On the Infrared Spectra of Nucleic Acids and Certain of Their Components

Abstract

Preliminary results are reported on the infrared absorption in the region 700-1,800 cm.1 of yeast ribonucleic acid, thymus desoxyribonucleic acid, and some of their chem. constituents. The lack of solubility of these materials in other than aqueous solvents made it necessary to detn. the spectra in the solid phase. Three methods were used: (a) films evaporated in high vacuum onto NaCl plates, (b) finely ground powder layers between NaCl plates, and (c) continuous films cast onto NaCl plates. It was possible to correlate several of the absorption bands with particular atomic groupings, and to differentiate one pure material from another by their infrared spectra. Thus, ribonucleic acid was differentiated from desoxyribonucleic acid by their absorptions at frequencies lower than 1,100 cm.-1; thymine was differentiated from uracil and adenine by their absorptions between 900 and 1,200 cm.1, and thymine and uracil were detected in mixtures.