查看更多>>摘要：A monolithic column-based mass spectrometry(MS)analysis kit was prepared for whole blood analysis with MS.The kit is disposable and can be used for purification,storage,transportation and direct analysis of whole blood.The kit mainly consists of a capillary for quantitative microsampling,a cation exchange monolithic column for purification and storage,and a syringe for loading sample.This kit is very friendly to various users that one can easily siphon the blood in the kit followed by rapid clean-up.We established a quanti-tative method using the kit with a limit detection as low as 0.33 nmol/L,and achieved more than five orders of magnitude enhance-ment in sensitivity compared to direct nanoelectrospray ionization MS analysis.The column can avoid analyte exposure to environ-ment,which helps the storage of the sample for laboratory analysis.The relative standard deviation of immediate blood analysis and storage blood analysis within 10 d was less than 10％.This method has been successfully applied to the quantitative analysis of pro-cainamide hydrochloride in 2 μL rat blood.These results indicate that this disposable kit does have the potential to achieve highly sen-sitive quantitative MS analysis in biological samples,which is expected to become a cost-effective and powerful tool for in vitro diag-nostics.
查看更多>>摘要：A new family of dibenzoullazine derivatives was synthesized through 1,3-dipolar cycloaddition of polycyclic aromatic azomethine ylides with alkynylbenziodoxoles followed by oxidation.The benziodoxole moiety in the resulting products was used as a versatile linchpin for the synthesis of structurally diverse functional dibenzoullazines that are difficult to access by other synthetic methods.
查看更多>>摘要：Eight new guaiane-type sesquiterpenoid trimers,artemsieverolactones A-H,possessing unprecedented scaffolds via biocatalyzed[4+2]Diels-Alder cycloaddition reactions were identified from Artemisia sieversiana.Their structures were determined by compre-hensive spectroscopic data,single-crystal X-ray diffraction analyses,and ECD calculations.In terms of structure,artemsieverolactones A-H are first examples of sesquiterpenoid trimers from guaiane-type sesquiterpenoid through four different[4+2]Diels-Alder cy-cloaddition models.Antihepatic fibrosis assay suggested that five compounds exhibited activity against HSC-LX2 with IC50 values rang-ing from 37.8 to 117.1 μmol/L.The most active artemsieverolactone B(2)displayed significant inhibitory activity against HSC-LX2 with IC50 value of 37.8 μmol/L,which was 3 times more active than the positive drug silybin(IC50,139.7 μmol/L).Preliminary mechanism study revealed that artemsieverolactone B could inhibit the deposition of human collagen type Ⅰ(Col I),human hyaluronic acid(HA),and human laminin(HL)with IC50 values of 40.4 μmol/L(Col I),55.1 μmol/L(HL),47.3 μmol/L(HA),which was 2 to 3-fold more potent than silybin.
查看更多>>摘要：The photocatalytic oxidative coupling of thiols is one of the most popular methods to synthesize the disulfides.Triphenylamine and its derivatives(TPAs)are promising for the above reaction,but suffer from the easy polymerization and difficult separation.To overcome these obstacles while controlling the photogenerated electrons transfer directly to target substrates,herein,we constructed one TPA-based metal-organic framework(MOF),(Me2NH2)[Sr(TCBPA)]·DMA·3H2O(1),by direct self-assembly of tris(4'-carboxybiphe-nyl)amine(H3TCBPA)and photoredox inert strontium ion(Sr2+).DFT calculations revealed that the valence band maximum(VBM)and the conduction band minimum(CBM)are mainly located on TCBPA3-,successfully inhibiting the undesirable electron migration to metal nodes.Experimental results indicated that 1 displays superior performance than homogeneous H3TCBPA,which may result from the abundant π…π and C-H…π interactions between the well-arranged TCBPA3-and the build-in electric field between the anionic framework and the Me2NH2+.This work highlights that immobilizing TPAs into MOFs is one promising approach to designing hetero-geneous photocatalysts for the synthesis of disulfides by oxidative coupling of thiols.
查看更多>>摘要：Perovskite solar cells(PSCs)have been proven to be a promising option for photovoltaic conversion.With the aim to achieve efficient and stable PSCs,it is essential to explore dopant-free hole-transporting materials(HTMs)with high hole mobility.Herein,HTMs bear-ing electron donor(D)-electron acceptor(A)-electron donor(D)structures have been constructed with strong intramolecular charge transfer(ICT)effect,based on rational combination of dibenzo[a,c]phenazine and pyridine as electronic acceptors and anchoring groups to perovskite layer.Accordingly,high hole mobility(7.31 × 10-5 cm2·V-1·s-1)and photoelectric conversion efficiency(20.45％)have been achieved by dopant-free DPyP-based PSC.It afforded an efficient way to design HTMs with high hole mobility by adjust-ment of molecular configurations and electronic property of conjugated systems.
查看更多>>摘要：The invention of a well-defined Cu(Ⅲ)fluoride complex Me4N+[Cu(CF3)3(F)]-1 enabled to access a versatile of functionalized Cu(Ⅲ)complexes[Me4N]+[Cu(X)(CF3)3]-(X=C6F5,C6F5C≡C,CN,Cl,N3,tBuOO,SCN,OAc,SAr),many of them for the first time.The availability of these complexes allowed us to evaluate the trans-influence order of ligand in Cu(Ⅲ)complexes:Bn＞CF3-＞C6F5-＞N3-＞py～CH3-～C6F5C≡C＞NO2PhO-～tBuOO～CH3COO-＞F-.
查看更多>>摘要：Expressed protein ligation(EPL)provides a powerful tool to access large-size proteins with precise structures.Existing methods for constructing the critical protein thioester for EPL have predominantly relied on the recombinant intein fusion expressed in Escherichia coli(E.coli).Despite its powerful applications,the expression of thioester derived from eukaryotic protein in E.coli inherently suffers from its limited solubility,the inactivity of intein,premature hydrolysis and low yields.To overcome these obstacles,we present herein the facile one-flask synthesis of inaccessible protein α-thioester via a SUMO-protein-intein(SPI)sandwich model.The utility of SUMO enhances the protein fusion yield and solubility,prevents premature hydrolysis and simplifies the purification process.The inaccessi-ble protein thioester with internal Cys residues can be readily produced and is compatible with the EPL-desulfurization protocol used to prepare complex proteins,which is otherwise difficult to obtain using traditional methods.Its utility has been highlighted through the synthesis of human granulocyte colony-stimulating factor(G-CSF).
查看更多>>摘要：Metalla-isosilabenzenes and metalla-isogermabenzenes have been successfully synthesized by the formal[5+1]-cycloaddition of di-ethynylsilane or diethynylgermane with simple metal complexes.This is the first example of a heavier Group 14 metalla-isobenzene isomer bearing a cumulative double bond motif within a metallacycle.These novel complexes were fully characterized by NMR spec-troscopy and single-crystal X-ray diffraction analysis.The stabilization of the cyclic metal-vinylidene complexes has been analyzed using density functional theory(DFT)calculations.When the metalla-isosilabenzenes bearing Si-H bond were treated with the trityl salt as a hydride scavenger,the formation of silylium cation was observed spectroscopically.Both of metalla-isosilabenzenes and metalla-isogermabenzenes can readily undergo migratory insertion reactions to furnish siloles or germoles.
查看更多>>摘要：A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharma-ceuticals,materials,and organic synthesis,was described through C-F bond insertion into indoles using CHBr2F.The simple condi-tions,readily availability of CHBr2F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and 3-fluoroquinolone.The mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.
万方数据
维普