122 



AARON BENDICH 



III 



OH 



CH, 



N 



HO 



/^N 



H2O 



Brz 



OH 



N 



OH 



CH3 



/_Br Ag20 



/ 



z 



CH3 



N 



Thymine 



^OH 

 HO H 



XXXVl 



5 -Bromo -4 -hydroxy - 

 hydrothymine 



OH 

 OH 



HO H 



XXXV 



Thymine glycol 



H2O 



NaHC03 



or 

 Ba(OH)j 



CH3 



» NaOI 1 



CHI3 ^ c=o * 



! 

 CH2OH 



XXXVII 



Iodoform Acetol 



CO2 



COOH 



4- 



NH2 



I 

 C 



/- \ 

 O NH2 



Urea 



The chloric acid oxidation of guanine'^ to guanidine (and parabanic acid), 

 described above, has been utilized in isotope studies to isolate and analyze 

 carbon ^2.^^' •^^^•^'''' Guanidine (from C-2) is also derived from an acid- 

 permanganate oxidation of guanine f^^ urea (mainly from C-8) and carbon 

 dioxide are formed as well (cf. Edmonds et aZ."^). The acid-permanganate 

 oxidation of triply labeled adenine produces urea which arises from the 

 1 ,7- and 3,9-nitrogen atoms.*"^ 



The oxidative degradations of uric acid to alloxan, murexide, allantoin, 

 etc., are well known and are ably discussed in detail elsewhere.'^ •^^•^*^ These 

 degradations have been applied to biological studies involving isotopes"^""® 

 and to isotopically labeled uric acid."^ Uric acid in alkaline solution is oxi- 



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