Isolation and Characterization of Two Novel Nematicidal Depsipeptides from an Imperfect Fungus, Strain D1084

Two novel nematicidal cyclodepsipeptides, designated bursaphelocides A and B, were isolated from the culture filtrate of an imperfect fungus, strain D1084, belonging to Mycelia sterilia. Bursaphelocide A (1), containing 2-hydroxy-3-methylpentanoic acid, proline, isoleucine, N-methylalanine, N-methylvaline, and β-alanine in sequence, and bursaphelocide B (2), comprising 4-methylproline instead of proline in 1, are novel 2-hydroxy-3-methylpentanoic acid analogues of insecticidal destruxins.