Abstract To improve cell permeability, monomeric 3′-deoxyadenosine (cordycepin) and antivirally active trimeric 3′-deoxyadenylyl-(2′–5′)-3′-deoxyadenylyl-(2′–5′)-3′- deoxyadenosine (2′–5′) d 3 (AAA);(cordycepin-trimer core) were modified at the 2′-O-or 5′-O-position by myristic, cholic, and folic acid= tetradecanoic, 3α, 7α, 12α-trihy-droxy-5β- cholan-24-oic, and N-{4-{[(2-amino-3, 4-dihydro-4-oxopteridin-6-yl) methyl] amino} ...