Inhibitory effects of triphosphate derivatives of oxetanocin G and related compounds on eukaryotic and viral DNA polymerases and human immunodeficiency virus reverse transcriptase

J Biochem. 1992 Jul;112(1):81-7. doi: 10.1093/oxfordjournals.jbchem.a123870.


In order to clarify the biological activities of (-)-oxetanocin G, and (-)-oxetanocin A and its carbocyclic analogue, (-)-carboxetanocin G, the inhibitory effects of triphosphate derivatives of these compounds (OXT-GTP, OXT-ATP, and C-OXT-GTP) on eukaryotic and viral DNA polymerases were examined. DNA polymerase alpha purified from calf thymus was weakly inhibited by OXT-GTP and OXT-ATP but strongly by C-OXT-GTP, the Ki value being 0.22 microM. On the other hand, rat DNA polymerase beta was not affected by these analogues. DNA polymerase gamma purified from bovine testes was very weakly inhibited by OXT-GTP and OXT-ATP, but not by C-OXT-GTP. DNA polymerase from herpes simplex virus type-II (HSV-II) was strongly inhibited by all three analogues, the Ki values ranging from 0.5 to 1.0 microM. Human immunodeficiency virus-encoded reverse transcriptase (HIV RT) was also strongly inhibited by these three analogues, the Ki value of C-OXT-GTP being slightly smaller than that of OXT-GTP or OXT-ATP. Analysis of products synthesized on singly primed M13 single-stranded DNA by DNA polymerase alpha, HSV-II DNA polymerase or HIV RT in the presence of the analogues revealed that OXT-GTP and C-OXT-GTP were incorporated into DNA and caused chain termination mainly at sites one or two nucleotides beyond the cytosine bases on the template.

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / pharmacology*
  • Animals
  • Antiviral Agents / pharmacology*
  • Base Sequence
  • Cattle
  • Guanine / analogs & derivatives
  • Guanine / pharmacology
  • Guanosine Triphosphate / analogs & derivatives*
  • Guanosine Triphosphate / pharmacology
  • HIV Reverse Transcriptase
  • Humans
  • Kinetics
  • Male
  • Molecular Sequence Data
  • Nucleic Acid Synthesis Inhibitors*
  • Rats
  • Reverse Transcriptase Inhibitors*
  • Structure-Activity Relationship
  • Viral Proteins / antagonists & inhibitors*


  • Antiviral Agents
  • Nucleic Acid Synthesis Inhibitors
  • Reverse Transcriptase Inhibitors
  • Viral Proteins
  • oxetanocin
  • oxetanocin G
  • oxetanocin guanosine triphosphate
  • Guanine
  • Guanosine Triphosphate
  • Adenosine Triphosphate
  • HIV Reverse Transcriptase
  • Adenine