In vitro binding of beta-propiolactone to calf thymus DNA and mouse liver DNA to form 1-(2-carboxyethyl) adenine.

In vitro reaction of beta-propiolactone (BPL) with calf thymus DNA and mouse liver DNA followed by acid (HCL) hydrolyses of the BPL-reacted DNA's resulted in the isolation of a new compound, 1-(2-carboxyethyl)-adenine (1-CEA). The structure was assigned on the basis of ultraviolet spectra at acidic, alkaline and neutral pH and electron impact and chemical ionization mass spectra as well as chemical synthesis of 1-CEA from BPL and 2'-adenosine-5'-monophosphoric acid. The only other compound previously isolated from the in vitro and in vivo reactions of BPL and DNA was 7-(2-carboxyethyl)guanine (7-CEG) which we also identified as a product of our in vitro reaction. Under the conditions used the main product of alkylation was 1-CEA and the ratios of the concentrations of 1-CEA to 7-CEG was approx 3 : 1. The possible effect of the formation of 1-CEA on the structure of DNA and its role in chemical carcinogenesis is discussed.