Non-nucleoside 5' triphosphates have applications in antiviral research. These acyclic DNA derivatives disrupt viral DNA synthesis and replication through competitive inhibition of the viral DNA polymerases and incorporation into viral DNA, which results in eventual termination of DNA elongation. The inhibition of human DNA polymerases may also occur; this action, however, is typically weak relative to the inhibition of viral polymerases that have lower fidelity (stringency) for their substrates. Triphosphate analogs of non-nucleosides are important controls for research of antiviral compounds.