ONS Donor Ligand Research Articles

ONS-donor ligand based Pt(II) complexes display extremely high anticancer potency through autophagic cell death pathway

The current study unveils ONS-donor ligand based Pt(II) complexes with unusual anticancer potency showing higher anticancer effect as compared to cisplatin. This series of Pt(II)(R-salicylaldimine)Cl (C1a-C4a) (R = 5-H, 5-CH3, F, 3-CH3O) complexes were prepared in single step in good isolated yields from commercially available materials. The chloride ancillary ligand of “a” series (C1a-C4a) was replaced with 4-picoline and “b” series of four complexes Pt(II)(R-salicylaldimine)(4-picoline)BF4 (C1b-C4b) (R = 5-H, 5-CH3, F, 3-CH3O) was obtained. All these complexes were characterized by different structure elucidation techniques. Among these, the structures of C1a, C2a, C2b and C3b were determined in solid state by single crystal X-ray analysis. We found quick aquation of “a” series of complexes in DMSO/water mixture that was well investigated by 1H NMNR, LCMS and ESI-MS, while “b” series of these complexes was quite stable over a month as described by the 1H NMNR in DMSO/D2O mixture. This ONS-donor ligand based class of Pt(II) complexes showed unusual anticancer potency in non-small cell lung cancer A549, colorectal cancer HT-29 and triple negative breast cancer MDA-MB-231 cells. These Pt(II) complexes induced PARP cleavage and significantly inhibited colony formation ability of cancer cells. Mechanistically, we found reduced aggressive growth of cancer cells by the induction of autophagic cell death via LC3-I/LC3-II expression and recruitment of LC3B to autophagosomal membrane. These complexes induced p21 expression, that suggested their potentials to suppress cell cycle progression. Significant activation of Caspase3/7-dependent apoptotic signaling was observed in cancer cells treated with these Pt(II) complexes. Morphological changes of cancer cells suggested their potentials to modulate epithelial-mesenchymal-transition (EMT) like features of cancer cells. Gel electrophoresis study revealed their interaction with plasmid DNA. Similarly, strong growth retardation effect and filamentous morphology was observed in Escherichia coli (E. coli). These ONS-donor Pt(II) complexes possessed strong anticancer effect in multiple human cancer cells via activation of multiple pathways for apoptotic and autophagic cell death.

Synthesis, crystal structures and antimicrobial activity of dimeric copper(II) complexes with 2-hydroxyphenyl-ethylidene-dithiocarbazates

The current work reports the synthesis and crystals structure of two copper(II) complexes [(CuL1)2] (1) and [(CuL2)2] (2), with S-allyl-2-(2-hydroxyphenyl-ethylidene)dithiocarbazato and S-benzyl-2-(2-hydroxyphenyl-ethylidene) dithiocarbazato (H2L1 and H2L2, respectively). The single-crystal X-ray analyses reveal dimeric structures of the complexes with a distorted square planar coordination geometry. The phenoxo bridging mode observed in these complexes is located between the two copper atoms with ONS-donor ligands. The crystal packings are stabilized by hydrogen bonds involving the adjacent molecules. The compounds were also characterized by physicochemical and spectroscopic methods. The antibacterial and antifungal properties of the free dithiocarbazates and its Cu(II) complexes have been evaluated against several multiresistant bacteria and fungi. In all experiments, a superior antimicrobial activity of the complexes was observed compared to the free ligands.

Synthesis, Characterization and Biological Activity of Zn(II) Complexes with Dibasic Tridentate ONS-Donor Ligand

Synthesis, Characterization and Biological Activity of Zn(II) Complexes with Dibasic Tridentate ONS-Donor Ligand

Towards a selective cytotoxic agent for prostate cancer: Interaction of zinc complexes of polyhydroxybenzaldehyde thiosemicarbazones with topoisomerase I

Four thiosemicarbazones ligands, H3T(1), H3M(2), H3E(3) and H3P(4) have been prepared with good yield by refluxing 2,4-dihydroxybenzaldehyde with N(4)-substituted thiosemicarbazide in ethanol (H3T(1)=2,4-dihydroxybenzaldehyde thiosemicarbazone; H3M(2)=2,4-dihydroxybenzaldehyde 4-methylthiosemicarbazone; H3E(3)=2,4-dihydroxybenzaldehyde 4-ethylthiosemicarbazone and H3P(4)=2,4-dihydroxybenzaldehyde 4-phenylthiosemicarbazone). Reactions of these ligands with zinc acetates in the presence of 2,2′-bipyridine lead to the formation of zinc(II) complexes of formulation [Zn(bpy)L](5–8) (bpy=2,2′-bipyridine; L=doubly deprotonated thiosemicarbazones=HT(5); HM(6); HE(7) and HP(8)). These compounds were characterized and their cytotoxicity and topoisomerase I inhibition activities studied. X-ray diffraction study indicates that complex 8 is five coordinated and the coordination geometry around zinc(II) is trigonal bipyramidal distorted square based pyramid (TBDSBP). The doubly deprotonated thiosemicarbazone acts as a tridentate ONS-donor ligand while 2,2-bipyridne as the NN-donor ligand. Complexes 6, 7 and 8 are more cytotoxic towards PC3 (prostate cancer cell line) than RWPE-1 (prostate normal cell line). The cytotoxicity and topoisomerase I inhibition activities seem to be dependent on the N(4) substituent of the thiosemicarbazone moiety.

Synthesis and Crystal Structures of Dioxomolybdenum(VI) Complexes with ONS-Donor Ligands

Three dioxomolybdenum complexes namely dioxo(5-chlorosalicylaldehyde thiosemicarbazonato) dime thylsulfoxide molybdenum(VI) (C1), dioxo(5-chlorosali- cylaldehyde 2-ethylthiosemicarbazonato) dimethylsulfox- ide molybdenum(VI) (C2) and dioxo(5-chlorosalicylal dehyde N-phenylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C3) were prepared. The compounds all crystallize in the triclinic space group P-1 with a = 7.3184(3) A ˚ , b = 7.5035(3) A ˚ , c = 14.9713(6) A ˚ , a = 85.005(2), b = 85.616(2), c = 66.987(2) for C1,

Crystal Structures of Dioxomolybdenum(VI) Complexes with ONS-Donor Ligands

Department of Chemistry, Pukyong National University, Busan 608-737, KoreaReceived March 9, 2004Key Words : Crystal structure, Dioxomolybdenum(VI) complexes, ONS-DonorMolybdenum chemistry has received the intense attentionbecause of its relevance to the active sites of molybdo-enzymes. The presence of the cis-dioxomolybdenum(VI)cation, [MoO

Spectral studies and structure of a 2-hydroxyacetophenone 3-hexamethyleneiminyl thiosemicarbazonate(-2) copper(II) complex containing 1,10-phenanthroline

The spectral studies and structure of a ternary complex of copper(II) with 2-hydroxyacetophenone 3-hexamethyliminylthiosemicarbazonate (L 2−) and 1,10-phenanthroline (phen) are reported. The thiosemicarbazone binds to the metal as a dianionic ONS-donor (L 2−) ligand, and forms a complex of the stoichiometry [CuLphen]. The copper(II) complex was characterized by IR and UV/Vis spectroscopies, as well as by solid state room-temperature magnetic susceptibility. Spin Hamiltonian and bonding parameters of the compound are calculated from the EPR spectra. Computer simulation of EPR spectrum in DMF at 77 K aided the calculation of magnetic and bonding parameters of the compound. The structure of the compound is solved by single crystal X-ray diffraction. The geometry around copper is distorted square pyramidal.

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF THE MIXED TER- AND BIDENTATE SCHIFF BASE TECHNETIUM(V) COMPLEX TcO{(o[sbnd]O[sbnd]C6H4) (CH3) C[dbnd]NN[dbnd]C(S) (SCH3)} {(CH3)2C[dbnd]NN[dbnd]C(S) (SCH3)}

Abstract The complex TcO{(o[sbnd]O[sbnd]C6H4)(CH3) C[dbnd]NN[dbnd]C(S)(SCH3)}{(CH3)2C[dbnd]NN[dbnd]C(S) (SCH3)} was prepared by the reaction of (n-Bu4N) [TcOCl4] in methanol with the Schiff base S-methyl-β-N-(2-hydroxyphenylethylidene)dithiocarbazate in acetone. The compound was characterized by elemental analysis, vibrational and optical spectroscopy, and X-ray crystallography. Crystal data: C15H19N4O2S4Tc, monoclinic, space group P21/c, a = 14.799(5), b = 7.470(2), c = 19.272(5)Å, U = 2064.4(1.8)Å3, Z = 4, D calc = 1.65 g cm−3. The structure was refined by least-squares methods to R = 0.102. The complex has a Tc=O bond distance of 1.633(8)Å, and the deprotonated phenolic oxygen of the terdentate ONS-donor ligand is coordinated trans to the oxo oxygen.