Studies have been carried out on the effect of lanthanum-amino acid complexes on embryo development and nauplius growth ofPenaeus chinensis. The experimental results indicate that: (1)The optimum concentrations of lan...Studies have been carried out on the effect of lanthanum-amino acid complexes on embryo development and nauplius growth ofPenaeus chinensis. The experimental results indicate that: (1)The optimum concentrations of lanthanum-proline and Lanthanumphenylalanine for the development of eggs in monocell and dicell stages are 1.50～ 4.00mg/L and 0.50～3.00 mg/L, respectively, the egg hatching rates being raised by 21.0 ～ 46.0% and 23.0 ～42.8% ( P ＜ 0.05 ) respectively. (2)The optimum concentrations of lanthanum- proline complex and Lanthanum-phenylalanine complex for the growth ofnauplii are 1.50～4.00 mg/L and 0.50～3.00 mg/L, the metamorphosis rate from nauplius to protozoea being raised by 16.4 ～27.5% and 20.4～26.7% (P ＜ 0.05 ) respectively. (3)The positive effect of lanthanum-amino acid complexes on egg hatching and nauplius metamorphosis of Penaeus chinensis is better than that of lanthanum. With regard to the positive effect, lanthanum-proline complex is better than Lanthanum-phenylalanine complex.展开更多
Since nucleic acids(DNA and RNA) play very important roles in cells,they are molecular targets of many clinically used drugs,such as anticancer drugs and antibiotics.Because of clinical demands for treating various de...Since nucleic acids(DNA and RNA) play very important roles in cells,they are molecular targets of many clinically used drugs,such as anticancer drugs and antibiotics.Because of clinical demands for treating various deadly cancers and drug-resistant strains of pathogens,there are urgent needs to develop novel therapeutic agents.Targeting nucleic acids hasn’t been the mainstream of drug discovery in the past,and the lack of 3D structural information for designing and developing drug specificity is one of the main reasons.Fortunately,many important structures of nucleic acids and their protein complexes have been determined over the past decade,which provide novel platforms for future drug design and discovery.In this review,we describe some useful nucleic acid structures,particularly their interactions with the ligands and therapeutic candidates or even drugs.We summarize important information for designing novel potent drugs and for targeting nucleic acids and protein-nucleic acid complexes to treat cancers and overcome the drug-resistant problems.展开更多
Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane ...Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane and bpe = 1,2-bis（4-pyridinyl）ethylene）,were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square（4,4） grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.展开更多
The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface...The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface of mercury electrode,the redox process of Eu(Ⅲ)became more reversible than that of Eu(Ⅲ)-D-ribose in solution phase.展开更多
Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, mola...Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, H-1 NMR, thermogravimetric and differential thermal analysis.展开更多
Two complexes,NdL_3·2C_2H_5OH and NdL_3·2H_2O where L=cyclohexane-carboxylate anion,were synthesized and the structure of the former was determined by the single-crystal X-ray diffration method. The crystal ...Two complexes,NdL_3·2C_2H_5OH and NdL_3·2H_2O where L=cyclohexane-carboxylate anion,were synthesized and the structure of the former was determined by the single-crystal X-ray diffration method. The crystal is triclinic,Pspace group with the cell parameters:a=1.2385(6),b=1.2385(6),c=0.9421(5) nm.α=91.69(4)°,β=98.49(4)°,γ=99.16(5)°,Z=2,V=1.436 nm^3.The structure was refined to R value of 0.0866.Each Nd atom is connected with other two Nd atoms by two bidentate and two tridentate carboxyl groups to form a linear polymer.The Nd atom is further coordinated by a chelating carboxyl and two ethanol molecules.So the central atom is nine-coordinated with a distorted monocapped square-antiprism geometry.The infrared spectra and the thermal analysis of the complexes were also studied.展开更多
Spectroscopic properties of Nd^(3+),Er^(3+)-glutamic acid,aspartic acid and asparagine systems are investi- gated at different pH values and different Ln^(3+):amino acid ratios.The existence of 1:1 and 1:2.75 species ...Spectroscopic properties of Nd^(3+),Er^(3+)-glutamic acid,aspartic acid and asparagine systems are investi- gated at different pH values and different Ln^(3+):amino acid ratios.The existence of 1:1 and 1:2.75 species in solution of pH=1～5 is proved.The dependence of oscillator strength of “hypersensitive” transition and parameter T_2 on acidic-basic properties of the ligand and correlation between oscillator strength of “hypersensitive” transition and parameter T_2 are discussed.展开更多
Reactions of copper（Ⅱ） sulfate or copper（Ⅱ） perchlorate,samarium（Ⅲ）,erbium（Ⅲ） or neodymium（Ⅲ）nitrate（5/1 equiv.） with pyrazinohydroxamic acid（H2Pyzha） in H2O/Me0 H led to three new heterobimetallic ...Reactions of copper（Ⅱ） sulfate or copper（Ⅱ） perchlorate,samarium（Ⅲ）,erbium（Ⅲ） or neodymium（Ⅲ）nitrate（5/1 equiv.） with pyrazinohydroxamic acid（H2Pyzha） in H2O/Me0 H led to three new heterobimetallic 15-metallacrown-5 complexes.In a MeOH/H2O solution,when adding inorganic salts,the ligands exist as protonated metallacrowns.In the solid state,their structures are more complicated as confirmed by X-ray analysis：metallacrown[Sm（H2O）3 {Cu（pyzha）}5（H2O）2（MeOH）（HSO4）2]·（H2O）2（HSO4）（1）;[Nd（H2O）2（MeOH） {Cu（pyzha）}5（ClO4）2（H2O）5（NO3）]（2）;[Eu（H2O）2（MeOH） {Cu（pyzha）}5（ClO4）2（H2O）5（NO3）]（3）.The differentiation of atomic and ionic radii between the encapsulated lanthanide（Ⅲ） could be used to control the bowl-shape distortion of the metallacrowns from the planar geometry.The complex 1 clearly exhibits fluorescence behavior of samarium（Ⅲ）,while 2and 3 show that of copper（Ⅱ） and ligand.展开更多
Metal complexes of anthranilic acid derivatives that constitute a novel class of non-sugar-type α- glucosidase inhibitors were synthesized and assessed in vitro for inhibitory activity. All of the AgO） complexes （9...Metal complexes of anthranilic acid derivatives that constitute a novel class of non-sugar-type α- glucosidase inhibitors were synthesized and assessed in vitro for inhibitory activity. All of the AgO） complexes （9-16） inhibited α-glucosidase at the nanomolar scale, while 3,5-dichloroanthranilic acid silver（1） （9） was the most potent （ICso = 3.21 nmol/L）. Analysis of the kinetics of enzyme inhibition indicated that the mechanism of the newly prepared silver complexes was noncompetitive. The structure-activity relationships were also analyzed, and thev are discussed in this report.展开更多
The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.79...The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.展开更多
It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed hav...It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.展开更多
Several chiral mixed-ligand complexes have been synthesized and their efficiency as catalysts for the asymmetric synthesis of chrysanthemic acid tested.
The similar floatabilities of calcium minerals and the huge difference between scheelite and wolframite have resulted in difficulties during their separation by flotation in Shizhuyuan Mine. In this study, novel colle...The similar floatabilities of calcium minerals and the huge difference between scheelite and wolframite have resulted in difficulties during their separation by flotation in Shizhuyuan Mine. In this study, novel collectors, lead complexes of benzohydroxamic acid（Pb-BHA）,were introduced to modify the surface properties of scheelite and wolframite, thereby effectively and selectively improving floatability. The Pb-BHA complexes are found to be selective for the separation of scheelite and calcium minerals with little use of depressants and enable the synchronous flotation of scheelite and wolframite.Hence, a novel flotation process was developed for the recovery of tungsten minerals. The process is simplified greatly, and the recovery is improved by almost 10%.Removing or decreasing the amount of water glass contributes to the improvement of tungsten and fluorite recovery and the circulation of water and reagents, which benefits the environment.展开更多
The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this...The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.展开更多
Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold i...Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold is significant.Herein we disclose a chiral N,N’-dioxide/Lewis acid complex-catalyzed asymmetric inverse-electron-demand Diels-Alder(IEDDA)reaction using electron-deficient 3-carboalkoxyl-2-pyrones and less electron-enriched aryl enol ethers as reactants.A wide range of non-and 1,2-disubstituted acyclic aryl enol ethers are applicable to deliver diverse chiral bridged bicyclic lactones in high yields and stereoselectivities(up to 96%yield,>20:1 dr,97:3 er).The bridged bicyclic lactone core can be easily converted into chiral aryl cyclohex-3-en ether scaffold.Notably,DFT calculations revealed a stepwise and endo mechanism to explain the high enantioselectivity controlled by the cooperative effect of the steric factors and the dispersion interactions between ligands and enol ethers.展开更多
Coffee is commonly consumed beverage in the world and it has been suggested to have beneficial effect.Chlorogenic acids(CGAs)are main ingredient of coffee beans which has been extensively used in nutraceuticals and me...Coffee is commonly consumed beverage in the world and it has been suggested to have beneficial effect.Chlorogenic acids(CGAs)are main ingredient of coffee beans which has been extensively used in nutraceuticals and medicine.Recently,various therapeutic effects of chlorogenic acids have been investigated.However,there are limited studies to investigate its anticancer properties.In the present study,we have used chlorogenic acid complex(CGA7)a decaffeinated water soluble green coffee bean extract to evaluate its cytotoxic effect on human and mouse cancer cell lines by using different approaches.From our results we found CGA7 treatment induces cell death in a dose and time dependent manner in different cancer cell lines.Further,CGA7 induced apoptosis was characterized by DNA fragmentation,PARP-1 cleavage,caspase-9 activation,and down regulation of Bcl-2,an anti-apoptotic protein and up regulation of pro-apoptotic protein BAX.Overall findings indicated that CGA7 complex a potent anticancer molecule found in green coffee beans could be a safe bioactive ingredient for prevention of cancer.展开更多
Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environment...Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients（e.g.,phosphorus（P））.In this study,ferrihydrite/goethite-humic acid（FH/GE–HA）complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity（Q（max））decreased in the order of FH（22.17 mg/g）〉FH-HA（5.43 mg/g）〉GE（4.67 mg/g）〉GE-HA（3.27 mg/g）.After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.展开更多
At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to co...At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.展开更多
Complex of rare earth with carboxylic acid was prepared by precipitation and direct method. It was copolymerized with such monomers as acrylic acid and other ones to synthesize ionomer of rare earth and organic polyme...Complex of rare earth with carboxylic acid was prepared by precipitation and direct method. It was copolymerized with such monomers as acrylic acid and other ones to synthesize ionomer of rare earth and organic polymer with different rare earth contents. Its glass-transition temperature and heat stability were analyzed by TG and DTA. Infra-red detector was used to show its structure. The effect of rare earth complex prepared by different methods on copolymerization and properties of copolymers was also discussed.展开更多
基金Supported by National Natural Science Fund of China (No: 39370548)
文摘Studies have been carried out on the effect of lanthanum-amino acid complexes on embryo development and nauplius growth ofPenaeus chinensis. The experimental results indicate that: (1)The optimum concentrations of lanthanum-proline and Lanthanumphenylalanine for the development of eggs in monocell and dicell stages are 1.50～ 4.00mg/L and 0.50～3.00 mg/L, respectively, the egg hatching rates being raised by 21.0 ～ 46.0% and 23.0 ～42.8% ( P ＜ 0.05 ) respectively. (2)The optimum concentrations of lanthanum- proline complex and Lanthanum-phenylalanine complex for the growth ofnauplii are 1.50～4.00 mg/L and 0.50～3.00 mg/L, the metamorphosis rate from nauplius to protozoea being raised by 16.4 ～27.5% and 20.4～26.7% (P ＜ 0.05 ) respectively. (3)The positive effect of lanthanum-amino acid complexes on egg hatching and nauplius metamorphosis of Penaeus chinensis is better than that of lanthanum. With regard to the positive effect, lanthanum-proline complex is better than Lanthanum-phenylalanine complex.
基金financially supported by the Georgia Cancer Coalition(GCC) Distinguished Cancer Clinicians and Scientists and by the US National Science Foundation(NSF MCB-0824837)
文摘Since nucleic acids(DNA and RNA) play very important roles in cells,they are molecular targets of many clinically used drugs,such as anticancer drugs and antibiotics.Because of clinical demands for treating various deadly cancers and drug-resistant strains of pathogens,there are urgent needs to develop novel therapeutic agents.Targeting nucleic acids hasn’t been the mainstream of drug discovery in the past,and the lack of 3D structural information for designing and developing drug specificity is one of the main reasons.Fortunately,many important structures of nucleic acids and their protein complexes have been determined over the past decade,which provide novel platforms for future drug design and discovery.In this review,we describe some useful nucleic acid structures,particularly their interactions with the ligands and therapeutic candidates or even drugs.We summarize important information for designing novel potent drugs and for targeting nucleic acids and protein-nucleic acid complexes to treat cancers and overcome the drug-resistant problems.
基金supported by the National Natural Science Foundation of China(No.21571093)the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.14HASTIT017)+1 种基金the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.14IRTSTHN008)the Foundation of Education Committee of Henan Province(No.142300410301)
文摘Two new Co（Ⅱ） coordination polymers,{[Co_3（Hchda）_2（chda）_2（bpp）_2（H_2O）_2]}_n 1 and {[Co（chda）（bpe）（H_2O）]·3H_2O}_n 2（H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis（4-pyridinyl）propane and bpe = 1,2-bis（4-pyridinyl）ethylene）,were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis（TGA）,and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square（4,4） grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.
文摘The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface of mercury electrode,the redox process of Eu(Ⅲ)became more reversible than that of Eu(Ⅲ)-D-ribose in solution phase.
文摘Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, H-1 NMR, thermogravimetric and differential thermal analysis.
文摘Two complexes,NdL_3·2C_2H_5OH and NdL_3·2H_2O where L=cyclohexane-carboxylate anion,were synthesized and the structure of the former was determined by the single-crystal X-ray diffration method. The crystal is triclinic,Pspace group with the cell parameters:a=1.2385(6),b=1.2385(6),c=0.9421(5) nm.α=91.69(4)°,β=98.49(4)°,γ=99.16(5)°,Z=2,V=1.436 nm^3.The structure was refined to R value of 0.0866.Each Nd atom is connected with other two Nd atoms by two bidentate and two tridentate carboxyl groups to form a linear polymer.The Nd atom is further coordinated by a chelating carboxyl and two ethanol molecules.So the central atom is nine-coordinated with a distorted monocapped square-antiprism geometry.The infrared spectra and the thermal analysis of the complexes were also studied.
文摘Spectroscopic properties of Nd^(3+),Er^(3+)-glutamic acid,aspartic acid and asparagine systems are investi- gated at different pH values and different Ln^(3+):amino acid ratios.The existence of 1:1 and 1:2.75 species in solution of pH=1～5 is proved.The dependence of oscillator strength of “hypersensitive” transition and parameter T_2 on acidic-basic properties of the ligand and correlation between oscillator strength of “hypersensitive” transition and parameter T_2 are discussed.
文摘Reactions of copper（Ⅱ） sulfate or copper（Ⅱ） perchlorate,samarium（Ⅲ）,erbium（Ⅲ） or neodymium（Ⅲ）nitrate（5/1 equiv.） with pyrazinohydroxamic acid（H2Pyzha） in H2O/Me0 H led to three new heterobimetallic 15-metallacrown-5 complexes.In a MeOH/H2O solution,when adding inorganic salts,the ligands exist as protonated metallacrowns.In the solid state,their structures are more complicated as confirmed by X-ray analysis：metallacrown[Sm（H2O）3 {Cu（pyzha）}5（H2O）2（MeOH）（HSO4）2]·（H2O）2（HSO4）（1）;[Nd（H2O）2（MeOH） {Cu（pyzha）}5（ClO4）2（H2O）5（NO3）]（2）;[Eu（H2O）2（MeOH） {Cu（pyzha）}5（ClO4）2（H2O）5（NO3）]（3）.The differentiation of atomic and ionic radii between the encapsulated lanthanide（Ⅲ） could be used to control the bowl-shape distortion of the metallacrowns from the planar geometry.The complex 1 clearly exhibits fluorescence behavior of samarium（Ⅲ）,while 2and 3 show that of copper（Ⅱ） and ligand.
文摘Metal complexes of anthranilic acid derivatives that constitute a novel class of non-sugar-type α- glucosidase inhibitors were synthesized and assessed in vitro for inhibitory activity. All of the AgO） complexes （9-16） inhibited α-glucosidase at the nanomolar scale, while 3,5-dichloroanthranilic acid silver（1） （9） was the most potent （ICso = 3.21 nmol/L）. Analysis of the kinetics of enzyme inhibition indicated that the mechanism of the newly prepared silver complexes was noncompetitive. The structure-activity relationships were also analyzed, and thev are discussed in this report.
文摘The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.
文摘It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.
文摘Several chiral mixed-ligand complexes have been synthesized and their efficiency as catalysts for the asymmetric synthesis of chrysanthemic acid tested.
基金financially supported by the National Natural Science Foundation of China (No.51634009)the Institutions of Higher Learning Discipline Innovation Conference Program (111 Project) (No.B14034)the Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources Innovation Driven Plan of Central South University (No.2015CX005)
文摘The similar floatabilities of calcium minerals and the huge difference between scheelite and wolframite have resulted in difficulties during their separation by flotation in Shizhuyuan Mine. In this study, novel collectors, lead complexes of benzohydroxamic acid（Pb-BHA）,were introduced to modify the surface properties of scheelite and wolframite, thereby effectively and selectively improving floatability. The Pb-BHA complexes are found to be selective for the separation of scheelite and calcium minerals with little use of depressants and enable the synchronous flotation of scheelite and wolframite.Hence, a novel flotation process was developed for the recovery of tungsten minerals. The process is simplified greatly, and the recovery is improved by almost 10%.Removing or decreasing the amount of water glass contributes to the improvement of tungsten and fluorite recovery and the circulation of water and reagents, which benefits the environment.
基金supported by the National Natural Science Foundation of China(nos.41171198,41403079)the Chongqing Research Program of Basic Research and Frontier Technology(no.cstc2015jcyj A20021)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(no.XDJK2015B035)
文摘The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.
基金National Natural Science Foundation of China(Nos.22001177,22203023)Guangdong Pearl River Talent Program(no.2021QN020268)+3 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515012381,2022A1515011859)Shenzhen Bay Laboratory Startup Fund(No.S201100003)Major Program of Shenzhen Bay Laboratory(No.S211101001-4)Shenzhen Bay Qihang Fellow Program(No.QH23001)for generous financial support.
文摘Chiral aryl cyclohex-3-en ether scaffold is widely present in bioactive natural products and drugs.The exploitation of efficient and enantioselective methods for the construction of aryl cyclohex-3-en ether scaffold is significant.Herein we disclose a chiral N,N’-dioxide/Lewis acid complex-catalyzed asymmetric inverse-electron-demand Diels-Alder(IEDDA)reaction using electron-deficient 3-carboalkoxyl-2-pyrones and less electron-enriched aryl enol ethers as reactants.A wide range of non-and 1,2-disubstituted acyclic aryl enol ethers are applicable to deliver diverse chiral bridged bicyclic lactones in high yields and stereoselectivities(up to 96%yield,>20:1 dr,97:3 er).The bridged bicyclic lactone core can be easily converted into chiral aryl cyclohex-3-en ether scaffold.Notably,DFT calculations revealed a stepwise and endo mechanism to explain the high enantioselectivity controlled by the cooperative effect of the steric factors and the dispersion interactions between ligands and enol ethers.
文摘Coffee is commonly consumed beverage in the world and it has been suggested to have beneficial effect.Chlorogenic acids(CGAs)are main ingredient of coffee beans which has been extensively used in nutraceuticals and medicine.Recently,various therapeutic effects of chlorogenic acids have been investigated.However,there are limited studies to investigate its anticancer properties.In the present study,we have used chlorogenic acid complex(CGA7)a decaffeinated water soluble green coffee bean extract to evaluate its cytotoxic effect on human and mouse cancer cell lines by using different approaches.From our results we found CGA7 treatment induces cell death in a dose and time dependent manner in different cancer cell lines.Further,CGA7 induced apoptosis was characterized by DNA fragmentation,PARP-1 cleavage,caspase-9 activation,and down regulation of Bcl-2,an anti-apoptotic protein and up regulation of pro-apoptotic protein BAX.Overall findings indicated that CGA7 complex a potent anticancer molecule found in green coffee beans could be a safe bioactive ingredient for prevention of cancer.
基金supported by the National Natural Science Foundation of China(Nos.41171198,41403079)the China Postdoctoral Science Foundation(No.2013M542238)+1 种基金the Chongqing Special Postdoctoral Science Foundation(No.Xm2014023)the Fundamental Research Funds for the Central Universities(No.XDJK2015B035)
文摘Iron oxide（FeO）coated by natural organic matter（NOM）is ubiquitous.The associations of minerals with organic matter（OM）significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients（e.g.,phosphorus（P））.In this study,ferrihydrite/goethite-humic acid（FH/GE–HA）complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity（Q（max））decreased in the order of FH（22.17 mg/g）〉FH-HA（5.43 mg/g）〉GE（4.67 mg/g）〉GE-HA（3.27 mg/g）.After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.
基金Project supported by Anguran Lead and Zinc Company(55/G/93)
文摘At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.
文摘Complex of rare earth with carboxylic acid was prepared by precipitation and direct method. It was copolymerized with such monomers as acrylic acid and other ones to synthesize ionomer of rare earth and organic polymer with different rare earth contents. Its glass-transition temperature and heat stability were analyzed by TG and DTA. Infra-red detector was used to show its structure. The effect of rare earth complex prepared by different methods on copolymerization and properties of copolymers was also discussed.
