REACTION OF APURINIC ACID WITH ALDEHYDE REAGENTS

The reaction of salmon sperm apurinic acid and the model compound barium (2-deoxy-d-ribose-3,5) diphosphate with a number of compounds containing the 1bNH2 group has been studied. Two different types of reaction are apparent. In one case, with compounds containing an oxygen atom adjacent to the 1bNH2 group (i.e., having the group 1bO1bNH2) reaction occurs to yield a polysubstituted derivative of the apurinic acid. The second type of reaction involves the reaction of molecules which contain the 1bNH1bNH2 group. As indicated in a preliminary report1 reaction of apurinic acid with such compounds in slightly acid solution leads initially, by β-elimination of the phosphate ester group from C-3 of the 2-deoxyribose units, to fragments of two types, I and II, where the grouping 1bHC2bN1bR is formed by reaction of the aldehyde group with the reagent R1bNH2. Product I arises from a part of the apurinic acid chain in which there is a sequence of aldehyde sites (sites formerly occupied by purine bases in the parent DNA), whereas II arises from a sequence of pyrimidine clusters terminating in a nonglycosylated sugar residue. In some cases, rearrangement products of I (both from apurinic acid and the model compound) and II have been separated. These rearrangement products retain the residue derived from the aldehyde reagent but appear to lack the characteristic ultraviolet absorption of the 1bCH2bCH1bCH2bN1b system. The possible nature of these products is discussed. © 1969.