C. Ponnamperuma, C. Sagan, R. Mariner
Jul 20, 1963
Citations
2
Influential Citations
136
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Quality indicators
Journal
Nature
Abstract
In view of the fact that several fundamental coenzymes of intermediate metabolism and plant photosynthesis are nucleoside phosphates, and as all of these molecules contain purines and pyrimidines that have strong ultraviolet absorption maxima near 2600 A deg , the possibility arises that the absorption of ultraviolet photons by purines and pyrimidines provided the bond energy for the synthesis of nucleoside phosphates in primitive tissues. To test the hypothesis, such syntheses were attempted under laboratory conditions. Labeled adenine, adenosine, and adenylic acid were sealed in aqueous solutions in Vycor tubes with approximately stoichiometric quantities of ribose, phosphoric acid, or polyphosphate ester. The solutions were irradiated by four General Electric ultraviolet germicidal lamps. During a one hour irradiation, the samples absorbed a total of approximates 10/sup 8/ ergs. Reaction products were analyzed by paper chromatography, autoradiography, and ultraviolet absorption. Positions of the carriers were detected by shadowgrams. Coincidence both in position and in shape between the carriers on the shadowgrams and the radioactivity on the autoradiograph were chromatographic bases for identification. Ultraviolet excitation of adenine accounts for the synthesis of adenosine, but participation of phosphorus compounds in the reaction is obscure. It was concluded that ultraviolet irradiation of solutions of desoxyribosemore » purines and pyrimidines may have some relevance to the problem of nucleoside phosphate origins. (H.M.G.)« less