4-Alkyliden-β-lactams conjugated to polyphenols: Synthesis and inhibitory activity

A series of compounds combining the β-lactam and polyphenol scaffold have been prepared and evaluated for inhibition of human leukocyte elastase and matrix metallo-proteases MMP-2 and MMP-9. The design of these compounds has been based on the 'overlapping-type' strategy where two pharmacophores are linked in a single molecule. The most powerful compound against elastase was an N-galloyl-4-alkyliden β-lactam, [3-[1-(tert-butyl-dimethyl-silanyloxy)- ethyl]-4-oxo-1-(3,4,5-tris-benzyloxy-benzoyl)-azetidin-2-ylidene]-acetic acid ethylester, with an IC50 of 0.5 μM; while the most powerful against MMP-2 was a 4-alkyliden β-lactam arylated on the C-3 hydroxy side chain (3,5-bis-benzyloxy-4-hydroxy-benzoic acid 1-(2-benzyloxycarbonylmethylene- 4-oxo-azetidin-3-yl)-ethyl ester) with an IC50 of 4 μM. Of the total 35 compounds tested, high levels of inhibition of elastase and of MMPs were separately exerted by distinct molecules. © 2005 Elsevier Ltd. All rights reserved.