rational design led to the discovery of highly potent MMP inhibitors. In particular, biphenyl derivatives bearing at the para position COCH3 and OCF3 substituents permitted to inhibit gelatinases MMP-2 and MMP-9, with IC50 values as low as 30 nM and 21 nM, respectively, whereas the introduction at the same position of the bulkier SO2CH3 group afforded a potent collagenase MMP-8 inhibitor with an IC50