354 CHEMISTRY OF THE LEUCOMAINS. 



Kriiger, by modifying the experimental conditions, adding sodium 

 nitrite in small portions to a solution of adenin in dilute sulphuric 

 acid at 70°, obtained an almost quantitative conversion. 



This formation of hypoxanthin from adenin is analogous to 

 Strecker's transformation of guanin into xanthin by a similar action 

 of nitrous acid (see guanin). In both cases the change of a highly 

 nitrogenized into a less nitrogenized body is accomplished by replac- 

 ing an NHj group by O. The change is somewhat analogous to that 

 seen in the conversion of primary amins into primary alcohols. Thus, 



C,H5.NH, + HNO, = CjHjOH + N, + H,0. 

 Ethti.^hin. Ethyl Alcohol. 



In the extraction of adenin from the mother liquor of tea leaves 

 after removal of caffein, if urea is not added to the nitric acid, 

 nearly one-half of the adenin may be converted into hypoxanthin. 

 By processes of putrefaction adenin is converted into hypoxanthin 

 and guanin into xanthin (Schindler). A similar conversion of 

 adenin and guanin takes place rapidly in the pancreas after death 

 and it is not unlikely that this change is due to the action of nitrous 

 acid produced by bacteria. Adenin undergoes this decomposition 

 more rapidly than do the other purin bases. In view of the ease 

 with which this conversion of adenin and guanin takes place it is 

 quite probable that similar changes may take place within the cell 

 nucleus proper and as a result hypoxanthin and xanthin form in 

 greater or less amount. The formation of xanthin from guanin 

 represents the conversion of a guanidin residue into a urea group. 

 The amido group in all probability is split off as ammonia and goes 

 to make urea. 



Adenin unites with bases, acids, and salts. The salts of adenin 

 with mineral acids can be recrystallized, thus differing from the cor- 

 responding salts of guanin and hypoxanthin, which are dissociated 

 by the action of water. The solutions of the salts, however, show 

 an acid reaction to litmus, but not to methyl orange. The addition 

 of ammonia to concentrated aqueous solutions of its salts yields 

 crystalline adenin. 



The hydrochlorid, CjHjNg.HCl -|- ^HjjO, forms colorless, trans- 

 parent, strongly refracting crystals. One part of the anhydrous 

 salt is soluble in 41.9 parts of cold water. Microscopically it is 

 distinct from that of hypoxanthin and adenin-hypoxanthin. From 

 the composition of the gold salt it is highly probable that a hydro- 

 chlorid, C5HJN5.2HCI, exists analogous to that of guanin. In the 

 course of the synthesis of adenin Fischer prepared a di-iodid. 



The nitrate, C^H^NyHNO, + |HjO, crystallizes from the aqueous 

 solution in fine, stellate needles. One part of the dry salt dissolves 

 in 110.6 parts of water. 



The sulphate, (CjH^NJj.HjSO^ -I- 2B.f), can be obtained from the 



