1894.] Chemico-Physiological Discoveries: The Cell. 113 
may consequently consider adenin as adenylimid, while 
hypoxanthin may be appropriately termed adenyloxide. As 
might be expected from the close relationship between these 
two bodies, adenin can be readily converted into hypoxanthin; 
and in a similar manner the allied base guanin can be trans- 
formed into xanthin. Thus, Schindler” finds by experiment 
that adenin dissolved in water and exposed to putrefaction at 
about 20° C. with exclusion of air, in time entirely disappears, 
a large amount of hypoxanthin appearing in its place and 
likewise a trace of xanthin. In other words, oxygen-free 
adenin is made by this process to combine with oxygen, being 
converted into the related oxygen-containing body hypoxan- 
thin, with a giving up of ammonia. Guanin by a like 
method of treatment is changed into xanthin. The reactions 
involved are very simple as the following equations show : 
GHN +: HO sae C,H,N,O -} NH, 
denin Hypoxanthin Ammonia 
CH,N;,O + H,O maa C;H,N,0, a NH, 
Guanin Xanthin Ammonia 
We thus have every reason for believing that when 
hypoxanthin results from the breaking down of nuclein it 
passes through the intermediate stage of adenin. In other 
words, adenin is a primary cleavage product of nuclein, or 
rather of nucleic acid, while hypoxanthin is a secondary 
product coming directly from the adenin. In a similar man- 
her, guanin isa primary decomposition product of nucleic acid,. 
xanthin being in the same sense a secondary product. These- 
ur bases are plainly closely related and intimately associated, 
in many ways, and all are alike cleavage products of the nu- 
clein obtainable from cell nuclei. But the primary bodies. 
adenin and guanin are evidently far more susceptible to the- 
changes going on in living cells than their neighbors hypox- 
anthin and xanthin. All four, however, are capable of com- 
plete decomposition with formation of a variety of decompo- 
11 Zeitschrift fiir Physiologische Chemie. Band 13, p. 432. 
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