Convergent synthesis of ribonuclease L-active 2′,5′-oligoadenylate-peptide nucleic acids

2-5A was conjugated to N-(2-aminoethyl)-glycyl PNA by periodate oxidization, followed by coupling with amino-derivatized PNA and final cyanoborohydride reduction. An adduct of 2-5A pentamer with tetrameric thymine PNA activated RNase with the same potency as earlier versions of 2-5A-PNA or 2-5A-DNA.