8 CHOLINE 



been widely studied. A summary of the early work on acetylcholine has been 

 published by Gaddum.^^ 



Hunt^^ described a biological test for choline based on its conversion to 

 acetylcholine and the demonstration of the effect of the ester in lowering 

 blood pressure in cats or rabbits or in decreasing the amplitude of the beat 

 of the frog's heart. Ackermann and Mauer*" prepared the acetylcholine salt 

 of dipicrylamine, insoluble red crystals yielding a red solution with acetone 

 suitable for colorimetric estimation. Rossi et al}^ compared various deriva- 

 tives and found that the formation of the crystalline silicotungstate was a 

 useful method of distinguishing choline and acetylcholine. 



Inukai and Nakahara^^ isolated phosphorylcholine from beef liver. A 

 yield of 0.3 g. of the crystalline picrate was obtained from 200 kg. of fresh 

 beef liver. The crystals, which were an addition compound of 1 mole of picric 

 acid and 2 moles of the ester, softened at 225° and melted at 228°. Both the 

 synthesis and hydrolysis of phosphorylcholine by intestinal phosphatase 

 have been reported.*^- '^ The enzymatic cleavage of phosphorylchoHne has 

 been studied extensively by Baccari.^^ ■ ^^ 



Isolation from animal tissues of a water-soluble substance believed to be 

 the phosphorylchoHne ester of sphingosine has been reported by a number 

 of investigators.^"' ^^-^ King and Aloisi^^ isolated glycerylphosphoric acid 

 from an acid extract of beef pancreas and assumed that it resulted from 

 hydrolysis of glycerylphosphorylcholine (GPC). Schmidt et al}^ isolated 

 the latter compound from incubated pancreas and, on the basis of diffi- 

 culties in the isolation of homogeneous products of this type, questioned 

 the identity of the product previously isolated by King and SmalP^ and 

 believed by them to be sphingosylphosphorylcholine. Kahane and L6vy^^-^^ 



38 J. H. Gaddum, Ann. Rev. Biochem. 4, 311 (1935). 



" R. Hunt, /. Pharmacol. Exptl. Therap. 7, 301 (1915). 



^0 D. Ackermann and H. Mauer, Hoppe-Seyler's Z. physiol. Chem. 279, 114 (1943). 



*i L. Rossi, A. D. Marenzi, and R. Lobo, Anales.farm. y bioquim. {Buenos Aires) 13, 



31 (1942). 

 « F. Inukai and W. Nakahara, Proc. Imp. Acad. (Tokyo) 11, 260 (1935). 

 « S. Bouchilloux and A. Tissieres, Bull. soc. chim. biol. 29, 955 (1947). 

 <4 J. Roche and S. Bouchilloux, Arch. sci. physiol. 2, 283 (1948). 

 « V. Baccari, Boll. soc. ital. biol. sper. 21, 48 (1946). 

 " V. Baccari and G. Auricchio, Boll. soc. ital. biol. sper. 22, 559 (1946). 

 ^' E. Strack, E. Neubaur and H. Geissendorfer, Hoppe-Seyler's Z. physiol. Chem. 229, 



25 (1934). 

 ^8 F. J. Booth, Biochem. J. 29, 2071 (1935). 



<9 F. J. Booth and T. H. Milroy, /. Physiol. (London) 84, 32P (1935). 

 BO D. H. Smyth, Biochem. J. 29, 2067 (1935). 

 " E. J. King and C. W. Small, Biochem. J. 33, 1135 (1939). 

 52 E. J. King and M. Aloisi, Biochem. J. 39, 470 (1945). 



" G. Schmidt, B. Hershman, and S. J. Thannhauser, /. Biol. Chem. 161, 523 (1945). 

 " E. Kahane and J. Ldvy, Compt. rend. 219, 431 (1944). 



