Assembly of isoquinolines via CuI-catalyzed coupling of beta-keto esters and 2-halobenzylamines

CuI-catalyzed coupling of 2-halobenzylamines with beta-keto esters or 1,3-diketones in i-PrOH under the action of K(2)CO(3) produced 1,2-dihydroisoquinolines as the coupling/condensative cyclization products, which underwent smooth dehydrogenation under air atmosphere to afford substituted isoquinolines.     

Hypothesis of active components in volatile oil from a Chinese herb formulation, 'Shao-Fu-Zhu-Yu decoction', using GC-MS and chemometrics

Traditional Chinese medicine (TCM) with few or no side effects has increasingly attracted attention all over the world. However, the bioactive components and the therapeutic mechanisms are usually not understood because of the complex chemical compositions of these medicines. In this paper, GC-MS coupled with a chemometric method was developed for analysis of active components in volatile oil from a Chinese herb formulation, "Shao-Fu-Zhu-Yu Decoction". The volatile oils, obtained by hydrodistillation from "Shao-Fu-Zhu-Yu Decoction" (SFZYD) and its constituent herbs with abundant volatile oil (Angelica sinensis, Ligusticum chuanxiong, Cinnamomum cassia, Foeniculum vulgare, Zingiber officinale), were chemically analyzed using GC-MS and bioassayed using oxytocin-induced uterine contraction assay in vitro. Then, a mathematic model relating the chemical compositions and their activities in inhibiting mice uterine contraction was established for hypothesis of the bioactive compounds based on chemometrics. As a result, nine compounds which might contribute to the inhibition of oxytocin-induced uterine contraction were selected, and the activities of some of them were further confirmed by our experiments and/or the literature. The data suggest that the developed method is helpful for screening bioactive components from complex mixtures, such as the extracts of TCM.     

Synthesis and fungicidal activity of novel 3,5-diarylpyrazole derivatives

(E)-3-(2-chlorophenyl)-1-(2,4-dichlorophenyl) prop-2-en-1-one was prepared from 2-chlorobenzaldehyde followed by cyclization with hydrazine monohydrate. Eight new 3-(2,4-Di-chlorophenyl)-5-(2-chlorophenyl)-4,5-dihydro-N-acylpyrazole derivatives were synthesized and characterized by elemental analysis, IR and ¹H NMR spectroscopy. The experimental results show that the inhibition ratio of compounds 3f towards H. Oryzae and P. oryzae at 50 mg·L⁻¹ is 55.2% and 57.1%, respectively. The inhibition ratio of compounds 3g towards H. Oryzae, P. oryza, S. Sclerotiorum at 50 mg·L⁻¹ is 53.3%, 60.0%, 50.4% respectively. __________ Translated from Chinese Journal of Applied Chemistry, 2007, 27(7): 835–837     

Recent advances in electric analysis of cells in microfluidic systems

Microfluidics offers an ideal platform to integrate cell-based assays with electric measurements. The technological advances in microfluidics, microelectronics, electrochemistry, and electrophysiology have greatly inspired the development of microfluidic/electric devices that work with a low number of cells or single cells. The applications of these microfluidic systems range from the detecting of cell culture density to the probing of cellular functions at the single-cell level. In this review, we introduce the recent advances in the electric analysis of cells on a microfluidic platform, specifically related to the quantification and monitoring of cells in static solution, on-chip patch-clamp measurement, and examination of flowing cells. We also point out future directions and challenges in this field. Figure Different microfluidic devices applied to electrical analysis of cells     

On meromorphic solutions of f 3 + g 3 = 1

We show that meromorphic solutions f, g of f ³ + g ³ = 1 in must be constant, if and have the same zeros (counting multiplicities). Received: 12 March 2007     

An organic p-type dopant with high thermal stability for an organic semiconductor

To overcome the thermal instability of a p-doped organic hole transporting layer using the state-of-the-art p-type dopant, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, a potent electron accepter, 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, has been found to possess superior thermal stability and proved to be an excellent p-type dopant.     

Effect of swift heavy ions in Ni-Al nanocrystalline films studied by X-ray absorption spectroscopy

X-ray absorption spectroscopic measurements have been used to compare the electronic structures of swift heavy ions (100 MeV Si ions) irradiated and pristine Ni-Al nanocrystalline films. Results from X-ray diffraction (XRD), X-ray absorption near-edge structure (XANES) spectra at Al K-, and Ni L(2,3)-edges and extended X-ray absorption fine structure (EXAFS) at Ni K-edges are discussed. The observed XRD peaks indicate the improvement of crystalline nature and Al(111) clustering after the swift heavy ion interactions. While the XANES spectra at Ni L(2,3)-edges show decrease in the intensity of white line strength, the Al K-edge shows increase in intensity after irradiation. Above results imply that swift heavy ions induce low Z (i.e., Al) ion mass transport, changes in Al sp-Ni-d hybridization, and charge transfer. EXAFS results show that crystalline nature is improved after swift heavy irradiation which is consistent with XRD results.     

Separation of aromatic acids by wide-bore electrophoresis with nanoparticles prepared by electrospray as pseudostationary phase

A model mixture of six aromatic acids has been separated using a laboratory-made wide-bore electrophoretic device with aminopropyl-modified nanoparticles used as pseudostationary phase. Optimization of preparation of nanoparticles by an electrospray (ES) method is described. With the optimized electrophoretic method, 30 mmol/L acetate running buffer, pH 4.5, containing 1.0 mg/mL of nanoparticles as an additive was used, and 3.0 kV applied potential, improved resolution was achieved. The average theoretical plate number obtained was above 5.0 x 10(4) theoretical plates per meter with the highest value achieved in certain runs exceeding 1.0 x 10(5) theoretical plates per meter, which was better than previously reported results (approximately 6.7 x 10(4) theoretical plates per meter). Furthermore, repeatabilities of 2, 6.5, and 6% were obtained for the migration time, peak areas, and peak height, respectively. Additionally, sample capacity and sensitivity were improved by hundredfold using the novel wide-bore electrophoresis system compared to traditional CE.     

A sensitive method for determination of salvianolic acid A in rat plasma using liquid chromatography/tandem mass spectrometry

Salvianolic acid A (SAA), a major effective constituent of Salvia miltiorrhizas, is widely used in traditional Chinese medicine. A sensitive rapid analytical method was established and validated for SAA in rat plasma, which was further applied to assess the pharmacokinetics of SAA in rats receiving a single oral dose of SAA. The method used liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode with chloramphenicol as the internal standard. A simple liquid-liquid extraction based on ethyl acetate was employed. The combination of a simple sample cleanup and short chromatographic run time (3 min) increased the throughput of the method substantially. The method was validated over the range 1.4-1000 ng/mL with a correlation coefficient >0.99. The lower limit of quantification was 1.4 ng/mL for SAA in plasma. Intra- and inter-day accuracies for SAA were 95-113 and 98-107%, and the inter-day precision was less than 12%. This method is more sensitive and faster than previous methods. After a single oral dose of 100 mg/kg of SAA, the mean peak plasma concentration (Cmax) of SAA was 318 ng/mL at 0.5 h, the area under the plasma concentration-time curve (AUC0-12 h) was 698 +/- 129 ng.h/mL, and the elimination half-life (T1/2) was 3.29 h.