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′position...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.展开更多
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 selec...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.展开更多
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 (...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.展开更多
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...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.展开更多
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 el...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.展开更多
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 indu...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.展开更多
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, ...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.展开更多
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 p...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.展开更多
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 ind...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.展开更多
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 c...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.展开更多
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...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.展开更多
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: monocl...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.展开更多
Two new three-dimensional coordination polymers, namely [Mn(L)(bpdc)]n(1), [Mn(L)0.5(ndc)]n(2)(L = 1,4-bis(2-methylbenzimidazole)butane, H2 bpdc = 4,4'-biphenyldicarboxylic acid, H2 ndc = 2,6-naphthale...Two new three-dimensional coordination polymers, namely [Mn(L)(bpdc)]n(1), [Mn(L)0.5(ndc)]n(2)(L = 1,4-bis(2-methylbenzimidazole)butane, H2 bpdc = 4,4'-biphenyldicarboxylic acid, H2 ndc = 2,6-naphthalenedicarboxylic acid) have been successfully synthesized under hydrothermal conditions. Two complexes were characterized by physico-chemical, spectroscopic methods and single-crystal X-ray diffraction. Complex 1 shows a 3D → 3D 5-fold interpenetrated network with a 4-connected uninodal dia topology. Complex 2 possesses a 3D → 3D 3-fold interpenetrating architecture with a binodal(4,5)-connected xah topology. The fluorescence and thermal properties of the title complexes were discussed.展开更多
Eight binary and ternary solid complexes of Eu 3+ with pyridine 2, 6 dicarboxylic acid (H 2DPC), 1,10 phen anthroline (phen) and methylbenzoic acid (MBA), including o MBA, m MBA and p MBA, were synthesise...Eight binary and ternary solid complexes of Eu 3+ with pyridine 2, 6 dicarboxylic acid (H 2DPC), 1,10 phen anthroline (phen) and methylbenzoic acid (MBA), including o MBA, m MBA and p MBA, were synthesised. Their compositions were confirmed by elemental analysis. The coordination mode of ligands with Eu 3+ was studied by NMR and IR. The coordination number of eight complexes was also investigated. Furthermore, the influence on chemical shift and NMR spectrum shape by induction effect, screening effect and paramagnetic character of Eu 3+ were discussed in detail.展开更多
The binary and ternary solid complexes of Eu 3+ and La 3+ with pyridine 2,6 dicarboxylic acid (H 2DPC) and 1,10 phen anthroline were synthesized. Their compositions confirmed by elemental analysis are N...The binary and ternary solid complexes of Eu 3+ and La 3+ with pyridine 2,6 dicarboxylic acid (H 2DPC) and 1,10 phen anthroline were synthesized. Their compositions confirmed by elemental analysis are Na 3[Ln(DPC) 3]·2H 2O(Ln=La, Eu) and NaEu(DPC) 2·phen·4H 2O. The coordination mode of ligands with metal ions was studied by NMR. The influences on NMR spectra by induciton effect, screening effect and paramagnetic character of rare earth ions are discussed in this paper. The NMR studies show that these three complexes have similar symmetry and regular change of chemical shifts. Pyridine 2,6 dicarboxylic acid is a tridentate ligand. The coordination number of europium and lanthanum is nine in each of the binary complexes. The coordination number of europium is at least eight in the ternary complex.展开更多
he present paper covers a model involving Donnan memhrane equilibrium andadsorption eluilibrium to describe the retention process for diprotic organic acids inion-exclusion chromatography. On this basis the microcompu...he present paper covers a model involving Donnan memhrane equilibrium andadsorption eluilibrium to describe the retention process for diprotic organic acids inion-exclusion chromatography. On this basis the microcomputer simulation of elu-tion behaviour for dicarboxylic acids was investigated. Influences of eluent acidityand sample concentration on the retention value were studied. The theoreticallypredicted results are in reasonable agreement with the experimental data.展开更多
Some spectral properties and luminescence intensities of Tb 3+ chelates of substituted pyridine 2, 6 dicarboxylic acids and 4 phenyl pyridine 2, 6 dicarboxylic acid analogues were measured in some solutions...Some spectral properties and luminescence intensities of Tb 3+ chelates of substituted pyridine 2, 6 dicarboxylic acids and 4 phenyl pyridine 2, 6 dicarboxylic acid analogues were measured in some solutions (H 2O and EtOH etc.) by synergistic effect of EDTA. The substitution at the aromatic ring has a significant effect upon the observed luminescence intensities, excitation wavelengths, and lifetime of the complexes. Moreover, the changes in the environment cause great variation in those properties of certain Tb 3+ chelates. The results show that some of hte chelates (4 acetaminopoxypyridine 2, 6 dicarboxylic acid, 4 ethoxypyridine 2, 6 dicarboxylic acid and 4 methoxypyridine 2, 6 dicarboxylic acid etc.) have a stronger emission and longer lifetime at room temperature and may thus be used as perfectly sensitizers in fluorescence analysis.展开更多
基金Work supported by the National Natural Science Foundation of China and Chinese Academy of Sciences
文摘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.
基金financial supported by the National Key R&D program of China(2018YFB1501602)the National Natural Science Foundation of China(22121001,22172127 and 91945301)。
文摘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.
文摘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.
基金Supported by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDA09030102)National Key R&D Program of China(2017YFB0307301)the Science Foundation of Fujian Province
文摘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.
基金Supported by the Key Scientific and Technological Project of Henan(122102210250)the Foundation of Henan Educational Committee(13A150102)the key disciplines of analytical chemistry of Henan province
文摘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.
文摘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.
文摘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.
文摘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.
基金This work was supported by the National Key R&D Program of China(2018YFA0901500)the National Natural Science Foundation of China(21706124,21727818)+1 种基金the Key Science and Technology Project of Jiangsu Province(BE2016389)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture of China.
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(No.21201002)the Foundation of State Key Laboratory of Structural Chemistry(20130016)+1 种基金Anhui Provincial Natural Science Foundation(1308085QB22)Training Programs of Innovation and Entrepreneurship for Undergraduates(201410360023 and 201410360157)
文摘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.
基金Supported by the Open Fund Project of Key Laboratory of Functional Organometallic Materials of Hengyang Normal University(GN15K02)the Science Foundation of Hengyang Normal University(16D06)
文摘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.
基金Project supported by the National Natural Science Foundation of China(No.51474086)Natural Science Foundation-Steel and Iron Foundation of Hebei Province(B2015209299)
文摘Two new three-dimensional coordination polymers, namely [Mn(L)(bpdc)]n(1), [Mn(L)0.5(ndc)]n(2)(L = 1,4-bis(2-methylbenzimidazole)butane, H2 bpdc = 4,4'-biphenyldicarboxylic acid, H2 ndc = 2,6-naphthalenedicarboxylic acid) have been successfully synthesized under hydrothermal conditions. Two complexes were characterized by physico-chemical, spectroscopic methods and single-crystal X-ray diffraction. Complex 1 shows a 3D → 3D 5-fold interpenetrated network with a 4-connected uninodal dia topology. Complex 2 possesses a 3D → 3D 3-fold interpenetrating architecture with a binodal(4,5)-connected xah topology. The fluorescence and thermal properties of the title complexes were discussed.
文摘Eight binary and ternary solid complexes of Eu 3+ with pyridine 2, 6 dicarboxylic acid (H 2DPC), 1,10 phen anthroline (phen) and methylbenzoic acid (MBA), including o MBA, m MBA and p MBA, were synthesised. Their compositions were confirmed by elemental analysis. The coordination mode of ligands with Eu 3+ was studied by NMR and IR. The coordination number of eight complexes was also investigated. Furthermore, the influence on chemical shift and NMR spectrum shape by induction effect, screening effect and paramagnetic character of Eu 3+ were discussed in detail.
文摘The binary and ternary solid complexes of Eu 3+ and La 3+ with pyridine 2,6 dicarboxylic acid (H 2DPC) and 1,10 phen anthroline were synthesized. Their compositions confirmed by elemental analysis are Na 3[Ln(DPC) 3]·2H 2O(Ln=La, Eu) and NaEu(DPC) 2·phen·4H 2O. The coordination mode of ligands with metal ions was studied by NMR. The influences on NMR spectra by induciton effect, screening effect and paramagnetic character of rare earth ions are discussed in this paper. The NMR studies show that these three complexes have similar symmetry and regular change of chemical shifts. Pyridine 2,6 dicarboxylic acid is a tridentate ligand. The coordination number of europium and lanthanum is nine in each of the binary complexes. The coordination number of europium is at least eight in the ternary complex.
文摘he present paper covers a model involving Donnan memhrane equilibrium andadsorption eluilibrium to describe the retention process for diprotic organic acids inion-exclusion chromatography. On this basis the microcomputer simulation of elu-tion behaviour for dicarboxylic acids was investigated. Influences of eluent acidityand sample concentration on the retention value were studied. The theoreticallypredicted results are in reasonable agreement with the experimental data.
文摘Some spectral properties and luminescence intensities of Tb 3+ chelates of substituted pyridine 2, 6 dicarboxylic acids and 4 phenyl pyridine 2, 6 dicarboxylic acid analogues were measured in some solutions (H 2O and EtOH etc.) by synergistic effect of EDTA. The substitution at the aromatic ring has a significant effect upon the observed luminescence intensities, excitation wavelengths, and lifetime of the complexes. Moreover, the changes in the environment cause great variation in those properties of certain Tb 3+ chelates. The results show that some of hte chelates (4 acetaminopoxypyridine 2, 6 dicarboxylic acid, 4 ethoxypyridine 2, 6 dicarboxylic acid and 4 methoxypyridine 2, 6 dicarboxylic acid etc.) have a stronger emission and longer lifetime at room temperature and may thus be used as perfectly sensitizers in fluorescence analysis.