Low-dimensional compounds containing bioactive ligands. Part VI: Synthesis, structures, in vitro DNA binding, antimicrobial and anticancer properties of first row transition metal complexes with 5-chloro-quinolin-8-ol.

A series of new 3d metal complexes with 5-chloro-quinolin-8-ol (ClQ), [Mn(ClQ)2] (1), [Fe(ClQ)3] (2), [Co(ClQ)2(H2O)2] (3), [Ni(ClQ)2(H2O)2] (4), [Cu(ClQ)2] (5), [Zn(ClQ)2(H2O)2] (6), [Mn(ClQ)3]·DMF (7) and [Co(ClQ)3]·DMF·(EtOH)0.35 (8) (DMF=N,N-dimethylformamide), has been synthesized and characterized by elemental analysis, IR spectroscopy and TG-DTA thermal analysis. X-ray structure analysis of 7 and 8 revealed that these molecular complexes contain three chelate ClQ molecules coordinated to the central atoms in a deformed octahedral geometry and free space between the complex units is filled by solvated DMF and ethanol molecules. Antimicrobial activity of 1-6 was tested by determining the minimum inhibitory concentration and minimum microbicidal concentration against 12 strains of bacteria and 5 strains of fungi. The intensity of antimicrobial action varies depending on the group of microorganism and can be sorted: 1>ClQ>6>3/4>2>5. Complexes 1-6 exhibit high cytotoxic activity against MDA-MB, HCT-116 and A549 cancer cell lines. Among them, complex 2 is significantly more cytotoxic against MDA-MB cells than cisplatin at all tested concentrations and is not cytotoxic against control mesenchymal stem cells indicating that this complex seems to be a good candidate for future pharmacological evaluation. Interaction of 1-6 with DNA was investigated using UV-VIS spectroscopy, fluorescence spectroscopy and agarose gel electrophoresis. The binding studies indicate that 1-6 can interact with CT-DNA through intercalation; complex 2 has the highest binding affinity. Moreover, complexes 1-6 inhibit the catalytic activity of topoisomerase I.

Low-dimensional compounds containing bioactive ligands. V: Synthesis and characterization of novel anticancer Pd(II) ionic compounds with quinolin-8-ol halogen derivatives.

Three novel palladium(II) complexes, NH2(CH3)2[PdCl2(CQ)] (1) (CQ=5-chloro-7-iodo-quinolin-8-ol), NH2(CH3)2[PdCl2(dClQ)] (2) (dClQ=5,7-dichloro-quinolin-8-ol) and NH2(CH3)2[PdCl2(dBrQ)] (3) (dBrQ=5,7-dibromo-quinolin-8-ol) have been prepared and characterized. Their structures contain square-planar [PdCl2(XQ)](-) complex anions in which deprotonated XQ ligands are coordinated to the Pd atoms via the pyridine nitrogen and the phenolato oxygen atoms, other two cis-positions are occupied by two chlorido ligands. Negative charges of these anions are balanced by uncoordinated dimethylammonium cations. Coordination of the XQ ligands to Pd(II) atom was confirmed by the differences in the stretching ν(OH) and ν(CN) vibrations in the IR spectra of ligands and prepared complexes while bands of aliphatic CH and NH stretching vibrations observed in the spectra of 1-3 confirm the presence of dimethylammonium cations in the complexes. The binding of complexes 1-3 to calf thymus DNA was investigated using UV-visible and fluorescence emission spectrophotometry. The fluorescence spectral results indicate that the complexes can bind to DNA through an intercalative mode. The Stern-Volmer quenching constants obtained from the linear quenching plot are in the 1.04 × 10(4) to 4.35 × 10(4) M(-1) range. The complexes exhibit significant anticancer activity tested on A2780 cells and cisplatin resistant cell line A2780/CP.

Low-dimensional compounds containing bioactive ligands. IV. Unusual ionic forms of 5-chloroquinolin-8-ol.

Bis(5-chloro-8-hydroxyquinolinium) tetrachloridopalladate(II), (C(9)H(7)ClNO)(2)[PdCl(4)], (I), catena-poly[dimethylammonium [[dichloridopalladate(II)]-µ-chlorido]], {(C(2)H(8)N)[PdCl(3)]}(n), (II), ethylenediammonium bis(5-chloroquinolin-8-olate), C(2)H(10)N(2)(2+)·2C(9)H(5)ClNO(-), (III), and 5-chloro-8-hydroxyquinolinium chloride, C(9)H(7)ClNO(+)·Cl(-), (IV), were synthesized with the aim of preparing biologically active complexes of Pd(II) and Ni(II) with 5-chloroquinolin-8-ol (ClQ). Compounds (I) and (II) contain Pd(II) atoms which are coordinated in a square-planar manner by four chloride ligands. In the structure of (I), there is an isolated [PdCl(4)](2-) anion, while in the structure of (II) the anion consists of Pd(II) atoms, lying on centres of inversion, bonded to a combination of two terminal and two bridging Cl(-) ligands, lying on twofold rotation axes, forming an infinite [-µ(2)-Cl-PdCl(2)-](n) chain. The negative charges of these anions are balanced by two crystallographically independent protonated HClQ(+) cations in (I) and by dimethylammonium cations in (II), with the N atoms lying on twofold rotation axes. The structure of (III) consists of ClQ(-) anions, with the hydroxy groups deprotonated, and centrosymmetric ethylenediammonium cations. On the other hand, the structure of (IV) consists of a protonated HClQ(+) cation with the positive charge balanced by a chloride anion. All four structures are stabilized by systems of hydrogen bonds which occur between the anions and cations. π-π interactions were observed between the HClQ(+) cations in the structures of (I) and (IV).

A potential anti-cancer agent: 5-chloro-7-iodo-8-hy-droxy-quinolinium dichlorido(5-chloro-7-iodo-quinolin-8-olato-κN,O)palladium(II) dihydrate.

The title Pd(II) coordination compound, (C(9)H(6)ClINO)[PdCl(2)(C(9)H(4)ClINO)]·2H(2)O, was prepared as a potential anti-cancer agent. Its structure is ionic and consists of a square-planar [PdCl(2)(CQ)](-) complex anion (CQ is 5-chloro-7-iodo-quinolin-8-olate), with the Pd(II) atom surrounded by two chloride ligands in a cis configuration and one N,O-bidentate CQ mol-ecule, a protonated anion of CQ as counter-cation and two non-coordinated water mol-ecules. The water mol-ecules are involved in O-H⋯O and N-H⋯O hydrogen bonds, which inter-connect the HCQ(+) cations into a chain parallel to [010]. Apart from these inter-actions, the structure is also stabilized by face-to-face π-π inter-actions [centroid-centroid = 3.546 (3) Å], which occur between the phenolic parts of the complex anions and cations.