ANTIVIRAL ACTIVITY OF BICYCLIC PYRIMIDINE NUCLEOSIDES

A number of pyrimidine nucloesides, which may show two hydrogen bondin g modes, have been prepared and tested for antiviral activity against a series of viruses. Whilst none of the compounds described showed sig nificant activity against human immunodeficiency virus (HIV), the bicy clic 2'-deoxynucleoside, [ 2], derived from the base 6H, 8H-3,4-dihydr opyrimido[4,5-c][1,2]oxazin-7-one, was shown to inhibit herpes simplex virus type 1 (HSV-1) at similar concentrations as BVDU1 and ACV. Comp ounds 13, ofuranosyl)-6H,8H-2-methyl-3,4-dihydropyrimido[4,5 -c][1,2]o xazin-7-one, and 14, N-4-hydroxy-5-(2-chloroethyl)-2'-deoxyuridine, we re as active as ACV against varicella-zoster virus (VZV).