Phosphoramidon is a chemical compound derived from cultures of Streptomyces tanashiensis. It is an inhibitor of the enzyme thermolysin, of the membrane metallo-endopeptidase, and of the endothelin converting enzyme. Chemically, phosphoramidon differs from its closely related peptidase inhibitor talopeptin by a single stereocenter.
Because of its enzyme inhibitory properties, phosphoramidon is widely used as a biochemical tool.