Viridicatumtoxin A

Viridicatumtoxin A (also simply called viridicatumtoxin) is a fungus-derived tetracycline-like antibiotic, whose chemical structure was determined in 1976. It is found in "Penicillium viridicatum", "Penicillium aethiopicum", among other fungi.
Like viridicatumtoxin B, viridicatumtoxin A inhibits growth of "Staphylococcus aureus", including methicillin resistant "S. aureus" and quinolone-resistant "S. aureus", with an activity 8 to 64 times greater than that of tetracycline.