Functionalized aurones as inducers of NAD(P)H:quinone oxidoreductase 1 that activate AhR/XRE and Nrf2/ARE signaling pathways: Synthesis, evaluation and SAR

Abstract

The chemopreventive potential of functionalized aurones and related compounds as inducers of NAD(P)H:quinone oxidoreductase 1 (NQO1, EC 1.6.99.2) are described. Several 4,6-dimethoxy and 5-hydroxyaurones induced NQO1 activity of Hepa1c1c7 cells by 2-fold at submicromolar concentrations, making these the most potent inducers to be identified from this class. Mechanistically, induction of NQO1 was mediated by the activation of AhR/XRE and Nrf2/ARE pathways, indicating that aurones may be mixed activators of NQO1 induction or agents capable of exploiting the proposed cross-talk between the AhR and Nrf2 gene batteries. QSAR analysis by partial least squares projection to latent structures (PLS) identified size parameters, in particular those associated with non-polar surface areas, as an important determinant of induction activity. These were largely determined by the substitution on rings A and B. A stereoelectronic role for the exocyclic double bond as reflected in the E LUMO term was also identified. The electrophilicity of the double bond or its effect on the conformation of the target compound are possible key features for induction activity. © 2010 Elsevier Masson SAS.