| Definition: |
An epoxide which is a carboxamide obtained by the formal condensation of one of the carboxy groups of oxirane-2,3-dicarboxylic acid with N-{4-[(3-aminopropyl)amino]butyl}-L-tyrosinamide. It is a natural product, isolated from Gliocladium sp. F-2665. TMC-52B acts as an inhibitor of cysteine proteinases, particularly cathepsin B (EC 3.4.22.1), cathepsin L (EC 3.4.22.15), and papain (EC 3.4.22.2); IC50 values are 200 nM, 10 nM, and 7 nM, respectively. The epoxide group has trans configuration but its exact stereochemistry is uncertain: it is either (2R,3R) or (2S,3S). |