I 



A Cheap Source for Glutamic Acid. 



205 



benzoyl- and phthalyl-taurin, and Bergell 1 has attempted to use 

 /3-naphthalinsulphotaurin as a means of estimating taurin in urine. 



We have found that taurin like the carboxy amino acids 2 

 reacts with a-naphthylisocyanate to yield the corresponding 

 hydantoic acid. The barium salt of a-naphthylureidoethyl sul- 

 phonic acid was prepared by adding to a concentrated solution of 

 taurin which contained an equivalent amount of KOH, 1% 

 equivalents of a-naphthylisocyanate and the mixture was shaken at 

 frequent intervals for an hour. The insoluble dinaphthyl urea was 

 filtered off and on acidifying with HC1 the solution thickened but 

 the free hydantoic acid did not separate. On addition of BaCl 2 

 solution the barium salt of the hydantoic acid was precipitated. 

 This was washed with small quantities of ice water and then with 

 alcohol and was dried to constant weight. Estimations of C, H, 

 and Ba gave (per gram of substance) the following results. 



104 (1686) 



A cheap and convenient source for glutamic acid. 



By CARL L. A. SCHMIDT and G. L. FOSTER. 



[From the Department of Biochemistry and Pharmacology of the 

 University of California, Berkeley.] 



One of the pressing needs of biochemistry and allied sciences 

 is an adequate supply of pure amino acids. While methods for 

 the isolation and purification of these substances are well known, 



1 Bergell, P., Z. physiol. Chem., 1916, xcvii, p. 260. 



2 Neuberg, C. and Manasse, A., Ber. d. d. chem. Gesell., 1905, xxxviii, 2359. 

 Loewy, A., Deut. med. Woch., 1905, xxxi, 1918. 



Neuberg, C, and Strauss, H., Berlin klin. Woch., 1906, xliii, 258. 

 Hirschstein, L., Berlin klin. Woch., 1906, xlviii, 589. 

 Neuberg, C, and Manasse, A., Berlin klin. Woch., 1906, xliii, 734. 

 Wohlgemuth, J., and Neuberg, C, Med. Klinik, 1906, ii, 227. 

 Neuberg, C, and Rosenberg, E., Biochem. Z., 1907, v, 456. 

 Levene, P. A., and Van Slyke, D. D., Biochem. Z., 1908, xiii, 440. 

 Hirschberg, E., Dissert. Berlin, 1910. 



Found 



Calculated for 

 Ba(CioH7NHCONHCH 2 CH 2 S03)j 



C. 

 H. 

 Ba 



0.419 

 0.039 

 0.187 



0.431 

 0.036 

 0.189 



