title: Half-sandwich ruthenium–arene complexes with thiosemicarbazones: synthesis and biological evaluation of [(η⁶-p-cymene)Ru(piperonal thiosemicarbazones)Cl]Cl complexes.
abstract: The synthesis and characterization of a number of organometallic ruthenium(II) complexes containing a series of bidentate thiosemicarbazone ligands derived from piperonal is reported. The structure of compounds have been confirmed by spectroscopic analysis (IR and NMR) as well as X-ray crystallographic analysis of [(η⁶-p-cymene)Ru(pPhTSC)Cl]Cl (4) (pPhTSC is piperonal-N(4)-phenylthiosemicarbazone). The interaction of the complexes ([(η⁶-p-cymene)Ru(pEtTSC)Cl]Cl) (3) (pEtTSC is piperonal-N(4)-ethylthiosemicarbazone) and 4 with calf thymus DNA, human serum albumin (HSA) and pBR322 plasmid DNA were studied by spectroscopic, gel electrophoresis and hydrodynamic methods. The apparent binding constant for the interaction with DNA was determined to be 3.97×10³ M⁻¹ and 4.07×10³ M⁻¹ at 293 K for 3 and 4 respectively. The complexes bind strongly to HSA with binding constants of 2.94×10⁴ M⁻¹ and 12.2×10⁴ M⁻¹ at 296 K for 3 and 4 respectively. The in vitro anticancer activity of 3 and 4 has been evaluated against two human colon cancer cell line (HCT-116 and Caco-2) with IC50 values in the range of 26–150 μM. Both 3 and 4 show good activity as a catalytic inhibitor of human topoisomerase II at concentrations as low as 20 μM. The proficiency of 3 and 4 to act as antibacterial agents was also evaluated against six pathogenic bacterial strains with the best activity seen against Gram-positive strains.
authors.affiliation: Division of Science, Lyon College, 2300 Highland Road, Batesville, AR 72501, USA. floyd.beckford@lyon.edu
authors.forename: Floyd
authors.initials: F
authors.lastname: Beckford
authors.forename: Deidra
authors.initials: D
authors.lastname: Dourth
authors.forename: Michael
authors.initials: M
authors.lastname: Shaloski
authors.forename: Jacob
authors.initials: J
authors.lastname: Didion
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Thessing
authors.forename: Jason
authors.initials: J
authors.lastname: Woods
authors.forename: Vernon
authors.initials: V
authors.lastname: Crowell
authors.forename: Nikolay
authors.initials: N
authors.lastname: Gerasimchuk
authors.forename: Antonio
authors.initials: A
authors.lastname: Gonzalez-Sarrías
authors.forename: Navindra P
authors.initials: NP
authors.lastname: Seeram
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry; D001547:Benzaldehydes / Q000737:chemistry; D052117:Benzodioxoles / Q000737:chemistry; D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D000081007:Cymenes; D004247:DNA / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D008024:Ligands; D039821:Monoterpenes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001547:Benzaldehydes; D052117:Benzodioxoles; D000081007:Cymenes; D008024:Ligands; D039821:Monoterpenes; D009942:Organometallic Compounds; D013882:Thiosemicarbazones; C007210:4-cymene; D012428:Ruthenium; D004247:DNA; C427203:calf thymus DNA; C005454:piperonal