The isolation and structure of modified bioactive nucleosides from Jaspis johnstoni

Two cytotoxic pyrrolo[2,3-d]pyrimidine nucleosides, toyocamycin and 5-(methoxycarbonyl)tubercidin, have been isolated from the Fijian sponge Jaspis johnstoni. The structures were solved primarily by 13C nmr and mass spectral methods and confirmed by comparison to reported values in the literature. Small amounts of the corresponding aglycones were also isolated.