Kuehneromycins A and B, two new biological active compounds from a Tasmanian Kuehneromyces sp. (Strophariaceae, Basidiomycetes).

In a search for new inhibitors of RNA-directed DNA-polymerases kuehneromycin A (1) was isolated from fermentations of a Tasmanian Kuehneromyces species. Its structure was elucidated by spectroscopic methods. Kuehneromycin A (1) is a non-competitive inhibitor of avian myeloblastosis virus (Ki 200 microM) and moloney murine leukemia virus (Ki 40 microM) reverse transcriptases. The second compound, kuehneromycin B (2) is a strong inhibitor of platelet aggregation stimulated with different inducers. In addition, both compounds exhibit cytotoxic and antimicrobial activities.