1-.Beta.-D-Arabinofuranosylcytosine 5'-palmitoyl ester 2(1H)-Pyrimidinone, {4-amino-1-[5-O-(1-oxohexadecyl)-.beta.-D-arabinofuranosyl]-} 31088-06-9 AIDS-126993 AIDS126993 Arabinosyl cytosine palmitate Aracytidine 5'-palmitate NSC135962 P-Ara-C PALMO-ARA-C Palm O-ara-C Palmitoyl cytarabine