Synthesis, structure, and in vitro cytotoxicity of organoplatinum(II) complexes containing aryl olefins and quinolines

Abstract

Ten new organoplatinum(II) complexes, [PtCl(Saf)(8-OQ)] (1), [Pt(Saf-1H)(8-OQ)] (2), [PtCl(Meug)(8-OQ)] (3), [Pt(Meug-1H)(8-OQ)] (4), [PtCl(Meteug)(8-OQ)] (5), [PtCl(Meteug)(Q)] (6), [Pt(Meteug)(Q-COO)] (7), [Pt(Eteug-1H)(Q)] (8), [Pt(Eteug-1H)(8-OQ)] (9), and [Pt(Eteug-1H)(Q-COO)] (10) (where Saf = safrole, Meug = methyleugenol, Meteug = methyl eugenoxyacetate, Eteug = ethyl eugenoxyacetate, Q = quinoline, 8-OQ = 8-hydroxyquinolinate, and Q-COO = quinolin-2-carboxylate), were synthesized and characterized by spectroscopic methods. The position of N and O donors of quinoline ligands in comparison with the ethylenic double bond and the aromatic C5 of the aryl olefins in platinum(II) coordination sphere of 1–10 was determined using their NOESY spectra and confirmed by single-crystal X-ray diffraction of 10. Complexes 1, 2, 3, 4, and 9 exhibit impressive activities on four human cancer cell lines KB, Hep-G2, Lu, and MCF7 with IC₅₀ = 1.4–9.6 μM. Complexes 1, 2, 4, and 9 gave better antitumor activity than cisplatin against examined cell lines.

Graphical abstract

Keywords:

• Platinum(II) complex
• Platinacycle
• Safrole
• Eugenol
• 8-Hydroxyquinoline
• Anticancer complex

Acknowledgement

The Hercules Foundation is thanked for supporting the purchase of the diffractometer through project AKUL/09/0035.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) [grant number 104.02-2012.66].