Penicillic acid is a naturally occurring mycotoxin produced by some species of fungi, including Penicillium. It is commonly found in decaying fruits, vegetables, grains, and cheese. Synonyms for penicillic acid include mycophenolic acid, mycophenolate, and 6-(1,3-dihydroxy-1-methylbutyl)-2H-pyran-2-one. This organic acid has been extensively studied due to its potential health risks and its contribution to food spoilage. Penicillic acid is also known as a fungal metabolite or secondary metabolite, as it is produced by fungi as a byproduct of their metabolic activities. Its detection in foods is crucial to prevent contamination and ensure food safety.