**2. (2**′**-5**′**)Oligoadenylates modified on the heterocyclic base**

The contribution of various functional groups of each individual 2-5A nucleoside moiety is highly specific to both RNase L binding and activation. There have been scientific publications in which ppp(A2′p5′)2A or trimer thereof were modified in the nucleotide part and subsequently assessed for their sustained ability
