Antitumor activities of newly synthesized N4-acyl-1-beta-D-arabinofuranosylcytosine.

New derivatives of 1-beta-D-arabinofuranosylcytosine were synthesized and their antitumor activities were tested against mouse leukemia L1210. Among the 50 compounds investigated, a series of N4-acyl derivatives with long-chain saturated fatty acids were found to be highly active. The most active derivatives were N4-stearoly-1-beta-D-arabinofuranosylcytosine, which was administered in the form of suspension, and N4-behenoyl-1-beta-D-arabinofuranosylcytosine given in the form of solution. They were superior to the parent compound, 1-beta-D-arabinofuranosylcytosine, in that smaller dosages exhibited strong activities regardless of the treatment schedule, and they were also resistant to cytidine deaminase.