Design and biological features of platinum (II) complexes with 3-hydroxy-3-(Trifluoromethyl)cyclobutane-1,1-Dicarboxylate as a leaving ligand.

A series of platinum compounds 2a-5a and 2b-5b with fluoro-functional groups are designed and synthesized. Among them, complex 2b is the most effective agent with 3-hydroxy-3-(trifluoromethyl)cyclobutane-1,1-dicarboxylate as a leaving ligand, which showed better cytotoxic activity than compounds containing only CF or OH group at 3-position of cyclobutane-1,1-dicarboxylate. The water solubility of 2a is better than that of carboplatin (32 mg/mL vs. 16 mg/mL), and its antitumor activity on A549 is 4.6-fold higher than that of carboplatin. The IC value of 2b on A549 cells is 4.73 ± 0.64 μM, which is comparable to that of oxaliplatin and higher than that of carboplatin. Meanwhile, 2a and 2b are less toxic than oxaliplatin and cisplatin toward BEAS-2B cells. Moreover, 2a and 2b induce cell apoptosis in vitro by the Bax-Bcl-2-caspase-3 pathway and ferroptosis through inhibiting GPx-4 and elevating COX2. Results from in vivo experiment show that the inhibition rate of A549 xenograft tumor is cisplatin > 2b > oxaliplatin > 2a > carboplatin.