32 OPTICAL ACTIVITY OF BIOL. MATERIAL 



The theory of the organic origin of oil entered a new 

 phase when Tschngaeff and Walden (1900) pointed ont the 

 significance of the forgotten observations of Biot (1835) 

 on the optical activity of oil as a criterion of its origin (see 

 for further confirmation of these views Vernadsky, 1934). 

 Since the asymmetry of molecular aggregates and their 

 optical activity represent an attribute of the material of 

 living systems only, the theory of the organic origin of oil 

 can be considered as based on solid ground. 



The genesis of the optical activity of oil is far from clear. 

 Natural fats or glycerides, except lipoids of the lecithin 

 type and fats with active acid radicals, are optically inac- 

 tive and do not possess any structural dissymmetry. 

 Neuberg (1907) outlined the following scheme for the 

 transformations undergone by these structurally inactive 

 fats in the process of oil formation. Inactive trioleine, 

 which constitutes a considerable part of vegetable and 

 animal fats, would be the original source. By oxidation 

 or hydration, the structurally inactive free oleinic acid 

 would be transformed into a dissymmetric racemic body, 

 for instance, into dioxystearic acid. If now the racemic 

 trioleine with oxidized or hydratated radicals is subjected 

 to the asymmetry-producing action of the fat-splitting 

 enzymes, optically-active fatty acids would arise. Neu- 

 berg and Rosenberg (1907) performed all these transfor- 

 mations experimentally; after having obtained optically 

 active fatty acids out of structurally inactive material they 

 transformed these active acids into optically active oil. 

 According to another suggestion of Neuberg (1906), sup- 

 ported by Trask (1937), the active constituents of oil may 

 result from the transformation of proteins of dead bodies. 

 In putrefaction and in autolysis, the transformation of 

 amino-acids into corresponding fatty acids is possible ; 

 dextrorotatory isoleucine, for instance, has been trans- 

 formed into optically active capronic acid. The latter 

 could, by further condensation, give the numerous optically 

 active hydrocarbons of oil. 



