Simultaneous presence of unsaturation and long alkyl chain at P1′ of Ilomastat confers selectivity for gelatinase A (MMP-2) over gelatinase B (MMP-9) inhibition as shown by molecular modelling studies

Structural analogues of Ilomastat (Galardin®), containing unsaturation(s) and chain extension carrying bulky phenyl group or alkyl moieties at P1′ were synthesized and purified by centrifugal partition chromatography. They were analyzed for their inhibitory capacity towards MMP-1, MMP-2, MMP-3, MMP-9 and MMP-14, main endopeptidases involved in tumour progression. Presence of unsaturation(s) decreased the inhibitory potency of compounds but, in turn increased their selectivity for gelatinases. 2b and 2d derivatives with a phenyl group inhibited preferentially MMP-9 with IC50 equal to 45 and 38 nM, respectively, but also display activity against MMP-2 (IC50 equal to 280 and 120 nM, respectively). Molecular docking computations confirmed affinity of these substances for both gelatinases. With aims to obtain a specific gelatinase A (MMP-2) inhibitor, P1′ of Ilomastat was modified to carry one unsaturation coupled to an alkyl chain with pentylidene group. Docking studies indicated that MMP-2, but not MMP-9, could accommodate such substitution; indeed 2a proved to inhibit MMP-2 (IC50 = 123 nM), while displaying no inhibitory capacity towards MMP-9.

The synthesis and centrifugal partition chromatography (CPC) purification, molecular modelling, as well as the biological activities of structural analogues of Ilomastat as MMPs inhibitors are reported. The modifications of P1′ sites have demonstrated potent inhibitory and selective activities against either MMP-2 or MMP-9.Figure optionsDownload as PowerPoint slide