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Complexes [Co(biq)(μ1,5-dca)2]n (1) and [Ni(biq)(μ1,5-dca)2]n (2) (biq is 2,2′-biquinoline, dca is dicyanamide anion, N(CN)2−) have been characterized by crystal structure analysis, and spectral and magnetic measurements. The crystal structures of isostructural complexes 1 and 2 confirmed their polymeric two-dimensional system through the one double and two single μ1,5-bridging dca ligands. The structures are stabilized by π–π interactions between the aromatic rings of biq and the weak C–H⋯N hydrogen bonding interactions. The analysis of the magnetic response revealed the presence of the easy-plane anisotropy in 1 with D = 66.4 cm−1 and the presence of the easy-axis anisotropy in 2 with D = −5.76 cm−1 in good agreement with SA-CASSCF/NEVPT2 based ab initio predictions. Compound 1 exhibits a field-induced slow magnetic relaxation with a very long relaxation time, which was ascribed to the direct relaxation process influenced by the presence of the phonon-bottleneck effect with T−1.62 temperature dependence of the relaxation time in the applied magnetic field.

Aim: We investigated the antitumor effects of zinc(II) complex with S-propyl thiosalicylic acid [Zn( S-pr-thiosal)2] in 4T1 murine breast cancer model. Results: The Zn( S-pr-thiosal)2 complex reduced primary tumor growth in vivo and induced tumor cell apoptosis. The Zn( S-pr-thiosal)2 complex disrupted the balance between pro- and antiapoptotic Bcl-2 family members in 4T1 cells and induced G1/S cell cycle arrest. The Zn( S-pr-thiosal)2 complex increased the percentage of p16, p21 and p27 positive 4T1 cells. There was a significantly decrease in expression of STAT3 and its targets c-Myc and cyclin D3 in 4T1 cells treated with the Zn( S-pr-thiosal)2 complex thus contributing to G1/S cell cycle arrest and/or apoptosis. Conclusion: Our data suggest that the Zn( S-pr-thiosal)2 complex restricted tumor growth through induction of mitochondrial-driven apoptosis and suppression of cell cycle progression.

Three silver(I) complex compounds of halogen derivatives of 8-quinolinol (XQ), [Ag(HdClQ)2](NO3)·CH3OH (1), [Ag(HdBrQ)2](NO3) (2), and [Ag(BrQ)]n (3) (HdClQ = 5,7-dichloro-8-quinolinol, HdBrQ = 5,7-dibromo-8-quinolinol, and HBrQ = 7-bromo-8-quinolinol), have been prepared with the aim to study their anticancer properties. All compounds were characterized by IR and NMR spectroscopy and elemental analysis. Single-crystal X-ray diffraction analysis revealed that crystal structure of 1 is ionic, 2 is molecular while 3 is polymeric. All three XQ ligands in 1–3 are N,O-chelate coordinated to the Ag(I) central atoms which are in a deformed square planar (1), distorted tetragonal pyramidal (2), or distorted triangular arrangement (3). Stability of all compounds in DMSO was proved by 1H NMR and UV-vis spectroscopy. Biological activity has not been studied because of limited solubility of prepared compounds in DMSO/water mixture.

In this work, gallium(III) complex with cloxyquin (5-chloro-8-quinolinol, HClQ) ligands is shown to effectively inhibit proliferation of rhabdomyosarcoma cells, the frequent, aggressive, and poorly treatable cancer of children. It offers striking selectivity to cancer cells compared to noncancerous human fibroblasts. The data reveal that the complex induces ferroptosis in rhabdomyosarcoma cells, likely due to interfering with iron metabolism. Importantly, it can kill both bulk and stem rhabdomyosarcoma cells. To the best of our knowledge, this is the first compound based on metal other than Fe capable of inducing ferroptosis in cancer cells.

In this study, four hybrid organic-inorganic compounds (8-H

Seven new zinc(II) complexes, K[Zn(dClQ)3]·2DMF (1), K[Zn(dClQ)3]·2DMF·H2O (2), [Zn(dBrQ)2(H2O)]2·DMF·H2O (3), [Zn(BrQ)2(H2O)]2·H2O (4), (HdClQ)2[ZnCl4]·2H2O (5), [Zn(dClQ)2(H2O)2]·H2O (6) and [Zn(CQ)2(H2O)2] (7) (5,7-dichloroquinolin-8-ol (dClQ), protonated 5,7-dichloroquinolin-8-ol (HdClQ), 5,7-dibromoquinolin-8-ol (dBrQ), 7-bromoquinolin-8-ol (BrQ), 5-chloro-7-iodoquinolin-8-ol (CQ)) have been prepared. All complexes were characterized by IR spectroscopy, elemental analysis and, except 7, by X-ray structure analysis. Stability of complexes in dimethyl sulfoxide was verified by NMR spectra. Antimicrobial activity was tested against nine strains of pathogenic bacteria, five mould species and two yeast species. Cytotoxic activity was tested against colon cancer cell line HCT 116 and non-cancerous cell line CCD-18Co. While all complexes showed higher cytotoxicity than cisplatin, poor selectivity to normal cells was observed.

The newly synthesized coumarin derivative with dopamine, 3-(1-((3,4-dihydroxyphenethyl)amino)ethylidene)-chroman-2,4-dione, was completely structurally characterized by X-ray crystallography. It was shown that several types of hydrogen bonds are present, which additionally stabilize the structure. The compound was tested in vitro against different cell lines, healthy human keratinocyte HaCaT, cervical squamous cell carcinoma SiHa, breast carcinoma MCF7, and hepatocellular carcinoma HepG2. Compared to control, the new derivate showed a stronger effect on both healthy and carcinoma cell lines, with the most prominent effect on the breast carcinoma MCF7 cell line. The molecular docking study, obtained for ten different conformations of the new compound, showed its inhibitory nature against CDKS protein. Lower inhibition constant, relative to one of 4-OH-coumarine, proved stronger and more numerous interactions with CDKS protein. These interactions were carefully examined for both parent molecule and derivative and explained from a structural point of view.

The five coumarin derivatives 3-(1-(2-hydroxypropylamino)ethylidene)-chroman-2,4-dione (L1), 3-(1-(phenylamino)ethylidene)-chroman-2,4-dione (L2), 3-(1-(o-toluidino)ethylidene)-chroman-2,4-dione (L3), 3-(1-(m-toluidino)ethylidene)-chroman-2,4-dione (L4), 3-(1-(2-mercaptoethylamino)ethylidene)-chroman-2,4-dione (L5) and its corresponding complexes 3-(1-(2-hydroxypropylamino)-ethylidene)-chroman-2,4-dione-palladium(II) (C1), 3-(1-(phenylamino)-ethylidene)-chroman-2,4-dione-palladium(II) (C2), 3-(1-(o-toluidino)-ethylidene)-chroman-2,4-dione-palladium(II) (C3), 3-(1-(m-toluidino)ethylidene)-chroman-2,4-dione-palladium(II) (C4), 3-(1-(2-mercaptoethylamino)ethylidene)-chroman-2,4-dione-palladium(II) (C5), were synthesized and characterized with microanalysis, infrared, 1H and 13C NMR spectroscopy. The proposed structures of ligands L3 and L4 were confirmed on the basis of the X-ray structural study. The ligands and their complexes were tested for their in vitro antimicrobial activity against 17 species of bacteria and fungi. Testing is performed by the microdilution method, with the minimum inhibitory concentration (MIC) and the minimum microbicidal concentration (MMC) being determined.

Four gallium(III) complexes, [Ga(ClQ)3]⋅MeOH (1 – MeOH), [Ga(ClQ)3] (1), [Ga(BrQ)3] (2), [Ga(dIQ)3] (3) and [Ga(CQ)3] (4), were prepared (H-ClQ = 5-chloro-8-quinolinol, H-BrQ = 7-bromo-8-quinolinol, H-dIQ = 5,7-diiodo-8-quinolinol, H-CQ = 5-chloro-7-iodo-8-quinolinol) and characterised by elemental analysis, IR and NMR spectroscopy. Single crystal structure analysis of 1 – MeOH confirmed that the complex has a molecular structure with gallium(III) metal ion coordinated in mer-fashion by N- and O-donor atoms of three ClQ ligands. Stability of all complexes in DMSO was proved by 1H NMR spectroscopy. The in vitro antiproliferative activity of 1 was evaluated against the A2780, MBA-MB-231 and HCT116 cell lines. Complex 1 displays higher antiproliferative activity (IC50 values in the range 2.1–6 μ m ) compared to the ClQ ligand and cisplatin; and a significant selective antiproliferative potency (IC50 = 136 μ m , for normal MRC5pd30 cell line). Radical scavenging experiments revealed that complex 1 exhibits the highest antioxidant activity of the prepared complexes as well as the ligands.

From the system CuCl2–biq–NaN(CN)2 (biq is 2,2′-biquinoline), the binuclear molecular complex bis(μ-dicyanamido-κ2 N 1:N 5)bis[(2,2′-biquinoline-κ2 N,N′)(dicyanamido-κN 1)copper(II)], [Cu2(C2N3)4(C18H12N2)2] or [Cu2(biq)2(dca)2(μ1,5-dca)2] (1) [dca is dicyanamide, N(CN)2 −] was isolated and characterized by crystal structure analysis, and spectral, thermal and magnetic measurements. IR spectroscopy confirmed the presence of the biq and dca ligands in 1. Its solid-state structure consists of discrete centrosymmetric binuclear copper(II) units with double end-to-end dca bridges. Each CuII atom is in a distorted square-pyramidal environment with the equatorial plane formed by two nitrile N atoms from bridging dca groups, one of the two N atoms of the chelate biq molecule and one nitrile N atom from a terminal dca ligand, whereas the second biq N atom occupies the axial position. Thermal decomposition of 1 in an air atmosphere proceeds gradually, with copper(I) cyanide being the final decomposition product. Magnetic measurements revealed the formation of alternating spin chains and a relatively strong exchange interaction within the binuclear units was also confirmed by Broken Symmetry DFT (density functional theory) calculations.

Two copper(II) complexes with ligands derived from β-amino acids, 2-(1-aminocyclohexyl)acetic acid L1 and 2-(1-amino-4-(tert-butyl)cyclohexyl)acetic acid L2, were synthesized and characterized by microanalysis, infrared, UV–Vis and EPR spectra. The spectroscopically predicted structure of the square-planar copper(II) complex with 2-(1-aminocyclohexyl)-acetic acid C1 was confirmed by single-crystal X-ray analysis. The biological activities (antitumor activities and interaction with DNA) of the compounds were also investigated. The interactions of both complexes with calf thymus (CT) and herring testes (HT) DNA were examined by stopped-flow spectroscopy, by absorption (UV–Vis) and by emission spectral studies (ethidium bromide displacement studies). Both complexes were found to react a bit faster with HT-DNA than with CT-DNA. The obtained binding constants suggested a moderate intercalative binding mode between the complexes and DNA. In addition, fluorescence spectrometry of bovine serum albumin with the complexes showed a good fluorescence quenching of the complexes. The obtained copper(II) complexes have a relatively low cytotoxic effect on murine mammary carcinoma cell line, 4T1, a moderate effect on murine colon carcinoma cell line, CT26, and a relatively high cytotoxicity toward murine lung cancer cells, LLC1.

From the system CuCl2 – pbi – NaN(CN)2 −, polymeric [CuCl(μ1,5-dca)(pbi)]n·nH2O (1) complex (dca=dicyanamide, pbi=2-(2-pyridyl)benzimidazole) was isolated and characterized by structure analysis, spectral and magnetic measurements. Infrared spectroscopy confirmed the presence of pbi, dca and water molecules in 1. Its solid-state structure is formed by infinite chains running along the b axis. In the chain, the Cu(II) atom is penta-coordinated by two nitrogen atoms of chelate pbi ligand, by two nitrile nitrogen atoms of bridging μ1,5-dca and by chloride ligand which occupies the apical position of tetragonal pyramid around the Cu(II) atom. Asymmetric unit is supplemented by one molecule of solvated water, which along with chlorine atom serves as acceptors in intermolecular hydrogen bonds and along with π–π interactions create a 3D supramolecular structure. Magnetic measurements revealed the presence of a weak ferromagnetic exchange interaction J/kB =0.11 K.

The complex (2,2′-biquinoline-κ2 N,N′)(carbamoylcyanonitrosomethanide-κ2 N,O)chloridocopper(II) acetonitrile monosolvate, [Cu(C3H2N3O2)Cl(C18H12N2)]·CH3CN or [Cu(ccnm)Cl(biq)]·acn (acn is acetonitrile, biq is 2,2′-biquinoline and ccnm is carbamoylcyanonitrosomethanide), (I), was prepared as a result of nucleophilic addition of water to the dicyanonitrosomethanide ion in the presence of CuII and biq. IR spectroscopy confirmed the presence of ccnm, biq and acn in (I). The solid-state structure consists of the neutral complex containing ccnm and biq ligands, coordinated to the CuII atom in a bidendate chelating manner, and a chloride ligand, resulting in a distorted tetragonal pyramidal coordination of CuII. The asymmetric unit is supplemented by one molecule of solvated acn which, along with the nitrile group of ccnm, serves as an acceptor in intermolecular hydrogen bonding, creating infinite chains along the b axis. Magnetic measurements revealed a paramagnetic behaviour with a very small Weiss temperature Θ = −0.32 K and high anisotropy of the g tensor (g x = 2.036, g y = 2.120 and g z = 2.205).

Acridine thiosemicarbazones 3a–g, obtained through a two-step reaction between aromatic isothiocyanates and hydrazine followed by the treatment with acridin-9-carbaldehyde, in reaction with bifunctional reagents; methyl bromoacetate (MBA) and diethyl acetylenedicarboxylate (DEAD) afforded acridin-thiazolidinone derivatives 4a–g and 7a–f and not their regioisomers 6a–g and 9a–f. Derivatives 4a–g and 7a–f exhibit ZC2N6EN7C8 configuration. Upon standing in DMSO-d6 the thiazolidinones 4a–g and 7a–f spontaneously isomerized into ZC2N6ZN7C8 isomers 5a–g and 8a–f to give a mixture of the both stereoisomers. All compounds were fully characterized by multinuclear NMR, mass spectrometry (MS) and X-ray crystal structure of 4b is also described. X-ray diffraction study revealed that the representative compound 4b crystallized in the monoclinic crystal system with the C2/c space group and Z = 4. Intramolecular C1′ H1′⋯N-7 hydrogen bond between the acridine proton H-1′ and nitrogen N-7 of linker existed. This hydrogen bond is responsible for the E isomerism on C-8 atom which was observed in the NMR experiments. Quantum-chemical calculations and NOESY experiments confirmed ZC2N6ZN7C8 configuration of the transformed stereoisomers 5a–g and 8a–f.

In this contribution, four new compounds synthesized from 4-hydroxycoumarin and tyramine/octopamine/norepinephrine/3-methoxytyramine are characterized spectroscopically (IR and NMR), chromatographically (UHPLC-DAD), and structurally at the B3LYP/6-311++G*(d,p) level of theory. The crystal structure of the 4-hydroxycoumarin-octopamine derivative was solved and used as a starting geometry for structural optimization. Along with the previously obtained 4-hydroxycoumarin-dopamine derivative, the intramolecular interactions governing the stability of these compounds were quantified by NBO and QTAIM analyses. Condensed Fukui functions and the HOMO-LUMO gap were calculated and correlated with the number and position of OH groups in the structures. In vitro cytotoxicity experiments were performed to elucidate the possible antitumor activity of the tested substances. For this purpose, four cell lines were selected, namely human colon cancer (HCT-116), human adenocarcinoma (HeLa), human breast cancer (MDA-MB-231), and healthy human lung fibroblast (MRC-5) lines. A significant selectivity towards colorectal carcinoma cells was observed. Molecular docking and molecular dynamics studies with carbonic anhydrase, a prognostic factor in several cancers, complemented the experimental results. The calculated MD binding energies coincided well with the experimental activity, and indicated 4-hydroxycoumarin-dopamine and 4-hydroxycoumarin-3-methoxytyramine as the most active compounds. The ecotoxicology assessment proved that the obtained compounds have a low impact on the daphnia, fish, and green algae population.

Four N-oxides, 8-quinolinol N-oxide (8-HQNO), 5,7-dichloro-8-quinolinol N-oxide (HdClQNO), 5,7-dibromo-8-quinolinol N-oxide (HdBrQNO) and 7-iodo-8-quinolinol N-oxide (HIQNO) as well as their six copper complexes, CuCl2(8-HQNO)2(H2O) (1), CuCl2(HdClQNO)2(H2O)2 (2), Cu(dClQNO)2(CHCl3) (3), Cu(dClQNO)2(H2O) (4), {[Cu(dBrQNO)2]•2H2O}n (5) and CuCl2(HIQNO)2(H2O)4 (6) were synthesised as possible anticancer agents. Crystal structures of N-oxides contain planar molecules held together via hydrogen bonds involving oxygen atoms of N-oxide groups as acceptors. Crystal structure of 5 represents the first structure of a copper(II) complex with an N-oxide ligand derived from 8-HQNO and is formed by infinite chains. In the chain, the Cu(II) atom coordinates to six oxygen atoms from two bidentate chelating dBrQNO ligands occupying apexes of elongated tetragonal bipyramid with bridging oxygen atoms of N-oxide groups in axial positions. Antiproliferative activity of prepared N-oxides as well as their complexes was studied using in vitro MTT assay against the MDA-MB-231, HCT-116 and A549 cancer cell lines and their selectivity was verified on MSCs cells. Among the tested cancer cell lines, A549 and MDA-MB-231 cells were the most sensitive to the tested complexes. Complex 1 showed the highest cytotoxicity against both tumor cell lines. At concentration, which could be tested in animal models, 1 induced cell death in more than 50% of cancer cells and in 20% of MSCs indicating its selectivity.

Ionic cobalt(II) complex [Co(dcnm)(H2O)(phen)2](dcnm) (1) (dcnm = dicyanonitrosomethanide, phen = 1,10-phenantroline) has been prepared by a diffusion technique. Its structure is formed by [Co(dcnm)(H2O)(phen)2]+ complex cation and free dcnm counterion in the lattice which acts as a hydrogen-bond acceptor to the hydrogen bonds from the water ligand coordinated to the Co atom. The Co atom is six-coordinated in the form of a distorted octahedron by two chelate phen molecules (one of them is disordered over two equivalent positions), one O-coordinated dcnm ligand and one water molecule which is cis-coordinated to O atom of dcnm ligand. The structure is stabilized by the system of hydrogen bonds and π–π interactions. Magnetic properties of 1 are dominated by a strong easy-plane anisotropy yielding to the energy difference between the two lowest Kramers doublets higher than 150 cm−1. Two field-induced relaxation channels were observed by AC susceptibility study and were shown to be dominated by the direct spin-phonon relaxation at low temperatures. One of the relaxation channels is identified to be mediated by the electron-nuclear interaction.

New Pd(II) complexes with 7-bromo-quinolin-8-ol (BrQ), [Pd(BrQ)2] (1a) and (1b) and HBrQ[PdCl2(BrQ)] (2) have been synthesized and characterized. X-ray structure analysis of 1a and 1b revealed that the molecular structures of these square-planar polymorphs are very similar, nevertheless in the supramolecular structure the molecules are differently arranged and held by different intermolecular forces. The structure of 2 in DMSO solution was elucidated using one- and two-dimensional NMR experiments which showed that the complex decomposes to BrQ ligand. Antimicrobial activity of soluble complex 2 was tested by determining the minimum inhibitory concentration and minimum microbicidal concentration against 9 strains of bacteria and 5 strains of fungi; its activity on Proteus mirabilis is more than 250 times higher than a positive control. Complex 2 is also significantly more cytotoxic against human colorectal cancer cells HCT116 than cisplatin at all tested concentrations and this effect is particularly pronounced at low concentrations; cytotoxicity of BrQ is four times higher than cytotoxicity of 2 at these concentrations and is selectively cytotoxic. Interaction of 2 with DNA was investigated using UV–VIS spectroscopy and fluorescence spectroscopy; the binding studies indicate that complex 2 can interact with ctDNA through intercalation mechanism.

The new coumarine derivate with methyl ester of 2-((Z)-1(2,4-dioxochroman-3-ylidene)ethylamino)-3-methylbutanoic acid and the corresponding palladium(II) complex are synthesized and characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy. The proposed structure of the ligand was confirmed based on the X-ray structural study.

Molecular [CoIII(acnm)(bpy)(cenm)]·H2O (1) complex (acnm = amidocarbonyl(cyano)nitrosomethanide; bpy = 2,2′-bipyridine and cenm = cyano[imino(ethoxy)methyl]nitrosomethanide) was prepared as a result of simultaneous nucleophilic addition of water and ethanol to dicyanonitrosomethanide ions in the presence of Co(II) and bpy, and represents the first example of compound comprising both acnm and cenm ligands. Infrared spectroscopy confirmed the presence of acnm, bpy, cenm and water molecules in 1. Its solid state structure consists of neutral complexes containing acnm, cenm and bpy ligands bidentate chelate coordinated to Co(III) atom to form a distorted octahedron. Asymmetric unit is supplemented by one molecule of crystal water which along with amido and imine groups serves as donor in intermolecular hydrogen bonds creating infinite wave-like 2D sheets in the bc plane. One- and two-dimensional NMR experiments confirmed the structure of the complex unit in DMSO solution. Results of UV–VIS spectroscopy and magnetic measurements are consistent with the presence of Co(III) atom and therefore diamagnetic character of 1 and thermal analysis was used to follow its decomposition.

Starting from well-defined NH2(CH3)2[PdCl2(XQ)] complexes, coordination compounds of general formula Cat[PdCl2(XQ)] have been prepared by cationic exchange of NH2(CH3)2+ and Cat cations, where XQ are biologically active halogen derivatives of quinolin-8-ol (5-chloro-7-iodo-quinolin-8-ol (CQ), 5,7-dibromo-quinolin-8-ol (dBrQ) and 5,7-dichloro-quinolin-8-ol (dClQ)) and Cat is K+ or Cs+. The cation exchange of all prepared complexes, K[PdCl2(CQ)] (1), K[PdCl2(dClQ)] (2), K[PdCl2(dBrQ)] (3), Cs[PdCl2(CQ)] (4), Cs[PdCl2(dClQ)] (5) and Cs[PdCl2(dBrQ)] (6) was approved using IR spectroscopy, their structures in DMSO solution were elucidated by one- and two-dimensional NMR experiments, whereas their stability in solution was verified by UV-VIS spectroscopy. Interaction of complexes to ctDNA was investigated using UV-VIS and fluorescence emission spectroscopy. The minimum inhibitory concentration and the minimum microbicidal concentration values were detected against 15 bacterial strains and 4 yeast strains to examine the antimicrobial activity for the complexes. The in vitro antitumor properties of the complexes were studied by testing the complexes on leukemic cell line L1210, ovarian cancer cell line A2780 and non-cancerous cell line HEK293. The majority of the prepared compounds exhibited moderate antimicrobial and very high cytotoxic activity.

Eight spiroacridine derivatives containing the isoxazoline ring were synthesized and characterized using elemental analysis, IR, UV–vis, and NMR measurements. Their interactions with calf thymus DNA were extensively studied by various spectroscopic techniques and gel electrophoresis. The UV–visible and CD measurements implied that these derivatives interact with calf thymus DNA through intercalation. The Stern-Volmer quenching constants were determined and ranged from 0.126 × 10 4 to 1.394 × 10 4 M −1 . A topoisomerase I inhibition assay was performed with the spiroacridine derivatives.

Two new complexes, [Co II ( bpy ) 2 (dca) 2 ] ( 1 ) and [Co II ( bpy ) 2 (tcm) 2 ] ( 2 ) ( bpy = 2,2-bipyridine, dca = dicyanamide and tcm = tricyanomethanide) were prepared as powders. During their recrystallization on air, two other new complexes, [Co III ( bpy ) 2 CO 3 ]dcg (dcg = N,N′-dicyanoguanidine, (H 2 N)C(NCN) 2 ) ( 3 ) and [Co III ( bpy ) 2 CO 3 ]tcm·2H 2 O ( 4 ), have been prepared. Composition of both complexes was supported by the results of thermal analyses. The presence of Co(III) atom in 3 and 4 was confirmed by UV–Vis spectra, while the presence of dcg and tcm as free anions was proved by IR spectra of these complexes. Moreover, quantum chemical calculations confirmed that dcg in 3 is present in its anionic form. Single crystal X-ray structure determination of 3 and 4 revealed the presence of [Co III ( bpy ) 2 CO 3 ] + complex cations with dcg, its structure has not been published yet, and tcm counter anions, respectively. In both structures, a supramolecular networks built up from strong N–H⋯N, O–H⋯N, as well as weak C–H⋯N, C–H⋯O hydrogen bonds and aromatic π–π stacking besides electrostatic forces of attraction help to consolidate the packing.

Three gallium(III) complexes, [Ga(NQ)3] (1), Na3[Ga(SQ)3]·7H2O·3NaCl (2) and [Ga(ClNQ)3]·MeOH (3) were synthesised as possible anticancer agents (H-NQ = 5-nitro-8-quinolinol, H-SQH = 5-sulfo-8-quinolinol, H-ClNQ = 5-chloro-7-nitro-8-quinolinol) and characterised by elemental analysis, IR and NMR spectroscopy. Single crystal structure analysis of 1 revealed two crystallographically independent [Ga(NQ)3] molecules in the asymmetric part of the unit cell. Stability of the complexes 1 and 2 in solution was determined by 1H NMR spectroscopy. Complex 3 was not further studied due to the low solubility. Antiproliferative activity of complexes 1 and 2 was studied using in vitro MTT assay against the A2780, HCT116 and MDA-MB-231 cancer cell lines and the selectivity of the complexes was verified on noncancerous MRC5 pd30 cell line. Complex 1 showed high antiproliferative potency (IC50 = 3.6 ± 0.8 μM for HCT116) and noticeable selectivity of 1 against the cancer cell lines (IC50 = 32 ± 4 μM for normal MRC5 pd30 cell line) was also found. The complex 2 displayed the highest antioxidant activity of all tested complexes and free ligands.

Four new Pd(II) complexes with halogenderivatives of 8-quinolinol (HXQ) were prepared: [PdCl(NH(CH3)2)(CQ)] (1), [PdCl(NH(CH3)2)(dClQ)] (2), [PdCl(NH(CH3)2)(dBrQ)] (3) and [PdCl(NH(CH3)2)(BrQ)] (4), where HCQ is 5-chloro-7-iodo-8-quinolinol, HdClQ is 5,7-dichloro-8-quinolinol, HdBrQ is 5,7-dibromo-8-quinolinol and HBrQ is 7-bromo-8-quinolinol. The infrared spectroscopy confirmed the presence of XQ moiety in all complexes as well as dimethylamine ligands resulting from the decomposition of DMF used as solvent. Subsequent X-ray structural analysis confirmed that XQ ligands are chelate bind to Pd(II) atom through oxygen and nitrogen atoms, the dimethylamine molecules are attached via nitrogen atom, wherein the nitrogen atoms of XQ and of dimethylamine are in trans-positions. The fourth coordination place is occupied by chloride ligand, suggesting a square planar configuration of the central Pd(II) atom. The structures are stabilized by both H-bonds and π-π interactions while observing the formation of 2D or 3D structures. 1H and 13C NMR spectra of 1–4 confirmed their stability in dimethylsulfoxide. The radical scavenging experiments revealed relatively low antioxidant properties with 1 being the most potent antioxidant among prepared complexes. In vitro antiproliferative properties of the newly prepared complexes were studied on adenocarcinomic human alveolar basal epithelial cells A549, human colon cancer cell line HCT116, human breast cancer cell line MDA-MB-231 and their selectivity was studied on non-cancerous mouse mesenchymal stem cells MSCs. All the prepared complexes were toxic to the tumor cells and the higher cytotoxicity was induced by complex 1 against A549 cells at very low concentrations which would provide new potential antitumor drug that deserves much more attention in lung cancer research.

Isoalkyl (isoalkyl = isopropyl-(L1), isobutyl-(L2) and isoamyl-(L3)) derivatives of thiosalicylic acid (TSA) were prepared by alkylation of TSA with corresponding isoalkyl-chlorides in the alkaline water-ethanol solution. The new free copper(II)-complexes with corresponding S-isoalkyl derivatives of TSA (C1-copper(II)-complex with S-isopropyl derivative of thiosalicylic acid, C2-copper(II)-complex with S-isobutyl derivative of thiosalicylic acid and C3-copper(II)-complex with S-isoamyl derivative of thiosalicylic acid) have been synthesized by direct reaction of copper(II)-nitrate with ligand precursor and then characterized by microanalysis, infrared spectra (IR) and EPR (electron paramagnetic resonance) spectra. The spectroscopically predicted structure of the obtained binuclear copper(II)-complex with S-isopropyl derivative of thiosalicylic acid was confirmed by X-ray analysis. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Newly synthesized precursors S-isoalkyl derivatives of thiosalicylic acid and corresponding copper(II)-complexes moderately reduced viability of human and murine lung cancer cells, they showed similar cytotoxic effect on human colorectal cancer cells as cisplatin and lower cytotoxic effect than cisplatin toward normal fibroblasts, evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric technique. All new complexes exhibited apoptotic effect toward lung cancer cells, stronger than cisplatin, whereas only C3 induced significant apoptosis of colorectal cancer cells. Complex C1 showed significant antiproliferative effect against murine lung cancer cells, LLC1, while C2 reduced expression of Ki67 in human colorectal cancer cells. All tested complexes induced cell cycle arrest of HCT116 cells in G2/M phase.

From the system CuCl

The complex (2,2'-biquinoline-κ