Rapid Extraction of Essential Oil from Dried Cinnamomum cassia Presl and Forsythia suspensa(Thunb.)Vahl by Ionic Liquid Microwave Extraction

Ionic liquid (IL) was used as the microwave absorption medium to extract essential oils from dried Cinnamomum cassia Presl and Forsythia suspensa (Thunb.) Vahl, and the ionic liquid microwave extraction (ILME) was developed. Some experimental parameters for ILME were examined. The proposed method was compared with other methods, including hydrodistillation (HD), microwave hydrodistillation (MHD), solvent‐free microwave extraction (SFME) and improved solvent‐free microwave extraction (ISFME). Experimental results showed that compared with other extraction methods the ILME had some advantages, such as time‐saving, simplicity and usage of green solvents. The extraction time was less than 18 min at the microwave power of 440 W and 1.5 mL of ionic liquid was required. The constituents of essential oils obtained by the five methods are not obviously different.     

A new sesquiterpene from hairy root culture of Artemisia annua

<正>A new sesquiterpene(Z)-7-acetoxy-methyl-11-methyl-3-methylenedodeca-1,6,10-triene(AMDT) was isolnted and identified from the methanol extract of the hairy root culture of Artemisia annua.The structure of AMDT was determined based on the analysis of spectroscopic data,notably of the 2D NMR spectra.This new compound showed cytotoxicity against human tumor cell lines 95-D and HeLa with IC_(50) values of 27.08 and 20.12μmol/L,respectively.     

Methoxy poly (ethylene glycol) thiosulfonate: new activated polymer derivatives for thiol‐specific modification

Thiol‐reactive methoxy poly (ethylene glycol) (mPEG) derivatives, mPEG methanethiosulfonate (mPEG‐MTS) and mPEG phenylthiosulfonate (mPEG‐PTS), were synthesized by one‐step S‐alkylation of mPEG‐halide with the corresponding sodium thiosulfonate. These functionalized polymers were fully characterized by ¹H NMR, ¹³C NMR, GPC as well as MALDI‐TOF. To demonstrate the potential application of mPEG‐MTS and mPEG‐PTS, papain and recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) were used as prototype protein for thiol‐selective PEGylation. The PEGylated products were verified by one or more of the following methods: SDS‐PAGE, HPLC, HPSEC as well as MALDI‐TOF. Compared with native rhG‐CSF, the PEGylated rhG‐CSF was further characterized by in vitro cell proliferative assay and preserved 59% biological activity. Furthermore, mPEG20k‐MTS was used to modify BSA nanoparticles coated with thiol groups. FT‐IR and ζ‐potential assay demonstrated that mPEG thiosulfonate can be effectively immobilized at the nanoparticles' surface via disulfide linkage to form hydrophilic and neutral corona. Therefore, we have demonstrated thiol‐selective PEG derivatives, endowed with unusual versatility, for practical use and potential exploitation. Copyright © 2009 John Wiley & Sons, Ltd.     

Four New Nortriterpenoids from Schisandra lancifolia

Four new highly oxygenated nortriterpenoids, lancifodilactones O–R ( 1 – 4 ), together with six known ones, i.e., 5 – 10 , were isolated from the leaves and stems of Schisandra lancifolia. Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments and mass spectrometry. Compounds 1 – 3 were evaluated for their cytotoxicity against NB4, A549, SHSY5Y, PC‐3, and MCF‐7 cell lines. No compounds exhibited significant cytotoxicity, the IC₅₀ values being above 50 μM .     

Induction of trimeric [Mg3(OH)(CO2)6] in a porous framework by a desymmetrized tritopic ligand

The use of a desymmetrized tritopic ligand with both carboxyl and pyridyl functionalities leads to the first occurrence of the [Mg(3)(μ(3)-OH)(CO(2))(6)] trimer as the 3-D framework building block in a porous crystal that shows relatively high H(2) uptake (1.37% at 77 K and 1 atm).     

LC determination and pharmacokinetic study of the main phenolic components of Portulaca oleracea L. extract in rat plasma after oral administration

This study investigated the pharmacokinetics of hesperidin (HP), ferulic acid (FA) and p-coumaric acid (CA) in rat plasma after oral administration of Portulaca oleracea L. extract (POE). The plasma concentrations were determined by HPLC with vitexin-2″-O-rhamnoside (VR) as internal standard. The calibration curves were linear over the range 0.1-5?μg?mL(-1), 0.1-5?μg?mL(-1)and 0.015-3?μg?mL(-1) for HP, FA and CA, respectively. The validated method was suitable to the pharmacokinetic study of HP, FA and CA in rats after oral administration at a single dose of POE.     

Polyoxometalate-based inorganic-organic hybrid film structure with reversible electroswitchable fluorescence property

A novel inorganic-organic hybrid film structure based on polyoxometalate and conventional organic dye has been fabricated, whose fluorescence can be reversibly switched using the electrochromic component to activate or suppress the related fluorescence quenching mechanism upon applying reduction or oxidation potentials of polyoxometalates.     

Statefinder Diagnostic in Generalized Chaplygin Gas Model with and Without Viscosity

Statefinder diagnostic is a useful method which can distinguish one dark energy model from the others. In this paper, we apply this method to the GCG model with and without viscosity. It is shown that the evolving trajectory of the viscous GCG model in the s–r diagram is not only quite different from the model without viscosity but also different from other dark energy models.     

基于环形栅和半环形栅N沟道金属氧化物半导体晶体管的总剂量辐射效应研究

在商用0.35 μm互补金属氧化物半导体工艺上制备了两种栅氧化层厚度(t_ox)的条形栅、环形栅和半环形栅N沟道金属氧化物半导体 (n-channel metal oxide semiconductor, 简记为NMOS) 晶体管, 并进行了2000 Gy(Si)的总剂量辐射效应实验. 实验结果显示, 栅氧厚度对阈值电压漂移的影响大于栅氧厚度的3次方. 对于t_ox为11 nm的低压NMOS晶体管, 通过环形栅或半环形栅的加固方式能将其抗总剂量辐射能力从300 Gy(Si)提高到2000 Gy(Si)以上; 而对于t_ox为26 nm的高压NMOS晶体管, 通过环栅或半环栅的加固方式, 则只能在低于1000 Gy(Si)的总剂量下, 一定程度地抑制截止漏电流的增加. 作为两种不同的版图加固方式, 环形栅和半环形栅对同一t_ox的NMOS器件加固效果类似, 环形栅的加固效果略优于半环形栅. 对于上述实验结果, 进行了理论分析并阐释了产生这些现象的原因. 关键词： 环形栅 半环形栅 总剂量 辐射效应