A nucleoside analog with diverse biological activities is converted to cordycepin triphosphate which inhibits ATP-dependent DNA and RNA synthesis incorporates into DNA and RNA in SK-HEP-1 cells is active against B. subtilis at 0.1-1 mg/ml increases IL-10 secretion and mRNA expression in isolated human PBMCs at 24 Ug/ml increases survival of mice infected with C. albicans or C. krusei at 1 mg/kg per day