Cytotoxic, fungicidal nucleosides from blue green algae belonging to the Scytonemataceae.

Abstract
Tubercidin, toyocamycin, and the corresponding 5''-.alpha.-D-glucopyranose derivatives of the nucleosides are frequently responsible for much of the cytotoxicity and antimycotic activity associated with extracts of cultured cyanophytes belonging to the family Scytonemataceae. The 5''-.alpha.-D-glucopyranoses of tubercidin and toyocamycin, for example, are the major cytotoxic and fungicidal nucleosides in Fijian Plectonema radiosum and Hawaiian Tolypothrix tenuis, respectively.