title: Synthesis, crystal structures, and biological evaluation of manganese(II) and nickel(II) complexes of 4-cyclohexyl-1-(1-(pyrazin-2-yl)ethylidene)thiosemicarbazide.
abstract: 4-Cyclohexyl-1-(1-(pyrazin-2-yl)ethylidene)thiosemicarbazide (HL) and its transition metal complexes formulated as [Mn(L)(2)] (1) and [Ni(L)(2)] (2) have been prepared in 55-75% yield and characterized by elemental analysis, IR, MS, NMR and single-crystal X-ray diffraction studies. Biological activities of the synthesized compounds have been evaluated against selected Gram positive bacteria Bacillus subtilis, Gram negative bacteria Pseudomonas aeruginosa and the K562 leukemia cell line, respectively. The cytotoxicity data suggest that these compounds may be endowed with important biological properties, especially the nickel complex 2 with MIC = 31.2 μg/mL and IC(50) = 0.53 μM, respectively. Effect of the free ligand and its two complexes on Mitochondria membrane potential (MMP) and PI-associated fluorescence intensity as well as their effect on cell apoptosis in K562 leukemia cell line was also studied. The tested compounds may exert their cytotoxicity activity via induced loss of MMP.
authors.affiliation: Institute of Molecular and Crystal Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, PR China. limingxue@henu.edu.cn
authors.forename: Ming Xue
authors.initials: MX
authors.lastname: Li
authors.forename: Li Zhi
authors.initials: LZ
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Bian Sheng
authors.initials: BS
authors.lastname: Ji
authors.forename: Jun Wei
authors.initials: JW
authors.lastname: Zhao
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D018360:Crystallography, X-Ray; D006801:Humans; D006860:Hydrogen Bonding; D020014:K562 Cells; D008345:Manganese / Q000737:chemistry*; D008564:Membrane Potentials / Q000187:drug effects; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D012663:Semicarbazides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D012663:Semicarbazides; D008345:Manganese; C005151:thiosemicarbazide; D009532:Nickel