2022 Volume 70 Issue 7 Pages 483-491
The first total syntheses of natural phenanthrene alkaloids, namely, uvariopsamine (1), noruvariopsamine (2), 8-hydroxystephenanthrine (3), 8-methoxyuvariopsine (4), thalihazine (5), and secophoebine (6), have been realized. In addition, their in vitro antimalarial activity against the multidrug-resistant K1 strain of Plasmodium falciparum and in vitro cytotoxic activity against the human nasopharynx carcinoma (KB), small cell lung cancer (NCI-H187), and breast cancer (MCF7) human cancer cell lines were investigated. All the phenanthrene alkaloids showed significant antiplasmodial activity (IC50 1.07–7.41 µM), and most compounds displayed low to no toxicity against the three cancer cell lines tested. Particularly, 3 exhibited the best antimalarial activity with an IC50 value of 1.07 µM, no toxicity to NCI-H187 (IC50 > 50 µM), and low toxicity against KB (IC50 24.53 µM) and MCF7 (IC50 42.67 µM) cell lines.