Helvolic acid is a mycotoxin originally isolated from A. fumigatus that has broad-spectrum antibiotic activity against Gram-positive and Gram-negative bacteria. At 4-16 mg/L, it acted synergistically with erythromycin (500-2,000 mg/L) in vitro on five multi-drug resistant strains of S. aureus. At 10 mg/kg/d, it reduced tumor growth and prolonged survival synergistically with cyclophosphamide (20 mg/kg/d) in a mouse model of sarcoma but had no effect when administered alone.
