Aflastatin A, a novel inhibitor of the production of aflatoxin by aflatoxigenic fungi, has been isolated from the solvent extract of mycelial cake of Streptomyces sp. and its molecular formula was determined as C₆₂H₁₁₅NO₂₄.
Aflastatin A completely inhibited aflatoxin production by Aspergillus parasiticus NRRL 2999 in liquid medium or on agar plate at a concentration of 0.5μg/ml. The mycelial growth of this fungus was not affected in the liquid medium at the same concentration, while the hyphal extension rate was reduced on the plate together with some morphological changes. The growth of the fungus was not completely inhibited even at a concentration of 100μg/ml. Aflastatin A exhibits antimicrobial activity against some bacteria, yeasts and fungi as well as antitumor activity.