The title compound is an excellent substrate for E. coli PNP, as well as for its D204N mutant. The main product of the synthetic reaction is N9-riboside, but some amount of N7-riboside is also present. Surprisingly, 1,N6-ethenoadenine is also ribosylated by both wild-type and mutated (N243D) forms of calf PNP, which catalyze the synthesis of a different riboside, tentatively identified as N6-β-D-ribosyl-1,N6-ethenoadenine. All ribosides are susceptible to phosphorolysis by the E. coli PNP (wild type). All the ribosides are fluorescent and can be utilized as analytical probes.
Keywords: ethenoadenine; ethenoadenosine; fluorescent base analogs; nucleoside synthesis; purine-nucleoside phosphorylase.