Tanzawaic acids I–L: Four new polyketides from Penicillium sp. IBWF104-06

• Louis P. Sandjo,
• Eckhard Thines,
• Till Opatz and
• Anja Schüffler

Beilstein J. Org. Chem. 2014, 10, 251–258, doi:10.3762/bjoc.10.20

• same trans-decalinpentanoic acid skeleton as tanzawaic acids A–H. One of the new compounds was found to inhibit the conidial germination in the rice blast fungus Magnaporthe oryzae at concentrations of 25 μg/mL. Keywords: arohynapene; natural products; polyketides; structure elucidation; tanzawaic

• assignment, the structure of compound 4 was established as shown in Figure 5. The fourth member of the series was consequently named tanzawaic acid L (Figure 5). Along with compounds 1–4, four known polyketides were isolated and identified (Figure 5) as arohynapene A (5) [3], arohynapene B (6) [3], tanzawaic

• acid A (7) [1], and tanzawaic acid E (8) [2]. Their structures were established based on NMR data and by comparison with those reported in the literature. The structures of arohynapene A and tanzawaic acid E were furthermore supported by X-ray crystallography (Figure 6). In the latter case, the