Preparation of Platinum(II) Complexes with 1-β-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide and its Deoxy-analogue

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.

Dioxygen Affinity and Catalytic Performance of Bis-(furaldehyde) Schiff Bases Co(II) Complexes in Cyclohexene Oxidation

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.

Synthesis and Characterization of Chiral Mercury(II) and Cadmium(II) Complexes with 3,3'-Bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl

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.

Syntheses and Crystal Structures of Two New Hg(Ⅱ) and Cd(Ⅱ) Complexes with 2,3,5,6-Tetrakis-(2-pyridyl)Pyrazine

Under thermal gradient in solution phase, the reaction of Hg（Ⅱ） and Cd（Ⅱ） salts with 2,3,5,6-tetrakis-（2-pyddyl）pyrazine （tppz） in 1：1 molar ratio afforded dinuclear [{HgI2}2}- tppz）] （1） and mononuclear [CdI2（tppz）] （2） complexes. Single-crystal X-ray diffraction structural analysis reveals that the tppz acts as bis-tridentate and tridentate chelating ligands in 1 and 2, respectively. Metal（Ⅱ） ions adopt a distorted square pyramidal geometry and have the same coor- dination environment in both complexes. Based on the 1H NMR spectroscopy measurements, both complexes decompose in solution and release free tppz.

Elimination of GGTA1,CMAH,β4GalNT2 and CIITA genes in pigs compromises human versus pig xenogeneic immune reactions

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.

Preparation, Characterization and Antimicrobial Studies of Mn(II) and Fe(II) Complexes with Schiff Base Ligand Derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline

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 a band at 1622 cm−1 and this was assigned to the v (C=N), which is a feature of azomethine group. The same band was observed to shift to lower frequencies 1577 and 1599 cm−1 in the complexes suggesting coordination of the Schiff base with the respective metal(II) ions. Molar conductance values 14.58 and 12.65 Ω−1∙cm2∙mol−1 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.

Comparative Studies of Some Novel Cu(II) Polymeric Complexes Derived from Cyanoacetylhydrazine (CAH;L). The Role of Solvents Used on the Structure and Geometry of the Isolated Cu²⁺Complexes

Novel polymeric Cu2+ complexes derived from the reaction of cyanoacetylhydrazine (CAH;L) with CuCl2•2H2O in different solvents were synthesized and characterized. The isolated solid polymeric complexes were investigated using modern conventional physicochemical and spectral (IR, 1H-NMR, UV-Vis. ESR, Raman), magnetic and thermal studies. The results revealed that CAH behaves in different ways towards the coordination of the Cu2+ ion. The promotion of solvents to the cyano group was discussed on the basis of the solvent and the Cu2+ ion used. Magnetic and spectral studies suggest octahedral geometry is proposed for the Cu2+ complexes. EPR studies indicate the existence of polymeric complexes depending on the results of g-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.

Synthesis of Branched Polyethylene via Bulky α-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization

The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.

氧化石墨烯(GO)表面原位生长二硫化钼(MoS2)材料高效去除Hg(II)

Hg(II)指的是游离的Hg2+及其不稳定的络合物,是厌氧条件下微生物将其转化为毒性更大的甲基汞的主要形式。作为一种超毒性重金属,Hg(II)可对肾脏、肝脏、免疫系统、内分泌系统以及生殖系统造成不可逆的损伤。在此文章中,以氧化石墨烯(GO)为基底,以L-半胱氨酸、钼酸铵、聚乙烯吡咯烷酮(PVP)、葡萄糖为原料,利用水热法于氧化石墨烯(GO)表面原位生长二硫化钼(MoS2)制备GO改性材料(MoS2/GO)。通过扫描电子显微镜(SEM)和x射线光电子能谱(XPS)表征得到MoS2/GO为石墨烯表面原位生长的层状放射性花状结构,对Hg(II)有较好的吸附作用且吸附后MoS2/GO有明显形态变化。MoS2/GO在较宽pH范围内对Hg(II)均有良好的吸附能力,拟二级动力学模型可以更好的描述该吸附过程,这证明MoS2/GO对Hg(II)之间的结合主要为化学作用。Freundlich模型可以很好的描述Hg(II)的吸附行为为多层吸附,PVP作为插层剂起到了一定的作用,25℃下MoS2/GO对Hg(II)的最大吸附容量为868.38 mg/g。该材料原料毒性小、MoS2层间距相对较大,对Hg(II)有着更为优异的去除能力,可较好的应用在含Hg废水处理中。

Differential response of injured and healthy retinas to syngeneic and allogeneic transplantation of a clonal cell line of immortalized olfactory ensheathing glia:a double-edged sword

Olfactory ensheathing glia promote axonal regeneration in the mammalian central nervous system,including retinal ganglion cell axonal growth through the injured optic nerve.Still,it is unknown whether olfactory ensheathing glia also have neuroprotective properties.Olfactory ensheathing glia express brain-derived neurotrophic factor,one of the best neuroprotectants for axotomized retinal ganglion cells.Therefore,we aimed to investigate the neuroprotective capacity of olfactory ensheating glia after optic nerve crush.Olfactory ensheathing glia cells from an established rat immortalized clonal cell line,TEG3,were intravitreally injected in intact and axotomized retinas in syngeneic and allogeneic mode with or without microglial inhibition or immunosuppressive treatments.Anatomical and gene expression analyses were performed.Olfactory bulb-derived primary olfactory ensheathing glia and TEG3 express major histocompatibility complex classⅡmolecules.Allogeneically and syngenically transplanted TEG3 cells survived in the vitreous for up to 21 days,forming an epimembrane.In axotomized retinas,only the allogeneic TEG3 transplant rescued retinal ganglion cells at 7 days but not at 21 days.In these retinas,microglial anatomical activation was higher than after optic nerve crush alone.In intact retinas,both transplants activated microglial cells and caused retinal ganglion cell death at 21 days,a loss that was higher after allotransplantation,triggered by pyroptosis and partially rescued by microglial inhibition or immunosuppression.However,neuroprotection of axotomized retinal ganglion cells did not improve with these treatments.The different neuroprotective properties,different toxic effects,and different responses to microglial inhibitory treatments of olfactory ensheathing glia in the retina depending on the type of transplant highlight the importance of thorough preclinical studies to explore these variables.

Synthesis and Characterization of Nickel(II) and Copper(II) Complexes with Schiff Base (1R,2R)-(-)-Diaminocyclohexane-N,N'-bis(3-tert-butyl-5-(4'-benzoic acid)-salicylidene)

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.

THE CHIRAL SELECTIVITY IN ACROSS－MEMBRANE TRANSPORT OF 1，2－DIAMINOCYCLOHEXANE PLATINUM（II）COMPLEXES AND THE CONTRIBUTION OF LEAVING GROUPS

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.

Chemically Modified <i>Cornulaca monacantha</i>Biomass for Bioadsorption of Hg (II) from Contaminated Water: Adsorption Mechanism

Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Cornulaca monacantha (CECM). Three levels of CECM having different nitrogen content were prepared. The CECM samples were characterized by estimating the nitrogen content. The ability of CECM to adsorb Hg (II) was investigated by using batch adsorption procedure. The data of the adsorption isotherm was tested by the Langmuir, Freundlich and Temkin models. The removal of Hg (II) onto CECM particles could be well described by the pseudo-second order model. The adsorption rate of mercury was affected by the initial Hg (II) ion concentration, initial pH, adsorbent concentration and agitation time as well as extent of modification. The adsorption experiments indicated that the CECM particles have great potential for the removal of Hg (II) from contaminated water. The maximum adsorption capacity, Qmax of the CECM towards Hg (II) ions was found to be 384.6 mg/g at 30?C. Similarly, the Freundlich constant, n was found to be 2.03 at 30°C.

Synthesis, Characterizations, Biological, and Molecular Docking Studies of Some Amino Acid Schiff Bases with Their Cobalt(II) Complexes

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.

Samarium(II) Diiodide Induced Polarity Inversion of π-Allyl Palladium Complexes: The Formation of Allylic Selenides

Allylic acetates were reduced with Pd(0)-SmI2 in the presence of ArSeBr to form corresponding allylic selenides in good yields.

Some Hybrid Systems of Chiral Schiff Base Zn(II) Complexes and Photochromic Spiropyrans for Environmental Ion Sensing

This is a review article including our recent results and some previous photo functional hybrid system having potential applications for environmental ion sensing. We have prepared several new and known chiral Schiff base Zn(II) complexes and measured (and also calculated) absorption and fluorescence spectra for sole complexes. After assembling hybrid systems with 1,3,3-trime- thylindolino-6’-nitrobenzopyrylospiran (SP) in methanol solutions, we measured spectral changes before and after alternate irradiation of UV and visible light. Intensity of fluorescence spectra for pale yellow Zn(II) complexes (λem = 450 nm, λex = 270 and 360 nm) was quenched by colorless SP (λem = 533 nm, λex = 612 nm). After UV light irradiation to form purple merocyanine (MC), photoisomerization resulted in changes of the intensity of absorption spectra as well as fluorescence spectra. Thus the hybrid systems could successfully act as molecular logic circuit by input (excitation by light) and output (intensity of fluorescence peaks). Moreover, we investigated concentration dependence of doped Zn(II) and Cu(II) ions to confirm quenching of intensity of fluorescence peaks by Zn(II) and Cu(II) MC complexes for metal ion sensing in solutions.

Magnetic analyses of isosceles tricobalt(II) complexes containing two types of octahedral high-spin cobalt(II) ions

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.

Micellar Effect on Photoinduced Electron Transfer Reactions of Ruthenium(II) Polypyridyl Complexes with Quinones: Effect of CTAB

Photoinduced electron transfer reaction between the excited state ruthenium (II) polypyridyl complexes and quinones has been investigated in cetyltrimethylammonium bromide using luminescent quenching techniques. The complexes have the absorption and emission maximum in the range 452 - 468 nm and 594 - 617 nm respectively. The static nature of quenching is confirmed from the ground state absorption studies. The association constants for the complexes with quinones are calculated from the Benesi-Hildebrand plots using absorption spectral data. The value of quenching rate constant (kq) is highly sensitive to the nature of the ligand and the quencher, the medium, structure and size of the quenchers. Compared to the aqueous medium, the electron transfer rate is altered in CTAB medium. The oxidative nature of the quenching is confirmed by the formation of Ru3+ ion and quinone anion radical.

Synthesis, spectral characterization, catalytic andbiological studies of new Ru(II) carbonyl Schiff base complexes of active amines

The synthesis and characterization of several hexa – coordinated Ru(II) complexes of the type [Ru(CO)(B)(L)] (B = PPh3/AsPh3/py/pip;L = di-basic tetradentate ligand derived from the condensation of isatin with diamines) were reported. IR, electronic, 1H- NMR, 31P-NMR of the complexes are discussed. An octahedral geometry has been tentatively proposed for all these complexes. The new complexes have been tested for the catalytic activity in the reaction of oxidation of alcohols in the presence of N-me- thylmorpholine–N-oxide as co-oxidant. The new complexes were also exhibited antimicrobial investigations.

Synthesis, Characterization and DFT Studies of Two Zinc(II) Complexes Based on 2-Isopropylimidazole

Two novel coordination compounds, [Zn(L)2(OOCH)2] (1) and [Zn(L)3(OCHO)](OCHO)]·H2O (2) (where L = 2-isopropylimidazole, C6H10N2) have been prepared by reaction of 2-isopropylimidazole with zinc(II) formate at room temperature using toluene as solvent. These compounds were characterized by elemental and thermal analyses, IR, 1HNMR and 13CNMR spectroscopies, single crystal X-ray diffraction and DFT studies. The Zn centers in 1 and 2 adopt pseudo-tetrahedral coordination geometries. Compound 1 crystallizes in the monoclinic system P2/c space group whereas compound 2 crystallizes in the P-1 space group of the triclinic crystal system. Several types of hydrogen intra-/intermolecular interactions are observed in these materials and extend into a two-dimensional leaf like network in 1 and a two-dimensional lattice of rectilinear pillars in 2. Compounds 1 and 2 were also optimized and their frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential, natural bond orbitals were investigated using density functional theory (DFT). In fact the induced structural differences from complex 1 to complex 2 led to the reduction of the frontier molecular orbital energy gap by 1.338 eV and a decrease of the chemical hardness by 0.669 eV.