Palladium(0)catalyzed reactions of propargylic carbonates and dialkyl cycloalkanone-α,α-dicarboxylates

Propargylic carbonates reacted with dialkyl cycloalkanone-α,α′-dicarboxylates under the catalysis of Pd(0)complex to give bicyclic compounds in high yields.The two electron-withdrawing groups at α and α′positions of cycloalkanone rings are essential for the annulation reaction.

Syntheses,crystal structures,and catalytic properties of three zinc(Ⅱ),cobalt(Ⅱ)and nickel(Ⅱ)coordination polymers constructed from 5⁃(4⁃carboxyphenoxy)nicotinic acid

Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3.

Transition metal coordination polymers with flexible dicarboxylate ligand:Synthesis,characterization,and photoluminescence property

Under solvothermal conditions,six new coordination polymers(CPs)[Mn(L)(phen)(H_(2)O)]_(n)(1),[Co(L)(phen)(H_(2)O)]_(n)(2),[Cu(L)(phen)(H_(2)O)]_(n)(3),[Zn_(2)(L)_(2)(phen)2(H_(2)O)]_(n)(4),[Zn(L)(phen)]_(n)(5),and[Cd(L)(phen)2]_(n)(6)were synthesized by reactions of dicarboxylate ligand 2,2'-(1,2-phenylenebis(methylene))bis(sulfanediyl)dinobutyric acid(H_(2)L)and 1,10-phenanthroline(phen)with the corresponding metal salts.Complexes 1-6 have been structurally characterized by single-crystal X-ray diffraction analyses,elemental analysis,IR,thermogravimetric analysis,and powder X-ray diffraction.The structures of 1-6 are 1D chains,which are further connected by hydrogen bonding interac-tions to form 3D supramolecular structures.Among them,1 and 2 are isomorphic with L2-of syn-conformation,while L2-shows anti-conformation in 3-6.In addition,the solid-state photoluminescence property of 4-6 was investigated.

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

Determination and Correlation for Solubility of Aromatic Acids in Solvents

Solubility of benzoic acid, terephthalic acid and 2,6-naphthalene dicarboxylic acid in water, acetic acid, N.N-dimethylformamide, N.N-dimethylacetamide, dimethyl sulphoxide and Ar-methyl-2-ketopyrrolidine were measured by dynamic method. The solubilities were calculated by UNIFAC group contribution method, in which new groups, BCCOOH and NCCOOH, were introduced to express the activity coefficients of aromatic acids and new interaction parameters of the new groups were expressed as the function of temperature, which were determined from the experimental data. The new interaction parameters provided good calculated result. The experimental data were also correlated with Wilson and y-h models, and results were compared with present UNIFAC model.

Measurement and Correlation for Solubility of Dimethyl-2,6-naphthalene Dicarboxylate in Organic Solvents

Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measured systems were correlated by UNIFAC group contribution method. A new main group （aromatic ester, ACCOO） was defined to express the activity coefficients of the aromatic ester. New interaction parameters of the ACCOO group were expressed as the first-order function of temperature and were determined from the experimental data. The calculated results for the new interaction parameters were satisfactory. The measured systems were also correlated with the Wilson and 2-h models, and the results were compared with those of the UNIFAC model.

Protective Effect of Dimethyl-4,4'-Dimethoxy-5,6,5',6'-Dimethylene Dioxybiphenyl-2,2'-Dicarboxylate (DDB) against Carcinogen-Induced Rat Liver Nuclear DNA Damage

The protective effect of DDB against carcinogen-induced DNA damage was examined in the present investigation. Preincubation of rat liver nuclei with DDB (1 mmol.L-1) resulted in 60% inhibition of binding of 3H-benzo (a) pyrene to nuclear DNA. Unscheduled DNA synthesis (UDS) induced by aflatoxin BI (10^(-7) mol.L-1) in freshly isolated rat hepatocytes was also inhibited by DDB (10^(-6)-10^(-3)mol.L-1). Oral administration of DDB at 200 mg.kg-1 once daily for 3 d induced a significant increase of liver cytosol glutathione-S-transferase and microsomal UDPG-transferase activity in mice. These results indicate that DDB is able to directly or indirectly antagonize certain carcinogen-induced DNA damages.

Organic Carboxylate Ligand Tuned Topological Variations in Three Zn(Ⅱ)Coordination Polymers:Syntheses,Crystal Structures and Photoluminescent Properties

Three new Zn（Ⅱ） coordination polymers, namely [Zn2（suc）2（bib）2]n·nH2 O（1）, [Zn（glu）（bib）]n·4 nH2 O（2）, and [Zn（adp）（bib）]n（3）（bib = 1,4-bis（N-imidazolyl）butane, H2 suc = succinic acid, H2 glu = glutaric acid, H2 adp = adipic acid） have been hydrothermally synthesized and structurally characterized. Compound 1 features a 3D framework with 4-connected hxg-d topological network, compound 2 is comprised of 2D 44-sql-type sheets, and the adjacent 2D sheets are further packed into a 3D supramolecular architecture via intermolecular hydrogenbonding interactions, and compound 3 is a 3D framework with 4-fold interpenetrating dia topology. The structural comparison of these three compounds demonstrates that the topological variations can be well controlled by employing aliphatic dicarboxylate ligands with different spacer lengths. Moreover, the thermal stabilities and photoluminescent properties of them were also studied in detail.

Synthesis, Crystal Structure and Properties of a New Zn(II) Coordination Polymer Constructed from 2,3-Pyridine Dicarboxylic Acid and 1,1′-(1,4-Butanediyl)bis(imidazole)

A new coordination polymer, namely [Zn（pdc）（bbi）]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-（1,4-butanediyl）bis（imidazole）}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436（3）, b = 16.988（5）, c = 12.106（4）, β = 92.204（5）°, V = 1733.6（9）3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F（000） = 864, μ（MoKa） = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn（II） is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn（II） ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.

Syntheses, Structures and Magnetic Properties of Two Co(II) Coordination Polymers with 2,5-Pyridine Dicarboxylic Acid

The hydro(solvo)thermal reactions of cobalt powder or its chloride with 2,5- pyridine dicarboxylic acid (H2PYDC) yielded two new complexes: [Co(II)2(PYDC)2(H2O)2- (H2O)4]n 1 and {Co(II)[NH2(CH3)2]2(PYDC)2}n 2. It is observed that the reactive solvents result in different connectivity modes of ligand and diverse dimensional extension of crystal structures. The correlation between structure and magnetic property will be discussed in this paper. Crystal data for 1: space group P1, a = 7.0419(17), b = 8.937(2), c = 9.6182(19) ?, α = 91.532(4), β = 99.869(10), γ = 107.889(11)o, V = 565.5(2) ?3, Z = 1, Dc = 1.845 g/cm3, μ = 1.56 mm-1, F(000) = 322 , R = 0.0505 and wR = 0.1580; and those for 2: space group C2/c, a = 14.9075(6), b = 8.2523(3), c = 16.9643(2) ?, β = 100.982(2)o, V = 2048.75(11) ?3, Z = 4, Dc = 1.560 g/cm3, μ = 0.892 mm-1, F(000) = 996, R = 0.0443 and wR = 0.1134.

Protective Effect of HO-1 Transfection against Ethanol-induced Osteoblast Damage

Heme oxygenase-1（HO-1） plays important roles in anti-oxidant, anti-inflammatory and immunoregulative activities. The aim of this study was to observe if HO-1 transfection could inhibit the damage of osteoblasts induced by ethanol. HO-1 was transfected into osteoblasts via constructed plasmid. After exposure to ethanol for 24 h, cytoactivity and apoptosis of osteoblasts were measured by MTT assay and flow cytometry, respectively. Furthermore, the oxidative stress and inflammatory factors in osteoblasts were measured. Compared to positive control group, the cytoactivity of transfected osteoblasts was significantly increased, and the apoptosis rate was significantly decreased（P〈0.05）. At the same time, the levels of reactive oxygen species（ROS）, methane dicarboxylic aldehyde（MDA）, tumor necrosis factor-α（TNF-α） and interleukin-1（IL-1） were significantly decreased（P〈0.05）, and superoxide dismutase（SOD） level was increased（P〈0.05） in the transfected osteoblasts as compared with positive controls. These results suggest that HO-1 plays a protective role in osteoblasts, and HO-1 transfection can effectively inhibit bone damage induced by ethanol.

Kinetics of 2-Methyl-6-acetyl-naphthalene Liquid Phase Catalytic Oxidation

In this paper, a kinetics model for the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid catalyzed by cobalt-manganese-bromide is proposed. The effects of the reaction temperature, catalyst concentration and ratio of catalyst on the lime evolution of the experimental concentration for the constituents including raw material, intermediates and product are investigated. The model parameters are determined in a nonlinear optimization, minimizing the difference between the simulated and experimental time evolution of the product composition obtained in a semi-batch oxidation reactor where the gas and liquid phase were well nuxed. The kinetics data demonstrate that the model is suitable to the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid.

Separation Behavior of U(VI) and Th(IV) on a Mixed Ion Exchange Column Using 2,6-Pyridine Dicarboxylic Acid as a Complexing Agent and Determination of Trace Level Thorium in Uranium Matrix Employing High Performance Ion Chromatography

Retention behavior of U(VI) and Th(IV) as their 2, 6-pyridine dicarboxylic acid (PDCA) complexes on reversed phase and ion exchange (cation, anion and mixed ion exchange) columns was studied and based on the results, a simple ion chromatography method for the determination of trace level thorium in uranium oxide using 0.075mM 2, 6-pyridine dicarboxylic acid (PDCA) and 1M KNO3 in 1.2M HNO3 as eluent (flow rate 1 mL/min)was proposed. The advantage of the developed method is that the separation of uranium matrix is not required prior to the ion chromatographic determination of trace Th. Separation was carried out on a mixed ion exchange stationary phase and a 10?4 M arsenazo (III) solution was used as post column reagent for detecting the separated metal ions. The separation of Th from uranium using PDCA in the present investigation is attributed through cation exchange mechanism. A calibration plot was constructed by following the standard addition method over the concentration range of 0.25 to 10 ppm of Th in the presence of uranium matrix, which resulted in a linear regression coefficient of 0.9978. The precision of the method was better than 5% and the LOD for Th was found to be 0.1ppm (S/N=3). The method has been validated by comparing the results with the results obtained from ICP-MS analysis where the This separated from the uranium matrix. The proposed method is simple, rapid, accurate and cost effective compared to techniques like ICP-MS or ICP-AES and is suitable for the routine kind of analysis.

An efficient electrocatalytic system composed of nickel oxide and nitroxyl radical for the oxidation of bio-platform molecules to dicarboxylic acids

Selective oxidation of biomass and its derivatives to dicarboxylic acids represents a promising route for biomass valorization.However,the co-presence of multiple functional groups in biomass molecules makes the selective oxidation of particular functional a challenging task.Here,we demonstrate an efficient electrocatalytic system consisting of nickel oxide(NiO)and a nitroxyl radical,i.e.,2,2,6,6-tetrame thylpiperidine-1-oxyl(TEMPO)or 4-acetamido-TEMPO(ACT),for the selective oxidation of key bioplatform molecules including glucose,xylose and 5-hydroxymethylfurfural(HMF)into corresponding dicarboxylic acids,i.e.,glucaric acid,xylaric acid,and 2,5-furandicarboxylic acid(FDCA).NiO is clarified as the active catalyst for the oxidation of aldehyde in bio-platform molecules to carboxylic acid,while TEMPO or ACT is responsible for the oxidation of primary alcohol to aldehyde.The combination of NiO and TEMPO or ACT significantly accelerated the tandem oxidation of aldehyde and hydroxyl groups in glucose,xylose and HMF,thus achieving excellent yields(83%-99%)of dicarboxylic acids.Moreover,the combination catalyst enables the selective oxidation of glucose and xylose with high concentrations(e.g.,20 wt%),which offers a promising strategy for biomass valorization.

Protective Effects of Dimethyl-4,4'-Dimethoxy-5,6,5',6'-Dimethylene Dioxybiphenyl-2,2'-Dicarboxylate on Damages of Isolated Rat Hepatocytes Induced by Carbon Tetrachloride and D-galactosamine

The protective effect of biphenyl dimethyl dicarboxylate (DDB) on chemically induced damages was studied in isolated suspended rat hepatocytes. The experimental results showed that DDB (200μg/106 cells) efficiently protected the hepatocytes against carbon tetrachloride (CC14 10 mrnol.L-1) and D-galactosamine (1 mmol.L-1) induced damages. Membranal lipid peroxidation (malondialdehyde, MDA formation) and glutamic pyruvic transaminase (GPT) release from the hepatocytes were markedly decreased. The damage of the cell surfaces of the hepatocytes were also reduced as seen under a scanning electron microscope (SEM). Pretreatment with DDB (300 mg-kg-1) orally ameliorated the reduction of liver glycogen and blood glucose caused by ip injection of D-galactosamine (800 mg-kg-1) in mice. When normal rats were given DDB 300 mg-kg-1 once daily for 10 d, the free ribosomal protein and RNA in the liver increased significantly. These results indicate that DDB is of beneficial effects on both damaged and normal hepatocytes.

Microbial production of L-malate from renewable non-food feedstocks

L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical industries.Driven by the pursuit of a sustainable economy,microbial production of L-malate has received much attention in last decades.In this review,we focus on the utilization of wastes and/or byproducts as feedstocks for the microbial production of L-malate.Firstly,we present the recent developments on the natural or engineered metabolic pathways that dedicate to the biosynthesis of L-malate,and also provide a comprehensive discussions on developing high-efficient producers.Then,the recent achievements in microbial production of L-malate from various carbon sources were concluded and discussed.Furthermore,some abundant non-food feedstocks which have been used for microbial production of other chemicals were reviewed,as they may be potential candidate feedstock for L-malate production in future.Finally,we outlined the major challenges and proposed further improvements for the production of L-malate.

Synthesis,Electrochemical and Fluorescent Properties of a New Zinc(Ⅱ) Complex through Self-assembly Reaction of 2,2'-Bipyridine-3,3'-dicarboxylic Acid

A new Zn（Ⅱ） complex [Zn（Phen）2（C（12）H6O4N2）（H2O）]·3H2O with 2,2-bipyridine-3,3-dicarboxylic acid and 1,10-phenanthroline（Phen） as ligands was synthesized, and the crystal data are as follows： monoclinic, space group P2（1/n）, a=12.5581（11）, b=17.3382（17）, c=15.6687（14） , β=110.579（2）o, Mr=731.02, V=3193.9（5） 3, Dc=1.520 g/cm3, Z=4, μ（Mo Kα）=0.833 mm（-1）, F（000）=1508, the final R=0.0431 and w R=0.0936. In the title complex, the central Zn（Ⅱ） ion is located in a distorted octahedral coordination environment. The electrochemical and fluorescent properties were studied. The title complex possesses irreversible electron transfer in the electrode reaction, and it has a strong emission peak in the range of 470505 nm, with the excitation wavelength being 488 nm.

Preparation of Dicarboxyl Cellulose Nanocrystals from Agricultural Wastes by Sequential Periodate-Chlorite Oxidation

Agricultural waste straw is the renewable resource with the highest annual yield in the world.In value-added applications of agricultural waste,dicarboxyl cellulose nanocrystals(DCCs)are prepared from rice,wheat,and corn straw by sequential periodate-chlorite oxidation.In this study,DCCs from rice,wheat,and corn straw were characterized by transmission electron microscopy(TEM),Fourier transform infrared spectrometer,X-ray diffractometer(XRD),and thermal gravimetric analysis(TGA).The carboxyl content of the DCCs was also investigated.XRD results show that the crystallinity index decreased after sequential periodate-chlorite oxidation;however,the cellulose I structure was maintained.TEM results show that rod-shaped DCCs with an average length and width of 287.0 nm and 9.9 nm,respectively,were successfully prepared by sequential periodate-chlorite oxidation.The carboxyl content of the DCCs was around 3.9 mmol/g,and not affected by the type of straw.Experiments to study the removal of copper ions in aqueous medium were performed with the prepared DCCs.The adsorption capacities of copper ions were 131,162,and 144 mg/g for DCCs prepared from rice,wheat,and corn straws,respectively.The results show that DCCs prepared from rice,wheat,and corn straws by sequential periodatechlorite oxidation have potential for the removal of copper ions from aqueous medium.

The study of anti-hepatitis drug dimethyl dicarboxylate biphenyl on invasion of human hepatocellular carcinoma MHCC97-H cells and its active mechanisms

Objective： To assess the anti-invasive effect of DDB and its possible active mechanism in human hepatocellular carcinoma MHCC97-H with high metastasis potential. Methods： MTT assay was used to evaluate the cytotoxicity of DDB to MHCC97-H cells and the anti-adhesion of DDB on MHCC97-H cells to laminin （LN） and fibronectin （FN）. The anti-invasive effect of DDB was detected by the transwell chamber experiment. VEGF, nm23-H1 and uPAR mRNA transcriptions were determined by RT-PCR assay. The secretion and expression of a-fetal protein （AFP） were analyzed by ELISA and flow cytometry, respectively. Results： DDB at non-cytotoxic concentrations （10, 50 and 100 μmol/L） obviously inhibited the adhesion of MHCC97-H on LN and FN. In the transwell chamber experiment, the inhibition rates of the invasion of DDB 50 and 100 μmol/L on MHCC97-H cells were 25.8% and 32.3%, respectively. By RT-PCR assay, DDB 50 and 100 μmol/L decreased VEGF, nm23-H1 and uPAR mRNA expressions in MHCC97-H cells. The ELISA assay showed that 50, 100 and 200 μmol/L DDB decreased the AFP secretion of MHCC97-H cells, the inhibitory rates were 16.5%, 17.5% and 48.5%, respectively. DDB also decreased the expression of AFP in MHCC97-H cells by flow cytometry assay. Conclusion： DDB, an anti-hepatitis drug, at non-cytotoxic concentrations showed significant anti-invasion effect in human hepatocellular carcinoma MHCC97-H cells, and the inhibition of VEGF, nm23-H1 and uPAR expression should contribute to the anti-invasion property of DDB.

Crystal Structures and Photoluminescent Properties of Two Cd^(2＋) Coordination Polymers Constructed from an 8-Hydroxyquinolinate Ligand

In order to perform a study on the structural modulation in the Cd（Ⅱ）-L architecture（HL =（E）-2-[2-（3-pyridyl）ethenyl]-8-hydroxyquinoline）, two different dicarboxylic acids, namely, 2-aminoterephthalic acid（H_2ATA） and 4,4￠-biphenyldicarboxylic acid（H_2BPDC）, are employed as the secondary auxiliary ligands. Two new complexes [Cd_2L_2（ATA）]（1） and [Cd_2L_2（BPDC）·2MeO H· 4H_2O]（2） with distinct 3D frameworks were obtained. In complex 1, ligands ATA bridge the 1D Cd（Ⅱ）-L infinite chains into a 3D polymeric coordination network. Complex 2 is a 3D porous framework, in which adjacent 2D Cd（Ⅱ）-L coordination layers were linked together by the coor- dinated BPDC ligands. The variant structures of two complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. In addition, the photoluminescent properties（fluorescent emission, lifetime, and quantum yield） of polymers 1 and 2 were also investigated in the solid state.