Abstract
An analogue of the 2-5A core trimer containing an 8-(4-aminobutyl)-aminoadenosine (1; A) residue at the 2′(3′)-terminus [2; (2′,5′)A2A∗] was synthesized. The conformation of (2′,5′)A2A∗ was studied by 1H, 13C-NMR, and CD spectroscopy. The (2′,5′)A2A∗ exhibits very low binding ability to the RNase L of mouse L cells, but slightly enhanced resistance to digestion by SVPD compared to the parent trimer.