Cytotoxicity of N6-cycloalkylated adenine and adenosine analogs to mouse hepatoma cells.

Cytotoxic effect(s) of N6-cycloalkylated adenine and adenosine derivatives, upon the viability of mouse hepatoma cells, were studied in vitro. N6-Cyclopropyl- and N6-cyclobutyladenine and adenosine derivatives (33 micrograms/ml; 24-48 h) exerted significant cytotoxic effects upon the cells. N6-Cyclopentyl- and N6-cyclohexyladenines exerted similar effects under different experimental conditions (133-166 micrograms/ml; 48-72 h), while no significant cytotoxic effect(s) were observed with the corresponding adenosine derivatives under these conditions. Observed physical changes in the treated cells included cell elongation, short stubby filaments, wide intracellular spaces and ruptured cell membranes. N6-Cycloalkylated nucleosides were usually more cytotoxic than the cycloalkylated bases.