rearrangement under acidic conditions of 5 supported the correctness of the assigned structure. An ultraviolet spectroscopic approach suggested that the neutral species of 5 exists in H2O mainly as the N(7)-OH tautomer (21). In the in vitro bioassay of antileukemicactivity against murine L5178Y cells, 5 was weakly cytotoxic, with IC50 of 100 micrograms/ml. It did not show any antimicrobial activity even at 1000