The platinum (II) complexes of the [Pt (N4,N7-Ribavirin) (DMSO) Cl], [Pt (N4,N7-De-oxyribavirin) (DMSO) Cl] were obtained by the reactions of cis-[Pt (DMSO)2 Cl2] and K[Pt (DMSO) Cl3] with 1-??-D-ribofuranosyl-1,2,4-t...The platinum (II) complexes of the [Pt (N4,N7-Ribavirin) (DMSO) Cl], [Pt (N4,N7-De-oxyribavirin) (DMSO) Cl] were obtained by the reactions of cis-[Pt (DMSO)2 Cl2] and K[Pt (DMSO) Cl3] with 1-??-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (Ribavirin) and its deoxy-analogue (deoxyribavirin). The preparation of 1-(2'-deoxy-?-D-ribofuranosyl) -1,2,4-triazole-3-carboxamide was also performed through a four-step procedure, protection of 3', 5'-dihydroxyl group of Ribavirin with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (TPDS-Cl), phenoxythio-carbonylation of the 2'-hydroxyl group of 3', 5'-O-TPDS-Ribavirin with phenoxythiocarbonyl-chloride (PTC-Cl), reduction of 2′-O-phenoxythiocarbonyl ester of 3', 5'-O-TPDS-Ribavirin with tri-n-butyltin hydride and AIBN, deprotection of 3', 5'-O-TPDS-Ribavirin with tetrabutylammon-ium fluoride in THF.展开更多
The uptake kinetics of platinum(II)complexes of 1,2 -diaminocyclohexane(dach)isomers(1R,2R-dach, 1R,2S-dach. 1S,2S-dach) with various leaving groups, Chloride(CI), oxalate (OX),squaric acid(SA), and demethylcantharic ...The uptake kinetics of platinum(II)complexes of 1,2 -diaminocyclohexane(dach)isomers(1R,2R-dach, 1R,2S-dach. 1S,2S-dach) with various leaving groups, Chloride(CI), oxalate (OX),squaric acid(SA), and demethylcantharic acid (DA) was studied in the plasma isotonic buffer. The experimentalresults show that across-membrane transport of all the platinum complexes studied follows a firstorder Kinetic process and a passive diffustion mechanism. The uptake rate constants of these platinum(II)complexes decrease in the following sequence with the k value(h-1):CI>SA>OX>DA. It isnoteworthy that the k values of the platinum(II)complexes with same leaving group reduce as: 1R,2R-dach>1R,2S-dach>1S,2S-dach. Based on these results, it is firstly suggested that the erythocytemembrane recognizes the chirality of these platinum complexes.展开更多
The observed magnetic data for two isosceles tricobalt(II) complexes have been successfully analyzed, considering the axial distortion around each cobalt(II) ion, the local spin-orbit coupling, the anisotropic exchang...The observed magnetic data for two isosceles tricobalt(II) complexes have been successfully analyzed, considering the axial distortion around each cobalt(II) ion, the local spin-orbit coupling, the anisotropic exchange interactions, and the intermolecular exchange interactions. The complexes each contains two types of octahedral high-spin cobalt(II) ions (CoA and CoB) in the shape of an isosceles triangle (CoA1–CoB–CoA2), and the contribution of the orbital angular momentum is significant. The exchange interaction between the CoA and CoB ions is practically negligible (J = ~ 0), whereas the interaction between the CoA1 and CoA2 ions is ferromagnetic (J’ > 0) for both complexes.展开更多
Anodic oxidation of Co, Cu, Zn, and Sn metals in an acetone solution of 1,1-malonayl-bis(4-p- Chlorophenylthiosemicarbazide) yields complexes of composition with general formula [Co2(pClMaTS)(H2O)6]·2H2O, [Cu2(pC...Anodic oxidation of Co, Cu, Zn, and Sn metals in an acetone solution of 1,1-malonayl-bis(4-p- Chlorophenylthiosemicarbazide) yields complexes of composition with general formula [Co2(pClMaTS)(H2O)6]·2H2O, [Cu2(pClMaTS)(H2O)6], [Zn2(pClMaTS)(H2O)6] and [Sn2(pClMaTS)(H2O)6]·2H2O. Chelation was investigated based on elemental analysis, conductivity, magnetic moment, spectral (UV-Vis, IR, Raman, 1HNMR, mass), thermal, and ESR studies. The Raman and infrared spectral studies suggests the tridentate behavior of the ligand from each tail. Since the ligand has two thiose- micarbazide groups, it may acts in an SNO tridentate fashion from each side with one of the two metal ions forming a polynuclear complex coordinating through both of the lone pair of electrons the enolic oxygen of the carbonyl group (C=O), the azomethine nitrogen (C=N) and the thioenol form of the thiocarbonyl group (C=S). The differential thermogravimetric analysis (DTG) curves were used to study the decomposition steps of the isolated complexes using Horowitz-Metzger (HM) and Coats-Redfern (CR) methods. The kinetic thermodynamic parameters such as: E*, ΔH*, ΔS*and ΔG* are calculated from the DTG curves.展开更多
There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory ef...There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory effects. Several Schiff bases also display α-glucosidase inhibitory effects. In this study, we focused on safe and highly effective complexes including Zn(II) ion. We prepared and characterized the Zn(II) complexes with four different Schiff bases (N-salicylidene-β-alanine (N-sβ), N-N’-bis (salicylidene) ethylenediamine (N-bsE), N, N’-bis (salicylidene)-phenylenediamine (N-bsP), and 1-[(2-dimethylaminoethylimino) methyl]naphtholate (DMN)) and investigated their α-glucosidase inhibitory effects in vitro, using α-glycosidases from Saccharomyces sp. and rat small intestine, and in vivo, using a sucrose tolerance test. The Zn(II) complexes with DMN showed the highest in vitro and in vivo α-glucosidase inhibitory effects in this study.展开更多
The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2',6',2″-terpyridine...The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2',6',2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH (1), X=Cl (2), X-CN (3)) were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π*(terpy) type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz (Ru)+Tr/p(X)--π* (terpy) transition with MLCT/XLCT (metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer) character, whereas that of 3 at 529 nm is related to a dyz (Ru)+π(terpy)-π* (terpy) transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm (1), 913 nm (2), and 838 nm (3) have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru(II) complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.展开更多
The interactions between human erythrocyte spectrin(SP) and Pt(II) complexes with different composition and configuration were studied by fluorescence and circular dichroism spectra. The results showed that there are ...The interactions between human erythrocyte spectrin(SP) and Pt(II) complexes with different composition and configuration were studied by fluorescence and circular dichroism spectra. The results showed that there are 4.7×10 2 binding sites of cisplatin(CDDP) in a spectrin tetramer(SPT). Among them, about 70 sites with apparent binding constant K 1】3.47×10 6 were of highest affinity, 1.8×10 2 sites with K 2 = 3.47×10 6 were of high affinity, and other 2.2×10 2 sites with K 3 = 8.77×10 5 were of low affinity. The conformation change of spectrin, depending on the concentration of Pt(II) complex and molar ratio(R) of Pt(II) complex to spectrin, was induced by the binding of Pt(II) complexes. It indicated that the interaction of both CDDP and cis diaquodiamine platinum(DADP) with SP followed a two step first order kinetic process in the first stage (1 h), and the kinetic constants were determined. In the second stage, the induced conformation change, polymerization and depolymerization of SP were probably involved. It was noticed that in the reaction of SP and Pt(II) complexes with 1,2 cyclohexanediammine isomers as chiral carrier ligand, stereo matching played a more important role than the affinity of Pt(II) to thiol groups of SP.展开更多
Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of th...Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.展开更多
The activities of the catalytic hydrolysis of phosphate diester (BNPP) [bis(p-nitrophenyl)phosphate diester] and plasmid DNA (pUC 18) by mononuclear macrocyclic polyamine metal complexes have been investigated i...The activities of the catalytic hydrolysis of phosphate diester (BNPP) [bis(p-nitrophenyl)phosphate diester] and plasmid DNA (pUC 18) by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper. The results showed that the highest activity in hydrolysis of BNPP was obtained with le--Zn(II) complex (composed of lipophilic group) as catalyst. The hydrolysis rate enhancement is up to 3.64 × 10^4 fold. These metal complexes could effectively promote the cleavage of plasmid DNA (pUC18) at physiological conditions.展开更多
Two homochiral mercury (1) and cadmium (2) complexes derived from chiral twisted biphenyl pyridine ligand (3,3'-bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl) have been synthesized and chara...Two homochiral mercury (1) and cadmium (2) complexes derived from chiral twisted biphenyl pyridine ligand (3,3'-bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl) have been synthesized and characterized by IR, microanalysis, TGA, UV-Vis, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 2. For 1, a = 14.2038(16), b = 14.3630(17), c = 7.0257(8), V = 1433.3(3)3, Mr = 878.91, Dc = 2.037 g/cm3, μ = 7.549 mm-1, F(000) = 824, the final GOF = 1.017, R = 0.0296 and wR = 0.0645 for 2925 observed reflections with I 2σ(I). For 2, a = 14.212(3), b = 14.392(3), c = 7.0498(14), V = 1442.0(5)3, Mr = 790.72, Dc = 1.821 g/cm3, μ = 2.924 mm–1, F(000) = 760, the final GOF = 1.075, R = 0.0340 and wR = 0.0834 for 3144 observed reflections with I 2σ(I). The crystal structures of 1 and 2 are isostructural and each adopts a two-dimensional supramolecular network which contains the C–H···π interactions.展开更多
Schiff base derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline and its Mn(II) and Fe(II) complexes were synthesized and characterized by melting point and decomposition temperature, elemental analysi...Schiff base derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline and its Mn(II) and Fe(II) complexes were synthesized and characterized by melting point and decomposition temperature, elemental analysis, molar conductivity, infrared (IR) spectral analysis, atomic absorption spectroscopy (AAS) analysis, solubility test, and magnetic susceptibility. The Fourier-transform infrared spectroscopy (FTIR) spectral data of the Schiff base determined showed <span><span style="font-family:Verdana;">a band at 1622 cm</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> and this was assigned to the </span><i><span style="font-family:Verdana;">v </span></i><span style="font-family:Verdana;">(C=N), which is a feature of azomethine group. The same band was observed to shift to lower frequencies 1577 and 1599 cm</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> in the complexes suggesting coordination of the Schiff base with the respective metal(II) ions. Molar conductan</span></span><span><span style="font-family:Verdana;">ce values 14.58 and 12.65 Ω</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span></span>cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span></span>mol</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> show that the metal complexes were non-electrolyte in nature. The magnetic susceptibility of the complexes was determined and the gram magnetic susceptibility of the complexes was found to be positive, revealing that they are paramagnetic. The elemental analysis of the complexes for C, N and H determined suggested 1:1 metal to ligand ratio. The result of the antimicrobial studies showed that, the metal(II) complexes exhibited better antibacterial and antifungal activity than the Schiff base.</span></span>展开更多
Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>...Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>2</sub>O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, <sup>1</sup>H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that <strong>CAH</strong> behaves in different ways towards the coordination of the Cu<sup>2+</sup> ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu<sup>2+</sup> ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu<sup>2+</sup> complexes. EPR studies indicate the existence of polymeric complexes depending on the results of <i>g</i>-values. The results suggest that the number of copper atoms ranges from three to twelve atoms. The molecular modeling is drawn and some chemical characteristics are calculated such as chemical reactivity and energy components are investigated between the different types of the ligands.展开更多
Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Curren...Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Current knockout strategies are mainly aimed at the genes causing hyperacute immune rejection(HAR)that occurs in the first few hours while adaptive immune reactions orchestrated by CD4 T cell thereafter also cause graft failure,in which process the MHCⅡmolecule plays critical roles.Methods:Thus,we generate a 4-gene(GGTA1,CMAH,β4GalNT2,and CIITA)knockout pig by CRISPR/Cas9 and somatic cell nuclear transfer to compromise HAR and CD4 T cell reactions simultaneously.Results:We successfully obtained 4KO piglets with deficiency in all alleles of genes,and at cellular and tissue levels.Additionally,the safety of our animals after gene editing was verified by using whole-genome sequencing and karyotyping.Piglets have survived for more than one year in the barrier,and also survived for more than 3 months in the conventional environment,suggesting that the piglets without MHCⅡcan be raised in the barrier and then gradually mated in the conventional environment.Conclusions:4KO piglets have lower immunogenicity,are safe in genomic level,and are easier to breed than the model with both MHCⅠandⅡdeletion.展开更多
Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characteri...Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082(2), b = 15.447(3), c = 18.784(4)A^°, V= 3505.7(12)A^°3, Mr = 731.50, Dc = 1.386 g/cm^3, μ = 0.606 mm^-1, F(000) = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I 〉 2σ(I). For 2, a = 12.181(2), b = 15.501(3), c = 18.877(4) A^°, V = 3564.3(12)A^°3, Mr = 736.33, Dc = 1.372 g/cm^3, μ = 0.665 mm^-1, F(000) = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I 〉 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.展开更多
The synthesis and structural characterization of cobalt(II) complexes of amino acid Schiff bases was prepared from Salicylaldehyde and three amino acid (Valine, Leucine, and Isoleucine)?in basic medium. The metal comp...The synthesis and structural characterization of cobalt(II) complexes of amino acid Schiff bases was prepared from Salicylaldehyde and three amino acid (Valine, Leucine, and Isoleucine)?in basic medium. The metal complexes was synthesized by treating an ethanolic solution of the ligand with appropriate amount of metal salts [1:2] [M:L] ratio. The synthesized Schiff bases and their metal complexes have been investigated on the bases of elemental chemical analysis, FTIR, electronic spectral,?1HNMR,?13CNMR, MS, molar conductance and magnetic susceptibility measurements. The electronic spectra of the metal complexes and their magnetic susceptibility measurements suggest octahedral structures are the probable coordination geometries for the isolated complexes. The Schiff bases and their metal complexes were preliminary scanned against various strains of microbes to study their biological effect.展开更多
The reaction of the cobalt(II) meso-tetraphenylporphyrin (TPP) starting material with an excess of 2-aminophenol (Hon) in organic solvents, yields the cobalt(II) porphyrin species [CoII(TPP)(Hon)2] (1). This compound ...The reaction of the cobalt(II) meso-tetraphenylporphyrin (TPP) starting material with an excess of 2-aminophenol (Hon) in organic solvents, yields the cobalt(II) porphyrin species [CoII(TPP)(Hon)2] (1). This compound has been characterized by UV-vis., IR, MSI MS and 1H NMR spectroscopy. The UV-vis data and especially the proton NMR results, for the isolated product, indicated that complex 1 is a Co(II) mesoporphyrin derivative.The X-ray molecular structure of the title compound bis(2-aminophenol) (tetraphenylporphyrinato) cobalt(II) has been determined. This structure is the first one reported of a metalloporphyrin with a 2-aminophenol axial ligand species. The central metal is hexacoordinated by the four nitrogen atoms of the pyrrole rings and the nitrogen atoms of the two Hon trans axial ligands.展开更多
文摘The platinum (II) complexes of the [Pt (N4,N7-Ribavirin) (DMSO) Cl], [Pt (N4,N7-De-oxyribavirin) (DMSO) Cl] were obtained by the reactions of cis-[Pt (DMSO)2 Cl2] and K[Pt (DMSO) Cl3] with 1-??-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (Ribavirin) and its deoxy-analogue (deoxyribavirin). The preparation of 1-(2'-deoxy-?-D-ribofuranosyl) -1,2,4-triazole-3-carboxamide was also performed through a four-step procedure, protection of 3', 5'-dihydroxyl group of Ribavirin with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (TPDS-Cl), phenoxythio-carbonylation of the 2'-hydroxyl group of 3', 5'-O-TPDS-Ribavirin with phenoxythiocarbonyl-chloride (PTC-Cl), reduction of 2′-O-phenoxythiocarbonyl ester of 3', 5'-O-TPDS-Ribavirin with tri-n-butyltin hydride and AIBN, deprotection of 3', 5'-O-TPDS-Ribavirin with tetrabutylammon-ium fluoride in THF.
文摘The uptake kinetics of platinum(II)complexes of 1,2 -diaminocyclohexane(dach)isomers(1R,2R-dach, 1R,2S-dach. 1S,2S-dach) with various leaving groups, Chloride(CI), oxalate (OX),squaric acid(SA), and demethylcantharic acid (DA) was studied in the plasma isotonic buffer. The experimentalresults show that across-membrane transport of all the platinum complexes studied follows a firstorder Kinetic process and a passive diffustion mechanism. The uptake rate constants of these platinum(II)complexes decrease in the following sequence with the k value(h-1):CI>SA>OX>DA. It isnoteworthy that the k values of the platinum(II)complexes with same leaving group reduce as: 1R,2R-dach>1R,2S-dach>1S,2S-dach. Based on these results, it is firstly suggested that the erythocytemembrane recognizes the chirality of these platinum complexes.
文摘The observed magnetic data for two isosceles tricobalt(II) complexes have been successfully analyzed, considering the axial distortion around each cobalt(II) ion, the local spin-orbit coupling, the anisotropic exchange interactions, and the intermolecular exchange interactions. The complexes each contains two types of octahedral high-spin cobalt(II) ions (CoA and CoB) in the shape of an isosceles triangle (CoA1–CoB–CoA2), and the contribution of the orbital angular momentum is significant. The exchange interaction between the CoA and CoB ions is practically negligible (J = ~ 0), whereas the interaction between the CoA1 and CoA2 ions is ferromagnetic (J’ > 0) for both complexes.
文摘Anodic oxidation of Co, Cu, Zn, and Sn metals in an acetone solution of 1,1-malonayl-bis(4-p- Chlorophenylthiosemicarbazide) yields complexes of composition with general formula [Co2(pClMaTS)(H2O)6]·2H2O, [Cu2(pClMaTS)(H2O)6], [Zn2(pClMaTS)(H2O)6] and [Sn2(pClMaTS)(H2O)6]·2H2O. Chelation was investigated based on elemental analysis, conductivity, magnetic moment, spectral (UV-Vis, IR, Raman, 1HNMR, mass), thermal, and ESR studies. The Raman and infrared spectral studies suggests the tridentate behavior of the ligand from each tail. Since the ligand has two thiose- micarbazide groups, it may acts in an SNO tridentate fashion from each side with one of the two metal ions forming a polynuclear complex coordinating through both of the lone pair of electrons the enolic oxygen of the carbonyl group (C=O), the azomethine nitrogen (C=N) and the thioenol form of the thiocarbonyl group (C=S). The differential thermogravimetric analysis (DTG) curves were used to study the decomposition steps of the isolated complexes using Horowitz-Metzger (HM) and Coats-Redfern (CR) methods. The kinetic thermodynamic parameters such as: E*, ΔH*, ΔS*and ΔG* are calculated from the DTG curves.
文摘There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory effects. Several Schiff bases also display α-glucosidase inhibitory effects. In this study, we focused on safe and highly effective complexes including Zn(II) ion. We prepared and characterized the Zn(II) complexes with four different Schiff bases (N-salicylidene-β-alanine (N-sβ), N-N’-bis (salicylidene) ethylenediamine (N-bsE), N, N’-bis (salicylidene)-phenylenediamine (N-bsP), and 1-[(2-dimethylaminoethylimino) methyl]naphtholate (DMN)) and investigated their α-glucosidase inhibitory effects in vitro, using α-glycosidases from Saccharomyces sp. and rat small intestine, and in vivo, using a sucrose tolerance test. The Zn(II) complexes with DMN showed the highest in vitro and in vivo α-glucosidase inhibitory effects in this study.
文摘The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2',6',2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH (1), X=Cl (2), X-CN (3)) were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π*(terpy) type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz (Ru)+Tr/p(X)--π* (terpy) transition with MLCT/XLCT (metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer) character, whereas that of 3 at 529 nm is related to a dyz (Ru)+π(terpy)-π* (terpy) transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm (1), 913 nm (2), and 838 nm (3) have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru(II) complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.
文摘The interactions between human erythrocyte spectrin(SP) and Pt(II) complexes with different composition and configuration were studied by fluorescence and circular dichroism spectra. The results showed that there are 4.7×10 2 binding sites of cisplatin(CDDP) in a spectrin tetramer(SPT). Among them, about 70 sites with apparent binding constant K 1】3.47×10 6 were of highest affinity, 1.8×10 2 sites with K 2 = 3.47×10 6 were of high affinity, and other 2.2×10 2 sites with K 3 = 8.77×10 5 were of low affinity. The conformation change of spectrin, depending on the concentration of Pt(II) complex and molar ratio(R) of Pt(II) complex to spectrin, was induced by the binding of Pt(II) complexes. It indicated that the interaction of both CDDP and cis diaquodiamine platinum(DADP) with SP followed a two step first order kinetic process in the first stage (1 h), and the kinetic constants were determined. In the second stage, the induced conformation change, polymerization and depolymerization of SP were probably involved. It was noticed that in the reaction of SP and Pt(II) complexes with 1,2 cyclohexanediammine isomers as chiral carrier ligand, stereo matching played a more important role than the affinity of Pt(II) to thiol groups of SP.
文摘Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.
基金supported by the Science and Technology Department(No.04JY029-018)Education Department of Sichuan Province(No.2006ZD049).
文摘The activities of the catalytic hydrolysis of phosphate diester (BNPP) [bis(p-nitrophenyl)phosphate diester] and plasmid DNA (pUC 18) by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper. The results showed that the highest activity in hydrolysis of BNPP was obtained with le--Zn(II) complex (composed of lipophilic group) as catalyst. The hydrolysis rate enhancement is up to 3.64 × 10^4 fold. These metal complexes could effectively promote the cleavage of plasmid DNA (pUC18) at physiological conditions.
基金supported by NNSFC (20971085)"973" Programs (2007CB209701 and 2009CB930403)the Key Project and Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry
文摘Two homochiral mercury (1) and cadmium (2) complexes derived from chiral twisted biphenyl pyridine ligand (3,3'-bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl) have been synthesized and characterized by IR, microanalysis, TGA, UV-Vis, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 2. For 1, a = 14.2038(16), b = 14.3630(17), c = 7.0257(8), V = 1433.3(3)3, Mr = 878.91, Dc = 2.037 g/cm3, μ = 7.549 mm-1, F(000) = 824, the final GOF = 1.017, R = 0.0296 and wR = 0.0645 for 2925 observed reflections with I 2σ(I). For 2, a = 14.212(3), b = 14.392(3), c = 7.0498(14), V = 1442.0(5)3, Mr = 790.72, Dc = 1.821 g/cm3, μ = 2.924 mm–1, F(000) = 760, the final GOF = 1.075, R = 0.0340 and wR = 0.0834 for 3144 observed reflections with I 2σ(I). The crystal structures of 1 and 2 are isostructural and each adopts a two-dimensional supramolecular network which contains the C–H···π interactions.
文摘Schiff base derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline and its Mn(II) and Fe(II) complexes were synthesized and characterized by melting point and decomposition temperature, elemental analysis, molar conductivity, infrared (IR) spectral analysis, atomic absorption spectroscopy (AAS) analysis, solubility test, and magnetic susceptibility. The Fourier-transform infrared spectroscopy (FTIR) spectral data of the Schiff base determined showed <span><span style="font-family:Verdana;">a band at 1622 cm</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> and this was assigned to the </span><i><span style="font-family:Verdana;">v </span></i><span style="font-family:Verdana;">(C=N), which is a feature of azomethine group. The same band was observed to shift to lower frequencies 1577 and 1599 cm</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> in the complexes suggesting coordination of the Schiff base with the respective metal(II) ions. Molar conductan</span></span><span><span style="font-family:Verdana;">ce values 14.58 and 12.65 Ω</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span></span>cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">∙</span></span></span>mol</span><sup><span style="font-family:Verdana;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span></span>1</span></sup><span style="font-family:Verdana;"> show that the metal complexes were non-electrolyte in nature. The magnetic susceptibility of the complexes was determined and the gram magnetic susceptibility of the complexes was found to be positive, revealing that they are paramagnetic. The elemental analysis of the complexes for C, N and H determined suggested 1:1 metal to ligand ratio. The result of the antimicrobial studies showed that, the metal(II) complexes exhibited better antibacterial and antifungal activity than the Schiff base.</span></span>
文摘Novel polymeric Cu<sup>2+</sup> complexes derived from the reaction of cyanoacetylhydrazine (<strong>CAH</strong>;<strong>L</strong>) with CuCl<sub>2</sub>•2H<sub>2</sub>O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, <sup>1</sup>H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that <strong>CAH</strong> behaves in different ways towards the coordination of the Cu<sup>2+</sup> ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu<sup>2+</sup> ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu<sup>2+</sup> complexes. EPR studies indicate the existence of polymeric complexes depending on the results of <i>g</i>-values. The results suggest that the number of copper atoms ranges from three to twelve atoms. The molecular modeling is drawn and some chemical characteristics are calculated such as chemical reactivity and energy components are investigated between the different types of the ligands.
基金National Key Research and Development Program,Grant/Award Number:2019YFA0903800,2021YFA0805701,2021YFA0805905 and 2022YFA1103603CAS Project for Young Scientists in Basic Research,Grant/Award Number:YSBR-012+2 种基金STI 2030-Major Project,Grant/Award Number:2023ZD0407503National Natural Science Foundation of China,Grant/Award Number:32071456 and 82241224Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDA16030000。
文摘Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Current knockout strategies are mainly aimed at the genes causing hyperacute immune rejection(HAR)that occurs in the first few hours while adaptive immune reactions orchestrated by CD4 T cell thereafter also cause graft failure,in which process the MHCⅡmolecule plays critical roles.Methods:Thus,we generate a 4-gene(GGTA1,CMAH,β4GalNT2,and CIITA)knockout pig by CRISPR/Cas9 and somatic cell nuclear transfer to compromise HAR and CD4 T cell reactions simultaneously.Results:We successfully obtained 4KO piglets with deficiency in all alleles of genes,and at cellular and tissue levels.Additionally,the safety of our animals after gene editing was verified by using whole-genome sequencing and karyotyping.Piglets have survived for more than one year in the barrier,and also survived for more than 3 months in the conventional environment,suggesting that the piglets without MHCⅡcan be raised in the barrier and then gradually mated in the conventional environment.Conclusions:4KO piglets have lower immunogenicity,are safe in genomic level,and are easier to breed than the model with both MHCⅠandⅡdeletion.
基金supported by the Natural Science Foundation of Anhui Province (No. KJ2008B166)
文摘Two homochiral metallosalen complexes, Ni(salen) (salen = (1R,2R)-(-)-diamino- cyclohexane-N,N′-bis(3-tert-butyl-5-(4′-benzoic acid)-salicylidene) 1 and Cu(salen) 2, have been synthesized and characterized by IR, microanalysis, TGA, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 4. For 1, a = 12.082(2), b = 15.447(3), c = 18.784(4)A^°, V= 3505.7(12)A^°3, Mr = 731.50, Dc = 1.386 g/cm^3, μ = 0.606 mm^-1, F(000) = 1544, the final GOOF = 1.043, R = 0.0496 and wR = 0.1248 for 4791 observed reflections with I 〉 2σ(I). For 2, a = 12.181(2), b = 15.501(3), c = 18.877(4) A^°, V = 3564.3(12)A^°3, Mr = 736.33, Dc = 1.372 g/cm^3, μ = 0.665 mm^-1, F(000) = 1548, the final GOOF = 1.062, R = 0.0575 and wR = 0.1508 for 4562 observed reflections with I 〉 2σ(I). The crystal structures of 1 and 2 are isostructural with very similar supramolecular structures. An infinite two-dimensional network is generated by hydrogen bonding interactions and intermolecular π…π interactions.
文摘The synthesis and structural characterization of cobalt(II) complexes of amino acid Schiff bases was prepared from Salicylaldehyde and three amino acid (Valine, Leucine, and Isoleucine)?in basic medium. The metal complexes was synthesized by treating an ethanolic solution of the ligand with appropriate amount of metal salts [1:2] [M:L] ratio. The synthesized Schiff bases and their metal complexes have been investigated on the bases of elemental chemical analysis, FTIR, electronic spectral,?1HNMR,?13CNMR, MS, molar conductance and magnetic susceptibility measurements. The electronic spectra of the metal complexes and their magnetic susceptibility measurements suggest octahedral structures are the probable coordination geometries for the isolated complexes. The Schiff bases and their metal complexes were preliminary scanned against various strains of microbes to study their biological effect.
文摘The reaction of the cobalt(II) meso-tetraphenylporphyrin (TPP) starting material with an excess of 2-aminophenol (Hon) in organic solvents, yields the cobalt(II) porphyrin species [CoII(TPP)(Hon)2] (1). This compound has been characterized by UV-vis., IR, MSI MS and 1H NMR spectroscopy. The UV-vis data and especially the proton NMR results, for the isolated product, indicated that complex 1 is a Co(II) mesoporphyrin derivative.The X-ray molecular structure of the title compound bis(2-aminophenol) (tetraphenylporphyrinato) cobalt(II) has been determined. This structure is the first one reported of a metalloporphyrin with a 2-aminophenol axial ligand species. The central metal is hexacoordinated by the four nitrogen atoms of the pyrrole rings and the nitrogen atoms of the two Hon trans axial ligands.