EI-2346, a novel interleukin-1beta converting enzyme inhibitor produced by Streptomyces sp. E-2346. I. Taxonomy of producing strain, fermentation, isolation, physico-chemical properties, and biological properties.

EI-2346, a novel interleukin-1beta converting enzyme (ICE) inhibitor, was isolated from the culture broths of Streptomyces sp. E-2346. EI-2346 selectively inhibited the human recombinant ICE activity with an IC50 value of 3.9 microM, without inhibiting elastase and cathepsin B. EI-2346 also inhibited mature interleukin-1beta secretion from THP-1 cells induced by LPS with an IC50 value of 5.2 microM.