Nucleic acids. 14. Synthesis and antiviral activity of some 5'-esters of 9-beta-D-arabinofuranosyladenine (ara-A)

Synthesis of some 5'-amino-2',5'-dideoxy-5-iodouridine derivatives and their antiviral properties against herpes simplex virus

In an attempt to improve the antiviral efficacy of 5'-amino-2',5'-dideoxy-5-iodouridine (AIdU) the N-acetyl and N,3'-O-diacetyl derivatives were prepared. N-Acetylation of AIdU increased its ability to inhibit the phosphorylation of thymidine by the deoxypyrimidine kinase of herpes simplex virus type 1 (HSV1) while diacetylation had the converse effect. The affinity of the corresponding compounds containing uracil or thymine for virus deoxypyrimidine kinase was also determined. A range of N-acyl-, N-sulphonyl- and N,3'-O-diacyl- derivatives of AIdU were synthesized; enhanced inhibition of deoxypyrimidine kinase by a number of these compounds was observed. The previous observation that 5'-azido-2',5'-dideoxy-5-iodouridine has antiherpetic activity in vivo led us to investigate its 3'-O-acetyl derivative as well as the corresponding compound containing uracil. None of the derivatives described showed antiviral activity in cell culture against HSV1; acylation failed to enhance the potency of AIdU against HSV1 in vivo.

Anti-herpesvirus activity of adenine arabinoside analogues in tissue culture and a genital infection of mice and guinea pigs

Four analogues of adenine arabinoside (ara-A) were compared for activity against herpes simplex virus (HSV) in tissue culture and in a genital infection of mice and guinea pigs. These analogues, 5'-monophosphate (ara-AMP), 5'-valerate ester (ara-AV), 2'3'-diacetate ester (ara-ADA), and 2',3',5'- triacetate ester (ara-ATA) have greater water and lipid solubility and resistance to deamination than ara-A. In mouse embryo fibroblast cells, similar viral inhibitory levels were noted with ara-A, AMP, and ara-Av, while ara-ADA and ara-ATA were 6-10 time less active. In mice infected intravaginally with HSV type 2 (HSV-2), intravaginal treatment with 10% concentrations of each of the compounds beginning 3 h after viral challenge, had no effect on infection rates, titers of virus in vaginal secretions, mortality rates or the mean day of death as compared with placebo-treated controls. In the HSV-2 genital infection of guinea pigs, treatment with 10% vaginal creams or placebo vehicle was initiated 6 or 24 h after viral inoculation. In animals treated at 6 h with ara-A, ara-AMP and ara-AV, there was complete inhibition of viral replication in the vaginal tract and development of external genital lesions. When treatment with these three drugs was delayed 24 h after infection, there was no effect on vaginal virus titers, but lesions severity was reduced by ara-A or ara-AMP therapy. Ara-ATA was ineffective whether begun at 6 or 24 h. The greater solubility in water and lipid as well as the resistance to deamination of ara-AMP and ara-AV did not appear to enhance their antiviral activity over that of ara-A. Additionally, ara-ADA and ara-ATA exhibited less activity both in tissue culture and in the experimental genital infections.