Three Novel Spin‐Labeled Substrates for Enzymatic Incorporation into Nucleic Acid Lattices

Abstract The synthesis of one C(4)‐spin‐labeled uridine‐5′‐diphosphate (C(4)‐UDP) and two nitroxide‐containing 2′‐deoxyuridine‐5′‐triphosphate (dUTP) analogs are reported. The C(4)‐UDP derivative was incorporated into copolymers by polynucleotide phosphoxylase (PNPase); one of the two dUTP analogs, substituted at position C(4), was a good substrate for TdT, whereas the other one, substituted at position C(5), served as substrate for E. coli DNA polymerase (Pol I).