5-(2-bromoethyl)-2'-deoxyuridine: a selective inhibitor of herpes simplex viruses in vitro.

A new pyrimidine analog, 5-(2-bromoethyl)-2'-deoxyuridine (BEUdR), was tested in vitro for antiviral activity on Herpes simplex virus types 1 and 2. As reference compounds, ACG, BVUdR and PAA were used. Compared to ACG and BVUdR, BEUdR resulted less potent on both HSV-1 and HSV-2. However, a 50% inhibition of the multiplication of uninfected cells could be obtained only at very high BEUdR concentration (ID50 = 8500 microM). This makes BEUdR the least toxic analog known and gives it a selective index comparable to, if not better, than of ACG and BVUdR.