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A new cobalt(II) complex ( 1) of 5-chloro-8-hydroxyquinoline was prepared and structurally characterized using , electrospray ionization , elemental analysis, single-crystal X-ray diffraction as well as powder X-ray diffraction. Its biological activities including DNA binding and anticancer activity were investigated. The DNA binding study of complex 1 suggested that it interacted with calf thymus DNA mainly via an intercalative binding mode. The in vitro anticancer activity of complex 1 was screened against a series of tumor cell lines as well as the normal liver cell line HL-7702 using MTT assay. complex 1 showed much higher cytotoxicity than corresponding metal salt and ligand towards the five tested tumor cell lines, in which T-24 was the most sensitive tumor cell line towards 1, with IC50 value of 7.04 ± 0.06 μM. complex 1 was found to greatly induce cell cycle arrest in T-24 cells at S phase, and consequently to induce cell apoptosis in a dose-dependent mode suggested by cell apoptosis analysis via Hoechst 33258 and acridine orange/ethidium bromide staining assays. The cell apoptosis mechanism of 1 was studied targeting the mitochondrion-mediated pathway, since the apoptotic mechanism in the T-24 cells treated by 1 was investigated by (ROS) detection, intracellular calcium concentration measurement and caspase-9/3 activity assay. The results suggested that the cell apoptosis induced by 1 was closely related to the loss of mitochondrial membrane potential, ROS production and enhancement of intracellular [Ca2+], which would trigger the caspase-9/3 activation via a mitochondrial dysfunction pathway. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Three new copper(II) complexes of 5-pyridin-2-yl-[1,3]dioxolo[4,5-g]isoquinoline (PYP), i.e. [Cu2(PYP)2Cl4] (1), [Cu4(PYP)4(ClO4)2(H2O)2](ClO4)2·2H2O (2), and [Cu2(PYP)2Cl4] n (3), were synthesized and fully characterized. In comparison to free PYP, complexes 1–3 exhibited enhanced cytotoxicity against tested human tumor cell lines BEL-7404, SK-OV-3, A549, A375, MGC-803 and NCI-H460, with IC50 values ranging from 0.31 to 30.76 μM. Complexes 1–3 exhibited lower cytotoxicity to HL-7702 than them to cancer cells. Complex 1 induced apoptotic death of BEL-7404, which involved mitochondria in the process. Caspase-3 activation assay indicated that 1 could be an efficient activator of caspase-3. DNA binding studies by UV–vis, DNA-melting, competitive binding, CD, viscosity measurement and agarose gel electrophoresis, revealed that intercalation might be the most likely binding mode of 1 with DNA. [Copyright &y& Elsevier]

Three cerium complexes: [Ce(ClQ)4] (1) (H-ClQ = 5,7-dichloro-8-hydroxylquinoline), [Ce(ClIQ)4]·CH2Cl2·0.5H2O (2) (H-ClIQ = 5-chloro-7-iodo-8-hydroxylquinoline) and [Ce2(BrQ)4(H-BrQ)(H2O)3Cl2]·1.5H2O (3) (H-BrQ = 5,7-dibromo-8-hydroxylquinoline) were synthesized. The structures of 1 and 2 are mononuclear whereas 3 has a binuclear structure. Compared with the H-ClQ, H-ClIQ and H-BrQ, complexes 1–3 exhibited significantly higher cytotoxicity (IC50 = 0.09–5.23 μM) to SK-OV-3 and BEL-7404, 1 and 2 exhibited higher cytotoxicity to NCI-H460. Most the complexes and ligands exhibited higher cytotoxicity than cisplatin. Complexes 1–3 are much more sensitive to SK-OV-3 than to human normal liver cell HL-7702. Their antitumor activities were achieved through cell apoptosis and arrest at G0/G1-phase. Studies on the binding properties of 1–3 to DNA indicate that intercalation is the most probable binding mode. [ABSTRACT FROM AUTHOR]

Abstract: Six new platinum(II) complexes with mono-aminophosphonate ester were synthesized and characterized by elemental analysis, 1H NMR, ESI-MS as well as single crystal X-ray diffraction analysis. They are mononuclear structures. In all the crystal structures of complexes 1–6, the platinum centre adopts an approximately square-planar geometry, which were found to possess excellent solubility in both organic solvents and water and exhibit considerable cytotoxicity against MG-63, SK-OV-3 and HepG2 cell lines, but low cytotoxicity towards normal human liver cell HL-7702. In contrast to cisplatin, their antitumour activities are achieved through the induction of cell apoptosis by G1 cell-cycle arrest. [Copyright &y& Elsevier]

Abstract Two platinum(II) complexes, [Pt(ClQ)(DMSO)Cl] (ClQ-Pt) and [Pt(BrQ)(DMSO)Cl] (BrQ-Pt), with 5,7-dichloro-2-methyl-8-quinolinol (H-ClQ) and 5,7-dibromo-2-methyl-8-quinolinol (H-BrQ) as ligands, respectively, have been synthesized and characterized. The single-crystal X-ray diffraction characterization as well as other spectroscopic and analytical studies of ClQ-Pt and BrQ-Pt revealed that the coordination geometry of Pt(II) can be described as a four-coordinated square planar geometry. By MTT assay, ClQ-Pt displayed the most potent activity, with IC 50 values of 5.02–34.38 μM against MGC80-3, T-24, Hep-G2 and BEL-7402 tumor cells. Among them, the T-24 cells the highest sensitivity to ClQ-Pt and BrQ-Pt with IC 50 value of 5.02 ± 0.62 μM and 18.02 ± 1.05 μM, respectively. In addition, ClQ-Pt caused a higher percentage of apoptotic T-24 cells (ca. 33.75%) than that of BrQ-Pt (ca. 23.85%) and cisplatin (ca. 12.82%). Mechanistic studies revealed that ClQ-Pt and BrQ-Pt caused T-24 cell cycle arrest at the S phase, as shown by the down-regulation of cyclin A and CDK2 expression levels. In addition, ClQ-Pt and BrQ-Pt also caused mitochondrial dysfunction. Interestingly, the in vitro anticancer activity of ClQ-Pt was higher than those of BrQ-Pt and cisplatin, more selective for T-24 tumor cells than for normal HL-7702 cells. Taken together, we concluded that the 5- and 7-substitution groups of the ClQ ligands play an important role in determining the anti-proliferation activity of the corresponding Pt(II) complexes. Graphical abstract Image 1 Highlights • New complexes ClQ-Pt and BrQ-Pt with H-ClQ and H-BrQ have been synthesized and characterized. • T-24 cells was found to be the most sensitive towards both ClQ-Pt and BrQ-Pt. • ClQ-Pt and BrQ-Pt also caused mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

Abstract In this work, we designed and synthesized tacrine platinum(II) complexes [PtClL(DMSO)]⋅CH 3 OH (Pt1), [PtClL(DMP)] (Pt2), [PtClL(DPPTH)] (Pt3), [PtClL(PTH)] (Pt4), [PtClL(PIPTH)] (Pt5), [PtClL(PM)] (Pt6) and [PtClL(en)] (Pt7) with 4,4′-dimethyl-2,2′-bipyridine (DMP), 4,7-diphenyl-1,10-phenanthroline (DPPTH), 1,10-phenanthroline (PTH), 2-(1-pyrenecarboxaldehyde) imidazo [4,5-f]-[1,10] phenanthroline (PIPTH), 2-picolylamine (PM) and 1,2-ethylenediamine (en) as telomerase inhibitors and p53 activators. Biological evaluations demonstrated that Pt1 Pt7 exhibited cytotoxic activity against the tested NCI H460, Hep-G2, SK-OV-3, SK-OV-3/DDP and MGC80-3 cancer cell lines, with Pt5 displaying the highest cytotoxicity. Pt5 exhibited an IC 50 value of 0.13 ± 0.16 μM against SK-OV-3/DDP cancer cells and significantly reduced tumor growth in a Hep-G2 xenograft mouse model (tumor growth inhibition (TGI) = 40.8%, p < 0.05) at a dose of 15.0 mg/kg. Interestingly, Pt1 Pt7 displayed low cytotoxicity against normal HL-7702 cells. Mechanistic studies revealed that these compounds caused cell cycle arrest at the G2/M and S phases, and regulated the expression of CDK2, cyclin A, p21, p53 and p27. Further mechanistic studies showed that Pt5 induced SK-OV3/DDP cell apoptosis via dysfunction of mitochondria, inhibition of the telomerase activity by directly targeting the c-myc promoter, and activation of the p53 signaling pathway. Taken together, Pt5 has the potential to be further developed as a new antitumor drug. Graphical abstract Pt5 induced SK-OV-3/DDP cell apoptosis via dysfunction of mitochondria, inhibition of the telomerase activity and activation of the p53 signaling pathway. Image 1 Highlights • We designed and synthesized tacrine platinum(II) complexes Pt1 Pt7 as telomerase inhibitors and p53 activators. • Pt5 display high in vivo and in vitro anticancer activity. • Pt5 may trigger cell apoptosis via a mitochondrial dysfunction pathway. [ABSTRACT FROM AUTHOR]

A new platinum(II) complex of [Pt II (L) (pn)]Cl·2H 2 O ( 1 ) (pn = 1,3-propanediamine) with 2-(4-methoxy-phenyl)imidazo [4,5-f]-[1,10]phenanthrolin (H-L) was synthesized and characterized. In complex 1 , the platinum adopts a four-coordinated square planar geometry. Complex 1 exhibited selective cytotoxicity against NCI–H460, BEL-7402, SK-OV-3, SK-OV-3/DDP and HeLa cell lines with IC 50 values in the micromolar range (9.7–35.8 μM), but low cytotoxicity toward normal human liver HL-7702 cells. Complex 1 caused HeLa cell cycle arrest at S phase and it induced HeLa apoptosis by the activation of caspase-3/9. Various experiments showed that complex 1 preferred to bind with G-quadruplex in c-myc. Taken together, we found that complex 1 exerted its antitumor activity mainly via inhibiting telomerase by interaction with c-myc quadruplex and activation of caspase-3/9. [ABSTRACT FROM AUTHOR]

Abstract: Three mononuclear silver(I) complexes with 8-hydroxyquinoline, 8-hydroxy-2-methylquinoline and 5-chloro-8-quinolinol were synthesized and characterized by elemental analysis, NMR, ESI-MS as well as single crystal X-ray diffraction analysis. All the structures of complexes 1–3 with the silver center adopting an approximately four-coordinated distorted tetragonal pyramid geometry were found to exhibit selective cytotoxicity against HepG2, NCI-H460, BEL-7404 and HeLa cell lines with IC50 values generally in the micromolar range (1.7–14.6μM), but low cytotoxicity towards normal human liver cell HL-7702. A combination of flow cytometric analysis and molecular probe observation indicated that complexes 1–3 could induce HepG2 cell apoptosis. Molecular mechanism studies suggested that complexes 1–3-induced apoptosis is mediated through the intrinsic apoptotic pathway with changes in mitochondrial membrane potential by finally activating effector caspase-3/9 to trigger cell apoptosis. Further studies revealed that complexes 1 and 2 caused cell cycle arrest at S phase, while complex 3 induced G1 cell cycle arrest in HepG2 cells. Taken together, these results suggest that complexes 1–3 may be potential candidates for cancer therapy. [Copyright &y& Elsevier]

Abstract: Three tin(IV) complexes [Sn(ClQ)2Cl2] (1), [Sn(BrQ)2Cl2] (2) and [Sn(ClIQ)2Cl2] (3) were prepared (H-ClQ = 5,7-dichloro-8-hydroxylquinoline, H-BrQ = 5,7-dibromo-8-hydroxylquinoline, H-ClIQ = 5-chloro-7-iodo-8-hydroxylquinoline) and their in vitro cytotoxicities against BEL7404, SKOV-3, NCI-H460, HL-7702 cell lines were evaluated. The complexes showed high anti-proliferative activity toward the tested cell lines with IC50 values ranging from 20 nM to 5.11 μM. Compared with 5,7-dihalo-8-quinolinol, most complexes exhibited significantly enhanced cytotoxicity (except 2 against SKOV-3 and NCI-H460). They also displayed some selective cytotoxicity favoring the tested tumor cells over the normal human liver HL-7702 cells. Compared with their quinolinol ligands, complexes 1–3 bind more strongly with DNA. Intercalation is the most probable binding mode for both the complexes and their quinolinol ligands. [Copyright &y& Elsevier]

Abstract: Three new compounds of Ga(III), Au(III), Sn(IV) with matrine (MT), [H-MT][GaCl4] ( 1 ), [H-MT][AuCl4] ( 2 ) and [Sn(H-MT)Cl5] ( 3 ), have been synthesized and characterized by elemental analysis, IR, ESI-MS and single crystal X-ray diffraction methods. The crystal structural analyses indicate that 1 and 2 are ionic compounds, whereas 3 is a tin(IV) complex formed by the monodentate MT via its carbonyl oxygen atom of MT coordinating to Sn(IV). Their in vitro cytotoxicity towards eight selected tumour cell lines has been evaluated by MTT (3-[4,5-Dimentylthiazole-2-yl]-2,5-diphenpyltetra-zolium bromide) method, and compounds 1 and 2 exhibit enhanced activity, such as 1 to SW480, 2 to HeLa, HepG2 and MCF-7, which exceeds matrine and cisplatin, and display synergistic contribution of their components. The cell cycle analyses show that compounds 1 , 3 and MT exhibit cell cycle arrest at the G2/M phase. Interactions of these compounds with calf thymus DNA (ct-DNA) have been investigated by spectroscopic analyses. The planar extension of the intercalative metal–matrine compounds increases the interaction of the metal–matrine with DNA, indicating that the cationic metal ions and configuration of the intercalated metal–matrine will affect the extent of interaction. Compound 2 , [H-MT][AuCl4], exhibits more intensive binding ability to DNA, which may correlate with intercalation and other action mode. The circular dichroism spectra of the ct-DNA bound with metal–MT compounds also suggest that ct-DNA interacted with 1 , 2 , 3 does not influence its secondary structure. Furthermore, both compounds 1 and 2 exhibit effective inhibition ability to topoisomerase (TOPO I) at concentration of 50μM, while matrine and compound 3 do not. [ABSTRACT FROM AUTHOR]