A hallmark of targeted cancer therapies is selective toxicity among cancer cell lines. We evaluated results from a viability screen of over 200,000 small molecules to identify two chemical series, oxalamides and benzothiazoles, that were selectively toxic to the same four of 12 human lung cancer cell lines at low nanomolar concentrations. Sensitive cell lines expressed cytochrome P450 (CYP) 4F11, which metabolized the compounds into irreversible stearoyl CoA desaturase (SCD) inhibitors. SCD is recognized as a promising biological target in cancer and metabolic disease. However, SCD is essential to sebocytes, and accordingly SCD inhibitors cause skin toxicity. Mouse sebocytes were unable to activate the benzothiazoles or oxalamides into SCD inhibitors, providing a therapeutic window for inhibiting SCD in vivo. We thus offer a strategy to target SCD in cancer by taking advantage of high CYP expression in a subset of tumors.

Stearoyl-CoA desaturase (SCD) catalyzes the first step in the conversion of saturated fatty acids to unsaturated fatty acids. Unsaturated fatty acids are required for membrane integrity and for cell proliferation. For these reasons, inhibitors of SCD represent potential treatments for cancer. However, systemically active SCD inhibitors result in skin toxicity, which presents an obstacle to their development. We recently described a series of oxalic acid diamides that are converted into active SCD inhibitors within a subset of cancers by CYP4F11-mediated metabolism. Herein, we describe the optimization of the oxalic acid diamides and related N-acyl ureas and an analysis of the structure-activity relationships related to metabolic activation and SCD inhibition.

A novel [3+2]-cycloaddition between azomethine imines and lithium ynolates is described to synthesize bicyclic pyrazolidinones. These bicyclic pyrazolidinones are versatile intermediates to form β-amino acids and monocyclic pyrazolidinones. High diastereoselectivity and stereospecificity allows access to optically active products.

No abstract