An electrochemical sensor based on carbon composites derived from bisbenzimidazole biphenyl coordination polymers for dihydroxybenzene isomers detection.

Co-based coordination polymers (CoCP) based on 4,4'-bis(1H-benzo[d]imidazol-1-yl)-1,1'-biphenyl (BMB) ligand have been synthesized for the first time by the solvothermal method. The CoCP was carbonized at 700 °C under a nitrogen atmosphere to obtain carbide coordination polymer (C-CoCP) with a unique two-dimensional layered network structure. C-CoCP@GO was obtained by binding with GO and C-CoCP, its morphology and structure were investigated by XRD, SEM, EDS, FTIR, and TGA, which confirmed its two-dimensional stacked layered structure with high catalytic activity and large specific surface area. A highly sensitive electrochemical sensor was constructed for the simultaneous detection of hydroquinone and catechol based on the prepared carbon-based composite. Under optimized conditions, the working potentials (vs. Ag/AgCl) of HQ and CC are at 0.097 V and 0.213 V, respectively. The sensor exhibited an extremely wide linear range of 3-600 µM and 3-1750 µM for hydroquinone (HQ) and catechol (CC), respectively, with limits of detection (LOD) of 0.46 µM and 0.27 µM. The electrode material demonstrated stability over 14 days without significant attenuation of the response signal. Impressively, the sensor shows high stability, reproducibility, and selectivity due to the stable carbon skeleton structure of the C-CoCP material. In addition, it can be applied to the detection of hydroquinone in real samples with high interference immunity and high recovery. Hence, the C-CoCP@GO composite proved to be a great prospect and highly sensitive sensing platform for the detection of phenolic isomers.

Two novel zinc-based MOFs as luminescence sensors to detect phenylglyoxylic acid.

Automobile exhaust gases, plastic pollutants, smoking, and other harmful substances can cause serious harm to human beings and the environment. Styrene, as a common airborne toxin, enters the human body through breathing or the skin and is discharged in the form of phenylglyoxylic acid (PGA). Therefore, specific, sensitive and trace detection of PGA is particularly important. Here, two zinc-based metal-organic frameworks {[Zn2L1(DMF)2H2O](DMF)2H2O}n, {[Zn4(L2)2(DMF)2(H2O)3](DMF)8}n (L1 = 2,5-bis((3-carboxylphenyl)amino)terephthalic acid, L2 = 2,5-bis((4-carboxyphenyl)amino)terephthalic acid) have been reported as 1 and 2, respectively. Both 1 and 2 present 3D structures, which can both be simplified as 4,4,4-c net topology. It is worth mentioning that 2 has two different kinds of Zn SBUs as connecting nodes in the structure. Besides, compared with the other materials for the detection of PGA, 1 and 2 exhibit relatively low detection limits (LODs), both in water and in urine (where the LODs for 1 in water and urine were 0.33 µM and 0.43 µM in the range of 0-0.39 mM, and those for 2 were 0.28 µM and 0.49 µM in the range of 0-0.59 mM, respectively). In addition, the sensors have excellent anti-interference ability, high stability, rapid response, and can easily distinguish between different concentrations of PGA with the naked eye. The developed paper probes were suitable for practical sensing applications for portable detection of PGA in urine.

Three novel metal-organic frameworks with different coordination modes for trace detection of anthrax biomarkers.

Dipicolinic acid (DPA) is an anthrax biomarker. Its serious consequences make its detection a great need. In this paper, three novel metal-organic frameworks (MOFs) with different coordination modes were synthesized by a simple solvothermal method, which can be used as highly efficient fluorescence sensors for the highly selective and sensitive trace detection of DPA. MOFs 1-3 showed rapid responses to DPA (<30 s), and the limits of detection (LODs) were calculated to be 1.01 × 10-6 M-1 (MOF 1), 1.17 × 10-6 M-1 (MOF 2) and 2.07 × 10-6 M-1 (MOF 3). DPA detection based on MOFs 1-3 in fetal bovine serum is highly reliable based on the high recovery rates (90% to 115%). Hence, the three MOF-based sensors can be used in the real-time detection of DPA.

Two new lanthanide complexes with 5-(Pyrazol-1-yl)nicotinic acid: Structures and their anti-cancer properties.

Two new lanthanide complexes [PrL2(EA)2]NO3 (complex 1) and [SmL2(EA)2]NO3 (complex 2) (H2L = 5-(Pyrazol-1-yl)nicotinic acid, EA = CH3CH2OH) were synthesized. The structures were characterized by single crystal X-ray and elemental analysis. The interaction between the complex and fish sperm DNA(FS-DNA) was monitored using ultraviolet and fluorescence spectroscopy, and the binding constants were determined. Both complexes showed the ability to effectively bind DNA, and the molecular docking technology was used to simulate the binding of the complex and DNA. In addition, through the annexin V-Fluorescein Isothiocyanate(FITC)/ Propidium Iodide (PI) test experiment, tetrazollium [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) in vitro test, and cell morphology apoptosis studies, it was shown that the complex can effectively induce HeLa tumor cell apoptosis. Compared with cisplatin and complex, complex 1 shows significant cancer cell inhibition, and we hope that this new type of complex will open up new ways for the next generation of drugs in biomedical applications.

Highly Emissive Metal-Organic Frameworks for Sensitive and Selective Detection of Nitrofuran and Quinolone Antibiotics.

The overuse of antibiotics makes its detection very significant for human health. New facile methods and high-performance sensory materials will be urgently needed for detection of antibiotics. Unfortunately, there are few reports on fluorescence enhancement of antibiotics detection. Herein, based on the modulability of the coordination mode, we proposed two MOFs with different coordination modes based on different metal ions: Zn-MOF (1) and Cd-MOF (2). The fluorescence of 1 and 2 can be efficiently and selectively quenched by nitrofuran antibiotics (nitrofurazone, NFZ and furazolidone, FZD) and chloramphenicol (CAP), respectively. Particularly, the matched energy levels between 2 and enrofloxacin (ENR) enables 2 with turn-on sensing for ENR. Moreover, apart from the sensitivity and selectivity, 1 and 2 also have strong recyclable ability, fast response time and anti-interference ability, which make them great potential sensory materials to detect antibiotics.

Three coordination polymers with regulated coordination interactions as fluorescent sensors for monitoring purine metabolite uric acid.

A facile optical sensor for uric acid (UA), an early pathological signature for the metabolic function of humans, was developed based on water-stable coordination polymers (CPs). Herein, three new isostructural fluorescent CPs, [Ln(TCPB)(DMF)3]n (Ln = La, CP 1; Ce, CP 2 and Pr, CP 3; H3TCPB = 1,3,5-tris(1-(2-carboxyphenyl)-1H-pyrazol-3-yl)benzene), with various metal ions were solvothermally synthesized. Significantly, by regulating the metal-organic coordination interactions, the fabricated CP 3 can quantitatively recognize UA with higher sensitivity compared with CP 1 and CP 2. The mechanism for the sensing properties further demonstrates the best performance of CP 3 and the excellent selectivity for UA monitoring. This work represents the strategy of designing fluorescent CP sensors to determine UA and provides a convenient approach for developing analysis platforms for the assessment of related disease progress and human health monitoring.

A Water-Stable Lanthanide Coordination Polymer as Multicenter Platform for Ratiometric Luminescent Sensing Antibiotics.

As a hot topic of global concern, the distinguishing and detecting of antibiotic pollution is crucial owing to its adverse effect on ecosystems and human health stemming from excessive use and poor management. Herein, a water-stable lanthanide coordination polymer sensor (Dy-TCPB) with multiple emitting centers is prepared. The versatile Dy-TCPB can conveniently differentiate various antibiotics, and displays a self-calibration luminescent response to nitrofurazone (NFZ) and furazolidone (FZD). Each antibiotic exhibits notable correlation to a unique combination of the two ligand-to-Dy ion emission intensity ratios, enabling two-dimensional fingerprint recognition. Furthermore, the novel self-calibration sensor demonstrates effective recognition of NFZ and FZD with excellent sensitivity and selectivity, and detection limits as low as 0.0476 and 0.0482 µm for NFZ and FZD, respectively. The synthetic approach for the fabrication of a singular coordination polymer exhibiting multiple emissions provides a promising strategy for the development of facile and effective ratiometric sensors.

A series of novel complexes firstly constructed by 1,4-phenylenedioxydiacetic acid plays a role in disruption of DNA gene expression and induction of apoptosis.

A set of five metal-organic frameworks, namely, [Cd2(L)2BIP(H2O)2·6H2O]n(1), [Ce(L)1.5(H2O)2·H2O]n(2),[Sm(L)1.5(H2O)2·3H2O]n(3),[Gd(L)1.5(H2O)2·3H2O]n(4),[Ho(L)1.5(H2O)2·3H2O]n(5), have been prepared under hydrothermal conditions (1,4-H2L=1,4-Pheny lenedioxydiacetic acid; 1,4-BIP=1,4-bis(2-pyridylmethyl)piperazi-ne; C2H5OH=EtOH). The long BIP ligand (N⋯N separation of ca. 8.355Å) induces interpenetration of 1 to increase both the framework stability and the density of effective catalytic metal centers. Characterization of all complexes has been carried out by means of IR spectroscopy, single crystal and powdered sample X-ray diffraction (PXRD) through conventional and synchrotron radiation, Thermogravimetric (TG), fluorescent measurement (liquid and solid), DNA molecular docking, cancer cell apoptosis morphology through fluorescent inverted microscope, IC50, which the cytotoxic activity of the complexes was tested against two different cancer and one normal cell lines. The results indicate that all the complexes are potential fluorescent light-emitting materials and the flour (2, 3, 4, 5) complexes present remarkable anti-cancer effect.

Two novel dinuclear ellipsoid Ni(II) and Co(II) complexes bridged by 4,5-bis(pyrazol-1-yl)phthalic acid: Synthesis, structural characterization and biological evaluation.

Two novel complexes, [Ni2(L)2(H2O)3]·4(H2O) (1) and [Co2(L)2(H2O)3]·5(H2O) (2) [H2L = 4,5-bis(pyrazol-1-yl) phthalic acid] were synthesized and characterized by spectroscopy (IR, 1H NMR), and elemental analysis. The structures for the complexes were determined by X-ray crystallography providing the dinuclear ellipsoid Ni(II) and Co(II) complexes bridged by 4,5-bis(pyrazol-1-yl)phthalic acid ligands with same coordination modes. The interaction capacity of the complexes with FS-DNA (fish sperm DNA) has been investigated by UV and fluorescence spectroscopy. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic activity of the complexes was tested against two different cancer cell lines, HeLa (human cervix epithelia carcinoma cells) and KB (human oral epithelial carcinoma cells), exhibiting significant cancer cell inhibitory rate. Furthermore, flow cytometry experiments and morphological apoptosis studies showed that the complexes induced apoptosis of KB tumor cell lines. The good visualization images supported with the experimental results of structure-activity relationship.

Association between high mobility group box­1 protein expression and cell death in acute pancreatitis.

The present study used caerulein stimulation of AR42J rat pancreatic cells as an in vitro acute pancreatitis (AP) model to investigate proteins differentially expressed in apoptosis and necrosis. AR42J cells were stimulated with 10­8mol/l caerulein and incubated for 24 h. Apoptosis and necrosis were detected using flow cytometry. The sorted Annexin V­positive cells (apoptotic) and the Annexin V/propidium iodide double­positive cells (necrotic) were analysed using proteomics. Results showed that numerous proteins were differentially expressed in these 2 groups. Functional enrichment analysis was performed on the differentially expressed genes using the Database for Annotation, Visualization and Integrated Discovery. High mobility group box­1 protein (HMGB1) was specifically expressed in the necrosis group. Models of varying degrees of AP were established using caerulein at concentrations of 10­9, 10­8, 10­7, 10­6 and 10­5 mol/l. The percentage of apoptotic and necrotic cells in each group was determined using flow cytometry. Protein expression levels of HMGB1 were detected by western blot analysis. The present study showed that as the concentration of caerulein increased, the percentage of necrotic cells and the protein expression levels of HMGB1 increased. HMGB1 is involved in many biological processes, including the chromosomal protein glycyl lysine isopeptide cross­link. HMGB1 may be involved in the early stage of pancreatitis, potentially by inducing the development of cell death by necrosis. These results provide an experimental basis for clinical intervention in AP.

pH Dependent synthesis of two isomeric dinuclear Cerium(II) complexes: Structures, DNA interactions, cytotoxic activity and apoptotic study.

Two isomeric dinuclear Cerium(II) complexes 1 and 2, formulated as Ce2(phen)2(NO3)2(L)4 [L=phenylacetic acid, phen=1,10-phenanthroline] was synthesized under solvothermal conditions at different pH values. The two complexes were characterized by elemental analysis, IR and single crystal X-ray diffraction. Complexes 1 and 2 were studied the binding with DNA and against cytotoxic activity. Fluorescence analysis indicated that the two complexes can bind to DNA. The changes with different gradient concentration of DNA added into the complexes in absorption spectra show a strongπ-stacking interaction between the complexes and DNA base pairs. The Cerium(II) complexes showed good cytotoxic activity against cancer cell lines, being 2 the most potent complex. Apoptotic studies of the two novel dinuclear complexes showed significant inhibitory rate on cancer cell growth line KB.

Synthesis, structures, molecular docking, cytotoxicity and bioimaging studies of two novel Zn(II) complexes.

Two novel compounds [Zn2(Endc)2(bipy)2(H2O)3]·4(H2O)·2(O)(1), [Zn2(Endc)2(phen)2(H2O)]·(O)(2) (bipy = 2,2-bipyridine, phen = 1,10-phenanthroline, and Endc = endo-norbornene-cis-5,6-dicarboxylicacid) have been synthesized and characterized. In this paper abbreviations are FS-DNA (fish sperm DNA), HeLa (human cervix epithelia carcinoma cells), KB (human oral epithelial carcinoma cells), LO2 (human liver cell L-O2), EtBr (ethidium bromide), DMF (Dimethyl Formamide), MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium]). The binding of complexes with Fish Sperm DNA were measured by electronic absorption spectra and fluorescence spectroscopy. The ability of these complexes to cleave the pBR322 plasmid DNA or the KB and HeLa DNA extracted in our laboratory was demonstrated by gel electrophoresis assay. The cytotoxic effects of these complexes were examined on two tumor cell lines, HeLa, KBr and one normal cell line LO-2. UV absorption and fluorescence spectra indicate the ability of the complexes bond to DNA with different binding affinity. Gel electrophoresis assay demonstrates which one complex more effective DNA-cleavage activity. The cytotoxic activity of the complexes was tested against two different cancer and one normal cell lines. The two complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate and lower cytotoxicity toward the normal cell lines. The unique interaction mode with DNA and cancer cells inhibition effect clearly revealed the relationship between the structure and the activity of the novel antitumor agent Zn(II) complexes.

The Syntheses, Structures, Fluorescence Properties and Biological Activity of two Novel Zinc(II) Complexes Controlled by the Tripodal Imidazole Ligand.

Two new zinc complexes, namely Zn(L(1))ClCH2NO(1) and {Zn(L(2))CH2NO}n▪N(CH3)3▪ClO4(2) (L(1) = 3,5-di(1H-imidazol-1-yl)pyridine L(2) = 1,3,5-tris(1-imidazolyl) benzene), have been synthesized, and characterized by IR spectra, elemental analysis, and a single crystal X-ray diffraction. Fluorescence spectroscopy indicated that two complexes presented strong DNA binding affinity constants to fish sperm DNA (FS-DNA). Gel electrophoresis assay demonstrated the ability of the complex to cleave the HL-60 DNA. Apoptotic study showed the complex exhibited significant cancer cell(KB) inhibitory rate.

The structures, cytotoxicity, apoptosis and molecular docking controlled by the aliphatic chain of palladium(II) complexes.

A new series of Pd(II) complexes derived from benzenealkyl dicarboxylate ligands, [Pd(Ln)(phen)] (phen=2,9-dimethyl-1,10-phenanthroline, complex 1: L1=phenylmalonate; complex 2: L2=benzylmalonate; complex 3: L3=(2-phenylethyl)malonate; complex 4: L4=(3-phenylpropyl)malonate) have been synthesized under room temperature condition. These complexes contain a long dicarboxylate aliphatic chain. They were characterized by elemental analysis, infrared spectroscopy, single crystal X-ray diffraction. The binding of complexes with fish sperm DNA (FS-DNA) was investigated by UV absorption and fluorescence spectra. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic activity of the complexes was tested against two different cancer cell lines, HeLa and HL-60. Cytotoxic activity studies showed the four complexes exhibited significant cancer cell inhibitory rate. Further flow cytometry experiments showed that the cytotoxic Pd(II) complexes induced apoptosis of HL-60 tumor cell lines. The molecular dynamic simulations and docking methods were used to predict the DNA binding affinity of Pd(II) complexes by the resulting relative binding energy of complexes with DNA -6.01, -6.25, -7.24 and -7.59 kcal/mol, while with DNA-topoisomerase I (Topo I) -7.98, -9.25, -10.2 and -11.5 kcal/mol, respectively. The good visualization images supported with the experimental results of structure-activity relationship between cytotoxicity and carbon chain length.

Syntheses, characterization, interaction with DNA, cytotoxic and apoptosis of two novel complexes of Zn(II) and Mn(II) with 2-methyl-1H-4,5-imidazoledicarboxylic acid.

Two new complexes, Zn(L)2(H2O)2 (1) and Mn(L)2(H2O)2 (2) [L = 2-Methyl-1H-4,5-imidazoledicarboxylic acid] were synthesized and characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction. Intramolecular weak interactions, such as hydrogen-bond and intermolecular interactions were presented in the complexes. The activities of the complexes binding with DNA, and cytotoxic activities were studied. The binding of complexes with fish sperm DNA (FS-DNA) was investigated by fluorescence spectra. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic activities of the complexes were tested against the KB cell line. Cytotoxic activity studies showed the two complexes exhibited significant cancer cell inhibitory rate. The most active compound was complex 1 with IC50 and CC50value of 36.5, 429, with the selectivity index (SI = 11.75) among the tested compounds.

A Novel Cobalt(II) Coordination Complex Constructed from H2Pyri and 4,4'-Bipy: Synthesis, Characterization and Bioactivity.

The new complex of {[Co(4,4'-Bipy)(H2O)4]·(Pyri) · 3H2O}n (4,4'-Bipy = 4,4'-bipyridyl, H2Pyri = 3,5- Pyridinedicarboxylic acid) was synthesized and characterized by IR, element analysis and X-ray single-crystal diffraction. The binding of the complex with extracted HeLa cells DNA was investigated by UV and fluorescence spectrum. Gel electrophoresis assay demonstrated the ability of the complex cleaving the extracted HC-DNA. The complex exhibited a higher cytotoxicity against tumor cells in vitro. Furthermore, the apoptotic tests indicated the complex had an apoptotic effect on HeLa cells.

Effect of carbon chain length on biological activity of novel palladium (II) complexes.

A series of complexes [Pd(L1)(Phen)]·2H2O (1), [Pd(L2)(Phen)]·H2O (2), [Pd(L3)(Phen)]·H2O (3), [Pd(L4)(Phen)]·2H2O (4) and [Pd(L5)(Phen)]·2H2O (5) were prepared. The complexes were characterized by IR, (1)H NMR, elemental analysis, and single-crystal X-ray diffractometry. The binding of the complexes was investigated by fluorescence spectrum and UV spectrum, showing the ability of interaction with DNA of intercalative mode. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 DNA. Moreover, the five complexes bind to DNA with different binding affinities, in ascending order: complex 1 < 2<3 < 4 < 5. Evaluation of cytotoxic activity of the complexes against five different cancer cell lines proved that the complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate.

Recent advances in multinuclear complexes as potential anticancer and DNA binding agents.

In the search for new metal-based anticancer agents as effective candidates for cisplatin, a lot of strategies such as synthesis of cisplatin analogs, trans-platinum compounds and non-platinum metal complexes have been put forward in the last forty years. The concept of multinuclearity for improving the chemotherapeutic activity has been proven in multinuclear platinum complexes such as BBR3464, recently, the effective approach has been successfully transferred to ruthenium complexes. In this review, we highlighted the recent progress in multinuclear platinum complexes and ruthenium complexes as anticancer agents, and their novel DNA binding properties such as phosphate clamps, long range DNA cross links, bisintercalation, interduplex cross links and DNA-protein cross-links were summarized to shed light on the rational design of polynuclear complexes as anticancer agents.

Synthesis, characterization, interaction with DNA and cytotoxicity of Pd(II) and Pt(II) complexes containing pyridine carboxylic acid ligands.

Four metal complexes [Pd(L(1))Cl(2)·2H(2)O] (1), [Pt(L(1))Cl(2)·2H(2)O] (2), [Pd(L(2))Cl(2)·H(2)O] (3) and [Pt(L(2))Cl(2)·H(2)O] (4) (L(1) = 2,2'-bipyridyl-5,5'-dicarboxylic acid, L(2) = 2,2'-bipyridyl-4,4'-dicarboxylic acid) have been synthesized under hydrothermal conditions and fully characterized by IR and (1)H-NMR spectra, elemental analysis, and X-ray single crystal diffraction analysis. Interactions of these complexes with fish sperm DNA (FS-DNA) were investigated using UV-Vis absorption and fluorescence spectroscopic methods. Further insight was brought by quantum chemistry calculations by means of G03 package and taking B3LYP functional Lanl2dz Gen basis set. Agarose gel electrophoresis run on pBR322 plasmid DNA gave proof that all four complexes exhibit efficient DNA cleavage. Complexes 1-4 manifested cytotoxic specificity and a significant cancer cell inhibitory rate. Independent apoptosis tests under the light microscope, performed on hematoxylin-eosin stained HeLa cells, evidenced morphological changes induced by all the complexes.

Synthesis, characterization and cytotoxicity of a carboxylic ligand 2,2-bis(3-phenylpropyl) malonic acid and a corresponding Mn(II) complex.

The organic ligand Hbpmc and the polymeric complex [Mn(bpmc)(2)(4,4'-bipy)(H(2)O)(2)](n)·3H(2)O (4,4'-bipy = 4,4'-bipyridine, Hbpmc = 2,2-bis(3-phenylpropyl) malonic acid), which have both a lipophilic group (aromatic ring) and a hydrophilic group (non-coordination carboxyl), were synthesized and characterized by IR spectra, elemental analysis and X-ray single-crystal diffraction. The interaction of the complexes with HC-DNA was investigated by fluorescence spectroscopy. Gel electrophoresis assay demonstrates the ability to cleave the extracted HC-DNA. The value of IC(50) is to understand the effect of cytotoxic activity which is lower than cisplatin and higher than the ligand Hbpmc. The apoptotic tests show that the complexes apparently have an apoptotic effect on Hela cells.