Synthesis and evaluation of fatty acyl ester derivatives of cytarabine as anti-leukemia agents.

Cytarabine is a chemotherapeutic agent predominately used for the treatment of acute myeloid leukemia and lymphoblastic leukemia. Cytarabine is a polar nucleoside, has a short plasma half-life, and its use is associated with severe side effects. Fatty acyl derivatives of cytarabine were synthesized with the expectation to improve cellular uptake and generate derivatives with a longer duration of action. Multi-step protection and deprotection reactions of hydroxyl and amino groups and conjugation with a fatty acid (i.e., myristic acid and 12-thioethyldodecanoic acid) afforded 5'-O-substituted, 2'-O-substituted, and 2',5'-disubstituted fatty acyl derivatives of cytarabine. 2',5'-Dimyristoyl derivative of cytarabine was found to inhibit the growth of CCRF-CEM cells by approximately 76% at concentration of 1 microM after 96 h incubation.