Preparation of an Artificial Ribonucleoside with pyrimido[4,5-d]pyrimidine-2,4,5,7-(1H,3H,6H,8H)-tetraone as a Base and its Discriminating Ability for Natural Nucleosides

An artificial ribonucleoside with pyrimido[4,5-d]pyrimidine-2,4,5,7-(1H,3H,6H,8H)-tetraone (PPT) as a nucleobase was prepared, and its binding affinity for natural nucleosides, e.g., 2'-deoxyadenosine, 2'-deoxycytidine, 2'- deoxyguanosine, and thymidine derivatives, was investigated. This investigation revealed that, as expected, the nucleoside with PPT has good binding affinity for the four natural nucleosides to form with them some stable complexes in dimethyl sulfoxide, though the structure of the complex is not clear yet. Thus, this artificial nucleoside has high potential as a universal nucleoside.