BE-16627B is a novel metalloproteinase (MP) inhibitor isolated from Streptomyces sp. BE16627B selectively inhibited MPs such as human stromelysin and 92 kD gelatinase. After the cells were cultured with BE16627B for 5 days, BE16627B inhibited MP activity in the primary culture supernatants from synovial cells in a dose-dependent fashion without showing apparent cytotoxicity or affecting the production and secretion of MPs. Its IC50 for active collagenolysis before activation by trypsin was 25 microM.
