Cladoic Acid, an Anti-<i>Trypanosoma cruzi</i> Polyketide from <i>Cladosporium</i> sp. TP-F2020

A new polyketide, cladoic acid, was isolated from a fungus of the genus <i>Cladosporium</i>. The structure of the highly oxygenated <i>trans</i>-decalin ring with an all-<i>E</i> triene side chain was elucidated by extensive spectroscopic analysis. The unique chair/twist-boat conformation of the <i>trans</i>-decalin core and the flexibility of the B-ring were demonstrated by computer-aided conformational analysis. Cladoic acid was active against <i>Trypanosoma cruzi</i> and inhibited the proliferation of amastigotes and epimastigotes with IC₅₀ values of 27 and 46 μM, respectively, but it did not show any appreciable activity against P388 murine leukemia cells, bacteria, or fungi, indicating it is a potential candidate for drug development against Chagas disease.