omega-Acryloyl anionic surfactants, whose polar heads are derived from amino acids, have been telomerized to prepare polyanions of a predetermined molecular weight. The main goal of this study was to verify whether the antiviral activity is influenced by the degree of polymerization of the polyanions. The oligomeric polyanions were evaluated for their activity against human immunodeficiency virus (HIV-1 or HIV-2) and various other RNA and DNA viruses. With regard to their anti-HIV activity, a minimum number of anionic groups was necessary to achieve an inhibitory effect. Moreover, to be active the overall conformation of the polyanion must be such that the anionic groups are located on the external site of the molecule. With some of the polyanions, a 50% inhibition concentration (IC50) as low as 1 microgram/ mL, or even 0.1 microgram/mL, was noted against HIV-1 in CEM-4 and MT-4 cells, respectively. The most potent polyanions also proved active against human cytomegalovirus and herpex simplex virus at concentrations of 5-10 and 20-40 micrograms/mL, respectively. No activity was observed against any of the other viruses tested (i.e., vesicular stomatitis, Sindbis, Semliki forest, parainfluenza, Junin, Tacaribe, Coxsackie, polio, reo, and vaccinia). No toxicity for the host cells was observed at concentrations up to 200 micrograms/mL.

The chemical synthesis of certain 4-substituted pyrazolo[3,4-d]pyrimidine nucleosides is described. Using 1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidin-4-one (1) as the starting material, the reactive intermediate 4-chloro-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine (2) was prepared in excellent yield. Compound 2 served as a versatile precursor for the synthesis of a number of 4-substituted pyrazolo[3,4-d]pyrimidine nucleosides. In antitumor studies of these nucleosides, in vitro and in vivo, it was found that any alteration of the 4-amino substituent of 4-amino-1-beta-D-ribofuranosylpyrazolo[3,4-d]pyrimidine (3) was accompanied by a significant decrease or loss of antitumor activity. On the other hand, introduction of certain substituents at the 3 position of 3 (synthesis reported previously) led to a dramatic increase in antitumor activity in comparison to the parent compound.