Inhibition of p53-Murine Double Minute 2 (MDM2) Interactions with 3,3′-Spirocyclopentene Oxindole Derivatives

3,3′-Spirocyclopentene oxindoles structurally related to Wang’s spiropyrrolidine oxindoles have been highlighted as a new class of antiproliferative agents against cancer cell lines with wild-type p53 status (IC50 up to 0.96 μM on SJSA-1 and 2.9 μM in HCT116 p53-wt). Inhibition of the MDM2-p53 interactions has been demonstrated through in vitro HTRF assays (IC50 up to 3.1 nM), while Western blot analysis showed activation of p53 selectively in HCT116 cancer cell lines with wild-type p53.