Identification and isolation of insecticidal oxazoles from Pseudomonas spp.

• Florian Grundmann,
• Veronika Dill,
• Andrea Dowling,
• Aunchalee Thanwisai,
• Edna Bode,
• Narisara Chantratita,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 749–752, doi:10.3762/bjoc.8.85

• intermediates were also investigated revealing interesting biological activities for several compounds despite their overall simple structures. Keywords: insecticidal activity; labradorin; oxazole; Pseudomonas; secondary metabolite; Findings During our search for novel natural products from entomopathogenic

• known oxazole derivatives labradorin 1 (3, 241.1 m/z [M + H]+, C15H16N2O), labradorin 2 (4, 255.2 m/z [M + H]+, C16H18N2O) and pimprinaphine (5, 275.1 m/z [M + H]+, C18H14N2O) (Figure 1) [8][9]. Detailed analysis of the HPLC–MS data showed WS-30581 A (6, 227.1 m/z [M + H]+, C14H14N2O) [10] as an

• produces compounds 3–6 but not 1 and 2. Furthermore two novel oxazole derivatives named labradorin 3 (7, 268.4 m/z [M + H]+, C17H20N2O) and labradorin 4 (8, 283.2 m/z [M + H]+, C18H22N2O) were detected, but they could not be isolated due to their very low production. Labeling experiments were performed in