2010 Volume 21 Issue 4

Synthesis and biological evaluation of nitric oxide-releasing matrine derivatives as anticancer agents
Li Qin He , Jing Liu , Deng Ke Yin , Yi Hua Zhang , Xiao Shan Wang
2010, 21(4): 381-384  doi: 10.1016/j.cclet.2009.11.033
[Abstract](180) [FullText HTML] [PDF 249KB](0)
A series of furoxan-based nitric oxide-releasing matrine derivatives(10a-f)were synthesized.The biological evaluation showed that compounds 10a,10b,10e and 10f had stronger cytotoxic activities than 5-fluorouracil against human hepatoma cells(HepG2) in vitro.
Synthesis and characterization on a novel series of protic pyrrolidinium surfactants
Fu Min Ma , Xiao Chen , Xu Dong Wang , Yu Rong Zhao , Qiu Hong Li , Xiu Yue , Chao Lv
2010, 21(4): 385-387  doi: 10.1016/j.cclet.2009.12.031
[Abstract](179) [FullText HTML] [PDF 888KB](0)
A novel series of protic tertiary pyrrolidinium surfaetants were prepared and characterized by different techniques.These compounds show good conductivity and efficient ability to reduce surface tension.Thermogravimetric analysis proves their high thermal stability at decomposition temperatures over 250℃.Their lyotropic and thermotropic liquid crystalline properties are also discussed.
Total synthesis of endothelin 1 by microwave-assisted solid phase method
Hai Qian , Wei Chen , Jin Pei Zhou , Wen Long Huang , Hui Bin Zhang , Jing Jin
2010, 21(4): 388-390  doi: 10.1016/j.cclet.2009.12.016
[Abstract](163) [FullText HTML] [PDF 233KB](0)
A microwave-assisted solid phase synthesis for endothelin 1 is presented.Reduced endothelin 1 was synthesized efficiently on Wang resin under microwave irradiation using Fmoc/tBu orthogonal protection strategy.The whole peptide was cleaved from the resin and two disulphide bridges were formed under air oxidation at room temperature.The purity and efficiency of synthesizing the peptide is much higher than other methods used before.
Synthesis of a highly hydrophobic cyclic decapeptide by solid-phase synthesis of linear peptide and cyclization in solution
Jian Chen , Bei Zhang , Cao Xie , Yi Lu , Wei Wu
2010, 21(4): 391-394  doi: 10.1016/j.cclet.2009.11.026
[Abstract](174) [FullText HTML] [PDF 319KB](0)
A general method was described to synthesize a highly hydrophobic cyclic peptide,cyclo[(L)W(L)W(L)W(L)W(L)Q]where underlines indicate D-configuration of the amino acid,by a two-step solid-phase/solution synthesis strategy.The linear decapeptide was assembled by standard Boc chemistry on solid-phase and subsequently cyclized in solution with high efficiency and reproducibility.In subsequent purification by semi-preparative HPLC,50%(v/v)DMF/H2O was employed as the solvent to overcome the difficulty of solubilization for the hydrophobic cyclic decapeptide and achieved a total yield of 30-35% with a purity of over 98%.
Synthesis of quinoxaline derivatives catalyzed by PEG-400
Xia Zhong Zhang , Jin Xian Wang , Yong Jun Sun , Hong Wen Zhan
2010, 21(4): 395-398  doi: 10.1016/j.cclet.2009.12.015
[Abstract](160) [FullText HTML] [PDF 229KB](0)
Polyethylene glycol(PEG)was found to be an effective catalyst for the condensation of 1,2-diamines with 1,2-dicarbonyl compounds to afford the corresponding quinoxaline derivatives in excellent yields under mild reaction conditions.
Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride
Khodabakhsh Niknam , Alireza Hasaninejad , Madihe Arman
2010, 21(4): 399-402  doi: 10.1016/j.cclet.2009.12.008
[Abstract](159) [FullText HTML] [PDF 378KB](0)
Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin-2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃ under solvent-free conditions.
Zn(NO3)2·6H2O/2,4,6-trichloro-1,3,5-triazine(TCT)a mild and selective system for nitration of phenols
Firouzeh Nemati , Hossein Kiani
2010, 21(4): 403-406  doi: 10.1016/j.cclet.2009.11.017
[Abstract](156) [FullText HTML] [PDF 221KB](0)
Certain phenols and naphthols were nitrated regioselectively with Zn(NO3)2·6H2O/TCT in acetonitrile as solvent at room temperature and short reaction time in good yields.The reaction condition was mild.TCT is a cheap and commercially available reagent.It performed as an acid catalyst in this transformation.
Synthesis and characterization of new optically active copoly(amid-imide)s based on N-phthalimido-L-aspartic acid and aromatic diamines
Khalil Faghihi , Hamidreza Alimohammadi
2010, 21(4): 407-411  doi: 10.1016/j.cclet.2009.12.007
[Abstract](156) [FullText HTML] [PDF 525KB](0)
In this article,six new optically active copoly(amide-imide)s (10a-f) were synthesized through the direct polycondensation reaction of N-phthalimido-L-aspartic acid(4)with 1,5-diamino naphthalene(8),3,4-diainino benzophenone(9) in the presence of therphthalic acid(7),fumaric acid (6) and adipic acid (5) as a second diacid in a medium consisting of N-methyl-2-pyrrolidone,triphenyl phosphite,calcium chloride and pyridine.The resulting copolymers were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherent viscosity,solubility tests and UV-vis spectroscopy.Thermal properties of resulting copolymers (10a-c) containing three different second diacid in the main chain were compared by using TGA and DTG thermograms.
One-pot synthesis of 2-aminothiazoles in PEG-400
Dhanaji V. Jawale , Dinesh L. Lingampalle , Umesh R. Pratap , Ramrao A. Mane
2010, 21(4): 412-416  doi: 10.1016/j.cclet.2009.11.035
[Abstract](163) [FullText HTML] [PDF 222KB](0)
A facile one-pot synthesis of 2-aminothiazoles has been carded in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric α-bromoketones as well as the volatile,toxic organic solvents.
Properties of a novel acid dye 1-amino-4-[(6-nitro-2-benzothiazolyl)amino]-9,10-anthraquinone-2-sulfonic acid with anti-UV capability
Hao Fei Huang , Wei Ma , Bing Tao Tang , Shu Fen Zhang
2010, 21(4): 417-420  doi: 10.1016/j.cclet.2009.11.010
[Abstract](161) [FullText HTML] [PDF 407KB](0)
A novel acid dye acid was synthesized by the condensation reaction between bromamine acid and 2-amino-6-nitrobenzothiazole and its anti-UV protection properties were evaluated.The results showed that silk dyed with this dye had very good ultraviolet radiation protection capability and excellent dyeing performance.The UV-absorption mechanism of this dye was also discussed.
ZnO-beta zeolite:As an effective and eco-friendly heterogeneous catalyst for the synthesis of benzothiazole derivatives
Santosh S. Katkar , Pravinkumar H. Mohite , Lakshman S. Gadekar , Kaluram N. Vidhate , Machhindra K. Lande
2010, 21(4): 421-425  doi: 10.1016/j.cclet.2009.10.020
[Abstract](164) [FullText HTML] [PDF 993KB](0)
A cheap and recyclable ZnO-beta zeolite was used as catalyst for the synthesis of benzothiazole derivatives.This method provides several advantages such as environmental friendliness,short reaction times,high yields,simple work-up procedure and catalyst was successfully reused for four cycles without significant loss of activity.
Synthesis and biological evaluation of ethyl 6-alkoxy-7-phenyl-4-hydroxy-3-quinolinecarboxylates against Eimeria tenella
Yuan Yuan Zhang , Xing Yan Zeng , Kui Nie , Zhi Cheng Zhong , Yu Liang Wang , Yu Zhong Wang
2010, 21(4): 426-428  doi: 10.1016/j.cclet.2009.12.006
[Abstract](155) [FullText HTML] [PDF 221KB](0)
A series of ethyl 6-alkoxy-7-phenyl-4-hydroxy-3-quinolinecarboxylates were designed and synthesized.Their structures were confirmed by 1H NMR,13C NMR,IR and HRMS.The biological activities were primarily evaluated against Eimeria tenella according to Anticoccidial Index(ACI)method in vivo.The results showed that compounds 5e,5f and 5i exhibited anticoccidial activities against E.tenella at 27 mg kg-1.
Potassium dihydrogen phosphate catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles
Ratnadeep S. Joshi , Priyanka G. Mandhane , Mohammad U. Shaikh , Rajesh P. Kale , Charansingh H. Gill
2010, 21(4): 429-432  doi: 10.1016/j.cclet.2009.11.012
[Abstract](161) [FullText HTML] [PDF 212KB](0)
A simple and efficient method has been developed; benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate(KH2PO4)under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent yields.The method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 min.The present method is simple,efficient,and cost-effective.
Two new ceramides from the stems of Piper betle L.
Xiang Zhong Huang , Yan Yin , Jian Hui Dai , Hui Liang , Yun Dai , Lian Bai
2010, 21(4): 433-436  doi: 10.1016/j.cclet.2009.11.047
[Abstract](163) [FullText HTML] [PDF 224KB](0)
Two new ceramides,(2S,3S,4R)-2-N-[(2'R)-2'-hydroxypentacosanoylamino]-nonacosane-1,3,4-triol(1)and(2S,3S,4R,8E)-2-N-[(2'R)-2'-hydroxytetracosanoylamino]-8-eicosylene-1,3,4-triol(2)have been isolated from the stems of Piper betle L.collected from Baoshan city of Yunnan Province in China.Their structures were determined by spectroscopic and chemical methods.
A new iridoid glycoside from Paederia scandens
Da Hai He , Jin Song Chen , Xiao Ling Wang , Ke Yi Ding
2010, 21(4): 437-439  doi: 10.1016/j.cclet.2009.12.009
[Abstract](160) [FullText HTML] [PDF 254KB](0)
A new glycoside named 6β-O-β-D-glucosylpaederosidic acid(1)was isolated from Paederia scandens and its structure was elucidated on the basis of spectroscopic and chemical evidence,together with four known iridoids,paederoside(2),paederosidic acid(3),paederosidic acid methyl ester(4),and deacetyl asperulosidic acid methyl ester(5).Compound 5 was isolated from this plant for the first time.
Two new tetrahydronaphthalenes from the stem of Impatiens balsamina L.
Xiu Mei Chen , Shi Hui Qian , Feng Feng
2010, 21(4): 440-442  doi: 10.1016/j.cclet.2009.12.019
[Abstract](152) [FullText HTML] [PDF 211KB](0)
Two new tetrahydronaphthalenes,lα,2α-diol-4α-ethoxy-1,2,3,4-tetrahydronaphthalene(1)and lα,2α,4β-triol-1,2,3,4-tetrahydronaphthalene(2),were isolated from the stem of Impatiens balsamina L.Their structures were elucidated by various spectroscopic methods.
A novel caged-prenylxanthone from Garcinia bracteata
Zhi Na , Hua Bin Hu , Qing Fei Fan
2010, 21(4): 443-445  doi: 10.1016/j.cclet.2009.12.030
[Abstract](161) [FullText HTML] [PDF 226KB](0)
A novel caged-prenylxanthone xanthone,neobractatin(1),was isolated from the twig of Garcinia bracteata.Its structure was elucidated by spectroscopic methods,especially 2D NMR techniques.
New polyhydroxylated metabolite derived from biotransformation of diosgenin by the white-rot fungus Coriolus versicolor
Guang Wei Wu , Xiao Jun Li , Yi Gao , Yuan Jia , Jin Ming Gao
2010, 21(4): 446-448  doi: 10.1016/j.cclet.2009.11.018
[Abstract](163) [FullText HTML] [PDF 234KB](0)
Microbial transformation of diosgenin(1)was carried out with the white-rot fungus,Coriolus versicolor.A new polyhydroxyl metabolite,(25R)-spirost-5-ene-3β,7β,21-triol(2),was obtained as a result of hydroxylation.Its structure was elucidated on the basis of 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis.
New triterpenoid sapoin from Ardisia gigantifolia Stapf.
Qiang Qiang Gong , Li Hua Mua , Ping Liu , Shi Lin Yang , Bo Wang , Yu Lin Feng
2010, 21(4): 449-452  doi: 10.1016/j.cclet.2009.12.029
[Abstract](161) [FullText HTML] [PDF 282KB](0)
One new triterpenoid sapoin with two known triterpenoid sapoins:3β-O-{α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranose-(1→2)]-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl}-3β-hydroxy-13β,28-epoxy-oleanan-16-oxo-30-al(1),3β-O-{α-Lrhamnopyranosyl-(1→3)-[(β-D-xylopyranosyl-(1→2)]-β-D-galactopyranosyl-(1→4)-[(β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside}-16α-hydroxy-13,28-epoxy-oleanane(2)and cyclamiretin A 3β-O-α-L-rhamnopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside(3)were isolated from Ardisia gigantifolia Stapf.Their structures were elucidated by means of 1H and 13C NMR spectroscopic studies,including2D-NMR technique.
Novel additives for the separation of organic acids by ion-pair chromatography
Ying Ying Zhong , Wen Fang Zhou , Zhen Zhen Hu , Mei Lan Chen , Yan Zhu
2010, 21(4): 453-456  doi: 10.1016/j.cclet.2009.12.032
[Abstract](158) [FullText HTML] [PDF 239KB](0)
This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar.Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes can be varied over a large range by varying the additive concentration.The results indicate that the additives of proper concentrations can reduce the retention times of different organic acids while the resolution remains the same.The larger the molecular weight is,the greater the shift of the retention time is.This greatly expands the scope of macromolecular polar compounds that can be separated by ion-pair chromatography with the advantages of retention times being greatly reduced.
Application of a simple calorimetric data analysis on the binding study of cyanide ions by Jack bean urease
G. Rezaei Behbehani , A. A. Saboury , M. Mohebbian , S. Ghammamy
2010, 21(4): 457-460  doi: 10.1016/j.cclet.2009.10.021
[Abstract](173) [FullText HTML] [PDF 309KB](0)
Cyanide ion was studied as an effector of Jack bean urease(JBU)at 300 K in 30 mmol/L Tris buffer,pH 7 by isothermal titration calorimetry(ITC).The simple novel model was used for CN-+JBU interaction over the whole range of CN-concentrations.The binding parameters recovered from the simple novel model were attributed to the cyanide ion interaction.It was found that cyanide ion acted as a noncooperative inhibitor of JBU,and there is a set of 12 identical and independent binding sites for CN-ions.The dissociation equilibrium constant is 750 μmol/L.The molar enthalpy of binding is △H=-13.6 kJ mol-1.The technique used provided an accurate and quick assessment of the effectiveness of the compounds to inhibit Jack bean urease.
99mTc-AMD3100:A novel potential receptor-targeting radiopharmaceutical for tumor imaging
Jin Ming Zhang , Jia He Tian , Tian Ran Li , Hai Yu Guo , Li Shen
2010, 21(4): 461-463  doi: 10.1016/j.cclet.2009.12.018
[Abstract](164) [FullText HTML] [PDF 612KB](0)
The chemokine CXCR4 receptor is over-expressed in a wide variety of tumors.AMD3100,which was a prototypenon-peptide antagonist of CXCR4 receptor,was labeled with 99mTC.99mTC-AMD3100 was verified by thin layer radiochromatography (TLRC).The tumor-localizing properties of 99mTc-AMD3100 were evaluated and proved in mice bearing Hep-G2 tumor xenograft.99mTc-AMD3100 was a promising,novel receptor-specific radiopharmaceutical with potentialapplication in the imaging of human tumors.
A comparative study of four 20-membered N2S4-crown ethers as ionophores for polymeric membrane silver selective electrodes
Jun Zhang , Shun Yang Yu , Tan Ji Yin , Xue Feng Hu , Wei Qin
2010, 21(4): 464-467  doi: 10.1016/j.cclet.2009.11.028
[Abstract](162) [FullText HTML] [PDF 267KB](0)
Four 20-membered N2S4-monoazathiacrown ethers have been synthesized and explored as neutral ionophores for Ag+-selective electrodes.Potentiometric responses reveal that the flexibility of the ligands has great effect on the selectivity and sensitivity to Ag+ions.The electrode based on ionophore 9,10,20,25-tetrahydro-5H,12H-tribenzo[b,n,r][1,7,10,16,4,13]tetrathiadiaza cycloicosine6,13-(7H,14H)-dione(C)with 2-nitrophenyl octyl ether(ο-NPOE)as solvent in a poly(vinyl chloride)(PVC)membrane matrix shows a measuring range of 1.0×10-6 to 1.0×10-3 mol/L with a Nemstian slope of 54.9±0.3 mV/decade.This electrode has high selectivity for Ag+with negligible interference from many other cations and can be used in a wide pH range of 3.6-9.2.
Effect of charge at an amino acid of basic fibroblast growth factor on its mitogenic activity
Xiao Ping Wu , Xiao Kun Li
2010, 21(4): 468-471  doi: 10.1016/j.cclet.2009.12.004
[Abstract](156) [FullText HTML] [PDF 727KB](0)
The amino acid at the 119th position of human basic fibroblast growth factor(hbFGF),lysine(K119),is a critical component for its mitogenic activity.However,little is known about the effects of the characteristics of this residue including charge on the mitogenic activity of hbFGE Herein,this basic residue was replaced with neutral glutamine residue and acidic glutamic acid residue to construct mutants hbFGFK119Q and hbFGFK119E,respectively.The mutants were produced by BL21(DE3)/pET3c expression system and purified to homogeneity by ionic exchange and heparin affinity chromatography from the supernatant of bacteria lysate.The mitogenic activity analysis showed that neutralization of charge at the 119th residue diminished the mitogenic activity of hbFGE whereas change of positive charge to negative charge at this residue had no significant effect on its mitogenic activity.Further MAP kinase activation assay revealed that the influence of different charge at the 119th position on the mitogenic activity of hbFGF was related to the signal molecular activation in MAPK pathway.It was deduced that the charge,either positive or negative,at the 119th position of hbFGF is crucial for its full mitogenic activity.
A novel impedance immunosensor based on O-phenylenediamine modified gold electrode to analyze abscisic acid
Qian Li , Ruo Zhong Wang , Zhi Gang Huang , He Song Li , Lang Tao Xiao
2010, 21(4): 472-475  doi: 10.1016/j.cclet.2009.12.005
[Abstract](152) [FullText HTML] [PDF 242KB](0)
An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA)was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL.
Comparison of two thioxopeptide bond photoswitches in insect kinin
Zhi Yuan Cong , Long Fei Yang , Ling Jiang , Dan Ye , Shou Liang Dong
2010, 21(4): 476-479  doi: 10.1016/j.cclet.2009.12.033
[Abstract](152) [FullText HTML] [PDF 228KB](0)
The photoisomerization abilities of secondary thioxopeptide bond(CS-NH)and thioxo prolyl bond(CS-N)incorporated into the C-terminal pentapeptide of insect kinin were compared.H-Phe-Phe-Ψ[CS-NH]-D-Ala-Trp-Gly-NHz and H-Phe-Tyr-Ψ[CS-N]-Pro-Trp-Gly-NH2 were studied by UV-vis absorption.The isomerization energy barriers of the two segments,Ac-Phe-Ψ[CS-NH]-D-Ala-NH2 and Ac-Tyr-Ψ[CS-N]-Pro-NH2 picked from the two peptides,were calculated using ab initio method.The cis isomer of CS-N is more stable than that of CS-NH due to higher energy barrier,so the former is more suitable in peptide structure-activity relationship studies.
Interaction between a novel intramolecular charge transfer fluorescent probe PFEP and human serum albumin
Dong Ju , Sheng Mei Song , Yan Bo Wu , Shao Min Shuang , Chuan Dong
2010, 21(4): 480-483  doi: 10.1016/j.cclet.2009.11.042
[Abstract](134) [FullText HTML] [PDF 685KB](0)
The interaction mechanism between human serum albumin(HSA)and 1-phenyl-3(fluorenone-2-yl)-5-(9-ethylcarbazole-3-yl)-2-pyrazoline(PFEP)was investigated by fluorescence and absorption titration techniques in combination with molecular modeling method.Stern-Volmer plots at different temperatures proved that PFEP could quench the intrinsic fluorescence of HSA attributed to a static quenching procedure.The association constants were calculated in the range of 1×105-8×105 mol-1 at different pH conditions,and the stoicbiometric ratio of binding was 1:1 between PEEP and HSA.Molecular modeling study showed that the distance between indole moiety of the Trp214 residue and the carbazole group at the terminal of PFEP was 4.45 Å in the optimal model.
Synthesis and morphology of triangular pyramid-shaped puerarin microparticle with nanostructure
Chuan Hua Lu , Qun Wei Zhang
2010, 21(4): 484-487  doi: 10.1016/j.cclet.2009.11.039
[Abstract](131) [FullText HTML] [PDF 2241KB](0)
A type of triangular pyramid-shaped microparticles of puerarin was synthesized by using oil-in-oil microemulsion approach which is simple and economical under the action of copper substrate.The pyramid-shaped microparticles would be made up of deposit of nanospheres or nanorods and have two significant characters.One is its complex surface morphology like coral reef.The other is a lot of nanopores in existence in the microparticle body.Two possible formation routes were speculated.
Structure and properties of low-dielectric-constant poly(acetoxystyrene-co-octavinyl-polyhedral oligomeric silsesquioxane)hybrid nanocomposite
Chao Zhang , Hong Yao Xu , Xian Zhao
2010, 21(4): 488-491  doi: 10.1016/j.cclet.2009.11.038
[Abstract](137) [FullText HTML] [PDF 993KB](0)
Low-dielectric-constant poly(acetoxystyrenezhi-co-octavinyl-polyhedral oligomeric silsesquioxane)(PAS-POSS)organic-inorganic hybrid nanocomposite was successfully synthesized via one-step free radical polymerization and characterized by FTIR,high-resolution 1H NMR,29Si NMR,DSC,TGA,AFM,spectroscopic ellipsometry and dielectric constants measurements.The results show Tg and Tdec were elevated dramatically due to the incorporation of inorganic POSS cores.Spectroscopic ellipsometry and dielectric constants measurement display the incorporation of POSS into PAS homopolymer can apparently reduce the dielectric constant of materials due to the increase of relative porosity of the hybrid nanocomposites.
Mechanisms of imidacloprid resistance in Nilaparvata lugens by molecular modeling
Gen Yan Liu , Wei Miao , Xiu Lian Ju
2010, 21(4): 492-495  doi: 10.1016/j.cclet.2009.12.017
[Abstract](138) [FullText HTML] [PDF 850KB](0)
Homology models of the ligand binding domain of the wild-type and Y151S mutant brown planthopper(Nilaparvata lugens)α1and rat(Rattus norvegicus)β2 nicotinic acetylcholine receptor(nAChR)subunits were generated based on the crystal structure of acetylcholine binding protein of Lymnaea stagnalis.Neonicotinoid insecticide imidacloprid was docked into the putative binding site of wild-type and mutant α1β2 dimeric receptors by Surflex-docking,and the calculated docking energies were in agreement with experimental results.The resistance mechanisms and corresponding binding modes of imidacloprid on nAChRs containing the Y151S target-site mutation were discussed.
Preparation of polymer brushes on attapulgite surfaces via a combination of CROP and click reaction
Jiu Cun Chen , Yun Pu Wang , Hao Dong Wang , Shuo Yun Wei , Hong Jun Li , Xiao Dong Yan
2010, 21(4): 496-500  doi: 10.1016/j.cclet.2009.11.025
[Abstract](134) [FullText HTML] [PDF 1461KB](0)
In this work,by a combination of controlled ring-opening polymerization(CROP)and click reaction,we reported a facile and useful method to synthesize linear poly(ε-caprolactone)at attapulgite nanocomposites with well-defined structures.For this,first,the chlorine terminated attapulgite was prepared by the self-assembly of 3-chloropropyltrimethoxysilane from the surfaces of attapulgite.And then,the terminal chlorines of modified attapulgite were substituted with azido groups.As the second step,linear propargyl-terminated poly(ε-caprolactone)(PCLs)with different molecular weights were synthesized by the CROP of ε-CL monomer in toluene with Sn(Oct)2 as a catalyst and propargyl alcohol as an initiator.Finally,the azido-terminated attapulgites were reacted with propargyl-terminated PCLs via the click reactions.
An ionic 2D inorganic-organic hybrid of tris[((1H-tetrazol-5-yl)methyl)morpholine]dodecatungstophosphate(Ⅴ)pentahydrate:Synthesis X-ray crystal structure and spectroscopic characterizations
Mohsen Nikpour , Hossein Eshtiagh-Hosseini , Masoud Mirzaei , Amir Aghaei Kaju , Ya Guang Chen , Soroush Zarinabadi
2010, 21(4): 501-505  doi: 10.1016/j.cclet.2009.11.024
[Abstract](134) [FullText HTML] [PDF 439KB](0)
A unique ionic hybrid material[C6H12N5O]3[(PO4)W12O36]·5H2O has been synthesized from the reaction of((1H-tetrazole-5-yl)morphline and α-H3 [(PO4)W12O36]·21H2O.It has successfully been charactrized by elemental analysis.IR and 1HNMR spectroscopies,TGA and single-crystal X-ray diffraction method.Thetitle compound is constructed from the three [C6H12N5O]+cations and α-Keggin[(PO4)W12O36]3-polyoxoanion.The most remarkable structural feature of this hybrid can be described as two-dimensional inorganic infinite plane-like(2D/∞[(PO4)W12O36]3-)which forming via van der Waais interactions along the x axis.
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net