FR901277, a novel inhibitor of human leukocyte elastase from Streptomyces resistomycificus. Producing organism, fermentation, isolation, physico-chemical and biological properties.

A novel human leukocyte elastase inhibitor, FR901277 was discovered in the fermentation broth of Streptomyces resistomycificus No. 7622. FR901277 has a molecular weight of 961 and a molecular formula of C47H63N9O13. The mode of inhibition is competitive, with a Ki of 1.2 x 10(-8) M. Oral administration of FR901277 at doses from 32 to 320 mg/kg significantly prevented human leukocyte elastase-induced foot edema in mice.