The effect of U.V.‐light on some components of the nucleic acids. IV. The influence of oxygen on the extent of the first irreversible reaction, shown by uracil and orotic acid

Abstract

Abstract The percentage of orotic acid, sensitive to ultraviolet light, has been found to depend on the concentration of oxygen in solution. Diminishing this concentration by bubbling through nitrogen or hydrogen, the sensitivity increases from 14 % to 37 %. Saturation of the solution with oxygen leads to protection (instead of 14 % an irreversible loss of 7%). One of the reactions, shown by uracil on irradiation (“the first irreversible reaction”) also exhibits this relationship. The possibility of an intermediate triplet state is proposed.