With focus on exploring the structural demands of adenosine triphosphate pockets of different target enzymes, the 3'-amido-3'-deoxyadenosines 1-7 were synthesized. The inhibitory activity of these compounds on a selected cyclin-dependent kinase as model target in anticancer research was evaluated in vitro. A starfish oocyte enzyme based assay revealed a decreased inhibitory activity in comparison to adenosine. Consequently, the introduction of spacefilling lipophilic 3'-amido substituents alters the enzyme inhibition in an unfavorable manner.