P-glycoprotein (P-gp) is an important factor leading to multidrug resistance (MDR) in cancer treatment. The co-administration of anticancer drugs and P-gp inhibitors has been a treatment strategy to overcome MDR. In recent years, tyrosine kinase inhibitor Lapatinib has been reported to reverse MDR through directly interacting with ABC transporters. In this work, a series of P-gp inhibitors (1–26) was designed and synthesized by integrating the quinazoline core of Lapatinib into the molecule framework of the third-generation P-gp inhibitor Tariquidar. Among them, compound 14 exhibited better MDR reversal activity than Tariquidar. The docking results showed compound 14 displayed the L-shaped molecular conformation. Importantly, compound 14 increased the accumulation of Adriamycin (ADM) and rhodamine 123 (Rh123) in MCF7/ADM cells. Besides, compound 14 significantly increased ADM-induced apoptosis and inhibited the proliferation, migration and invasion of MCF7/ADM cells. It was also demonstrated that compound 14 significantly inhibited the growth of MCF7/ADM xenograft tumors by increasing the sensitivity of ADM. In summary, compound 14 has the potential to overcome MDR caused by P-gp.

P-糖蛋白（P-gp）是癌症治疗中导致多药耐药（MDR）的重要因素。抗癌药物和P-gp抑制剂联合给药一直是克服MDR的治疗策略。近年来，酪氨酸激酶抑制剂拉帕替尼被报道可通过与ABC转运蛋白直接相互作用来逆转MDR。本工作通过将拉帕替尼的喹唑啉核心整合到第三代P-gp抑制剂Tariquidar的分子框架中，设计合成了一系列P-gp抑制剂（ 1-26 ）。其中，化合物14表现出比Tariquidar更好的MDR逆转活性。对接结果显示化合物14呈现L型分子构象。重要的是，化合物14增加了MCF7/ADM 细胞中阿霉素 (ADM) 和罗丹明 123 (Rh123) 的积累。此外，化合物14显着增加ADM诱导的细胞凋亡并抑制MCF7/ADM细胞的增殖、迁移和侵袭。还证明化合物14通过增加ADM的敏感性而显着抑制MCF7/ADM异种移植肿瘤的生长。综上所述，化合物14具有克服P-gp引起的MDR的潜力。