Akanthomycin, a New Antibiotic Pyridone from the Entomopathogenic Fungus Akanthomyces gracilis

Organic extracts of the entomopathogenic fungus Akanthomyces gracilis ARS 2910 contained antibiotics active against Staphylococcus aureus. Bioassay-guided fractionation of the CH₂Cl₂ extract yielded the antibacterial compound akanthomycin as a mixture of atropisomers along with the closely related compounds 8-methylpyridoxatin and cordypyridone C. Akanthomycin was characterized using X-ray crystallography and NMR.