中国化学快报

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Sulfanilic acid catalyzed solvent-free synthesis of 1,5-benzodiazepine derivatives

Jaiprakash N. Sangshetti, Nagnnath D. Kokare, Devanand B. Shinde

中国化学快报. 2007, 18(11): 1305-1308. https://doi.org/10.1016/j.cclet.2007.09.022

摘要 ( )

可视化

Sulfanilic acid has been found to be an efficient catalyst for the synthesis of 1, 5-benzodiazepines from o-phenylenediamine and ketones. This method is simple, effective and environmentally friendly and gives better yields.

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Oxalic acid catalyzed solvent-free one pot synthesis of coumarins

Nagnnath D. Kokare, Jaiprkash N. Sangshetti, Devanand B. Shinde

中国化学快报. 2007, 18(11): 1309-1312. https://doi.org/10.1016/j.cclet.2007.09.008

摘要 ( )

可视化

Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present methods are the use of cheap and easy available catalyst, solvent-free reaction conditions, better yields and shorter reaction time.

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Facile synthesis of 9-(N-amino-4-fluoromethyl-3-pyrrolidinyl)-2-fluoro-6-aminopurine from trans-4-hydroxy-L-proline

Ye Qing Li, Ming Lu, Chun Xu Lu, Sai Jian Zhu, Qi Fa Liu

中国化学快报. 2007, 18(11): 1313-1315. https://doi.org/10.1016/j.cclet.2007.09.020

摘要 ( )

可视化

A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-(p-nitrobenzyloxycarbonyl)-trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step reaction and 2-fluoro-6-azidopurine is described, and azanucleoside is fluorinated by new fluridizer 2, 2-difluoro-1, 3-dimethylimidazolidine (DFI). All reactions could be carried out under mild condition.

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Two new compounds derived from bufalin

Jun Zhao, Shu Hong Guan, Xiao Bin Chen, Wei Wang, Min Ye, De An Guo

中国化学快报. 2007, 18(11): 1316-1318. https://doi.org/10.1016/j.cclet.2007.09.023

摘要 ( )

可视化

The biotransformation of bufalin by cell suspension cultures of Platycodon grandiflorus was investigated and two new biotransformed products were obtained, which was 3-epi-telocinobufagin and 3-epi-bufalin-3-O-β-D-glucoside.

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The synthesis and spectroscopic investigation of vinylated meso-tetraphenylporphyrin

Jin Qiang Xue, Ya Qing Feng, Lei Wang, Ling Hui Wu

中国化学快报. 2007, 18(11): 1319-1322. https://doi.org/10.1016/j.cclet.2007.09.032

摘要 ( )

可视化

A series of new vinylated 5, 10, 15, 20-tetraphenylporphyrins have been synthesized and characterized by ¹H NMR, MS, UV-vis and fluorescence studies. Following selective excitation of the porphyrin compounds with UV light, the energy is transferred to the porphyrin core and reemitted as red light. In comparison to tetraphenylporphyrin (TPP), the luminescence properties are markedly improved.

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Synthesis of mangiferin derivates and study their potent PTP1B inhibitory activity

Hong Gang Hu, Ming Juan Wang, Qing Jie Zhao, Shi Chong Yu, Chao Mei Liu, Qiu Ye Wu

中国化学快报. 2007, 18(11): 1323-1326. https://doi.org/10.1016/j.cclet.2007.09.011

摘要 ( )

可视化

Protein tyrosine phosphatase 1B (PTP1B) has received considerable attention from the drug industry as a potential treatment fordiabetes mellitus. Mangiferin has been reported to possess significant antidiabetic activity. Based on the previous study, eight new mangiferin derivates were synthesized and evaluated for their PTP1B inhibitory activity. Some of them displayed good inhibitory activity on PTP1B.

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Microwave-assisted synthesis of new pyrimido[4',5':4,5]thiazolo[3,2-a]benzimidazol-4(3H)-one derivatives in solvent-free condition

A. Davoodnia, M. Roshani, E. Saleh Nadim, M. Bakavoli, N. Tavakoli Hoseini

中国化学快报. 2007, 18(11): 1327-1330. https://doi.org/10.1016/j.cclet.2007.09.004

摘要 ( )

可视化

Microwave-assisted synthesis of new 2-arylpyrimido[4', 5':4, 5]thiazolo[3, 2-a]benzimidazol-4 (3H)-ones from 3-aminothiazolo[3, 2-a]benzimidazol-2-carboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.

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Synthesis and anticancer activities of porphyrin induced anticancer drugs

Dong Hong Li, Jun Lin Diao, Ke Gui Yu, Cheng He Zhou

中国化学快报. 2007, 18(11): 1331-1334. https://doi.org/10.1016/j.cclet.2007.09.012

摘要 ( )

可视化

In view of the property of porphyrin's accumulation selectively in tumor, the ftorafur was modified by binding a porphyrin block to improve its tumor targeting and reduce its side effects. These novel porphyrin derivatives and metal compounds were synthesized under mild conditions with satisfactory yield, and the constructions of all these new compounds were characterized by UV, IR, MS, ¹H NMR spectra and elementary analysis. Their anticancer activities were evaluated by MTT assay; the results indicated that the anticancer activities of compounds 4a-c were twice as high as that of ftorafur.

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Synthesis and antitumor activity of heterocyclic acid ester derivatives of 20S-camptothecins

Di Zao Li, Yan Li, Xiao Guang Chen, Chen Gen Zhu, Jing Yang, Hong Yan Liu, Xian Dao Pan

中国化学快报. 2007, 18(11): 1335-1338. https://doi.org/10.1016/j.cclet.2007.09.014

摘要 ( )

可视化

A series of heterocyclic acid esters of camptothecins as new compounds had been synthesized by acylation method, their in vitro and in vivo antitumor activities were evaluated. The cytotoxic results showed that 6 possessed the best efficacy on six human cancer cell lines in the six classes of CPTs' derivatives. In vivo testing results indicated that 9 had better antitumor activity against mouse liver carcinoma H₂₂ than topotecan.

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A new method for inversion of hydroxyl group of carbocyclic nucleosides

Xiao Zhen Liu, Fei Wang, Dong Dong Luo, Xing Guo, Guang Qing Lei

中国化学快报. 2007, 18(11): 1339-1341. https://doi.org/10.1016/j.cclet.2007.09.002

摘要 ( )

可视化

The hydroxyl group of carbocyclic nucleosides was inversed when the compounds were treated with Me₃SiCl, KCN and a catalytic amount of NaI in DMF/CH₃CN.

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Synthesis and characterization of a novel main chain oxadiazole-based copolymer for n-type solar cell material

Xian Rong Cai, Hao Chen, Tao Zhang, Xing Xu, Ying Li, Qing Jiang

中国化学快报. 2007, 18(11): 1342-1346. https://doi.org/10.1016/j.cclet.2007.09.035

摘要 ( )

可视化

A novel oxadiazole-based copolymer has been successfully synthesized through the palladium-catalyzed cross-coupling polycondensation method. The copolymer P is soluble in common organic solvents. Its structure has characterized by ¹H NMR, ¹³C NMR, gel permeation chromatagraphy (GPC), UV-vis absorbance (Abs) and photoluniminescence (PL) spectroscopy, and cyclic voltammetry (CV). Investigation of its optical properties revealed that it is yellow emitting material, and the electrochemical analysis showed that P was well suited poly (2, 5-dioctyloxy-p-phenylenevinylene) (PDOCPV) for photovoltaic devices, so the copolymer P is able to act as an electron acceptor in combination with PDOCPVas the electron donor to quench photoluminescence of the copolymer in the blend, indicative of the efficient photoinduced electron transfer from the PDOCPV to the P.

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The synthesis and cytotoxic activity of novel organogermanium sesquioxides with anthraquinone or naphthalene moiety

Guo Qiang Shangguan, Lun Liang Huang, Xiao Gang Qu

中国化学快报. 2007, 18(11): 1347-1350. https://doi.org/10.1016/j.cclet.2007.09.029

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可视化

Four novel organogermanium sesquioxides with anthraquinone or naphthalene moiety were synthesized. The structures were characterized by IR, NMR and elemental analysis, and their cytotoxicities were evaluated against human chronic myeloid leukemia K562 cell lines. The cytotoxicity could be improved by the introduction of planar aromatic chromophore moiety to the parent compound, Ge-132.

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Synthesis of new 1,3-bis (phenylethynyl) disilazanes

Xiao Wen Hu, Zhi Min Zheng, Cai Hong Xu

中国化学快报. 2007, 18(11): 1351-1352. https://doi.org/10.1016/j.cclet.2007.09.036

摘要 ( )

可视化

Three new 1, 3-bis (phenylethynyl) disilazanes were synthesized from the reaction of 1, 3-dichlorodisilazanes with (phenylethynyl) lithium, and characterized by infrared (IR) spectra, nuclear magnetic resonance (NMR) and mass spectrometry (MS).

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Solvent-free esterification of poly (vinyl alcohol) and maleic anhydride through mechanochemical reaction

Bo Zhao, Can Hui Lu, Mei Liang

中国化学快报. 2007, 18(11): 1353-1356. https://doi.org/10.1016/j.cclet.2007.09.019

摘要 ( )

可视化

A solid-state mechanochemical processing, that is, pan-milling, was used to conduct the esterification of poly (vinyl alcohol) (PVA) with maleic anhydride (MA) through stress-induced reaction. FTIR spectrum study indicated the presence of ester linkages and olefinic double bonds in maleic anhydride cross-linked PVA. Thermal properties of the cross-linked product were characterized by DSC. The results showed its glass transition temperature was 20℃ higher than the original linear PVA and the thermal stability was also improved.

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Solventless synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles catalyzed by Fe (ClO₄)₃ at room temperature

Hossien A. Oskooie, Majid M. Heravi, Akbar Sadnia, Farahnaz K. Behbahani, Fatemeh Jannati

中国化学快报. 2007, 18(11): 1357-1360. https://doi.org/10.1016/j.cclet.2007.09.030

摘要 ( )

可视化

A series of 2-aryl-1-arylmethyl-1H-1, 3-benzimidazoles was synthesized expeditiously in good yields from o-phenylenediamines and aldehydes in the presence of Fe (ClO₄)₃ without solvent at room temperature.

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Asymmetric synthesis of 3-butylphthalide using isomannide and isosorbide as chiral auxiliaries

Zhen Li Min, Yi Hua Zhang, Yi Sheng Lai, Si Xun Peng

中国化学快报. 2007, 18(11): 1361-1363. https://doi.org/10.1016/j.cclet.2007.09.038

摘要 ( )

可视化

A new approach for asymmetric syntheses of (S) and (R)-3-n-butylphthalide (NBP) is presented. The diastereoselective addition of dibutylzinic to aromatic aldehyde 10 or 11 generated from isomannide-or isosorbide-derived chiral auxiliary afforded S-NBP or R-NBP in high optical yields.

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A novel alkenoic acid ester and a new benzophenone from Ranunculus ternatus

Ying Xiong, Ke Zhong Deng, Wen Yuan Gao, Yuan Qiang Guo, Tie Jun Zhang

中国化学快报. 2007, 18(11): 1364-1366. https://doi.org/10.1016/j.cclet.2007.09.017

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A novel alkenoic acid ester, (E)-4-hydroxy-dodec-2-enedioic acid-12-O-methyl ester and a new benzophenone, ethyl (S)-3-[2-(3, 4-dihydroxybenzoyl)-4, 5-dihydroxyphenyl]-2-hydroxypropanoate, together with a known compound, (E)-4-hydroxy-dodec-2-enedioic acids were isolated from the roots of Ranunculus ternatus. Their structures were elucidated by spectroscopic methods.

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Four new constituents from Taraxacum mongolicum

Shu Yun Shi, Qi Zhou, Hua Peng, Chang Xin Zhou, Ming Hui Hu, Qiao Feng Tao, Xiao Jiang Hao, Joachim Stöckigt, Yu Zhao

中国化学快报. 2007, 18(11): 1367-1370. https://doi.org/10.1016/j.cclet.2007.09.005

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Two new flavone glycosides, isoetin-7-O-β-D-glucopyranosyl-2'-O-α-L-arabinopyranoside (1) and isoetin-7-O-β-D-glucopyranosyl-2'-O-α-D-glucopyranoside (2), a new lignan, mongolicumin A (3), and a new guaianolide, mongolicumin B (4) were isolated from the aerial part of Taraxacum mongolicum. Their structures were elucidated mainly by spectral analyses.

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The photoluminescence of Co-Al-layered double hydroxide

Shuai Sun, Wan Guo Hou

中国化学快报. 2007, 18(11): 1371-1373. https://doi.org/10.1016/j.cclet.2007.09.024

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We report a new optical behaviour of pure Co-Al-layered double hydroxide (LDH). It was found that the Co-Al-LDH sample could emit fluorescence without any fluorescent substances intercalated. Its excitation spectrum shows a maximum peak near the wavelength 370 nm, the maximum emission peak appears at 430 nm and the photoluminescence colour of the Co-Al-LDH sample is blue. This new optical property will be expected to extend the potential applications of LDHs in optical materials field.

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A novel phycocyanin-Chla/c₂-protein complex isolated from chloroplasts of Chroomonas placoidea

Min Chen, Si Hui Li, Li Sun

中国化学快报. 2007, 18(11): 1374-1378. https://doi.org/10.1016/j.cclet.2007.09.025

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Nine pigment-protein complexes were separated and characterized from intact Chroomonas placoidea chloroplasts by IEF. The bands Ⅰ-Ⅵ with their isoelectric points (pI) values from 4 to 6 were phycocyanin components; bands Ⅷ and Ⅸ (pI=2.8-3.6) were chlorophyll-protein complexes. According to absorption and fluorescence spectra, band Ⅶ was designated as a novel phycocyanin-Chla/c₂-protein complex (pI≈3.4-3.7). These results indicated that phycocyanin is structurally and functionally coupled with chlorophyll-protein complex in C. placoidea, and probably interacted with electrostatic force in combination.

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A new sesquiterpene from Caragana intermediia

Zhi Hua Sun, Chang Qi Hu, Jin Yi Wang

中国化学快报. 2007, 18(11): 1379-1382. https://doi.org/10.1016/j.cclet.2007.09.034

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可视化

A new alloaromadendrane-type sesquiterpene, (-)-alloaromadendrane-3β, 9β-diol (1), has been isolated from the aerial part of Caragana intermediia. The structure of (-)-alloaromadendrane-3β, 9β-diol (1) was established by spectroscopic methods, including X-ray analysis that provided its relative stereochemistry. Bioassay showed that (-)-alloaromadendrane-3β, 9β-diol (1) possesses anti-pyricularia oryzae P-2b activity with MIC value of 10 μg/mL.

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Two new diterpenoids from Isodon serra

Fu Lin Yan, Lai Bin Zhang, Ji Xia Zhang, Han Dong Sun

中国化学快报. 2007, 18(11): 1383-1385. https://doi.org/10.1016/j.cclet.2007.09.026

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可视化

From the aerial part of Isodon serra, two new ent-6, 7-seco-kaurane-type diterpenoids, 15α, 20β-dihydroxy-6β-methoxy-6, 7-seco-6, 20-epoxy-1, 7-olide-ent-kaur-16-ene (1) and 6α, 15α-dihydroxy-20-aldehyde-6, 7-seco-6, 11α-epoxy-1, 7-olide-ent-kaur-16-ene (2) were isolated. Their structures were elucidated by spectroscopic means.

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Pterisemipol,a novel sesquiterpenoid from Pteris semipinnata L.

Qiang Zhang, Li Jiang Xuan

中国化学快报. 2007, 18(11): 1386-1388. https://doi.org/10.1016/j.cclet.2007.09.028

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可视化

A novel sesquiterpenoid, pterisemipol, was isolated from Pteris semipinnata L. Its skeleton, namely pterisane, was considered to be rearranged from protoilludane and its structure was elucidated on the basis of spectroscopic analysis.

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Gear-like array of (H₂O)₁₂ as building blocks in one-dimensional supramolecular assembly

Chun Hua Ge, Xiang Dong Zhang, Yong Chao Ma, Lei Guan, Chun Yue Shi, Xiao Yan Zhang, Ya Nan Guo, Qi Tao Liu

中国化学快报. 2007, 18(11): 1389-1391. https://doi.org/10.1016/j.cclet.2007.07.015

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可视化

The prepartion crystal structure of complex Co (Hsae)₂·2H₂O (1, H₂sae=N-salicylidene-2-iminoethanol) are reported X-ray analysis revealed that every six Co (Hsae)₂ forms a cyclic chip and every 12 water forms a novel gear-like cluster. Acting as building blocks, the gear-like water cluster and complex chip are connected in A-B fashion and extend into one-dimensional supramolecular chain. Hydrogen bond is the primary bridging force in the formation of supramolecular framework.

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A chiral stationary phase with special hydrophobic framework for ligand-exchange chromatography

Hong Yu Shi, Rui Juan Song, Yu Fu, Na Yao, Yuan De Long, Tian Bao Huang

中国化学快报. 2007, 18(11): 1392-1394. https://doi.org/10.1016/j.cclet.2007.09.016

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A novel chiral stationary phase (CSP1) for ligand-exchange chromatography (CLEC) was prepared by firstly using dimethylchlorosilane as an endcapping reagent for decreasing residual silanol group on the surface of silica gel, and then introducing L-Pro as a chiral selector and hydrophobic octyl group to the silica gel surface simultaneously. The enantioseparations of 14 DL-amino acids on CSP1 were achieved with the enantioselectivity α ranging from 1.09 to 2.44 and the resolution Rs being between 0.8 and 6.3. The chromatographic performances of CSP1 with the bonded phase (CSP2) prepared using reference method were compared. The results showed that the column efficiency and resolution Rs of chiral stationary phase could be improved by using the above modifying method.

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PAM-PAA microgel inverse opal photonic crystal and pH response

Yong Qiang He, Xiao Dong Wang, Jian Ying Wang, Yan Feng, Yong Qiang Zhao, Xiu Dong You

中国化学快报. 2007, 18(11): 1395-1398. https://doi.org/10.1016/j.cclet.2007.09.010

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可视化

The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels (IOH_PAM) or PAM/PAA inverse opal hydrogels (IOH_PAM/PAA) photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOH_PAM and IOH_PAM/PAA films, but the IOH_PAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content.

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Novel preparation of organic polymer-based monolithic column by microwave irradiation

Xiong Wen Ye, Yu Ping Zhang, Ling Bo Qu, Li Qun Fan, Bo Li

中国化学快报. 2007, 18(11): 1399-1402. https://doi.org/10.1016/j.cclet.2007.09.027

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可视化

Microwave irradiation was firstly attempted for the preparation of organic-based monoliths of poly (styrene-divinylbenzene-methacrylic acid), which single step in situ polymerization was carried out during 15 min. The column permeability, electrophoretic and chromatographic behaviors were comparatively evaluated using pressure-assisted CEC, CEC and low pressure-driven separation modes. The largest theoretical plates for the preparing column could be close to 18, 0000 plates/m for thiourea in the mode of p-CEC. It provided a viable alternative to traditional initiation means for the preparation of monolithic capillary columns.

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A novel selective fluorescent chemosensor for Cu (Ⅱ)

Mao Xiang Wang, Xiang Ming Meng, Man Zhou Zhu, Qing Xiang Guo

中国化学快报. 2007, 18(11): 1403-1406. https://doi.org/10.1016/j.cclet.2007.09.018

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可视化

A novel fluorescence enhancement Cu²⁺chemosensor derived from coumarin was prepared. Emission study found that it exhibits evident Cu²⁺-amplified fluorescence prior to Co²⁺, Pb²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Zn²⁺, Fe³⁺, Ag⁺ and Cd²⁺, and the largest emission enhancement factor is about 9 at a ratio of 2:1 (chemosensor 1/Cu²⁺)

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Synthesis of N-methylene phosphonic chitosan (NMPCS) and its potential as gene carrier

Dun Wan Zhu, Jin Gen Bo, Hai Ling Zhang, Wen Guang Liu, Xi Gang Leng, Cun Xian Song, Yu Ji Yin, Li Ping Song, Lan Xia Liu, Lin Mei, Xiu Lan Li, Yang Zhang, Kang De Yao

中国化学快报. 2007, 18(11): 1407-1410. https://doi.org/10.1016/j.cclet.2007.09.006

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可视化

N-Methylene phosphonic chitosan (NMPCS), an amphiphilic macromolecule with powerful chelating ability of Ca²⁺ ions, was synthesized and characterized. The physicochemical properties of NMPCS and the interactions between NMPCS and plasmid DNA were investigated by FTIR, ¹³C NMR, X-ray, agarose gel electrophoresis retardation assay, atomic force microscopy (AFM) and complexes with mean size of 80-210 nm were formed. Taking HeLa as host cell, luciferase expression mediated by NMPCS improved about 100 times compared to the expression mediated by chitosan.

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Electro-generation of TGA by Ni-mSA-mCS bipolar membrane

Zhen Xia Huang, Xi Zheng, Ri Yao Chen, Xiao Chen, Zhen Chen

中国化学快报. 2007, 18(11): 1411-1415. https://doi.org/10.1016/j.cclet.2007.09.031

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可视化

Ni-mSA-mCS bipolar membrane (BM) was prepared by sodium alginate (SA) and chitosan (CS), which were modified by Ca²⁺ and glutaraldehyde as linking reagents, respectively. mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid (TGA). The experiment results show that TGA was prepared effectively by electro-reduction of dithiodiglycolic acid (DTDGA) with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature (25℃) during the current density of 10 mA/cm². Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.

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Antioxidant activity of bovine serum albumin binding amino acid Schiff-bases metal complexes

Rong Min Wang, Juan Juan Mao, Jing Feng Song, Cai Xia Huo, Yu Feng He

中国化学快报. 2007, 18(11): 1416-1418. https://doi.org/10.1016/j.cclet.2007.09.015

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可视化

Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin (BSA), which afforded BSA binding Schiff-base metal complexes (BSA-SalGluM, M=Cu, Co, Ni, Zn). The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE. It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes. The effect of the antioxidant activity was investigated. The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes.

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Clustering properties of partly charged superfine particles in a light medium

Jing Sheng Li, Juan Wang, Qin Shen

中国化学快报. 2007, 18(11): 1419-1422. https://doi.org/10.1016/j.cclet.2007.09.001

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可视化

This paper investigated average cluster sizes (ACS) and cluster size distributions (CSD) at different shear rates by Brownian dynamics in non-, bi-, and uni-polar systems with partly charged superfine particles. The investigation indicates that clusters in nonpolar systems are the weakest and easiest to be damaged by increasing shear stresses; charged particles play important and different roles:in bi-polar system, it intends to strengthen clusters to some extent provided that the sign-like ions homogeneously arranged; in uni-polar system charged particles cracked the clusters into smaller ones, but the small clusters are strong to stand with larger shear stress. The relationship between ACS and shear rates follows power law with exponents in a range 0.18-0.28, these values are in a good agreement with experiment range but at the lower limit compared with other systems of non-metallic cluster particles.

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Relation between the permeability and the degree of coil overlap of polymer in the bulk state

Quan Fu An, Jin Wen Qian, Meng Wang, Yin Lu, Phillip Choi

中国化学快报. 2007, 18(11): 1423-1426. https://doi.org/10.1016/j.cclet.2007.09.007

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可视化

Based on the expression of the index of coil interpenetration (i. e., the degree of coil overlap, ξ_b) of amorphous polymers in the bulk state proposed by Qian, the ξ_b was rewritten as ξ_b=ρ_b[η]_θ/1.66 via Flory's intrinsic viscosity equation at theta conditions. The ξ_b of poly (vinyl chloride) (PVC) dense membranes with different molecular weights and cellulose diacetate (CA) dense membranes prepared using different solvents were determined. The permeability, permeation coefficient (P) of nitrogen and permeation flux (J) of liquid through both membranes, respectively, was measured. P and J decreased exponentially with increasing ξ_b for PVC and CA membranes were revealed.

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Temperature waves in chemical reaction-diffusion-heat conduction systems with two ends respectively subject to Dirichlet and no-flux conditions

Yu Min Han, Zhi Li, Jiu Li Luo

中国化学快报. 2007, 18(11): 1427-1430. https://doi.org/10.1016/j.cclet.2007.09.021

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可视化

Taking the Lindemann model as a sample system in which there exist chemical reactions, diffusion and heat conduction, we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous two-variable system with one end subject to Dirichlet conditions, while the other end no-flux conditions. Furthermore, the conditions for the emergence of temperature waves are found out by the linear stabiliy analysis and verified by a diagram for successive steps of evolution of spatial profile of temperature during a period that is plotted by numerical simulations on a computer. Without doubt, these results are in favor of the heat balance in chemical reactor designs.

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2007年, 第18卷, 第11期　刊出日期：2007-11-20

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2007年, 第18卷, 第11期 刊出日期：2007-11-20

2007年, 第18卷, 第11期　刊出日期：2007-11-20