Synthesis and antiherpes virus activity of 1,5-anhydrohexitol nucleosides

The synthesis of 1,5-anhydrohexitol nucleosides is described. These nucleoside analogues were obtained by alkylation of the heterocyclic bases with the tosylate 10 or by alkylation of the bases with the alcohol 12 under Mitsunobu conditions. The compounds were evaluated for antiviral and cytostatic activity. Highly selective activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) was noted for 1,5-anhydro-2,3-dideoxy-2-(5-iodouracil-1-yl)-D-arabino-hexitol 4b at a concentration of 0.07 microgram/mL. This activity must be dependent on a specific phosphorylation by the virus-encoded thymidine kinase (TK), since compound 4b was inactive against TK-deficient mutants of HSV-1. The corresponding cytosine 4c and guanine 4e analogues showed activity against HSV-1, HSV-2, and other herpes viruses (i.e. cytomegalovirus, varicella-zoster virus) at concentrations well below the cytotoxicity threshold (2 and 20 micrograms/mL, respectively). At these concentrations, compounds 4c and 4e proved also inhibitory to the growth of human T-cells (i.e. MT-4, CEM, MOLT-4).