A spirocyclic oxindole analogue:Synthesis and antitumor activities

A new synthesis of spirocyclic oxindole analogue spiro[piperidine-4,3’-pyrrolo[2,3-b]pyridin]-2’（1’H）-one 1 is described.The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ring by an intramolecular Buchwald-Hartwig amidation of carboxylic ami Je and aryl chloride.A small library was obtained by reductive amination of 1 with various aldehydes and was screened against human lung cancer cell A549,human liver cancer cell BEL7402,and human colon cancer cell HCT-8.The results show that most of the 1（?）rary compounds 2 have some inhibitory activities.2-（Trifluoromethoxy） benzylic substituted spirocyclic azaoxindole 2e was identified as a nanomolar inhibitor against human lung cancer cell A-549(IC₅₀=50 nmol/L).     

Friedel-Crafts alkylation of indoles with nitroalkenes catalyzed by Cu(Ⅱ)-imine complex

A series of new ligands L₁-L₇ were readily prepared in one step.Friedel-Crafts alkylation of indoles with nitroalkenes catalyzed by a novel Cu（Ⅱ）-L complex has been developed.The remarkable advantages of this reaction are mild reaction conditions,simple workup procedure,high yields of products and the use of ethanol as a green solvent.     

Eco-friendly synthesis of 2-substituted-2,3-dihydro-4(1H)-quinazolinones in water

2-Substituted-2,3-dihydro-4(1H)-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst.This protocol has advantages of high yield,simple work-up and environmental friendly procedure.     

Off-on-off luminescent switching of a dye containing imidazo[4,5-f][1,10]phenanthroline

A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibiy changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT) process,leading to off-on-off fluorescent molecular switching.     

High performance liquid chromatography with immobilized Ru(bpy)_3~(2+)-KMnO_4 chemiluminescence detection and its application in metabolism of repaglinide in pig liver microsomes

A novel high performance liquid chromatography-chemiluminescence（HPLC-CL） method for investigation of in vitro metabolism of repaglinide in pig liver microsomes with microdialysis sampling technique was developed.The chromatographic separation was performed on a Hypersil BDS-C18 column with an isocratic mobile phase consisting of methanol and 0.01 mol/L KH₂PO₄（pH 3.0）（volume ratio 75:25） at a flow rate of 1.0 mL/min.The detection was based on the chemiluminescence reaction of repaglinide with acidic potassium permanganate（KMnO₄） and tris（2,2’-bipyridyl）ruthenium（Ⅲ）(Ru（bpy）₃³⁺),which was immobilized on the cationic ion-exchange resin for obtaining high sensitivity and reducing consumption of expensive reagent.     

Effects of cosolvent on formation and morphology of microspheres in precipitation polymerization of divinylbenzene in supercritical carbon dioxide

Precipitation polymerizations of divinylbenzene(DVB) in pure supercritical carbon dioxide,and parallel runs with presence of a cosolvent were carried out.The results showed that use of acetone as the cosolvent contributed greatly to the formation of the monodisperse microspheres.PDVB microspheres,with obviously higher uniformity than reported up to date,were achieved using 6-7 mL of acetone in a reactor of 50 mL with DVB concentration of 0.4 mol/L under 16 MPa,a much lower pressure than previously reported without use of cosolvent.     

Pyridinium tribromide catalyzed condensation of indoles and aldehydes to form bisindolylalkanes

An efficient synthetic method for bis(indol-3-yl)alkane derivatives has been developed.In the presence of 5 mol%of pyridinium tribromide(PTB),the condensation of indoles and aldehydes proceeded smoothly under mild conditions,giving rise to the corresponding bis(indol-3-yl)alkanes in good to excellent yields.     

Synthesis and characterization of novel conjugated polymers based on 3-cyclobutene-l,2-dione moiety

Three novel conjugated polymers bearing 3,4-bis(4-hexylthiophen-2-yl)-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,~1H NMR and ~(13)C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers...     

Probing cytotoxicity of CdSe and CdSe/CdS quantum dots

Toxicities of CdSe and CdSe/CdS quantum dots(QDs) synthesized by ultrasound-assisted methods were investigated in vitro and in vivo.Five human cell lines were used to assess the cytotoxicity of as-prepared CdSe and CdSe/CdS by assays of MTT viability,red blood cell hemolysis,flow cytometry,and fluorescence imaging.The results show that these QDs may be cytotoxic by their influence in S and G2 phases in cell cycles.The cytotoxicity of QDs depends on both the physicochemical properties and related to target cells.     

Crystal structure of β-cyclodextrin-4-chlorobenzoic acid complex:Unusual C-Cl…π interaction between 4-chlorobenzoic acids in β-cyclodextrin dimer

The inclusion complex ofβ-cyclodextrin（β-CD） with 4-chlorobenzoic acid was synthesized and its crystal structure was determined by single crystal X-ray diffraction under cryogenic condition.The complex contains twoβ-CDs,two 4-chlorobenzoic acids and twenty-nine water molecules in the asymmetric unit,and can be formulated as 2(C₄₂H₇₀O₃₅)·2（C₇H₅O₂Cl）·29（H₂O）.In the crystal lattice,twoβ-CDs form a face-to-face dimer jointed together through hydrogen bonding between the secondary hydroxyl groups ofβ-CDs.Two 4-chlorobenzoic acid molecules which contact by C-Cl…πinteractions are included in theβ-CD dimer cavity.Theβ-CD dimers are arranged in brickwork-like pattern along the crystallographic a-axis.The effect of guest molecule length on the inclusion geometry was discussed by comparative study of someβ-CD complexes containing similar guests.