Novel Ilomastat analogs with substituted benzamide groups, instead of hydroxamic acid groups, were designed, synthesized and evaluated against MMP-2 and MMP-9. Among these analogs, the most potent compound 10a exhibited potent inhibitory activity against MMP-2 with IC50 value of 0.19 nM, which is 5 times more potent than that of Ilomastat (IC50 = 0.94 nM). Importantly, 10a exhibited more than 8300 fold selectivity for MMP-2 versus MMP-9 (IC50 = 1.58 μM). Molecular docking studies showed that 10a bond to the catalytic active pocket of MMP-2 by a non-zinc-chelating mechanism which was different from that of Ilomastat. Furthermore, the invasion assay showed that 10a was effective in reducing HEY cells invasion at 84.6% in 50 μM concentration. For 10a, the pharmacokinetic properties had been improved and especially the more desirable t1/2z was achieved compared with these of the lead compound Ilomastat.

A series of diketo tetrazoles and diketo triazoles were designed and synthesized as bioisosteres of α,γ-diketo acid, the active site inhibitor of HCV (Hepatitis C virus) polymerase NS5B. Among the synthesized compounds, 4-(4-fluorobenzyloxy)phenyl diketo triazole (30) exhibited anti-HCV activity with an EC50 value of 3.9 μM and an SI value more than 128. The reduction of viral protein and mRNA levels were also validated, supporting the anti-HCV activity of compound 30. These results provide convincing evidence that the diketo tetrazoles and diketo triazoles can be developed as bioisosteres of α,γ-diketo acid to exhibit potent inhibitory activity against HCV.A series of diketo tetrazoles and diketo triazoles were designed and synthesized as bioisosteres of α,γ-diketo acid. Among them, compound 30 exhibited potent anti-HCV activity with an EC50 value of 3.9 μM and an SI value more than 128. The reduction of viral protein and mRNA levels were also validated.