马胶蛋白是一种临床使用的辅助抗癌药物，但其温和的药效限制了其应用。为了提高马胶蛋白的抗癌活性，在四轮SAR指导的迭代结构优化过程中，构建了总共31个吲哚-马胶蛋白杂化体。所有合成的化合物均针对一系列人类癌细胞系（Hela，MCF-7，SGC-7901，HepG2）和两个正常细胞系（GES-1，LO2）进行了抗增殖活性评估。最活跃的杂合物8g表现出抗癌IC50值为0.9至1.2微米，比马胶蛋白强3个数量级。8g对癌细胞具有更好的选择性，其选择指数值从1.5升至6.2。机理研究通过细胞内点击化学手段证明8g分布于线粒体，并发现8g强烈诱导线粒体应激，表现出能量代谢障碍、线粒体膜电位降低、线粒体钙超载和ROS产生增加等特征。8g诱导的线粒体应激还导致胞色素c释放并促进半胱氨酸天冬酶3的活化，显著促进细胞死亡并抑制群体形成。Copyright © 2023 Elsevier Inc. All rights reserved.

Matrine is a clinically used adjuvant anticancer drug, yet its mild potency limited its application. To improve the anticancer activity of matrine, a total of 31 indole-matrine hybrids were constructed in four rounds of SAR-guided iterative structural optimization process. All of the synthesized compounds were evaluated for their antiproliferative activities against a panel of four human cancer cell lines (Hela, MCF-7, SGC-7901, HepG2) and two normal cell lines (GES-1, LO2). The most active hybrid 8g exhibited the anticancer IC50 values of 0.9 to 1.2 μM, which was 3-magnitude of orders more potent than matrine. 8g also showed better selectivity towards cancer cells with the selectivity index value raised from 1.5 to 6.2. Mechanistic studies demonstrated a mitochondrial distribution for 8g by intracellular click chemistry approaches, which led to the discovery that 8g strongly induced mitochondrial stress, as evidenced by impaired energy metabolism, depolarized mitochondrial membrane potential, overload of mitochondrial calcium and escalated ROS production. 8g-induced mitochondrial stress further led to the release of cytochrome c and subsequent activation of caspase 3, which significantly promoted cellular death and inhibited colony formation.Copyright © 2023 Elsevier Inc. All rights reserved.