94 AARON BENDICH 



9-/S-D-ribofuranosylpurine,"^ has an inhibitory effect on tubercle bacilli 

 and mitosis in Allium root cells."" It is of interest to record that Fischer 

 predicted (1907) the natural occurrence of purine when he wrote "... (ich) 

 halte . . . es nicht fiir unmoglich, das auch das Purin und die Methyl- 

 purine im tierischen oder pflanzhchen Organismus entstehen.""^ Syntheses 

 of purine from uric acid^' and from uracil'^' have been accomplished. 



Other purines and simple purine derivatives that abound in nature are 

 mainly of the hydroxy and amino type. Perhaps the most ^^'idespread are 

 related to adenine. Adenine occurs in the free form, for example, in human 

 urine along ^^ith hypoxanthine and xanthine (and its methylated forms),"* 

 in human feces together with hypoxanthine, xanthine, and guanine,"^ and 

 with guanine in cow's milk."^ It is found as the free base in many 

 plants. "^""^ It is a constituent of adenosine triphosphate (ATP), and a 

 number of coenzymes such as DPN, coenzyme A, etc.'"°'^"^^ (see Chapter 4). 

 The thiomethjdpentoside of adenine isolated from yeast,^^®-^" which has 

 been sho\\'n by degradation and sjTithesis'-*''^^ to be 9-(5'-deoxy-5'-meth- 

 ylthio-/3-D-ribofuranosyl) adenine, remained a laboratory curiosity until 

 its participation (in the form of a sulfonium derivative wath homocysteine) 

 in transmethylation reactions"^ '^^^ (see also Smith and Schlenk'^*) was dis- 



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112 Ref. 9, p. 68. 



113 O. Isay, Ber. 39, 250 (1906). 



"^ M. Kruger and G. Salomon, Z. physiol. Chem. 24, 364 (1898); 26, 350, 389 (1898-99). 



115 M. Kruger and A. Schittenhelm. Z. physiol. Chem. 35, 153 (1902). 



116 C. Voegtlin and C. P. Sherwin, /. Biol. Chem. 33, 145 (1918). 



117 K. Yoshimura, Z. physiol. Chem. 88, 334 (1913). 



11* A. Winterstein and F. Somlo, in "Handbuch der Pflanzenanalyse" (Klein, ed.), 



Vol. 4, p. 362. Springer, Vienna, 1933. 

 11' H. Bredereck, in "Physiologishe Chemie" (Tlaschentrager and Lehnartz, eds.), 



Vol. 1, p. 796. Springer, Berlin, 1951. 

 12" B. Lythgoe, Ann. Repts. on Progr. Chem. (Chem. Soc. London) 42, 175 (1945). 



121 D. M. Needham, Advances in Enzymol. 13, 151 (1952). 



122 Phosphorus Metabolism, 1 (1951). 



123 Phosphorus Metabolism, 2 (1952). 



124 G. W. Kenner, Fortschr. Chem. org. Naturstoffe 8, 96 (1951). 



125 W. S. McNutt, Fortschr. Chem. org. Naturstoffe 9, 401 (1952). 



126 J. A. Mandel and E. K. Dunham, /. Biol. Chem. 11, 85 (1912). 



127 V. Suzuki, S. Odake, and T. Mori, Biochem. Z. 154, 278 (1924). 



128 K. Satoh and K. Makino, Nature 165, 769 (1950). 



129 F. Weygand, Angew. Chem. 62, 336 (1950). 



130 J. Baddiley, O. Trauth, and F. Weygand, Nature 167, 359 (1951). 



131 J. Baddiley, /. Chem. Soc. 1951, 1348. 



132 G. L. Cantoni, ref. 123, p. 129. 



133 G. L. Cantoni, /. Am. Chem. Soc. 74, 2942 (1952). 



134 R. L. Smith and F. Schlenk, Arch. Biochem. and Biophys. 38, 159, 167 (1952). 



