Paecilodepsipeptide A, an antimalarial and antitumor cyclohexadepsipeptide from the insect pathogenic fungus Paecilomyces cinnamomeus BCC 9616

Paecilodepsipeptide A (1), a new cyclohexadepsipeptide possessing three D-amino acid residues, together with its linear analogues paecilodepsipeptides B (2) and C (3), was isolated from the insect pathogenic fungus Paecilomyces cinnamomeus BCC 9616. Structures of these compounds were elucidated primarily by NMR and mass spectroscopic analyses. The absolute configurations of the amino acid and hydroxy acid residues of 1 were addressed by HPLC analysis of its acid hydrolyzate using a chiral column and Marfey's method. Paecilodepsipeptide A (1) showed activity against the malarial parasite Plasmodium falciparum K1 with an IC50 value of 4.9 mu M. This compound also showed cytotoxicity to two cancer cell lines, KB (IC50 5.9 mu M) and BC (IC50 6.6 mu M); however, it was inactive against noncancerous Vero cells up to 67 mu M (50 mu g/mL).