Square Planar Platinum(II) Complexes with N,S-Donor Ligands: Synthesis, Characterisation, DNA Interaction and Cytotoxic Activity

Abstract

The platinum(II) complexes with N,S-donor ligand have been synthesised and characterised by physiological techniques like elemental, electronic, Fourier transform infrared, hydrogen-1 nuclear magnetic resonance ((1)H NMR) and liquid chromatography-mass spectrometry spectra. The synthesised complexes have been checked for their DNA binding ability by absorption titration and viscosity measurement, and the results show that the complexes binds to herring sperm DNA (HS DNA) via covalent mode of binding. The DNA cleavage activity of synthesised complexes has been carried out by gel electrophoresis experiment using supercoiled form of pUC19 DNA, showing the unwinding of the negatively charged supercoiled DNA. Brine shrimp (Artemia cysts) lethality bioassay technique has been applied for the determination of toxic property of synthesised complexes in terms of micromolars.

Anti- Mycobacterium tuberculosis activity of platinum(II)/ N , N -disubstituted- N ′-acyl thiourea complexes

“…This substantial change suggests deprotonation of the ligands, indicating coordination through the sulfur atom with a formally C\ \S single bond [20][21][22][23]. The absorptions at about 471 cm −1 in the IR spectra of the complexes can be assigned to the Metal-O vibration mode [24,25] and the assignment of the Pt\ \S stretching vibration bands at about 360 cm −1 are in accordance with the reported by Bayazeed H. Abdullah and others for platinum(II) complexes with s-donor ligands [26,27]. Thus, from the IR data it is possible to suggest that the N,N-disubstituted-N′-acyl thioureas are attached to the metal through the oxygen and sulfur, by a chelating system.…”

Palladium(II)/ N , N -disubstituted- N ′-acylthioureas complexes as anti- Mycobacterium tuberculosis and anti- Trypanosoma cruzi agents

“…The bands observed around 471-490 cm À1 were assigned to M-O [23,24]. Assignment of the Pd-S stretching vibration bands at about 360 cm À1 are in accordance to the reported literature [25,26]. The bands in the 551-556 cm À1 range are assigned to M-N (imino nitrogen) [20].…”

“…The distances for the C-S and C-O bonds in the chelate rings, listed in Table 2, are the characteristic of single and double bond lengths, respectively [9,21,27]. The N1-C1 and N2-N1 bond distances (average 1.3402 Å and 1.307 Å, respectively) present typical bond lengths of double bond character, suggesting an electron delocalization in the acyl thiourea moiety [21][22][23][24][25][26][27]. The C-O bond distances are slightly sensitive to the coordination of the ligand to the metal.…”

Recent Uses of Kröhnke Methodology: A Short Survey

“…Patel tested the cytotoxicity of square planar Pt(II) complexes with N,S donor ligands of 4-(4-X-phenyl)-2-phenyl-6-(2-thienyl)pyridine type (with X = Br or Cl) on brine shrimps. 57 With 4-(3-X-phenyl)-6-phenyl-2,2′-bipyridine ligands, Pt(II) complexes were able to unwind negatively supercoiled pUC19 plasmid and showed potent lethality against brine shrimp. 58…”