Antiherpes activity of [E]-5-(1-propenyl)-2′-deoxyuridine and 5-(1-propenyl)-1-β-d-arabinofuranosyluracil

5-(1-Propenyl)-1-β-d-arabinofuranosyluracil has been synthesized, and this compound and [E]-5-(1-propenyl)-2′-deoxyuridine have been tested for inhibition of herpes virus multiplication. Only [E]-5-(1-propenyl)-2′-deoxyuridine was found to be an active inhibitor reducing by 50% the plaque formation of herpes simplex virus type 1 (HSV-1) at about 1 μM. A comparison to the bromovinyl derivatives showed the following order of decreasing activity; $\text{[}\text{E}\text{]-5-(2-}\text{bromovinyl}\text{)-2′-}\text{deoxyuridine}\text{> 5-(2-}\text{bromovinyl}\text{)-1-β-}\text{d}\text{-}\text{arabinofuranosyluracil}\text{≥ [}\text{E}\text{]-5-(1-}\text{propenyl}\text{)-2′-}\text{deoxyuridine}\text{> 5-(1-}\text{propenyl}\text{)-1-β-}\text{arabinofuranosyluracil}$. HSV-1 mutants lacking thymidine kinase or resistant against acycloguanosine were resistant against [E]-5-(1-propenyl)-2′-deoxyuridine. All compounds seemed to be phosphorylated by HSV-1 thymidine kinase in a cell-free assay. The compounds were phosphorylated to a lower extent by cellular or HSV-2 thymidine kinase, and the HSV-2 strains tested were inhibited by less than 50% at 100 μM in plaque assays. A selective inhibition of HSV-1 DNA synthesis by [E]-5-(1-propenyl)-2′-deoxyuridine was observed in infected cells indicating an effect on viral DNA polymerase. [E]-5-(1-Propenyl)-2′-deoxyuridine had a low cellular toxicity and a therapeutic effect when applied topically to HSV-1-infected guinea pig skin.