Development of a general quantum-chemical descriptor for steric effects: Density functional theory based QSAR study of herbicidal sulfonylurea analogues
作者：
Xi, Zhen
* ;Yu, Zhihong;Niu, Zongwei;Ban, Shurong;Yang, Guangfu
（ 期刊：
Journal of Computational Chemistry ,2006年27(13):1571-1576 ISSN：0192-8651
通讯作者：
Xi, Zhen
作者机构：
[Xi, Zhen] Nankai Univ, State Key Lab Elementoorgan Chem, Tianjin 300071, Peoples R China.;Nankai Univ, Dept Biol Chem, Tianjin 300071, Peoples R China.;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Xi, Zhen] N;Nankai Univ, State Key Lab Elementoorgan Chem, Tianjin 300071, Peoples R China.
关键词：
quantum-chemical descriptor;density functional theory;QSAR;sulfonylurea herbicide;acetohydroxyacid synthase
摘要：
Quantitative structure‐activity relationship (QSAR) analysis has become one of the most effective approaches for optimizing lead compounds and designing new drugs. Although large number of quantum‐chemical descriptors were defined and applied successfully, it is still a big challenge to develop a general quantum‐chemical descriptor describing the bulk effects more directly and effectively. In this article, we defined a general quantum‐chemical descriptor by characterizing the volume of electron cloud for specific substituent using the method of density functional theory. The application of our defined steric descriptors in the QSAR analysis of sulfonylurea analogues resulted in four QSAR models with high quality (the best model: q2 = 0.881, r2 = 0.901, n = 35, s = 0.401, F = 68.44), which indicated that this descriptor may provide an effective way for solving the problem how to directly describe steric effect in quantum chemistry‐based QSAR studies. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1571–1576, 2006
语种：
英文
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Cloud point extraction preconcentration of manganese(II) from natural water samples using 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and triton X-100 and determination by flame atomic absorption spectrometry
作者：
Sun, Zhimei;Liang, Pei* ;Ding, Qiong;Cao, Jing
期刊：
Analytical Sciences ,2006年22(6):911-913 ISSN：0910-6340
通讯作者：
Liang, Pei
作者机构：
[Liang, Pei] Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;Huainan Normal Univ, Dept Biol & Chem, Huainan 232001, Peoples R China.
通讯机构：
[Liang, Pei] C;Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
摘要：
The possibility was investigated by using 1-phenyl-3-methyl-4-benzoyl-5- pyrazolone (PMBP) as the chelating reagent for separation and preconcentration of manganese(II) by cloud point extraction (CPE) and subsequent determination by flame atomic absorption spectrometry (FAAS). The effects of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on cloud point extraction were studied. Under the optimum conditions, preconcentration of 10 ml of sample solution permitted the detection of 1.45 ng mL-1 of manganese with an enrichment factor of 20. The proposed method was applied to the determination of trace manganese in water samples with satisfactory results. 2006 © The Japan Society for Analytical Chemistry.
语种：
英文
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Speciation of chromium by selective separation and preconcentration of Cr(III) on an immobilized nanometer titanium dioxide microcolumn
作者：
Liang, P* ;Ding, Q;Liu, Y
期刊：
JOURNAL OF SEPARATION SCIENCE ,2006年29(2):242-247 ISSN：1615-9306
通讯作者：
Liang, P
作者机构：
[Liu, Y; Liang, P; Ding, Q] Cent China Normal Univ, Key Lab Pesticide & Chem Biol, Minist Educ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Liang, P] C;Cent China Normal Univ, Key Lab Pesticide & Chem Biol, Minist Educ, Coll Chem, Wuhan 430079, Peoples R China.
关键词：
Chromium;Immobilized nanometer titanium dioxide;Inductively coupled plasma atomic emission spectrometry;Speciation
摘要：
Nanometer titanium dioxide immobilized on silica gel (immobilized nanometerscale TiO<inf>2</inf> particles) was prepared by a sol-gel method and characterized by X-ray diffraction and scanning electron microscopy. The adsorptive behavior of Cr(III) and Cr(VI) on immobilized nanometer TiO<inf>2</inf> was assessed. Cr(III) was selectively sorbed on immobilized nanometer TiO<inf>2</inf> in the pH range of 7-9, while Cr(VI) was found to remain in solution. A sensitive and selective method has been developed for the speciation of chromium in water samples using an immobilized nanometer TiO<inf>2</inf> microcolumn and inductively coupled plasma atomic emission spectrometry. Under optimized conditions (pH 7.0, flow rate 2.0 mL/min), Cr(III) was retained on the column, then eluted with 0.5 mol/L HNO<inf>3</inf> and determined by ICP-AES. Total chromium was determined after the reduction of Cr(VI) to Cr(III) by ascorbic acid. The adsorption capacity of immobilized nanometer TiO<inf>2</inf> for Cr(III) was found to be 7.04 mg/g. The detection limit for Cr(III) was 0.22 ng/mL and the RSD was 3.5% (n = 11, c = 100 ng/mL) with an enrichment factor of 50. The proposed method has been applied to the speciation of chromium in water samples with satisfactory results. ©2006 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim.
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英文
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低等白蚁肠道共生微生物的多样性及其功能
作者：
杨红;彭建新;刘凯于;洪华珠
期刊：
微生物学报 ,2006年46(3):496-499 ISSN：0001-6209
通讯作者：
Yang, H.
作者机构：
[杨红; 彭建新; 刘凯于; 洪华珠] 华中师范大学生命科学学院昆虫学研究所
关键词：
低等白蚁;共生;鞭毛虫;原核生物;多样性;功能
摘要：
低等白蚁肠道里存在着复杂的微生物区系，包括真核微生物鞭毛虫和原核生物，细菌及古细菌。低等白蚁的后肠以特别膨大的囊形胃及其氢氧浓度的明显梯度分布和丰富的微生物区系为特征，是白蚁进行木质纤维素消化的主要器官。后肠内的鞭毛虫能将纤维素水解并发酵为乙酸，二氧化碳和氢，为白蚁提供营养和能源。系统发育研究表明，低等白蚁肠道共生细菌的主要类群为白蚁菌群1、螺旋体、拟杆菌，低G＋Cmol％含量的革兰氏阳性菌和紫细菌等。而古细菌主要为甲烷短杆菌属的产甲烷菌。共生原核生物与二氧化碳的还原和氮的循环等代谢有关。但肠道共生微生物的具体功能和作用机制还有待进一步的揭示。
语种：
中文
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One-pot synthesis of spring-like superstructures consisting of layered tin(IV) hydrogen phosphate nanodisks
作者：
Qiao, H;Jia, FL;Ai, ZH;Li, ZS;Zhang, LZ*
期刊：
Chemical Communications ,2006年(19):2033-2035 ISSN：1359-7345
通讯作者：
Zhang, LZ
作者机构：
[Zhang, LZ] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Hubei, Peoples R China.;Nanjing Univ, Dept Phys, Ecomat & Renewable Energy Res Ctrr, Jiangsu 210093, Peoples R China.
通讯机构：
[Zhang, LZ] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
Spring-like superstructures consisting of layered tin(IV) hydrogen phosphate nanodisks can be obtained via a one-pot solvothermal reaction of tin tetrachloride and phosphoric acid in ethanol. These superstructures are active anode materials for the lithium-ion battery.
语种：
英文
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Substituent effects control the self-association of molecular clips in the crystalline state
作者：
Wang, Zhi-Guo;Zhou, Bao-Han;Chen, Yun-Feng;Yin, Guo-Dong;Li, Yi-Tao;...
期刊：
JOURNAL OF ORGANIC CHEMISTRY ,2006年71(12):4502-4508 ISSN：0022-3263
作者机构：
[Wu, An-Xin] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.;Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA.
通讯机构：
[Wu, An-Xin] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
摘要：
We report the X-ray crystal structure of 11 molecular clips and analyze the influence of substituents ( e. g., OMe, Me, and NO2) and their location on the observed crystal packing. Molecular clips 3a and 3b form tapelike structures in the crystal due to pi-pi interactions between the aromatic walls. Compounds 3d, 3eC, and 3fC form dimers driven by critical C-H center dot center dot center dot O interactions and then form tapes driven by pi-pi interactions in the crystal. These two building motifs, pi-pi and C-H center dot center dot center dot O interactions, can be used to rationalize the enantio- and diastereoselectivity observed in the X-ray crystal structures of the remaining five molecular clips. For example, the C-H center dot center dot center dot O interactions are found to dictate the formation of homochiral dimers in the structures of (+/-)-3eT and (+/-)-3fT and to control the diastereoselective formation of 6a(2)-6c(2) dimeric motifs with internal p-dimethoxy-o-xylylene walls. Overall, the results suggest that substituent effects that induce even weak intermolecular interactions ( e. g., C-H center dot center dot center dot O) can be used to reliably control crystal packing within glycoluril-based systems.
语种：
英文
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Determination of chitosan by cathodic stripping voltammetry
作者：
Lu, GH* ;Wang, LR;Wang, RX;Zeng, Y;Huang, X
期刊：
Analytical Sciences ,2006年22(4):575-578 ISSN：0910-6340
通讯作者：
Lu, GH
作者机构：
[Lu, GH] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.;Chizhou Coll, Dept Chem, Guichi 247000, Peoples R China.
通讯机构：
[Lu, GH] C;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
摘要：
A sensitive method for the determination of chitosan (CTS) by cathodic stripping voltammetry is presented. The method exploits a pair of oxidation-reduction peaks of CTS at -0.62 V (vs. SCE) and -0.54 V (vs. SCE), and an enhancement of the peak current of CTS observed in a 0.05 mol l-1 potassium hydrogenphthalate buffer solution (pH 2.5). The peak current is linear with the concentration of CTS from 5.0 × 10-7 to 1.5 × 10-5 g ml-1, and the detection limit is 1.0 × 10-7 g ml-1. We studied the characteristics and the mechanism of the electrode reaction, which proved that this process was diffusion controlled. This method was applied to determine the content of CTS in real samples with satisfactory results. 2006 © The Japan Society for Analytical Chemistry.
语种：
英文
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Biodegradation of imazapyr in typical soils in Zhejiang Province, China
作者：
Wang, XD* ;Zhou, SM;Wang, HL;Fan, DF
期刊：
环境科学学报(英文版) ,2005年17(4):593-597 ISSN：1001-0742
通讯作者：
Wang, XD
作者机构：
[Wang, XD] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.;Henan Agr Univ, Coll Agron, Zhengzhou 450002, Peoples R China.;Zhejiang Univ, Pesticides & Environm Toxicol Res Inst, Hangzhou 310029, Peoples R China.
通讯机构：
[Wang, XD] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
关键词：
biodegradation;imazapyr;sterile soil;non-sterile soil;imazapyr-degrading bacteria
摘要：
The degradation of imazapyr in non-sterile and sterile soils from four sampling sites in Zhejiang, China was studied. The results showed that the half-lives of imazapyr in non-sterile soils were in the range of 30 to 45 d, while 81 to 133 d in sterile(by autoclaving) soils.It means the rate constants of imazapyr under non-sterile conditions were 2.3-4.4 times faster than that under sterile(by autoclaving) conditions, evidently indicating that the indigenous microorganisms in soil play an important role in the degradation of imazapyr. The different sterilization methods could result in different degradation rates of imazapyr. The heat of sterilization of soil largely decreased the degradation. However, the sterile treatment of soil by sodium azide had a different effect from that by autoclaving. Further more, the mechanism was also discussed. Biodegradation in four non-sterile soils accounted for 62% to 78% of imazapyr degradation. In contrast,less than 39% of imazapyr degradation was associated with chemical mechanisms. Therefore, the degradation mechanism was predominantly involved in biology including organisms and microorganisms in soil. Two imazapyr-degrading bacterial strains were isolated in enrichment culture technique and they were identified as Pseudomonas fluorescenes biotype Ⅱ (ZJX-5) and Bacillus cereus(ZJX-9),respectively. When added at a concentration of 50 μg/g in mineral salts medium(MSM), ZJX-5 and ZJX-9 could degrade 81 % and 87%imazapyr after 48 h of incubation. For the treatment of incorporation of ZJX-5 or ZJX-9 into soil, the degradation rate enhanced 3-4 fold faster than that for control samples, which showed an important value in quick decontamination of imazapyr in soil.
语种：
英文
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Synthesis of (R)-2,3-epoxypropyl(1→3)-β-d-pentaglucoside
作者：
Huang, GL* ;Mei, XY;Liu, MX
期刊：
Carbohydrate Research ,2005年340(4):603-608 ISSN：0008-6215
通讯作者：
Huang, GL
作者机构：
Huazhong Univ Sci & Technol, Sch Life Sci & Technol, Wuhan 430074, Peoples R China.;Cent China Normal Univ, Sch Chem, Wuhan 430079, Peoples R China.;[Huang, GL] Huazhong Univ Sci & Technol, Sch Life Sci & Technol, E Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
通讯机构：
[Huang, GL] H;Huazhong Univ Sci & Technol, Sch Life Sci & Technol, E Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
关键词：
(R)-2,3-epoxypropyl;(1 -> 3)-beta-D-pentaglucoside;synthesis
摘要：
The title pentasaccharide was synthesized via a 2 + 3 strategy. The disaccharide donor, 3-O-acetyl-2-O-benzoyl-4,6-O-benzylidene-β-d- glucopyranosyl-(1→3)-2-O-benzoyl-4,6-O-benzylidene-α-d- glucopyranosyl trichloroacetimidate (8), was obtained by selective coupling of allyl 2-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranoside with 3-O-acetyl-2-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranosyl trichloroacetimidate (4), followed by deallylation, and trichloroacetimidation. Meanwhile, the trisaccharide acceptor, allyl 2-O-benzoyl-4,6-O-benzylidene- β-d-glucopyranosyl-(1→3)-2-O-benzoyl-4,6-O-benzylidene-β-d- glucopyranosyl-(1→3)-2-O-benzoyl-4,6-O-benzylidene-β-d- glucopyranoside (12), was prepared by coupling of allyl 2-O-benzoyl-4,6-O- benzylidene-β-d-glucopyranosyl-(1→3)-2-O-benzoyl-4, 6-O-benzylidene-β-d-glucopyranoside with 4, followed by deacetylation. Condensation of 8 with 12, followed by epoxidation, and deprotection, gave the target pentaoside. © 2005 Elsevier Ltd. All rights reserved.
语种：
英文
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A novel three-component one-pot reaction involving alkynes, urea or thiourea, and aldehydes
作者：
Huang, SL* ;Pan, YJ;Zhu, WL;Wu, AX
期刊：
Organic Letters ,2005年7(17):3797-3799 ISSN：1523-7060
通讯作者：
Huang, SL
作者机构：
[Huang, SL] Zhejiang Univ, Dept Chem, Hangzhou 310027, Peoples R China.;Cent China Normal Univ, Key Lab Pesticide & Chem Biol, Minst Educ, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, SL] Z;Zhejiang Univ, Dept Chem, Hangzhou 310027, Peoples R China.
摘要：
A novel three-component, one-pot condensation yielding 2-amino-4H-1,3-oxazines or 2-amino-4H-1,3-thiazines from alkynes, urea or thiourea, and aldehydes is described. [reaction: see text]
语种：
英文
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A competitive low-affinity binding model for determining the mutual and specific sites of two ligands on protein
作者：
Bai, GY;Cui, YF;Yang, YH;Ye, CH;Liu, ML*
期刊：
Journal of Pharmaceutical and Biomedical Analysis ,2005年38(4):588-593 ISSN：0731-7085
通讯作者：
Liu, ML
作者机构：
[Liu, ML] Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China.;Cent China Normal Univ, Dept Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, ML] C;Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China.
关键词：
competitive binding;mutual binding sites;NMR;relaxation rate;human serum albumin;tolmetin;salicylic acid
摘要：
A competitive low-affinity binding model was proposed for determining the number of mutual (overlapped) and specific binding sites of two ligands (A, B) on a protein (P). To use the model, one needs to carry out a titration experiment by adding either ligand A or B into a three-component system (A-B-P), and to monitor the spectroscopic parameter changes. Fitting the titration curve to the proposed model, one can get the mutual and specific binding sites of the two ligands on the protein. The model was examined by using human serum albumin (HSA) as a receptor and tolmetin (TOL) and salicylic acid (SAL) as ligands. Proton longitudinal relaxation rates (R-1) were measured on a 500-MHz NMR spectrometer during the titration and used to derive the mutual binding sites. It was found that among the binding sites of 32 +/- 4 for SAL and 28 +/- 2 for TOL on HSA, there were 17 +/- 5 mutual sites for the two ligands. This result indicates that, although HSA has large binding capacities for most ligands, there are still a reasonable amount of the low-affinity binding sites that are structure selective. (c) 2005 Elsevier B.V. All rights reserved.
语种：
英文
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Binding model construction of antifungal 2-aryl-4-chromanones using CoMFA, CoMSIA, and QSAR analyses
作者：
Wei, DG;Yang, GF
* （ ;Wan, J;Zhan, CG
期刊：
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY ,2005年53(5):1604-1611 ISSN：0021-8561
通讯作者：
Yang, GF
作者机构：
[Yang, GF] Minist Educ China, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.;Univ Kentucky, Coll Pharm, Dept Pharmaceut Sci, Lexington, KY 40536 USA.
通讯机构：
[Yang, GF] M;Minist Educ China, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
关键词：
2-Aryl-4-chromanones derivatives;Binding model;CoMFA;CoMSIA;Hansch-Fujita QSAR
摘要：
Flavonoids, generated by plants upon attack by a range of pathogens, are demonstrated to have a role in biotic and abiotic stress response phenomena in plants, and there is increasing evidence for the antibacterial, antifungal, and antiviral activities of these compounds. Using the bioisosterism strategy, a series of 2-aryl-4-chromanone derivatives based upon the structure of flavanones, a kind of flavonoid phytoalexins, were synthesized and tested for the antifungal activity against Pyricularia grisea, which have been reported in our previous papers. To further explore the comprehensive structure-activity relationship and construct the binding model for the antifungal compounds, two kinds of molecular field analysis techniques, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), were performed following a Hansch-Fujita QSAR study. Superimpositions were performed using three alignment rules, that is, centroid-based alignment, common substructure-based alignment, and field fit alignment, and statistically reliable models with good predictive power (CoMFA r2 = 0.952, q 2 = 0.727; CoMSIA r2 = 0.965, q2 = 0.751) were achieved on the basis of the common substructure-based alignment. The combined results of CoMFA, CoMSIA, and former Hansch-Fujita QSAR analyses resulted in comprehensive understanding about the structure-activity relationships, which led to this construction of a plausible binding model of the title compounds. © 2005 American Chemical Society.
语种：
英文
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纳米二氧化钛分离富集ICP-AES测定镉、钴、锌的研究
作者：
Shi, TQ* ;Liang, P;Li, J;Lu, HB
期刊：
光谱学与光谱分析 ,2005年25(3):444-446 ISSN：1000-0593
通讯作者：
Shi, TQ
作者机构：
[Shi, TQ] Jinggangshan Normol Coll, Jian 343009, Peoples R China.;Cent China Normal Univ, Ctr Anal & Testing, Wuhan 430079, Peoples R China.
通讯机构：
[Shi, TQ] J;Jinggangshan Normol Coll, Jian 343009, Peoples R China.
关键词：
纳米二氧化钛;分离富集;镉;钴;锌
摘要：
建立了纳米二氧化钛分离富集, 电感耦合等离子体原子发射光谱(ICP-AES)测定镉、钴和锌的新方法. 考察了溶液pH值、洗脱条件和干扰离子等因素对分析物分离富集的影响. 结果表明, 在pH 9～10范围内, Cd, Co和Zn可被纳米TiO2定量富集, 吸附于纳米TiO2上的金属离子可用0.1 mol·L-1的硝酸溶液完全解脱. 在优化的实验条件下, 纳米TiO2对Cd, Co和Zn的吸附容量分别为8.1, 6.9和15.1 mg·g-1. 本法对Cd, Co和Zn的检出限(3σ)分别为: 5.1, 3.4和2.9 ng·mL-1, 相对标准偏差(RSD)分别为4.3%, 4.6%和4.9%(n=9, c= 0.1 μg·mL-1). 该方法已成功地应用于环境样品中镉、钴和锌的测定, 分析结果满意.
语种：
中文
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Theoretical study toward understanding the catalytic mechanism of pyruvate decarboxylase
作者：
Wang, JY;Dong, H;Li, SH* ;He, HW
期刊：
JOURNAL OF PHYSICAL CHEMISTRY B ,2005年109(39):18664-18672 ISSN：1520-6106
通讯作者：
Li, SH
作者机构：
[Li, SH] Nanjing Univ, Lab Mesoscop Chem, Inst Theoret & Computat Chem, Dept Chem, Nanjing 210093, Peoples R China.;Cent China Normal Univ, Inst Organ Synth Chem Coll, Wuhan 430079, Peoples R China.
通讯机构：
[Li, SH] N;Nanjing Univ, Lab Mesoscop Chem, Inst Theoret & Computat Chem, Dept Chem, Nanjing 210093, Peoples R China.
摘要：
Density functional calculations are employed to explore the mechanisms of all elementary reaction steps involved in the catalytic cycle of pyruvate decarboxylase (PDC). Different models are constructed for mimicking the involvement of some key residues in a certain step. The effect of the protein framework on the potential energy profiles of active site models is approximately modeled by fixing some freedoms, based on the crystal structure of the PDC enzyme from Saccharomyces cerevisiae (ScPDC). Our calculations confirm that Glu51 is the most important residue in the formation of the ylide and the release of acetaldehyde via the proton relay between Glu51, N<inf>1'</inf>, and the 4'-amino group of thiamine diphosphate. The presence of Glu477 and Asp28 residues makes the decarboxylation of lactylthiamin diphosphate (LThDP) an endothermic process with a significant free energy barrier. The protonation of the α-carbanion to form 2-(1-hydroxyethyl)-thiamin diphosphate is found to go through a concerted double proton transfer transition state involving both Asp28 and His115 residues. The final step, acetaldehyde release, is likely to proceed through a concerted transition state involving carbon-carbon bond-breaking and the deprotonation of the α-hydroxyl group. The decarboxylation of LThDP and the protonation of the α-carbanion are two rate-limiting steps, relative to the facile occurrence of the ylide formation and acetaldehyde release. The catalytic roles of residues Glu51, Glu477, Asp28, and Gly417 in the active site of ScPDC in individual steps elucidated from the present study are in good agreement with those derived from site-directed mutagenesis. ©2005 American Chemical Society.
语种：
英文
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Readily tunable and bifunctional L-prolinamide derivatives: Design and application in the direct enantioselective aldol reactions
作者：
Chen, JR;Lu, HH;Li, XY;Cheng, L;Wan, J;...
期刊：
Organic Letters ,2005年7(20):4543-4545 ISSN：1523-7060
通讯作者：
Xiao, WJ
作者机构：
[Cheng, L; Chen, JR; Lu, HH; Xiao, WJ; Wan, J; Li, XY] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Hubei, Peoples R China.;[Xiao, WJ] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Xiao, WJ] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.
摘要：
(Chemical Equation Presented) Readily tunable and bifunctional L-prolinamides as novel organocatalysts have been developed, and their catalytic activities were evaluated in the direct asymmetric Aldol reactions of various aromatic aldehydes and cyclohexanone. High isolated yields (up to 94%), enantioselectivities (up to 99% ee), and anti-diastereoselectivities (up to 99:1) were obtained under the optimal conditions. © 2005 American Chemical Society.
语种：
英文
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RETRACTED: The application of quantum dots as fluorescent label to glycoarray
作者：
Huang, GL* ;Liu, TC;Liu, MX;Mei, XY
期刊：
Analytical Biochemistry ,2005年340(1):52-56 ISSN：0003-2697
通讯作者：
Huang, GL
作者机构：
Huazhong Univ Sci & Technol, Coll Life Sci & Technol, Key Lab Biomed Photon, Minist Educ, Wuhan 430074, Peoples R China.;Cent China Normal Univ, Sch Chem, Wuhan 430079, Peoples R China.;[Huang, GL] Huazhong Univ Sci & Technol, Coll Life Sci & Technol, Key Lab Biomed Photon, Minist Educ, East Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
通讯机构：
[Huang, GL] H;Huazhong Univ Sci & Technol, Coll Life Sci & Technol, Key Lab Biomed Photon, Minist Educ, East Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
关键词：
Detection;Fabrication;Glycoarray;Quantum dots
摘要：
A sensitive, specific, and rapid method for the detection of carbohydrate-protein interactions was demonstrated using quantum dots (QDs) as a fluorescence label coupled with protein. 1,3-Dipolar cycloaddition between azide and alkyne was exploited to attach α-d-glucopyranoside to a C 14 hydrocarbon chain that noncovalently binds to the microtiter well surface, and the product formation was detected by both electrospray ionization-mass spectrometry (ESI-MS) and QD- (or fluorescein isothiocyanate (FITC))-conjugated lectin binding. It indicated that the peak intensity of the fluorescence emission was proportional to the initial concanavalin A (Con A) concentration in the range of 2 × 10-3 μmol/L to 2 × 10-2 mmol/L with a detection limit at least 100 times lower than that of the FITC-based method. © 2005 Elsevier Inc. All rights reserved.
语种：
英文
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Synthesis, immunological activities, and scavenging ability toward superoxide anion of (1→3)-β-d-pentaglucoside and its epoxyalkyl derivatives
作者：
Huang, GL* ;Liu, MX;Mei, XY;Wang, Y
期刊：
Bioorganic & Medicinal Chemistry ,2005年13(12):3873-3877 ISSN：0968-0896
通讯作者：
Huang, GL
作者机构：
Huazhong Univ Sci & Technol, Minist Educ, Key Lab Biomed Photon, Wuhan 430074, Peoples R China.;Cent China Normal Univ, Sch Chem, Wuhan 430079, Peoples R China.;[Huang, GL] Huazhong Univ Sci & Technol, Minist Educ, Key Lab Biomed Photon, East Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
通讯机构：
[Huang, GL] H;Huazhong Univ Sci & Technol, Minist Educ, Key Lab Biomed Photon, East Campus,1037 Luoyu Rd, Wuhan 430074, Peoples R China.
关键词：
(1 -> 3)-beta-D-Pentagluco side;synthesis;epoxyalkyl derivatives;immunological activities;scavenging ability toward superoxide anion
摘要：
The epoxyalkyl (1→3)-β-d-pentaglucosides 2 and 3 were synthesized in order by acetylation, glycosidation, oxidation, and deacetylation of 1. The immunological activities (superoxide anion production activity, phagocytic activity, and lymphocyte proliferation) and scavenging ability toward superoxide anion of (1→3)-β-d-pentaglucoside (1) and its epoxyalkyl derivatives (2 and 3) were investigated. Superoxide anion released from human blood monocytes was measured by the reduction of ferricytochrome c. Phagocytosis by peritoneal macrophages was detected through a teal ingesting that measured the chicken red blood cells (CRBC). Lymphocyte proliferation was determined by the MTT method. The scavenging ability of 1, 2, and 3 toward superoxide anions was evaluated by means of chemiluminescence (CL). The results showed that 2 and 3 had a little higher immunological activity and scavenging ability toward superoxide anion than 1, which indicated that the reducing end of the oligoglucosides was quite important for maximum biological activity. © 2005 Elsevier Ltd. All rights reserved.
语种：
英文
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Application of multiwalled carbon nanotubes as solid phase extraction sorbent for preconcentration of trace copper in water samples
作者：
Liang, P* ;Ding, Q;Song, F
期刊：
JOURNAL OF SEPARATION SCIENCE ,2005年28(17):2339-2343 ISSN：1615-9306
通讯作者：
Liang, P
作者机构：
[Song, F; Liang, P; Ding, Q] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Liang, P] C;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
关键词：
Copper;FAAS;Multiwalled carbon nanotubes;Solid phase extraction
摘要：
The adsorption behavior of multiwalled carbon nanotubes (MWNTs) toward copper has been investigated systemically, and a new method has been developed for the determination of trace copper in water samples based on preconcentration with a microcolumn packed with MWNTs prior to its determination by flame atomic absorption spectrometry. The optimum experimental parameters for preconcentration of copper, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been investigated. Copper can be quantitatively retained by MWNTs in the pH range 5-8, and then eluted completely with 0.5 M HNO<inf>3</inf>. The detection limit of this method for Cu was 0.42 ng/mL, and the RSD was 3.5% at the 10 ng/mL Cu level. The method was validated using a certified reference material, and has been successfully applied for the determination of trace copper in water samples. ©2005 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim.
语种：
英文
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Study of Langmuir and Langmuir-Blodgett films of odorant-binding protein/amphiphile for odorant biosensors
作者：
Hou, YX
* ;Jaffrezic-Renault, N;Martelet, C;Tlili, C;Zhang, A
（ ;...
期刊：
LANGMUIR ,2005年21(9):4058-4065 ISSN：0743-7463
通讯作者：
Hou, YX
作者机构：
[Hou, YX] Ecole Cent Lyon, Ctr Genie Elect Lyon, CEGELY, F-69134 Ecully, France.;Cent China Normal Univ, Col Chem, Wuhan 430079, Peoples R China.;INRA, F-78352 Jouy En Josas, France.;Lab NanoBioEngn, E-08028 Barcelona, Spain.;CNRS, LAAS, F-31077 Toulouse, France.
通讯机构：
[Hou, YX] E;Ecole Cent Lyon, Ctr Genie Elect Lyon, CEGELY, F-69134 Ecully, France.
摘要：
To make ultrathin films for the fabrication of artificial olfactory systems, odorant biosensors, we have investigated mixed Langmuir and Langmuir-Blodgett films of odorant-binding protein/amphiphile. Under optimized experimental conditions (phosphate buffer solution, pH 7.5, OBP-1F concentration of 4 mg L<sup>-1</sup>, target pressure 35 mN m<sup>-1</sup>), the mixed monolayer at the air/water interface is very stable and has been efficiently transferred onto gold supports, which were previously functionalized by self-assembled monolayers (SAMs) with 1-octadecanethiol (ODT). Atomic force microscopy and electrochemical impedance spectroscopy were used to characterize mixed Langmuir-Blodgett (LB) films before and after contact with a specific odorant molecule, isoamyl acetate. AFM phase images show a higher contrast after contact with the odorant molecule due to the new structure of the OBP-1F/ODA LB film. Non-Faradaic electrochemical spectroscopy (EIS) is used to quantify the effect of the odorant based on the electrical properties of the OBP-1F/ODA LB film, as its resistance strongly decreases from 1.18 MΩ(before contact) to 25 kΩ(after contact). ©2005 American Chemical Society.
语种：
英文
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Degradation of 4-chlorophenol by a microwave assisted photocatalysis method
作者：
Ai, ZH;Yang, P;Lu, XH*
期刊：
Journal of Hazardous Materials ,2005年124(1-3):147-152 ISSN：0304-3894
通讯作者：
Lu, XH
作者机构：
[Lu, XH] Huazhong Univ Sci & Technol, Environm Sci Res Inst, Wuhan 430074, Peoples R China.;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Lu, XH] H;Huazhong Univ Sci & Technol, Environm Sci Res Inst, Wuhan 430074, Peoples R China.
关键词：
microwave assisted photocatalysis;electrodeless discharge lamp;4-chlorophenol
摘要：
In this work, the degradation of 4-chlorophenol (4CP) under simultaneous microwave assisted UV (electrodeless discharge lamp) photocatalysis technique (MW/UV/TiO<inf>2</inf>) was investigated. Several factors affecting the degradation of 4CP by MW/UV/TiO<inf>2</inf> method, such as the dosage of photocatalysts, the initial pH value of the solutions, gas bubbling, light intensity and addition of H<inf>2</inf>O<inf>2</inf> oxidant, were studied in detail. The synergistic effects between microwave irradiation and TiO <inf>2</inf> photocatalysis were also studied. The major intermediates were found to be chlorobenzene, phenol, hydroquinone, benzoquinone and 4-chlorocatechol. Based on the results, a general reaction pathway for the degradation of 4CP was proposed. ©2005 Elsevier B.V. All rights reserved.
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英文
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