np100890n_si_001.pdf (410.43 kB)

Insecticidal Cyclodepsipeptides from Beauveria felina

Download (410.43 kB)
journal contribution
posted on 25.04.2011 by Aude Langenfeld, Alain Blond, Sabelle Gueye, Patrick Herson, Bastien Nay, Joëlle Dupont, Soizic Prado
A novel cyclodepsipeptide, iso-isariin B (1), and the known isaridin E (2) were isolated from the entomopathogenic fungus Beauveria felina. Their structures were elucidated using MS/MS fragmentation and extensive 2D-heteronuclear NMR. The X-ray structure of isaridin E was obtained, showing two potent intramolecular H bonds and a type-VI turn with the HyLeu1-Pro2 amide bond in a cis conformation. Iso-isariin B (1) was active against the pest-insect Sitophilus spp. with an LD50 value of 10 μg/mL. This observation also gives some clues for ecological interpretation of cyclodepsipeptide production by B. felina.