Pleosporin A,an antimalarial cyclodepsipeptide from an elephant dung fungus (BCC 7069)

Cyclodepsipeptides SCH 217048 (1), SCH 218157 (2), and a new analog, pleosporin A (3), were isolated from cultures of an unidentified elephant dung fungus of the family Pleosporaceae. The structure of 3 was elucidated on the basis of detailed spectroscopic interpretation. The absolute configurations of 1–3 were determined by chiral column HPLC analysis and Marfey’s method. Cyclodepsipeptides 1–3 exhibited antimalarial activity against Plasmodium falciparum K1 with respective IC₅₀ values of 1.6, 6.4, and 1.6 μg/mL, while they did not show cytotoxicity against KB, MCF-7 and NCI-H187 cell-lines or non-cancerous Vero cells at 50 μg/mL.     

Poronitins A and B, 4-pyrone and 4-pyridone derivatives from the elephant dung fungus Poronia gigantea

New 4-pyrone and 4-pyridone derivatives, poronitins A (1) and B (2), and a new isocoumarin, 3,4-dihydro-6,8-dimethoxy-4-hydroxy-4-methyl-3-methyleneisochromen-1-one (3), were isolated from cultures of the elephant dung fungus, Poronia gigantea. The structures were elucidated on the basis of the NMR and MS data. Poronitin A (1) and known (R)-5-methylmellein were detected in all cultures (4 strains) of P. gigantea, which suggested that these metabolites maybe useful as chemotaxonomic markers.