CEREBRON. 611 



Whether the above-described cerebrosides are chemical individuals or 

 mixtures, i. e., impure substances, is still undecided. The purest cere- 

 broside thus far investigated is undoubtedly THIERFELDER'S cerebron, 

 and there is hardly any doubt that the above-mentioned cerebrosides 

 consist essentially of this body. 



Cerebron. This cerebrin, isolated by THIERFELDER and WORNER 

 and then especially studied by THIERFELDER, was first isolated by GAM- 

 GEE and called pseudocerebrin by him. THUDICHUM'S phrenosin is, 

 according to GIES/ identical with cerebron. Cerebron can be prepared 

 directly from the brain without saponification with baryta, by treat- 

 ment with alcohol containing benzene or chloroform at a temperature 

 of 50, and hence it is considered as existing preformed in the brain. 

 According to THIERFELDER, cerebron has the formula C48H9sN09; it 

 melts at 212, dissolves in warm alcohol, and separates out on cooling. 

 From proper solvents (acetone or methyl alcohol containing chloroform) 

 it may be separated as small needles or plates. If cerebron is suspended 

 in 85-per cent alcohol at a temperature of 50 C. it balls together in 

 amorphous masses, and from these needle- and leaf-shaped crystals 

 gradually form. It is dextrorotatory, and in about a 5-per cent solu- 

 tion in methyl alcohol (containing 75 per cent chloroform) is (Q;)D = +7.6 

 (KITAGAWA and THIERFELDER). According to THIERFELDER it yields 

 as cleavage products, galactose, cerebronic add (THUDICHUM " neuro- 

 stearic acid ") and sphingosin which is in part obtained as such and part 

 as dimethylsphingosin. The base sphingosin, CiyHssNC^, discovered 

 by THUDICHUM, is, according to THIERFELDER and to LEVENE. and JACOBS, 2 

 an unsaturated, diatomic, monoamino-alcohol which is readily soluble 

 in alcohol, ether, acetone and petroleum ether but insoluble in water, 

 nas an alkaline reaction and has not been obtained in a crystalline 

 state. The sulphate of dimethylsphingosin crystallizes, on the contrary, 

 from alcohol. Cerebronic acid is an oxyacid with the formula C2sH5oO3, 

 which is crystalline and which gives a crystalline methyl ester which 

 melts at 65 C. It has been obtained by LEVENE and JACOBS 3 in part 

 in a dextrorotatory and in part as an inactive form. The first melts 

 at 106-108 and the other at 82-85 C. 



Cerebron can best be prepared, according to THIERFELDER and 

 KITAGAWA, by decomposing the protagon in methyl alcohol containing 



1 Thierfelder and Worner, Zeitschr. f. physiol. Chem., 30; Thierfelder, ibid., 43, 

 44, 46, with Kitagawa, ibid., 49; with H. Loening, ibid., 68, 74, 77; Gamgee, Text- 

 book of Physiol. Chem., London, 1880; Thudichum, 1. c.; Gies, Journ. of Biol. 

 Chem., 1 and 2. 



2 Thierfelder and O. Riesser and K. Thomas, Zeitschr. f. physiol. Chem., 77; 

 Levene and Jacobs, Journ. of biol. Chem. 11. 



3 Journ. of biol. Chem., 12. 



