It is produced by the strain of Pen. puberulum. It is an antibiotic with activity against gram-positive bacteria, negative bacteria and mycobacterium. It is also used as a raw material for various semisynthetic penicillins. Penicillic acid, a kind of polyketide mycotoxin, has been found to restrain GDP-mannose dehydrogenase and sorts of other dehydrogenases. It causes DNA to break.