A newfungal metabolite designated calpinactam (1) was isolated from the culture broth of Mortierella alpina FKI-4905, and its structure was elucidated by spectroscopic analyses including NMR experiments. Calpinactam was found to be a hexapeptide with a caprolactam ring at its C-terminal. Its absolute stereochemistry was determined by amino acid analysis and totalsynthesis. Calpinactam selectively