Two new and five known oxazoles were identified from two different Pseudomonas strains in addition to the known pyrones pseudopyronine A and B. Labeling experiments confirmed their structures and gave initial evidence for a novel biosynthesis pathway of these natural oxazoles. In order to confirm their structure, they were synthesized, which also allowed tests of their bioactivity. Additionally, the bioactivities of the synthesis intermediates were also investigated revealing interesting biological activities for several compounds despite their overall simple structures.
Keywords: Pseudomonas; insecticidal activity; labradorin; oxazole; secondary metabolite.