in the form of nacreous, thin laminae (from benzene), melting point 106° C. Coccerin is nearly insoluble in cold alcohol or ether, and dissolves with great difficulty in cold benzene and glacial acetic acid. Cholesteryl Palmitate,C2GH43.0 . CO . C15H31, occurs in blood-serum;1 it forms snow-white plates, melting at 77°-78° C. (Hurthle),1 or long needles of silky lustre, melting at 77° C. (Herhig).2 It is prepared synthetically by Berthelofs method (cp. cholesteryl stearate) (Hilrtlile) or by passing a current of dry hydrochloric acid through a mixture of 30 grms. of cholesterol and 50 grms. of palmitic acid at a temperature of 124° C. (Herhig).2 Cholesteryl Oleate, C2GH43 . O . CO . C17H33, has been found conjointly with the palmitate in blood-serum. It crystallises in long, thin needles, melting at about 41° C., it is soluble in ether, chloroform, and benzene, but only sparingly so in alcohol; its rotatory power is [a]D =18° 48'. Cholesteryl Stearate, C2GH43.0 . CO . C17H35, has been prepared syn- thetically by heating one part of cholesterol with 8-10 parts of stearic acid to a temperature of 200° C. (Berth,elot). It has been stated to occur in wool wax conjointly with isocholesteryl stearate (cp. “Wool Wax,” chap. xiv.). It crystallises in small needles, melting at 65° C. This wax is nearly insoluble in alcohol, and but slightly soluble in ether. Isocholesteryl Stearate, C2GH43. O . CO . C17H35, has also been obtained by synthetical methods. It crystallises in fine needles, melting point 72° C., and is but very slightly soluble in boiling alcohol. Cholesteryl Cerotate, C2GH43 . O . CO . C26H51, is prepared by passing a current of dry hydrochloric acid through a mixture of cholesterol and cerotic acid at 145° C. for 2 hours; after repeated crystallisation from petroleum ether it forms a powdery non-crystalline mass (Herhig).2 It melts at 85‘5° C. Myricyl Melissate (Melissyl melissate), C30HG1. O . O . CO . C.2i)H.-,„ occurs in gum lac (Gascaro); it melts at 92° C. The statement made by Kissling,3 that melissyl melissate occurs in tobacco, has been refuted by Thorpe and Holmes1 Hence Kissling’s note as to the occurrence of this wax in hay stands in need of confirmation. 1 Hiirthle, Jonrn. Chern.. Soc. 1896, Abstr. i. 485. 2 Xeits.f. Offentl. Chm. 4 (1898), 227. 3 Chem. Veil. 1901, 684. 4 Jonrn. diem. Soc. 1901, 982.