Platinum(II) complexes conjugated and analogous to o-glycosides: synthesis, structural characterization and antitumor activity

The synthesis, characterization, cytotoxicity and antitumor activity of platinum(II) complexes coordinated to O-glycoside and analogous is reported. Through the acute toxicity tests, it was possible to fit the complexes into categories according to the OECD protocol. The cis-[PtCl₂(C₆H₁₄S₂O₂)-κ² S] complex was classified in category 3 and the cis-[PtCl₂(C₂₆H₃₈O₁₂S₂)-κ² S] complex was classified in category 4. This result demonstrates the lower toxicity achieved by the glycoside in comparison with its analogous system. Evaluations of tumor masses extracted from mice inoculated with Ehrlich carcinoma demonstrated percent inhibition similar to cisplatin and synthesized platinum complexes. Cisplatin showed 59% inhibition, while cis-[PtCl₂(C₆H₁₄S₂O₂)-κ² S] and cis-[PtCl₂(C₂₆H₃₈O₁₂S₂)-κ² S] complexes presented 57% and 59%, respectively. Although the glycosidic compounds exhibit tumor activity, reported in the literature, the presence of platinum ion was shown to be determinant for antitumor action according with the compounds tested, since the glycosidic ligand presented tumor inhibition of only 38%, with a similar antitumor activity in relation to cisplatin. (author)