Comparative study of the antiviral activity of acyl derivatives of 2,2'-anhydro-1-beta-D-arabinofuranosylcytosine and other nucleosides against encephalitis in mice.

Anti-deoxyribonucleic acid virus activities of 3'-O-acyl derivatives of 2,2'-anhydro-1-beta-d-arabinofuranosyl cytosine (cyclo-C) and 1-beta-d-arabinofuranosylcytosine (Ara-C) were evaluated by using an in vivo test system in mice. Among the derivatives tested, 3'-O-decanoyl cyclo-C hydrochloride was the most effective against herpes simplex virus-induced encephalitis in mice when the drug was administered directly into infected brains of mice (target-organ treatment). A comparative study of the treatment of herpetic encephalitis in mice with 3'O-decanoyl cyclo-C and other nucleosides, including Ara-C, 9-beta-d-arabinofuranosyladenine (Ara-A), and 5-iodo-2'-deoxyrudine (IUdR), proved Ara-A to be more efficacious than the other nucleosides, followed by 3'-O-decanoyl cyclo-C, which was more active than Ara-C and IUdR. Administration of 3'-O-acyl cyclo-C's by intraperitoneal injection, however, failed to demonstrate activity against herpetic encephalitis in mice. The antivaccinial activity of 3'-O-decanoyl cyclo-C was also compared with that of other compounds against encephalitis and dermal tail lesions in mice caused by vaccinia virus infection. Interaperitoneally administered 3'-O-decanoyl cyclo-C and Ara-C also showed no significant activity against the diseases. Under these test conditions, N-methylisatin-beta-thiosemicarbazone (Marboran) was the most active compound, followed by Ara-A.