2008 Volume 19 Issue 7

A simple and efficient synthesis of the valsartan
Chen Xi Zhang , Guo Jun Zheng , Fu Qiang Bi , Yu Lin Li
2008, 19(7): 759-761  doi: 10.1016/j.cclet.2008.04.032
[Abstract](116) [FullText HTML] [PDF 237KB](0)
Abstract:
Valsartan 1,one of the most important agents used in antihypertensive therapy today,was synthesized starting from L-valin methyl ester hydrochloride 2 through four steps in an overall yield of 60%.The key step involves the palladium-catalyzed SuzuKi coupling.This method overcomes many of the drawbacks associated with the previously reported syntheses and is more suitable for industrial production.
ZrOC12·8H2O catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles and substituted 1,4-di(4,5-diphenylimidazolyl)benzene
Jaiprakash N. Sangshetti , Nagnnath D. Kokare , Sandeep A. Kotharkar , Devanand B. Shinde
2008, 19(7): 762-766  doi: 10.1016/j.cclet.2008.05.007
[Abstract](128) [FullText HTML] [PDF 257KB](0)
Abstract:
A simple one-pot synthetic method for the preparation of 2,4,5-triaryl-lH-imidazoles from benzoin or benzil,ammonium acetate,aromatic aldehydes,and ZrOCl2·8H 2O catalyst is described.The ZrOCl2-8H2O catalyst was found to be equally effective for aromatic and heteroaromatic aldehydes and also for the preparation of substituted 1,4-di(4,5-diphenylimidazol-yl) benzene.
PMA-SiO2catalyzed synthesis of β-keto enol ethers
P. Srihari , S.S. Mandal , J.S.S. Reddy , R. Srinivasa Rao , J.S. Yadav
2008, 19(7): 767-770  doi: 10.1016/j.cclet.2008.05.006
[Abstract](125) [FullText HTML] [PDF 233KB](0)
Abstract:
An efficient conversion of β-diketones into corresponding β-keto enol ethers with catalytic amount of PMA-SiO2 has been achieve
Synthesis of 1,8-dioxooctahydroxanthenes utilizing PMA-SiO2as an efficient reusable catalyst
P. Srihari , S.S. Mandal , J.S.S. Reddy , R. Srinivasa Rao , J.S. Yadav
2008, 19(7): 771-774  doi: 10.1016/j.cclet.2008.05.005
[Abstract](130) [FullText HTML] [PDF 234KB](0)
Abstract:
PMA-SiO2 has been utilized as an efficient catalyst system in preparation of 1,8-dioxooctabydroxanthenes.
Cerium(Ⅳ) ammonium nitrate catalysed facile and efficient synthesis of polyhydroquinoline derivatives through Hantzsch multicomponent condensation
Cherkupally Sanjeeva Reddy , Mekala Raghu
2008, 19(7): 775-779  doi: 10.1016/j.cclet.2008.04.040
[Abstract](119) [FullText HTML] [PDF 280KB](0)
Abstract:
A general and convenient practical approach for the synthesis of polyhydroquinoline derivatives has been achieved via one-pot four-component Hantzsch condensation of aromatic aldehydes,dimedone,ethyl acetoacetate and ammonium acetate in the presence of a catalytic amount of cerium(Ⅳ) ammonium nitrate (CAN),in ethanol solvent at ambient temperature.Simple work-up,mild reaction conditions,inexpensive and non-toxic catalyst,and excellent product yields are the advantageous features of this method.
Novel generation of 9H-furo[3,2-b]chromen-9-ones from (E)-3-hydroxy-2-styrylchromones by excited state intramolecular proton transfer
Surinder Berar , Urmila Berar , Satish C. Gupta , Ramesh C. Kamboj
2008, 19(7): 780-782  doi: 10.1016/j.cclet.2008.04.011
[Abstract](118) [FullText HTML] [PDF 238KB](0)
Abstract:
Photocyclisation of substituted (E)-3-hydroxy-2-(1´-methyl-2´-phenylvinyl)-4-oxo-4H-1-benzopyrans to yield linear novel tricyclic 9H-furo[3,2-b]chromen-9-ones and angular fused tetracyclic xanthenones is described.
A facile synthesis of terminal arylacetylenes via Sonogashira coupling reactions catalyzed by MCM-41-supported mercapto palladium(0) complex
Ya Ping Xu , Rong Hua Hu , Ming Zhong Cai
2008, 19(7): 783-787  doi: 10.1016/j.cclet.2008.05.016
[Abstract](133) [FullText HTML] [PDF 276KB](3)
Abstract:
A variety of terminal arylacetylenes have been conveniently synthesized in good to high yields via Sonogashira coupling of aryl iodides with (trimethylsilyl)acetylene catalyzed by MCM-41-supported mercapto palladium(0) complex,followed by desilylation under mild conditions.This polymeric palladium catalyst can be reused many times without any decrease in activity.
Solar thermochemical reactions Ⅱ1:Synthesis of 2-aminothiophenes via Gewald reaction induced by solar thermal energy
Ramadan Ahmed Mekheimer , Mohamed Abdallah Ameen , Kamal Usef Sadek
2008, 19(7): 788-790  doi: 10.1016/j.cclet.2008.04.041
[Abstract](141) [FullText HTML] [PDF 182KB](0)
Abstract:
Green conditions have been developed for the synthesis of substituted 2-aminothiopbenes employing multicomponent reactions of a ketone with active methylene nitrile and elemental sulphur induced by free solar thermal energy.
Studies on the esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one with acid chlorides under different conditions
Ru Shu Sun , Yang Wang , Peng Xia
2008, 19(7): 791-794  doi: 10.1016/j.cclet.2008.04.038
[Abstract](124) [FullText HTML] [PDF 261KB](0)
Abstract:
The esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one (4) with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger,whereas the reactions gave unexpected 8-substituted products N-(8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-y1)amides (5a-c)and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates (6d-e) by using excessive acid chlorides.The structures of 10 new compounds were determined by 1H NMR,13C NMR,MS and HRMS,and the possible mechanism for the formation of unexpected products 5a-e and 6d-e was also proposed.
Practical and concise synthesis of 2-oxo-3,4,5,6-tetraethoxyazepane from D-glucono-1,5-lactone
Yan Jiao , Zhi Jie Fang , Yu Hua Jiang , Bao Hui Zheng , Jie Cheng
2008, 19(7): 795-796  doi: 10.1016/j.cclet.2008.04.044
[Abstract](136) [FullText HTML] [PDF 196KB](0)
Abstract:
2-Oxo-3R,4S,5S,6S-tetraethoxyazepane was conveniently synthesized from D-glucono-1,5-lactone with a yield of 10% overall.The key step of synthetic route-reductive 1,6-cyclization was completed efficiently by using Ph3P to give the expected lactam.
Preparation and chiral recognition of a novel chiral stationary phase for HPLC,based on mono(6A-N-1-(2-hydroxyl)-phenylethylimino-6A-deoxy)-β-cyclodextrin and covalently bonded silica gel
Xiao Ping Chen , Zhi Ming Zhou , Hao Yuan , Zi Hui Meng
2008, 19(7): 797-800  doi: 10.1016/j.cclet.2008.04.045
[Abstract](121) [FullText HTML] [PDF 595KB](0)
Abstract:
A novel chiral stationary phase (CSP) was prepared by immobilizing mono(6A-N-1-(2-hydroxyl)-phenylethylimino-6A-deoxy)-β-cyclodextrin onto the surface of silica gel via a longer spacer.This chiral stationary phase exhibited good enantios electivity for a variety of chiral compounds under reversed-phase conditions.
Synthesis and preliminary biological evaluation of the derivatives of O6-benzylguanine as inactivators of O6-alkylguanine-DNA alkyltransferase
Lei Zhang , Bing Jia , Chang Feng Hu , Fan Wang , Yu Xin Cui
2008, 19(7): 801-804  doi: 10.1016/j.cclet.2008.04.046
[Abstract](128) [FullText HTML] [PDF 283KB](0)
Abstract:
A series of new O6-BG derivatives (14-21,23-30) were synthesized as inactivators of O6-Alkylguanine-DNA alkyltransferase (AGT), and their ability to inhibit AGT was preliminary evaluated by MTT with O6-BG as the control. The result suggested compound 30 displayed a higher activity than O6-BG.
The first total synthesis of ligudentatin A
Chen Xi Zhang , Fu Qiang Bi , Yu Lin Li
2008, 19(7): 805-806  doi: 10.1016/j.cclet.2008.04.037
[Abstract](116) [FullText HTML] [PDF 215KB](0)
Abstract:
Ligudentatin A 1,a new phenolic norsesquiterpenes,was first synthesized starting from (+)-periUaldehyde 3 through five steps,successively,in an overall yield of 20.8%.The key steps were the Diels-Alder reaction and aromatization of enone to phenol.
Synthesis and photoactivity of phenylazonaphthalene peptide nucleic acid monomers
Jin Du Li , Miao Chen , Sheng Liu , Hao Bo Zhang , Zhi Lu Liu
2008, 19(7): 807-810  doi: 10.1016/j.cclet.2008.05.023
[Abstract](136) [FullText HTML] [PDF 342KB](0)
Abstract:
Phenylazonaphthalene peptide nucleic acid (PNA) monomers were successfully synthesized,and their photoisomerization was examined.The new PNA monomers showed reversible trans-cis isomerization with UV and visible light irradiation,which might be the foundation of photo-regulating the hybridization between PNA containing phenylazonaphthalene unit and DNA.Simultaneously,the fluorescence of the new PNA monomers might make them especially useful as structural probes.
Synthesis and antitumor activity of novel 10-amino acids ester homocamptothecin analogues
Liang You , Wan Nian Zhang , Zhen Yuan Miao , Wei Guo , Xiao Ying Che , Wen Ya Wang , Chun Quan Sheng , Jiang Zhong Yao , Ting Zhou
2008, 19(7): 811-813  doi: 10.1016/j.cclet.2008.05.011
[Abstract](127) [FullText HTML] [PDF 229KB](0)
Abstract:
Nine racemic homocamptothecin derivatives were synthesized and in vitro antitumor activities were evaluated by standard MTT method.The results showed that some of the compound had higher antitumor activity than iritecan.
Convenient synthesis of (2S,3R,4R,5S,6R)-2-(3-(4-ethylbenzyl)-4-chlorophenyl)-6-(hydroxymethyl)-tetrahydro-2H-pyran-3,4,5-triol
Yong Hai Liu , Da Li Li , Lu De Lu , Zhen Yuan Miao
2008, 19(7): 814-816  doi: 10.1016/j.cclet.2008.05.009
[Abstract](131) [FullText HTML] [PDF 263KB](0)
Abstract:
A convenient approach for the preparation of (2S,3R,4R,5S,6R)-2-(3-(4-ethylbenzyl)-4-chlorophenyl)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol 1 is developed.The target compound via four steps is synthesized from 4-bromo-2-(bromomethyl)-1-chlorobenzene and the isomers of undesired ortho-products were avoided during the preparation.
A new glycoside from Polygala tenuifolia Willd
Tun Hai Xu , Gang Lv , Tong Hua Liu , Ya Juan Xu , Yun Shan Si , Sheng Xu Xie , Hong Feng Zhao , Dong Han , Dong Ming Xu
2008, 19(7): 817-820  doi: 10.1016/j.cclet.2008.04.030
[Abstract](131) [FullText HTML] [PDF 222KB](0)
Abstract:
A new triterpenoid glycoside,3-β-O-β-D-glucopyranosyl presenegenin 28-O-α-L-arabipyranosyl(1→3)-β-D-xylopyranosyl(1→4)-[β-D-apiofuranosyl(1→3)]-α-L-rhanmopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-D-fucopyranosyl ester (1) was isolated from the Polygala tenuifolia Willd.,together with two known saponins,including polygalasaponinⅩⅩⅣ (2) and polygalasaponinⅩⅩⅧ(3).The structure of new compound was elucidated by spectroscopic methods.
Two new C-glycosylflavones from the leaves of Iris lactea var.chinensis
Wen Juan Shen , Min Jian Qin , Pan Shu , Chao Feng Zhang
2008, 19(7): 821-824  doi: 10.1016/j.cclet.2008.04.031
[Abstract](137) [FullText HTML] [PDF 264KB](0)
Abstract:
Two new acylated C-glycosylflavones were isolated from the leaves of Iris lactea vat.chinensis,and their structures were elucidated on the basis of extensive NMR experiments and mass spectrometry methods and were assigned as 5-hydroxy-4´-methoxyflavone-7-O-(β-D-2""4""-diacetylrhamnopyranosyl)-6-C-[O-(α-L-6´´´-acetyl-glucopyranosyl)-1→2-β-D-glucopyranoside] (irislactin A) and 5-hydroxy-4´,7-dimethoxyflavone-6-C-[O-(α-L-2´´´,3´´´-diacetylrhamno-pyranosyl)-1→2-β-D-glucopyranoside] (irislactin B).
Two new steroidal glucosides from Ophiopogon japonicus (L.f.) Ker-Gawl
Ya Jiuan Xu , Tun Hai Xu , Ling Zhu Hao , Hong Feng Zhao , Sheng Xu Xie , Yun Shan Si , Dong Han , Dong Ming Xu
2008, 19(7): 825-828  doi: 10.1016/j.cclet.2008.04.033
[Abstract](121) [FullText HTML] [PDF 200KB](0)
Abstract:
Two new steroidal glucosides,26-O-β-D-glucopyranosyl (25S)-furost-5-ene-1β,3β,22α,26-tetraol 1-O-β-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-fucopyranoside and (25R) spirost-5-ene-3β,14α-diol-3-β-O-β-L-rhamnopyranosyl-(1→2)-[β-D-xylopyranosyl(1→4)]-β-D-glucopyranoside,were isolated from the Ophiopogon japonicus (L.f.) Ker-Gaw.Their structures were elucidated by spectroscopic methods.
A new caffeic ester from Incarvillea mairei var.granditlora (Wehrhahn) Grierson
Yong Qing Su , Wei Dong Zhang , Chuan Zhang , Run Hui Liu , Yun Heng Shen
2008, 19(7): 829-831  doi: 10.1016/j.cclet.2008.05.003
[Abstract](139) [FullText HTML] [PDF 216KB](0)
Abstract:
A new cafferic ester,(+)-2-(1-hydroxyl-4-oxocyclobexyl) ethyl caffeate,was isolated from the 80% ethanol extract of the whole plants of Incarvillea mairei var.granditlora (Wehrhahn) Grierson.The structure of the compound was established by spectroscopic methods.
A new alkaloid from Castanea mollissima Blume
Dong Song Zhang , Hui Yuan Gao , Xiao Mei Song , Zhi Shu Tang , Li Jun Wu
2008, 19(7): 832-834  doi: 10.1016/j.cclet.2008.05.019
[Abstract](129) [FullText HTML] [PDF 225KB](0)
Abstract:
A new alkaloid,named 6-(2´, 3´-dihydroxy-4´hydroxymethyl-tetrahydro-furan-1´-y1)cyclopentadiene[c]pyrrole-1,3-diol,was isolated from the seeds of Castanea mollissima Blume.The structure was elucidated based on spectroscopic evidence including 2D NMR techniques.
A new hopane triterpenoid from Saxiglossum angustissimum
Hui Fang Pi , Zhi Hong Zhong , Han Li Ruan , Peng Zhang , Yong Hui Zhang , Ji Zhou Wu
2008, 19(7): 835-836  doi: 10.1016/j.cclet.2008.04.034
[Abstract](139) [FullText HTML] [PDF 206KB](0)
Abstract:
A new hopane triterpenoid,hopane 22,29-diol-29-formate(1),has been isolated from the whole herbs of Saxiglossum angustissimum (Gies.) Ching and its structure has been successfully determined on the basis of spectroscopic evidences.
A new compound with cytotoxic activities from the leaves of Panax ginseng C.A. Meyer
Li Bo Wang , Zhao Hua Wu , Hui Yuan Gao , Jian Huang , Bo Hang Sun , Li Jun Wu
2008, 19(7): 837-840  doi: 10.1016/j.cclet.2008.05.017
[Abstract](142) [FullText HTML] [PDF 244KB](0)
Abstract:
A new compound,3,6,20(S)-trihydroxy-12,23-epoxydammar-24-ene,6,20-di-O-β-D-glucopyranoside (1),was isolated from the leaves of Panax ginseng C.A.Meyer,whose structural elucidation was carried out by means of spectral analysis (including IR,HRFAB-MS and NMR).This compound showed the moderate eytotoxie activities against U937 and HeLa ceils by using the MTT method.
A new neuroprotective bakkenolide from the rhizome of Petasites tricholobus
Na Zhang , Mei Li Guo , Ge Zhang , Run Ping Li
2008, 19(7): 841-844  doi: 10.1016/j.cclet.2008.04.036
[Abstract](128) [FullText HTML] [PDF 239KB](0)
Abstract:
A new bakkenolide-type compound, bakkenolide-Va(1), was isolated from the rhizome of Petasites tricholobus. The structure was characterized on the basis of various NMR (1H, 13C, 1H-1H COSY, HMQC, HMBC and NOESY) and mass spectrometry data. The neuroprotective activity of bakkenolide-Va was investigated in primarily cultured neurons treated by hypoxia-glucose deprivation and various types of oxidative insults.
A new glycoside from the leaves of Neoalsomitra integrifoliola
Dong Min Su , Jing Qu , You Cai Hu , Shi Shan Yu , Wen Zhao Tang , Yun Bao Liu , Shuang Gang Ma , De Quan Yu
2008, 19(7): 845-848  doi: 10.1016/j.cclet.2008.04.043
[Abstract](122) [FullText HTML] [PDF 233KB](0)
Abstract:
A new ionone glycoside (6R,9R)-blumenyl α-L-rhanmopyranosyl-(1→6)-β-D-gluco-pyranoside (1),together with a new natural product 2-methoxyl-4-trans-propenyl-phenol α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2),was isolated from the leaves of Neoalsomitra integrifoliola.Their structures were elucidated by chemical and spectral analysis.Compound 1 showed weak anti-inflammatory and low-level antioxidant activities.
A new ent-abietane diterpenoid from Isodon macrophyllus
Zheng Yue Chen , Pei Yong Qiu , Yong Xue Wang , Su Ping Bai , Fu Lin Yan , Ji Xia Zhang , Han Dong Sun
2008, 19(7): 849-851  doi: 10.1016/j.cclet.2008.05.018
[Abstract](135) [FullText HTML] [PDF 264KB](0)
Abstract:
A new ent-abietane diterpenoid,named dayecrystal C,was isolated from the EtOAc extract of the dried leaves of Isodon macrophyllus.Its structure was determined on the basis of spectroscopic methods.
Two new diterpenoids from Rabdosia japonica var.glaucocalyx
Zhao Bao Xiang , Yi Xin Xu , Yang Shen , Li Jin , Hou Peng Wang , Hai Sheng Chen
2008, 19(7): 852-854  doi: 10.1016/j.cclet.2008.05.012
[Abstract](129) [FullText HTML] [PDF 194KB](0)
Abstract:
Two new diterpenoids,named glaucocalyxin F and glaucocalyxin X,respectively,were isolated from the whole plant of Rabdosia japonica (Burro.f.) Hara vat.glaucocalyx (Maxim.) Hara.Their structures was established on the basis of spectral analysis.
CdTe quantum dots as fluorescence sensor for the determination of vitamin B6 in aqueous solution
Jie Fang Sun , Cui Ling Ren , Li Hong Liu , Xing Guo Chen
2008, 19(7): 855-859  doi: 10.1016/j.cclet.2008.04.029
[Abstract](124) [FullText HTML] [PDF 847KB](1)
Abstract:
A novel,rapid and simple CdTe quantum dots (QDs) based technology platform was established for selective and sensitive determination of vitamin B6 in aqueous solution.It can perform accurate and reproducible quantification of vitamin B6 in pharmaceutical with satisfactory results.
Simultaneous spectrophotometric determination of cobalt,copper and nickel using 1-(2-thiazolylazo)-2-naphthol by chemometrics methods
Ali Niazi , Ateesa Yazdanipour
2008, 19(7): 860-864  doi: 10.1016/j.cclet.2008.04.047
[Abstract](129) [FullText HTML] [PDF 216KB](0)
Abstract:
The simultaneous determination of cobalt,copper and nickel using 1-(2-thiazolylazo)-2-naphthol (first figure of this article) by spectrophotometric method is a difficult problem in analytical chemistry,due to spectral interferences.By multivariate calibration methods,such as partial least squares (PLS) regression,it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range.Orthogonal signal correction (OSC) is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis.OSC is a suitable preprocessing method for PLS calibration of mixtures without loss of prediction capacity using spectrophotometric method.In this study,the calibration model is based on absorption spectra in the 550-750-nm range for 21 different mixtures of cobalt,copper and nickel.Calibration matrices were formed from samples containing 0.05-1.05,0.05-1.30 and 0.05-0.80 μg mL-1 for cobalt,copper and nickel,respectively.The root mean square error of prediction (RMSEP) for cobalt,copper and nickel with OSC and without OSC were 0.007,0.008,0.011 and 0.031,0.037,0.032 μg mL-1,respectively.This procedure allows the simultaneous determination of cobalt,copper and nickel in synthetic and real samples and good reliability of the determination was proved.
TiO2 nanotubes :A novel solid phase extraction adsorbent for the sensitive determination of nickel in environmental water samples
Xin Ning Zhao , Qi Zeng Shi , Guo Hong Xie , Qing Xiang Zhou
2008, 19(7): 865-867  doi: 10.1016/j.cclet.2008.05.004
[Abstract](132) [FullText HTML] [PDF 160KB](0)
Abstract:
A novel method was developed for the sensitive determination of nickel in environmental water samples by using TiO2 nanotubes,a new nanomaterial,as solid phase extraction absorbent.In general,TiO2 nanomaterials were often used for catalytic degradation of pollutants in environmental field,and only a very few application in environmental analytic chemistry.In present work,TiO2 nanotubes was firstly used for the enrichment of nickel and the factors would influence the preconcentration performance were optimized.Under the optimal conditions,TiO2 nanotubes exhibited its good enrichment capacity for nickel and the detection limit of the proposed method was 1 ng mL-1.The proposed method was validated with real water samples,and excellent results were obtained with the spiked recoveries in the range of 94.4-99.2%,respectively.
Novel hot-melting hyperbranched poly(ester-amine) bearing self-complementary quadruple hydrogen bonding units
Yi Peng Qiu , Li Ming Tang , Yu Wang , Shi You Guan
2008, 19(7): 868-870  doi: 10.1016/j.cclet.2008.05.001
[Abstract](126) [FullText HTML] [PDF 320KB](0)
Abstract:
Hyperbranched poly(amine-ester)s bearing serf-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties,which make them suitable as novel hot-melting materials.
Novel hot-melting hyperbranched poly(ester-amine) bearing self-complementary quadruple hydrogen bonding units
Li Zhou , Jiao Ning Tang , Bo Liu , Yi Guang Wu , Ai Lian Wang , Chuan Dong Liao
2008, 19(7): 871-876  doi: 10.1016/j.cclet.2008.05.015
[Abstract](128) [FullText HTML] [PDF 831KB](0)
Abstract:
The liquid membrane oscillation of a novel water (aqueous tetradecyl trimethyl ammoniumbromide,TTAB and alcohol sohition)/oil (picdcacid in chloroform sohition)/water (aqueous glucose solution) system was investigated.By using homemade device,the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid,types of alcohol and other organic solvents at different temperature were measured.The results show that the water (aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution)/oil (0.5 mmol/L of picric acid in chloroform solution)/water (aqueous glucose solution) system performed sustained and stable oscillation at 30℃.And the novel system can recognise added amino acid.
Fabrication and biocompatible characterization of magnetic hollow capsules
Hong Zhang , Xing Long Gong , Ling Yun Hao , Wan Quan Jiang
2008, 19(7): 877-880  doi: 10.1016/j.cclet.2008.05.002
[Abstract](125) [FullText HTML] [PDF 770KB](0)
Abstract:
Monodispersed Fe3O4/polypyrrole (PPy) hollow particles were synthesized via controllable in-sire deposition and polymerization techniques using poly(styrene-co-acrylic) (PSA) latex as template.Field-dependent magnetization plot illustrates that the capsules are superparamagnetic at 300 K.FTIR spectrum confirms that the myoglobin (Mb) molecule adsorbed on the surface of Fe3O4/PPy hollow particle essentially retains its native structure.Furthermore,direct electrochemistry of Mb can be realized on Fe3O4/PPy capsules modified pyrolytic graphite disk electrode,which indicates that the magnetic conductive polymer capsules can promote the electron transfer of protein.
Elimination of HBr from CH3Br by Cu+ and Au+ :A DFT study
Tao Hong Li , Chuan Ming Wang , Xiang Yi Liu , Xiao Guang Xie
2008, 19(7): 881-884  doi: 10.1016/j.cclet.2008.04.039
[Abstract](125) [FullText HTML] [PDF 273KB](0)
Abstract:
The elimination of HBr from CH3Br by ground state of Cu+ and Au+ has been investigated by using DFT methods.A mechanism of one-step HBr elimination leading to CuCH2+ was identified.For the formation of AuCH2+,besides the one-step mechanism,another two-step HBr elimination pathway through a C-Br bond insertion intermediate was also found,and this pathway is energetically more favorable than the one-step mechanism.The calculated reaction energy barriers show that the formation of AuCH2+ is energetically much more favorable than the formation of CuCH2+.The experimental observations are well explained.
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