Synthesis, structure and in vitro cytotoxicity of platinum(II) complexes containing eugenol and a quinolin-8-ol-derived chelator

Abstract

The synthesis of potassium (η-4-allyl-2-methoxyphenol)trichloridoplatinate(II), K[PtCl(CHO)], (1), starting from Zeise's salt and Ocimum sanctum L. oil has been optimized. Starting from (1), three new platinum(II) complexes, namely (η-4-allyl-2-methoxyphenol)chlorido(2-methylquinolin-8-olato-κN,O)platinum(II), (2), (η-4-allyl-2-methoxyphenol)chlorido(5-nitroquinolin-8-olato-κN,O)platinum(II), (3), and (η-4-allyl-2-methoxyphenol)chlorido(5,7-dichloroquinolin-8-olato-κN,O)platinum(II), [Pt(CHClNO)Cl(CHO)], (4), containing eugenol and a quinolin-8-ol derivative (R-OQ), have been synthesized and characterized by elemental analyses, MS, IR, H NMR and NOESY spectra. For (1) and (4), single-crystal X-ray diffraction studies were also carried out. Complexes (2)-(4) show good inhibiting abilities on three human cancer cell lines, i.e. KB, Hep-G2 and LU, with IC values of 1.42-17.8 µM. Complex (3) gives an impressively high activity against KB, Hep-G2, LU and MCF-7, with IC values of 1.42-4.91 µM, which are much lower than those of cisplatin and some other platinum(II) complexes.

Syntheses, Structures, and Bioactivity Evaluation of some Transition Metal Complexes with Aroylbis(N,N‐diethylthioureas) Derived from Natural Compounds

“…In the present study, antiproliferative effects of the ligands and their metal complexes on human MCF7 breast and HepG2 liver cancer cells were inspected using dose‐response assays. Table 4 lists the IC 50 values obtained and that of cisplatin determined under the same condition [20] …”

“…for C 18 H 22 O 7 N 2 S: C, 52.67; H, 5.40;N,6.83;S,7.81 %. Found: C,52.48;H,5.57;N,6.65;S,7. > 100 > 100 cisplatin [20] 45. [10b] To a suspension of NH 4 SCN (1.52 g, 0.02 mol) in 20 mL dry acetone was added dropwise solution of cinnamoyl chloride (3.33 g, 0.02 mol) in 20 mL dry acetone.…”

“…Table 4 values obtained and that of cisplatin determined under the same condition. [20] The results indicate that the ligand HL 1 and its complexes cause remarkable antiproliferative effects on the two tested cell lines, while the remaining compounds have almost no activity against the cancer cells. Although HL 1 and its Ni(II) and Cu(II) complexes (IC 50 values > 50 μM) show weak growth inhibition for both HepG2 and MCF7 cancer cells, the IC 50 values are comparable with those of some aroylthioureas, [18c,d] and similar homoleptic complexes tested against the same cell lines (Figure 6).…”

Tailored Functionalization of Natural Phenols to Improve Biological Activity

“…Moreover, eugenol can be used as a scaffold to synthesize biologically active natural products [ 183 , 184 ]. The possibility to introduce eugenol skeleton in complex structures such as phthalocyanines [ 185 ], platinum(II) complexes [ 186 ], and organic antimicrobial polymers [ 187 ] has been explored, obtaining new interesting biologically active species ( Figure 3 ).…”

“… Structure of eugenol phthalocyanine derivative ( EUG-1 ) [ 185 ] and eugenol Pt(II) complexes EUG-2-4 [ 186 ]. …”