Highly Potent and Intestine Specific P‐Glycoprotein Inhibitor to Enable Oral Delivery of Taxol

Abstract Taxol is widely used in cancer chemotherapy; however, the oral absorption of Taxol remains a formidable challenge. Since the intestinal p‐glycoprotein (P‐gp) mediated drug efflux is one of the primary causes, the development of P‐gp inhibitor is emerging as a promising strategy to realize Taxol's oral delivery. Because P‐gp exists in many tissues, the non‐selective P‐gp inhibitors would lead to toxicity. Correspondingly, a potent and intestine specific P‐gp inhibitor would be an ideal solution to boost the oral absorption of Taxol and avoid exogenous toxicity. Herein, we would like to report a highly potent and intestine specific P‐gp inhibitor to enable oral delivery of Taxol in high efficiency. Through a multicomponent reaction and post‐modification, various benzofuran‐fused‐piperidine derivatives were achieved and the biological evaluation identified 16 c with potent P‐gp inhibitory activity. Notably, 16 c was intestine specific and showed almost none absorption ( F =0.82 %), but possessing higher efficacy than Encequidar to improve the oral absorption of Taxol. In MDA‐MB‐231 xenograft model, the oral administration of Taxol and 16 c showed high therapeutic efficiency and low toxicity, thus providing a valuable chemotherapy strategy.