THE FLUORESCENCE PROPERTY OF DINUCLEOSIDE MONOPHOSPHATES CONTAINING ETHENOADENOSINE AND 5,6-DIHYDROURIDINE DERIVATIVES

The role of neighboring nucleotides in the quenching of ethenoadenosin e fluorescence as a constituent of dinucleotides is studied. Bisulfite reacts with the uracil moiety of dinucleoside monophosphate, Up epsil on A to yield an addition product, 5,6-dihydro-6-sulfouridylyl-ethenoa denosine. During the course of the reaction, the fluorescence of ethen oadenosine increases up to 8-fold, to the same intensity as that of mo nomeric ethenoadenosine. 5,6-Dihydrouridylyl-ethenoadenosine has a sim ilar fluorescence intensity. These results form evidence that the role played by a neighboring nucleotide in the quenching of ethenoadenosin e fluorescence in oligo- or polynucleotides is to generate an aromatic -aromatic interaction between these bases.