• angiogenesis;
  • high-content screening;
  • multi-drug resistance;
  • pironetin;
  • zebrafish

The natural product (−)-pironetin is a structurally simple small molecule microtubule-perturbing agent whose biological activities appear to be exquisitely dependent on defined stereochemistry and the presence of an eletrophilic α,β-unsaturated lactone moiety. We used alkaloid-catalyzed acyl halide-aldehyde cyclocondensation reactions in asymmetric total syntheses of (−)-pironetin and three synthetic analogs, and evaluated their biological activities by high-content analysis in cell culture and in a zebrafish model. Synthetic (−)-pironetin and 2,3-dihydro-3-hydroxypironetin caused mitotic arrest and programmed cell death in human lung cancer cells but not in normal lung fibroblasts, had nanomolar growth inhibitory activity in multi-drug resistant cells, and inhibited neovascularization in zebrafish embryos. Synthetic (−)-pironetin delayed the onset but increased the extent of tubulin assembly in vitro. The data illustrate the power of acyl halide-aldehyde cyclocondensation to generate biologically active synthetic analogs of stereochemically complex targets and suggest that (−)-pironetin and 2,3-dihydro-3-hydroxypironetin possess unique properties that may bestow them with advantages over existing microtubule-perturbing agents in the context of a whole organism or under conditions of multi-drug resistance.