Аннотация:A series of σ-aryl complexes of platinumcontaining fragment of 2,6-di-tert-butylphenolwas synthesized. The antioxidant activityof the compounds has been studied. It wasestablished by the CUPRAC test that R-Pt-Clpossesses the highest ability to one-electronreduction (TEAC=1,84 ± 0,05) compared toR-CH3, R-Pt-Br and the standard trolox. Usingthe DPPH test, it was found that R-Pt-SnCl3(EC50= 69±4 µM) was more active than thestarting R-Pt-Cl complex (EC50=84±5 µM).The cytotoxicity of the compounds R-Pt-Cl, R-Pt-Br and R-Pt-SCN was evaluated in the MTT test on human colon cancer (HCT-116), human lung cancer (A-549), human breast adenocarcinoma (MCF-7). I