Pharmacokinetic and Biodistribution Studies of [F]-Taccalonolide: A Covalent Microtubule Stabilizer with Antitumor Efficacy.

The taccalonolides are plant-derived microtubule stabilizers that covalently and specifically bind β-tubulin and provide antitumor efficacy in drug-resistant tumor models both in vitro and in vivo. Herein, we report the radiolabeling, in vitro uptake, and in vivo imaging of a F radiolabeled taccalonolide to investigate in vivo biodistribution, including accumulation in TNBC tumors. Biochemical and cellular studies demonstrate that fluorination does not alter biological activity and supports target engagement of the radiolabeled compound.