Abstract:
A Pt(II)-based complex [Pt(DMEEDA)Cl2], 1 (DMEEDA = N,N-dimethyl-N0-ethylethylenediamine), was
synthesized, where DMEEDA acted as the (N,N) bidentate carrier ligand. The diaqua complex
[Pt(DMEEDA)(H2O)2](NO3)2, 2, was obtained by the hydrolysis of dichloro complex 1. Further, its
substituted complex [Pt(DMEEDA)(L-cys)](NO3), 3, and [Pt(DMEEDA)(N-ac-L-cys)], 4 (where L-cys =
L-cysteine and N-ac-L-cys = N-acetyl-L-cysteine), were synthesized with amino acid L-cysteine and
its acetyl derivative. The complexes were characterized via different spectroscopic techniques, such as
UV-Vis, FT-IR, 1H NMR and ESI-MS. The structure of complex 1 was determined via X-ray diffraction
studies to be an orthorhombic crystal system with cell parameters a = 7.9970(2) Å, b = 16.9851(7) Å,
c = 16.0460(7) Å and a = 90(1); b = 90(1); g = 90(1) and space group (pccn). The DNA-binding
properties of the complexes were investigated via gel electrophoresis, and DNA-binding constants
were obtained from UV-Vis spectroscopic and fluorescence titration methods. Congruent with a
significant increase in DNA fragmentation, the growth inhibition potential of the synthesized Pt(II)
complexes has been remarkably higher in the hepatocarcinoma cell line (HepG2), as compared to
cisplatin. Moreover, these complexes show minimal toxicity to mouse primary hepatocytes and RAW
264.7 cells in vitro.
