152 



WALTER JONES 



the nucleic acid of the gland extract, but only one of them is subsequently 

 deaminized. This necessitates the conclusion that both thymus and pan- 

 creas contain two independent dearninizing ferments (guanase and ade- 

 nase), only one of which (adenase) is present in the spleen. 



An equally curious result was obtained with pig's liver. The end 

 products of self-digestion are guanine and xanthine. This is easily ac- 

 counted for by assuming that the guaiiine set free from the nucleic acid 

 remains unchanged, but that the adeninc is deaminized to hypoxan thine, 

 which in turn is oxidized to xanthine. 



Representing the purine ring with its three replaceable hydrogen atoms 



/H 

 by the symbol P H, the results of autodigestion may be expressed as fol- 



\ H 

 lows : 



/NH 2 

 P OH 

 \H 



guanine 



P OH 

 \H 



xanthine 



\H 



/H 



P XH 2 

 \H 



adenine 



/H 



P OH 



\H 



hypoxanthine 



hypoxanthine 



Pig's Thymus and Pancreas Pig's Spleen 



(Jones and Austrian (a), 1906) (Jones and Winternitz, 1905), 



/H 

 P 

 \H 



/OH 



P OH 



\01I 



Uric Acid 



P OH 

 \H 



guanine 



/OH 

 P OH 

 \H 



xanthine 

 i ? s Liver 



/H 



P OH 



\H 



hypoxanthine 



(Jones and Winternitz, 1905) 



