436 V. CHEMISTRY OF PHOSPHATIDES AND CEREBROSIDES 



blood. 2^*'2^^ Forrai^^^ was also able to demonstrate the enzyme in adrenal 

 tissue, the thyroid, testis, and malignant tissue; it is found in cartilage, 

 where it would appear to be of importance in bone formation. ^^-^^^ Glyc- 

 erophosphatase obtained from the digestive tract, kidney, lung, liver, and 

 bone has the optimum activity at the same pH of about 9.0. -^^•-'''' It is 

 thermolabile and apparently requires a co-factor for maximum activ- 

 ity. ^^^"^-^ The enzyme acts effectively on both the a- and the /3-glycero- 

 phosphates,^^^''-"^ although Kay-^** is of the opinion that the /3-form should 

 be more readily split than the a-isomer. Glycerophosphatase may bring 

 about a synthesis of glycerophosphate from its components. ^^^ It is be- 

 lieved to be identical with hexosediphosphatase and nucleotidase.-^" 



Both optically active forms of «- glycerophosphate have been synthesized 

 by Abderhalden and Eichwald.^-*^ Karrer and Benz"^^''' also prepared these 

 compoiuids, but were only partially successful in resolving the synthetic 

 product of Fischer and Pfahler'--* through the quinine salt. Baer and Fis- 

 cher--^ were able to prepare Z( — )-Q:-glycerophosphoric acid from d{-\-)- 

 acetoneglycerol, which was found to be 100% utilizable biologically. The 

 rf(-|-)-a-glycerophosphoric acid was later prepared by these investigators,^^" 

 starting with Z( — )-acetoneglycerol. It was readily hydrolyzed by various 

 phosphatases with an even greater velocity than the Z( — )-Q:-glycerophos- 

 phoric acid. However, it could not be utilized by the muscle press juice ac- 

 cording to the procedure of Meyerhof and Kiessling,^^^'^*^ in contrast to the 

 complete utilization of the Z( — )-isomer. One must conclude that the Z( — )- 

 rather than the d(+)-Q:-glycerophosphate is the physiologically utilizable 

 form. 



jS-Glycerophosphate has been prepared synthetically by Tutin and 

 Hann^^* and later by King and Pyman."^ It is optically inactive. Bur- 



"6 E. Forrai, Biochem. Z., 142, 282-290 (1923). 



"7 R. Robison, Biochem. J., 17, 286-293 (1923). 



^18 R. Robison and K. M. Soames, Biochem. J., 18, 740-754 (1924). 



219 H. D. Kav, Biochem. J., 20, 791-811 (1926). 



"» H. D. Kay, Biochem. J., 22, 855-866 (1928). 



"1 H. Erdtman, Z. physiol. Chem., 172, 182-198 (1927). 



2'" H. Erdtman, Z. physiol. Chem., 177, 211-220 (1928). 



"3 H. Kobavashi, J. Biochem. Japan, 8, 205-223 (1927). 



"* P. Fleury and Z. Siitu, Bull. soc. chim. [4], 39, 1716-1718 (1926). 



225 P. Karier and R. Freuler, "Die enzymatische Spaltung der a- und /3-Glycerin- 

 Phosphorsauren," Festschrift Alex Tschirch, 1926, p. 42. Cited from H. Thierfelder and 

 E. Klenk, Die Chemie der Cerebroside und Phosphatide, Springer, Berlin, 1930, p. 119. 



"6 E. Abderhalden and E. Eichwald, Ber., 51, 1308-1312 (1918). 



"^ P. Karrer and P. Benz, Helv. Chim. Acta, 9, 23-25 (1926). 



228 E. Fischer and E. Pfahler, Ber., 53, 1606-1621 (1920). 



229 E. Baer and H. O. L. Fischer, /. Biol. Chem., 128, 491-500 (1939). 



230 E. Baer and H. O. L. Fischer, J. Biol. Chem., 135, 321-328 (1940). 



231 O. Meyerhof and W. Kiessling, Biochem. Z., 264, 40-71 (1933). 



232 O. Meyerhof and W. Kiessling, Biochem. Z., 267, 313-348 (1933). 



233 H. King and F. L. Pyman, /. Chem. Soc, 105, 1238-1259 (1914). 



