Valilactone is a naturally occurring γ-lactone compound isolated from actinomycetes, functioning as a potent and specific inhibitor of acylpeptide hydrolase (APH) and prolyl oligopeptidase (POP). It is primarily utilized in biochemical and pharmacological research to investigate enzyme inhibition mechanisms, protein degradation pathways, and post-translational modifications. Valilactone's unique structure allows it to block the removal of N-acyl groups from peptides, making it a valuable tool in studies related to neurodegenerative diseases, cancer, and peptide metabolism. It is also explored for potential therapeutic applications in drug development targeting peptidase-related disorders.