Artificial Macrocycles as Potent p53–MDM2 Inhibitors

[Image: see text] Based on a combination of an Ugi four component reaction and a ring closing metathesis, a library of novel artificial macrocyclic inhibitors of the p53–MDM2 interaction was designed and synthesized. These macrocycles, alternatively to stapled peptides, target for the first time the large hydrophobic surface area formed by Tyr67, Gln72, His73, Val93, and Lys94 yielding derivatives with affinity to MDM2 in the nanomolar range. Their binding affinity with MDM2 was evaluated using fluorescence polarization (FP) assay and (1)H–(15)N two-dimensional HSQC nuclear magnetic resonance experiments.