434 V. CHEMISTRY OF PHOSPHATIDES AND CEREBROSIDES 



Table 5 

 Proportion of /3-Glycerophosphate Obtained from Various Phospholipids" 



" Adapted from P. Karrer and H. Salomon, Helv. Chitn. Ada, 9, 3-23 (1926). 

 «- H. H. Escher, Helv. Chim. Acta, 8, 686-G91 (1925). 



have been extremely variable. A number of the animal and plant phospha- 

 tides have yielded leA^o-rotatory salts, ^^^-^^^ ^vhile other workers could not 

 detect any optical activity in their preparations. ^^^•-*'- In other cases, glyc- 

 erophosphates having a dextro-rotation have been prepared from plant 

 phospholipids, ^**'^^^ as well as from preparations of brain lecithin and cepha- 

 lin,^"* On the other hand, Karrer and Salomon^* were able to separate not 

 only an optically inactive barium salt but also a dextro-rotatory as well as a 

 levo-rotatory glycerophosphate from the same preparation. The optical 

 properties of some a-glycerophosphates are summarized in Table 6. 



The hydrolysis of a- or ^-glycerophosphoric acid to glycerol and phos- 

 phoric acid cannot be brought about by bases. It proceeds only slowly 

 when dilute acids are employed. ""^•2"" However, a much more effective hy- 

 drolysis of the ester is produced by the enzyme glycerophosphatase. This 

 enzyme occurs in such plant sources as yeast, ^"^ takadiastase,^''^'^''^ and in 

 many plant seeds. -^''"-^^ It has also been sho^vn to be present in many 

 animal tissues, including the central nervous system,-^* intestinal mucosa, 

 kidneys, and, to a lesser extent, the lungs, with traces in the liver and 

 spleen. -^^'^^^ It is, however, absent from the pancreas, muscle, and 



20" S. Friinkel and L. Dimitz, Biochem. Z., 21, 337-347 (1909). 



2»6 F. Malengreau and G. Prigent, Z. physiol. Chem., 73, 68-84 (1911). 



2«6 R. H. A. Plimmer, Biochem. J., 7, 72-80 (1913). 



2" C. Neuberg and L. Karczag, Biochem. Z., 36, 60-67 (1911). 



2«» S. Akamatsu, Biochem. Z., 14^, 184-185 (1923). 



2«9 S. Akamatsu, Biochem. Z., 142, 186-187 (1923). 



"0 A. Nem6c, Biochem. Z., 93, 94-100 (1919). 



"1 A. Nem6c, Biochem. Z., 137, 570-575 (1923). 



"» A. Nem6c, Biochem. Z., 202, 229-235 (1928). 



"=> V. Vondrdcfik, Biochem. Z., 191, 88-94 (1927). 



»»* P. Grosser and J. ITusler, Biochem. Z., 39, 1-5 (1912). 



»« R. H. A. Plimmer, Biochem. J., 7, 43-71 (1913). 



