Hydrolysis of 2-Aminopurine Deoxyribonucleoside in Neutral Solution

Article abstract of DOI:10.1021/jo00249a019

At various temperatures between 50 and 110 deg C, 2-aminopurine deoxyribonucleoside is severalfold more prone to degradation in aqueous sodium cacodylate buffer, pH 6.9, than is its structural isomer, deoxyadenosine, as determined by HPLC analysis of hydrolysates.It is calculated that, at 37 deg C, the rate of hydrolysis of 2-aminopurine deoxyribonucleoside is 5 times as large as the rate of hydrolysis of deoxyadenosine.The decomposition of 2-aminopurine deoxyribonucleoside is almost unaffected by changes in ionic strength or buffer concentration, but is clearly accelerated by increasing acidity in the range from pH 5.8 to pH 7.15.While deoxyadenosine decomposes to produce the corresponding free base, adenine, as the sole UV-absorbing product, 2-aminopurine deoxyribonucleoside yields primarily 2,4-diamino-5-formamidopyrimidine rather than 2-aminopurine.The latter compound is also formed during hydrolysis of 2-aminopurine deoxyribonucleoside, but it arises largely in a secondary reaction from 2,4-diamino-5-formamidopyrimidine.The increased propensity to depurination evinced by 2-aminopurine deoxyribonucleoside in comparison to deoxyadenosine as well as the alteration of the heterocyclic base occurring during the hydrolysis is of interest in view of the mutagenic activity of 2-aminopurine.