(±) cis-Bisamido epoxides: A novel series of potent FXIII-A inhibitors

A novel class of potent FXIII-A inhibitors containing a (±) cis-bisamido epoxide pharmacophore is described. The compounds display highly potent inhibition of FXIII-A (IC50 = 5–500 nM) in an in vitro assay. In contrast to other types of previously described covalent transglutaminase inhibitors, the bis-amido epoxides exhibited no measurable reactivity with glutathione, therefore possibly rendering this class of compounds suitable for future in vivo investigations. Additionally, the compounds show selective inhibition for FXIII-A against the cysteine protease, cathepsin S although they proved to have similar potency with a closely related transglutaminase, TGII, to that observed for FXIII-A.