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971.
Shuhai Lin Hongde Liu Basem Kanawati Liangfeng Liu Jiyang Dong Min Li Jiandong Huang Philippe Schmitt-Kopplin Zongwei Cai 《Analytical and bioanalytical chemistry》2013,405(15):5105-5117
In the wake of genomics, metabolomics characterizes the small molecular metabolites revealing the phenotypes induced by gene mutants. To address the metabolic signatures in the hippocampus of the amyloid-beta (Aβ) peptides produced in transgenic (Tg) CRND8 mice, high-field ion cyclotron resonance–Fourier transform mass spectrometry supported by LC-LTQ-Orbitrap was introduced to profile the extracted metabolites. More than 10,000 ions were detected in the mass profile for each sample. Subsequently, peak alignment and the 80 % rule followed by feature selection based on T score computation were performed. The putative identification was also conducted using the highly accurate masses with isotopic distribution by interfacing the MassTRIX database as well as MS/MS fragmentation generated in the LTQ-Orbitrap after chromatographic separation. Consequently, 58 differentiating masses were tentatively identified while up to 44 differentiating elemental compositions could not be biologically annotated in the databases. Nonetheless, of the putatively annotated masses, eicosanoids in arachidonic acid metabolism, fatty acid beta-oxidation disorders as well as disturbed glucose metabolism were highlighted as metabolic traits of Aβ toxicity in Tg CRND8 mice. Furthermore, a web-based bioinformatic tool was used for simulation of the metabolic pathways. As a result of the obtained metabolic signatures, the arachidonic acid metabolism dominates the metabolic perturbation in hippocampal tissues of Tg CRND8 mice compared to non-Tg littermates, indicating that Aβ toxicity functions neuroinflammation in hippocampal tissue and new theranostic opportunities might be offered by characterization of altered arachidonic acid metabolism for Alzheimer’s disease. 相似文献
972.
A multi‐channel microchip electrophoresis using a programmed step electric field strength (PSEFS) method was investigated for fast parallel detection of feline panleukopenia virus (FPV) DNA. An expanded laser beam, a 10× objective lens, and a charge‐coupled device camera were used to simultaneously detect the separations in three parallel channels using laser‐induced fluorescence detection. The parallel separations of a 100‐bp DNA ladder were demonstrated on the system using a sieving gel matrix of 0.5% poly(ethylene oxide) (Mr = 8 000 000) in the individual channels. In addition, the PSEFS method was also applied for faster DNA separation without loss of resolving power. A DNA size marker, FPV DNA sample, and a negative control were simultaneously analyzed with single‐run and one‐step detection. The FPV DNA was clearly distinguished within 30 s, which was more than 100 times faster than with conventional slab gel electrophoresis. The proposed multi‐channel microchip electrophoresis with PSEFS was demonstrated to be a simple and powerful diagnostic method to analyze multiple disease‐related DNA fragments in parallel with high speed, throughput, and accuracy. 相似文献
973.
Jaeyoung Ko Janggyoo Choi Soo Kyung Bae Jinwoong Kim Kee Dong Yoon 《Journal of separation science》2013,36(24):3860-3865
A rapid and efficient high‐performance counter‐current chromatography (HPCCC) method was developed to separate five oligostilbenes from the roots of Vitis amurensis. An n‐hexane/ethyl acetate/methanol/water system (4:8:4:10, v/v/v/v) was selected as an optimal two‐phase solvent system of which the upper phase was used as the stationary phase and the lower phase was used as the mobile one. Partition coefficient values for the target compounds under these optimized conditions were 0.28 ( 1 , ampleosin A), 7.12 ( 2 , (+)‐g‐viniferin), 2.26 ( 3 , vitisin A), 5.38 ( 4 , wilsonol C), and 11.23 ( 5 , vitisin B). Flow‐rate gradient HPCCC (4 mL/min in 0–70 min, 8 mL/min in 70–250 min) was applied to isolate the target compounds in as high purity as possible within the shortest possible run time. Under these conditions, ampelopsin A (12.1 mg), (+)‐g‐viniferin (10.4 mg), vitisin A (2.8 mg), wilsonol C (3.2 mg), and vitisin B (37 mg) were isolated with >95% purity from 150 mg of enriched oligostilbene extract. Although the KD of the last eluted compound, vitisin B (KD = 11.23), was relatively large, it was eluted in 115–145 min using the two‐phase solvent system. This study shows that HPCCC is an efficient tool for the isolation and purification of natural products. 相似文献
974.
Quan‐Bin Han Wai‐Lun Tang Cai‐Xia Dong Hong‐Xi Xu Zhi‐Hong Jiang 《Journal of separation science》2013,36(7):1304-1310
Two‐phase solvent system plays crucial role in successful separation of organic compounds using counter‐current chromatography (CCC). An interesting two‐phase solvent system, composed of chloroform/ethyl acetate/methanol/water, is reported here, in which both phases contain sufficient organic solvents to balance their dissolving capacities. Adjusting the solvent system to get satisfactory partition coefficients (K values) for target compounds becomes relatively simple. This solvent system succeeded in sample preparation of aconitine (8.07 mg, 93.69%), hypaconitine (7.74 mg, 93.17%), mesaconitine (1.95 mg, 94.52%) from raw aconite roots (102.24 mg, crude extract), benzoylmesaconine (34.79 mg, 98.67%) from processed aconite roots (400.01 mg, crude extract), and yunaconitine (253.59 mg, 98.65%) from a crude extract of Aconitum forrestii (326.69 mg, crude extract). 相似文献
975.
Qixin Dong Jiajun Zhu Qiang Sui Chao Tang Xiaomei Wang Yunqiu Yu 《Journal of separation science》2013,36(7):1200-1208
In this study, the objective was to investigate the degradation behavior of Esomeprazole under different recommended stress conditions according to International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use [1] by HPLC. Our research showed that the effect of mobile phase species on separation was significant for the determination of Esomeprazole and its related compounds. Successful separation of the drug from its related impurities and degradation products formed under different stress conditions was achieved using ammonium acetate buffer/ACN by a gradient elution. Compared with phosphate buffer/ACN, ammonium acetate buffer/ACN under same pH and gradient showed a great improvement in resolution due to the change of elution order. The drug was subjected to stress conditions including acidic, alkaline, oxidative, photolytic, and thermal conditions. Extensive degradation occurred in acidic and oxidative conditions, while mild degradation was observed in alkaline and photolytic conditions. Besides, it turned out the drug was extremely stable under thermal condition. The stability‐indicating LC–UV method was validated with respect to linearity, precision, accuracy, specificity, and robustness. The LC–MS method was also adopted for the characterization of degradation products. Based on the m/z values and fragmentation patterns, the degradation pathway of the drug has been proposed. 相似文献
976.
Zhenbin Zhang Fangjun Wang Junjie Ou Hui Lin Jing Dong Hanfa Zou 《Analytical and bioanalytical chemistry》2013,405(7):2265-2271
A butyl–silica hybrid monolithic column for bioseparation by capillary liquid chromatography (cLC) was prepared with butyl methacrylate and alkoxysilanes through a “one-pot” process. The effects of polycondensation temperature, volume percentage of N,N′-dimethylformamide, and content of cetyltrimethylammonium bromide and butyl methacrylate on the morphologies of the hybrid monolithic columns prepared were investigated in detail. Baseline separations of proteins and small peptides on the hybrid monolithic column were achieved by cLC with gradient elution. In addition, the resulting hybrid column was also applied for analysis of tryptic digests of bovine serum albumin by cLC coupled with tandem mass spectrometry. The results demonstrate its potential application in separation of complex biological samples. 相似文献
977.
A high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization tandem mass spectrometry (HPLC-PAD–ESI-MS) method has been developed for the simultaneous identification and quantification of active compounds (rutin and quercetin) contained in Traditional Chinese Medicine (TCM) Euonymus alatus (Thunb.) Siebold (EAS). The herb samples from ten main origins and five medicinal portions (leaf, fruit, stem, pterygium and root) were investigated. The separation was performed on a Shim C18 column at 30 °C with an isocratic elution. Methanol (A) and water (0.5% methanoic acid, v/v) (B) were used as mobile phases. The recoveries of the two compounds were 100.184% and 100.417%, respectively, and all of them showed good linearity (r2 ? 0.9993) in relatively wide concentration ranges. The developed method was applied to identify and quantify the two major active compounds in the collected herb samples, and the results indicated that contents of the two compounds in EAS varied significantly from habitat to habitat. It was demonstrated that the proposed method was helpful for the quality evaluation of EAS. 相似文献
978.
Hang‐Ju Zhao Jian‐Ping Ma Qi‐Kui Liu Yu‐Bin Dong 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):716-720
A new 1,3,4‐oxadiazole‐containing bispyridyl ligand, namely 5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione (L), has been used to create the novel complexes tetranitratobis{μ‐5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione}zinc(II), [Zn2(NO3)4(C14H12N4OS)2], (I), and catena‐poly[[[dinitratocopper(II)]‐bis{μ‐5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione}] nitrate acetonitrile sesquisolvate dichloromethane sesquisolvate], {[Cu(NO3)(C14H12N4OS)2]NO3·1.5CH3CN·1.5CH2Cl2}n, (II). Compound (I) presents a distorted rectangular centrosymmetric Zn2L2 ring (dimensions 9.56 × 7.06 Å), where each ZnII centre lies in a {ZnN2O4} coordination environment. These binuclear zinc metallocycles are linked into a two‐dimensional network through nonclassical C—H...O hydrogen bonds. The resulting sheets lie parallel to the ac plane. Compound (II), which crystallizes as a nonmerohedral twin, is a coordination polymer with double chains of CuII centres linked by bridging L ligands, propagating parallel to the crystallographic a axis. The CuII centres adopt a distorted square‐pyramidal CuN4O coordination environment with apical O atoms. The chains in (II) are interlinked via two kinds of π–π stacking interactions along [01]. In addition, the structure of (II) contains channels parallel to the crystallographic a direction. The guest components in these channels consist of dichloromethane and acetonitrile solvent molecules and uncoordinated nitrate anions. 相似文献
979.
Dong‐Cheng Hu Chao‐Hu Xiao Guo‐Zhe Guo Yun‐Xia Yang Jia‐Cheng Liu 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(4):356-359
A one‐dimensional AgI coordination complex, catena‐poly[[silver(I)‐μ‐{2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol‐κ2N2:N3}] perchlorate monohydrate], {[Ag(C19H15N3O)]ClO4·H2O}n, was synthesized by the reaction of 2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol (L) with silver perchlorate. In the complex, the L ligands are arranged alternately and link AgI cations through one benzimidazole N atom and the N atom of the pyridine ring, leading to an extended zigzag chain structure. In addition, the one‐dimensional chains are extended into a three‐dimensional supramolecular architecture via O—H...O hydrogen‐bond interactions and π–π stacking interactions. The complex exhibits photoluminescence in acetonitrile solution, with an emission maximum at 390 nm, and investigation of the thermal stability reveals that the network structure is stable up to 650 K. 相似文献
980.
Lipeng Zhou Beibei Dong Si Tang Hong Ma Chen Chen Xiaomei Yang Jie Xu 《Journal of Energy Chemistry》2013,22(4):659-664
Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity. 相似文献