Antiherpes activity of some novel analogues of (E)-5-(2-bromovinyl)-2'-deoxyuridine (E-BrVUdR) in two different cell lines.

In a series of 5-vinyl-2'-deoxyuridine (VUdR) analogues (5-(2-X-vinyl)-UdRs) the (E)-5-(2-bromovinyl)-UdR (E-BrVUdR) proved the most potent inhibitor of plaque formation of two herpes simplex virus type 1 (HSV-1) strains in human embryonic lung fibroblast (HELF) and African green monkey kidney (Vero) cell cultures. The (Z)-5-(2-bromovinyl)-UdR (Z-BrVUdR) isomer and the 5-(2,2-dibromovinyl)-UdR (Br2VUdR) analogue were 10-20 times less efficient, whereas the (E)-5-(2-cyanovinyl)-UdR (CNVUdR) and the (E)-5-(2-carboxyvinyl)-UdR (COOHVUdR) derivative were only marginally active (10(3)-10(4) times less than E-BrVUdR). The antiherpes potential of the 5-(2-X-vinyl)-UdRs was compared with that of 5-iodo-, 5-fluoro-, 5-formyl- and 5-ethyl-UdR (IUdR, FUdR, fUdR, EUdR) as well as of 9-(2-hydroxyethoxymethyl)guanine (acyclovir, ACV), 2'-fluoro-5-iodo-1-beta-D-arabinofuranosyl(ara)-cytosine (FIAC), 2'-fluoro-5-methylarauracil (FMAU), arabinosylthymine (araT) and (E)-5-(2-bromovinyl)- and 5-vinyl-araU (BrVaraU, VaraU). In HELF cells the following order of decreasing activity against HSV-1-77 was found: E-BrVUdR greater than greater than BrVaraU greater than VaraU greater than FIAC greater than FMAU = VUdR = = Z-BrVUdR = ACV = araT = FUdR greater than Br2VUdR greater than greater than IUdR greater than fUdR greater than EUdR greater than CNVUdR greater than COOHVUdR. The inhibition of HSV-1 replication by most of the investigated compounds was somewhat weaker in the plaque inhibition assay on Vero than on HELF cells, but, in the case of the 5-X-araU reference compounds the activity was strongly reduced in Vero cells. In HELF cells the order of decreasing potential against HSV-2 strain 42/78 (HSV-2-42/78) was: FIAC = FMAU greater than greater than araT greater than IUdR = VUdR greater than ACV = FUdR = greater than fUdR = EUdR = VaraU greater than E-BrVUdR greater than Z-BrVUdR greater than Br2VUdR greater than greater than BrVaraU; CNVUdR and COOHVUdR were nearly inactive.