Study on Reaction of α‐Benzoylhemithioacetal with Alkylamines

α‐Benzoylhemithioacetal (1) reacted with alkylamines under mild conditions to give 2‐alkylamino‐2‐thiomethyl acetophenones (3) in good yields.     

二元超晶格弹性应力的能带理论计算

根据量子能带理论 ,采用经验赝势方法 ,对 (Pb) n/ (Bi) n,(Al) n/ (As) n 的假想简立方二元超晶格结构的弹性应力进行了计算 .结果表明弹性应力随超晶格周期λ的增加而迅速升高至一定大小后趋于稳定 ,且只有在周期较小时才同过渡金属氮化物超晶格硬度随周期的变化的趋势定性一致 ,为超晶格硬度随周期的变化提供了一种可能的解释     

Determination of asperosaponin VI in rat plasma by HPLC‐ESI‐MS and its application to preliminary pharmacokinetic studies

Asperosaponin VI (also named akebia saponin D) is a typical bioactive triterpenoid saponin isolated from the rhizome of Dipsacus asper Wall (Dipsacaceae). In this work, a sensitive high‐performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC‐ESI‐MS) assay has been established for determination of asperosaponin VI in rat plasma. With losartan as the internal standard (IS), plasma samples were prepared by protein precipitation with methanol. Chromatographic separation was performed on a C₁₈ column with a mobile phase of 10 mm ammonium acetate buffer containing 0.05% formic acid–methanol (32 : 68, v/v). The analysis was performed on an ESI in the selected ion monitoring mode using target ions at m/z 951.4 for asperosaponin VI and m/z 423.2 for the IS. The calibration curve was linear over the range 3–1000 ng/mL and the lower limit of quantification was 3.0 ng/mL. The intra‐ and inter‐assay variability values were less than 9.5 and 7.8%, respectively. The accuracies determined at the concentrations of 3.0, 100.0, 300.0 and 1000 ng/mL for asperosaponin VI were within ±15.0%. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of asperosaponin VI. Copyright © 2009 John Wiley & Sons, Ltd.     

A Novel Tandem Reaction for the Synthesis of Thieno[2,3-C] Pyrazole

Instudyonnewpharmaceuticalsandagrochemicals,theapplicationofheterocyclesisaveryimportantmethod,whichcanimprovethebiologicalactivities.Intheseyears.moreandmorenewagrochemicalshavebeensynthesizedwhichhavethestructurescontainingheterocycles.especiallypy...     

Studies on Chem icalCom position ofIron-m olybdenum Cofactor fromNitrogenase by Fluorescence Analysis

ＩｎｔｒｏｄｕｃｔｉｏｎＮｉｔｒｏｇｅｎａｓｅｆｒｏｍａｖａｒｉｅｔｙｏｆＮ２－ｆｉｘｉｎｇｏｒｇａｎｉｓｍｓｉｓｃｏｍｐｏｓｅｄｏｆｔｗｏ－ｃｏｍｐｏｎｅｎｔｐｒｏｔｅｉｎ，ＭｏＦｅ－ｐｒｏｔｅｉｎａｎｄＦｅ－ｐｒｏｔｅｉｎ．Ｆｅ－ｐｒｏｔｅｉｎｃｏｎｔａｉｎｓａｓｉｎｇｌｅＦｅ４Ｓ４－ｃｌｕｓｔｅｒ，ｗｈｉｃｈｈａｓｔｈｅｆｕｎｃｔｉｏｎｏｆｔｒａｎｓｆｅｒｉｎｇｅｌｅｃｔｒｏｎｓｆｒｏｍｄｏｎｏｒｔｏＭｏＦｅ－ｐｒｏｔｅｉｎ．ＭｏＦｅ－ｐｒｏｔｅｉｎｃｏｎｔａｉｎｓＰ－ｃｌｕｓｔｅｒｐａｉ…     

A New Rearrangement Reaction of 2-Phenyl Substituted Benzothiazepine with Ethoxycarbonyl Carbene─Mechanism of the Reaction and Structure of the Product

Intheprevi0usaFticlesl-2wehavereportedthatthereacti0n0fbenz0diazepinewithethoxycarbonylcarbenemayobtainnormal[2 l]cycIoadditi0npr0ductsregardlessthe2-substitUentismethyl0rphenyl.Howeverunderthesamec0nditi0nsthereaction0fbenzothiazepinewithethoxycarbonylcarbeneunderwentrearrangementreacti0n.Forexample,whenthe2-substituentismethyl,thereacti0nofbenzothiazepinewithethoxycarbonylcarbenegivearing-openingproductIIatroomorhightemperature'.Whenthe2-substituentisphenyl,weunexpectedlyfoundan0thernewrea…     

A New Lignan Glucoside from Lancea tibetica

L.tibeticaHook.f.etThorns.isanimportantTibetanmedicineusedfortreatmentofmanydiseases'.Thelignanglycosidesandtriterpenesfromthisplanthavebeenreported"'byHuidiZhangetal.ThispaperdescribesthestructureelucidationofanewIignanglucoside,namedtibeticosideA1...     

阴离子型芘基探针用于水体中对硝基苯胺的荧光检测

本研究利用阴离子型芘衍生物8-羟基芘-1,3,6-三磺酸三钠盐(HPTS),建立了一种快速、可视化的对硝基苯胺(PNA)荧光检测方法.检测原理主要是基于PNA通过非共价作用而导致的HPTS的荧光淬灭.通过测量加入PNA后HPTS在512 nm处荧光强度的变化,可以实现PNA的荧光检测.本方法的线性范围为10~120μmol/L,检出限(3σ/s)为4.6μmol/L.对本方法的抗干扰性以及方法的实际应用性进行了考察.结果表明,本方法具有低成本、高灵敏度、高选择性、操作简便等优点.     

Structure Evolution upon Uniaxial Drawing Skin‐ and Core‐Layers of Injection‐Molded Isotactic Polypropylene by In Situ Synchrotron X‐ray Scattering

The structure evolution of the oriented layer (skin) and unoriented layer (core) from injection‐molded isotactic polypropylene samples upon uniaxial drawing is probed by in situ synchrotron X‐ray scattering. The X‐ray data analysis approach, called “halo method”, is used to semiquantitatively identify the transformation process of crystal phase upon uniaxial drawing. The results verify the validation of the stress‐induced crystal fragmentation and recrystallization process in the deformation of the injection‐molded samples under different temperatures. Furthermore, the end of strain softening region in the engineering stress‐strain curves explicitly corresponds to the transition point from the stress‐induced crystal fragmentation to recrystallization process. Basically, the skin and core layers of the injection‐molded parts share the similar deformation mechanism as aforementioned. The stretching temperature which dramatically affects the relative strength between the entanglement‐induced tie chains and the adjacent crystalline lamellae determines the crystal structural evolution upon drawing. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1618–1631