Cladobotric Acids A−F: New Cytotoxic Polyketides from a New Zealand <i>Cladobotryum</i> sp.

Cladobotric acids A−F (1−6), fungal-derived polyketides, were isolated from the fermentation broth of a New Zealand Cladobotryum species. Structures were determined by extensive spectral analysis and X-ray crystallography, and the polyketide origin of 1−6 was concluded from feeding experiments with 13C-labeled precursors. The observed folding pattern for the polyketide chain is unusual for fungi. Cladobotric acids A−F (1−6) exhibited notable cytotoxicity against the murine P388 leukemia cell line and were also active against Bacillus subtilis and Candida albicans.