A Reversible Photochemical Alteration of Uracil and Uridine

Abstract

Various lines of evidence (1, 3, 4) have suggested that
\nthe primary effect of lethal and mutagenic doses of ultraviolet radiations upon living cells may be partially reversible, or at least compensated within the cell. In
\nconnection with a general study of the photochemistry
\nof nucleic acid derivatives, we have discovered that, under
\ncertain conditions, the initial photodecomposition product
\nof the pyrimidine, uracil, and the corresponding product
\nof the ribose nucleotide, uridine, may spontaneously revert
\nto the initial substances, uracil and uridine, respectively.