Design, synthesis, and biological evaluation of conformationally constrained analogues of naphthol AS-E as inhibitors of CREB-mediated gene transcription.

Cyclic AMP response element binding protein (CREB) is often dysregulated in cancer cells and is an attractive cancer drug target. Previously, we described naphthol AS-E (1) as a small molecule inhibitor of CREB-mediated gene transcription. To understand its bioactive conformation, a series of conformationally constrained analogues of 1 were designed and synthesized. Biological evaluation of these analogues suggests that the global energy minimum of 1 is the likely bioactive conformation.