Functionalized 3-benzylidene-indolin-2-ones: Inducers of NAD(P)H-quinone oxidoreductase 1 (NQO1) with antiproliferative activity

Functionalized benzylidene-indolin-2-ones are widely associated with antiproliferative activity. The scaffold is not normally associated with chemoprevention in spite of the presence of a nitrogen-linked Michael acceptor moiety that may predispose members to induction of NQO1, a widely used biomarker of chemopreventive potential. To investigate this possibility, we have synthesized and evaluated a series of functionalized 3-benzylidene-indolin-2-ones for induction of NQO1 in murine Hepa1c1c7 cells as well as antiproliferative activity against two human cancer cell lines (MCF-7, HCT116). The benzylideneindolinones were found to be good inducers of NQO1 activity, with 85% of test compounds able to increase basal NQO1 activity by more than twofold at concentrations of ⩽10 μM. By contrast, fewer compounds (11%) tested at the same concentration were able to reduce cell viability by more than 50%. Structure activity relationships showed that the nitrogen linked Michael acceptor moiety was an essential requirement for both activities. This common feature notwithstanding, substitution of the 3-benzylidene-indolin-2-one core structure affected NQO1 induction and antiproliferative activities in dissimilar ways, underscoring different structural requirements for these two activities. Nonetheless, promising compounds (10, 42, 45–48) were identified that combine selective induction of NQO1 with potent antiproliferative activity. A potential advantage of such agents would be the ability to provide added protection to normal cells by the up-regulation of NQO1 and other phase II enzymes while simultaneously targeting neoplastic cells.

Functionalized 3-benzylidene-indolin-2-ones combine selective induction of NQO1 with potent antiproliferative activity. They can potentially protect normal cells by upregulation of NQO1 and other phase II enzymes as well as simultaneously targeting neoplastic cells.Figure optionsDownload as PowerPoint slide