简介：bicyclo[2.2.2]与在C-8和C-9的一枚内酯的戒指，atisine类型C20-diterpenoid碱，辛烷C/D戒指系统成功地被综合，用氧化dearomatization/intramolecularDielsAlder反应。

简介：用复合酶法对大蒜多糖的提取工艺进行研究，并考察了不同浓度沉淀多糖的抗氧化活性；以多糖提取得率为指标，苯酚一硫酸法测定多糖的总糖含量，采用正交实验确定纤维素酶、木瓜蛋白酶和果胶酶的最佳配比，然后在单因素试验的基础上，采用正交实验优化复合酶提取大蒜多糖的最佳工艺；分别用羟基自由基（·OH）和1-二苯基-2-苦基肼基（DPPH·）有机自由基测定了大蒜多糖的抗氧化活性．复合酶法提取大蒜多糖的最佳酶配比：纤维素酶、木瓜蛋白酶、果胶酶的配比为1：60：5；最佳提取工艺条件：提取温度为55℃，提取时间为90min，pH值为4，料液比为1：30g／mL，该工艺条件下多糖提取得率达74．28％；80％的乙醇沉淀多糖对DPPH·和·OH的清除作用最显著，40％次之，粗多糖最弱．复合酶法提取大蒜多糖具有提取得率高的优点，并且大蒜具有一定的抗氧化作用．

简介：CarbonsupportedPt(Pt/C)electrocatalystswerepreparedwithglucoseasprotectionagentandNaBH4asreductant.ThePtnanoparticlesdepositedoncarbonsupportpresentedreducedsizeandwelldispersityattributedtotheprotectioneffectofglucose.GlucoseabsorbedontheparticlesurfacewasreadilyremovedbywaterwashingwithoutleadingtoagglomerationofthePtnanoparticles.Theas-preparedPt/Celectrocatalystsshowedimprovedmassactivityformethanolelectrooxidationcomparedtothecatalystpreparedwithoutglucoseprotection.TheimprovedperformanceisattributedtothelargerelectrochemicalactivesurfaceareathusincreasedactivesitesonthePt/Celctrocatalystspreparedundertheprotectionofglucose.

简介：Twooxo-vanadium(IV)complexes,[VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1)andVO(C2O4)(phen)(H2O)(2),where2,2′-bipy=2,2′-bipyridyl,phen=1,10-phenanthroline,weresynthesizedaspotentialfunctionalmodelsofvanadiumhaloperoxidases(VHPOs)inmixedsolventofethanolandwateratroomtemperature.Thecomplexeswerecharacterizedbyelementalanalysis,infrared(IR),UV-VisandX-raycrystallography.Structuralanalysesshowedthatvanadiumatomwascoordinatedbyaterminaloxygen,oneoxygenatomfromcoordinatedwater,twooxygenatomsfromthecarboxylategroupofoxalicacid,andtwonitrogenatoms(N1andN2)from2,2′-bipy/phen.Centralvanadiumatomsincomplexes1and2werebothinadistorted-octahedralenvironment,andsomeintermolecularhydrogenbondinglinkageswerealsoobservedineachcomplex.BrominationreactionactivityofthetwocomplexeswasevaluatedwithphenolredasorganicsubstrateinthepresenceofH2O2,Br-andphosphatebuffer,indicatingthattheycanbeconsideredasapotentialfunctionalmodelofVHPO.Inaddition,thermalanalysiswasalsoperformedanddiscussedindetail.

简介：1IntroductionFullerenehasreceivedconsiderableattentionandagreatresearchinginterestduetoitsuniquestructureandinterestingproperties[1-3].Manyfunctionalgroupshavebeenintroduced,oftenregion-orstereo-selectively,fortuningthephysicalpropertiesofC60andforconstructingsupramoleculararchitectures[4-6].AmongallkindsofC60derivatives,thediseoticmolecule-substitutedC60derivativesshowinterestingproperties,especially,liquidcrystalproperties.Uptonow,fewC60derivativeswithdiscotic-moleculargroupsandtheirliquidcrystalpropertieshavebeenstudied.In1996,Deschenauxetal.[7]reportedthefirstmesomorphicC60-ferrocenederivative.Tianetal.[8]synthesizedaC60-perylenederivativein2004.Nakanishietal.[9]preparedaseriesofuncommonliquidC60derivativeswith2,4,6-tris(alkyloxy)benzalgroupsin2006.Lately,Geertsetal.[10]describedthesynthesisofmesogenicphthalocyanine-C60.

简介：应用ABEEMσπ/MM方法,对乙酰胆碱酯酶抑制剂Tacrine（塔克宁）与组胺转甲基酶进行了分子对接.然后对乙酰胆碱酯酶与4种乙酰胆碱酯酶抑制剂的分子对接进行了研究.在研究中将受体分子固定,配体分子可自由移动,采用半柔性对接方式.通过对4种乙酰胆碱酯酶抑制剂与乙酰胆碱酯酶结合能大小的计算,得到结合能力大小顺序依次为：Donpezil（多奈哌齐）〉Huperzine（石杉碱甲）〉Rivastigmine（利发斯的明）〉Tacrine（塔克宁）.这个顺序与实验中得到的乙酰胆碱酯酶（AChE）抑制活性IC50值大小顺序相一致.为使用该方法进行抑制剂设计提供参考.

简介：Quartzcrystalmicrobalance(QCM)andcyclicvoltammetry(CV)wereusedtocharacterizethemonolayerofcytochromec(Cytc),whichwasadsorbedongoldfilmmodifiedwithalkanethiolmixedmonolayer.AdirectcomparisonofproteinsurfacecoveragescalculatedfromQCMandcyclicvoltammetricmeasurementsillustratesthattheratiooftheelectroactiveCytctothetotalsurface-confinedCytcis34%,whichsuggeststhattheorientationisamainfactoraffectingtheelectroactivityofCytc.Moreover,surfaceplasmonresonance(SPR)measurementcombinedwithCV'insitu'wasusedtoinvestigatetheconformationalchangeofCytcintheredoxprocess.Besides,Aunanoparticles(AuNPs)wereadsorbedonthesurfaceofCytc.TheresultindicatesthatAuNPspromoteelectrontransferbetweenCytcandthegoldelectrode,andSPRresultsuggestsAuNPsenhanceSPRsignal.

简介：应用量子化学从头计算和密度泛函理论（DFT）对HO2＋C2H2反应体系的反应机理进行了研究.在B3LYP/6-311G＊＊和CCSD（T）/6-311G＊＊水平上计算了HO2＋C2H2反应的二重态反应势能面.计算结果表明,主要反应方式为自由基HO2的H原子和C2H2分子中的C原子结合,经过一系列异构化,最后分解得到主要产物P1（CH2O＋HCO）.此反应是放热反应,化学反应热为-321.99kJ.mol-1.次要产物为P2（CO2＋CH3）,也是放热反应.

简介：基于中空纤维液相微萃取技术，建立了体液中血管紧张素转化酶抑制剂的离子色谱分析方法。采用中空纤维液相微萃取和离子色谱联用技术，对中空纤维萃取条件进行优化，优化的萃取条件为以正辛醇为萃取溶剂，供体相中pH值为6．0，在供体相中未添加NaCl，接受相为HCI（0．01mol／L），萃取时间为50min，搅拌速度为430r／min。雷米普利、盐酸贝那普利、盐酸喹那普利和福辛普利钠的富集系数分别为10．8、15．5、12．2和20．8倍。方法操作简单，环境友好，提高了离子色谱检测芳香胺类物质的灵敏度。