Precursor-directed biosynthesis of beauvericin analogs by the insect pathogenic fungus Paecilomyces tenuipes BCC 1614

Precursor-directed biosynthesis of beauvericin analogs, cyclohexadepsipeptide antibiotics, was investigated using the insect pathogenic fungus Paecilomyces tenuipes BCC 1614. Feeding l-isoleucine or d-alloisoleucine in liquid medium led to the enhanced production of beauvericin A and beauvericin B together with beauvericin and a missing analog, beauvericin C. Feeding experiments with d-isoleucine or l-alloisoleucine resulted in the production of diastereomers of beauvericins A, B and C, named allobeauvericins A, B and C, respectively.