简介：Theβ-carboxylicgroupplaysanimportantroleinthepeptideformation,esterificationandtheesterexchangeatthephosphorylgroupofN-phosphorylatedasparticacid.

简介：合成了二十个９羧基氧杂蒽类衍生物并通过ＣＩＭＳ和ＥＩＭＳ确定了所有化合物的结构。初步的药理实验表明部分化合物具有明显的抗痉挛作用

简介：PolyvinylChloridereactedwithchlorosulfonicacidtofromapolymercatalystPVC-SO3H.Thispolymercatalystwasfoundtohavehighactivityforresterificationreactionbetweencarboxylicacidsandalcohols.Thispaperdealswiththeconditionsinsynthesisofn-butlyacetatecatalyzedwithPVC-SO3H.ThePVC-SO3Hwasusedasacatalystforpreparing11estersofaceticacid,propionicacidandbutyricacidwiththeyieldsof82-92%.

简介：Thestudyonretentionbehaviorinsupercriticalfluidchromatography(SFC)isnecessarytounderstandthemechanismofthevariousinteractionsinSFC.TheretentionofSFCincarboxylicacidmethylester/polymethylsiloxane/CO2systemwasstudiedsystematicallyandtheretentionbehaviorofthiskindofcompoundsundervarioustypicaloperationconditionswasdescribedusingthemethodofanalternativeunifiedtheoryofchromatographicretention.Theresultsillustratedthatexpression:Ink.=a+b/T+cp+dp/T+ep2/Tcanbeusedtodescribequantitativelytheretentionbehaviorofcarboxylicacidmethylester/polymethylsiloxane/CO2systemintherangesofreduceddensityfrom0.549to1.411.Itwasalsofoundthattheentropyofsoluteinstationaryphaseisdependentonthedensityofsupercriticalfluid(SF)undertypicaloperatingconditionsofSFC.

简介：为从经由1,3-dimethylbenzimidazolium盐的相应的羧基的酸的脂肪族的醛的准备的一个新奇合成方法被提供。1,3-Dimethylbenzimidazolium盐很快与钠/乙醇然后hydrolyzed被减少与盐酸获得脂肪族的醛，1,3-dimethylbenzimidazolium在腌的酸能乐意地从相应的羧基的酸被完成。为有钠/乙醇的1,3-dimethylbenzimidazolium盐的减少的反应的机制被讨论。

简介：Gemfibrozilisawidelyusedlipidmodifyingdrugwithwell-establishedhypolipidemicandanti-atheroscleroticbenefits;however,thepresenceofacarboxylicacidmoietyinitsstructureisresponsibleforsideeffectsinthegastrointestinaltract.Theprincipleofbioisosterismwasappliedtodesignderivativesreplacingthecarboxylicacidgroup.Thecarboxylicacidgroupwasreplacedwithbioisotericgroups,suchas1,2,4-triazole-3-thiolandhydroxamicacid.Thederivativeswerethensynthesized,characterized,andevaluatedinratsforreducedgastrointestinalirritationandhypolipidemiceffects.Gemfibrozilwasusedasstandardforcomparison.Thederivativesdemonstratedlessgastricirritationandretainedhypolipidemiceffects,howeverthehypolipidemicaffectsweresignificantlylessthanthatofGemfibrozil.TheresultsofthisstudyoffersadirectionforfurtherresearchontheapplicationofbioisosterismforthedesignofnewderivativesofGemfibrozilandotherfibricacidderivatives.

简介：ThesupportedPtcatalysts(1wt%)werepreparedbytheincipientimpregnationmethodandanalyzedusingsynchrotron-basedX-raydiffraction,BETsurfacearea,oxygenadsorption,COpulsechemisorption,temperature-programmeddesorption(TPD)ofaceticacid,H2-TPD,NH3-TPD,O2-TPD,andH2-TPR.ThereactivityofPt-basedcatalystswasstudiedusingafixedbedreactorat300Cand4MPaforhydrodeoxygenationofaceticacid,wherePt/TiO2wasveryselectiveforethaneproduction.TPDexperimentsrevealedthatseveralconditionsmustbesatisfiedtoachievethishighselectivitytoethanefromaceticacid,suchasPtsites,moderateacidity,andmediummetal-oxygenbondstrengthintheoxidesupport.Thisworkprovidesinsightsindevelopingnovelcatalyticmaterialsforhydrocarbonproductionsfromvariousorganicsincludingbio-fuels.

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简介：由包含微生物引起的整个房间的催化剂的RhodococcuserythropolisAJ270，nitrilehydratase和amidase催化，在10点

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简介：二个Schiff底转移忍受morpholine戒指的方面链的金属建筑群，这被报导了被综合并且描绘，并且有一样的二建筑群基于代理人但是不同金属离子在这份报纸在p-nitrophenylpicolinate的催化水解作用被用作假装的hydrolase。PNPP催化水解作用的机制被结果建议并且支持光谱分析和运动计算。一个运动数学模型，适用于计算运动并且PNPP催化水解作用的热力学参数，在建议的机制的基础上被建立了。学习的结果证明二建筑群在PNPP催化水解作用的PNPP催化水解作用，和率举办一项好催化活动随缓冲区解决方案的pH值的增加被增加并且由建筑群的金属离子的极化效果影响了。

简介：ThehighlydispersedPt–ReOX(x≤1)sitesca.0.5nminsizewereformedviaasuccessiveandstronginteractionoftheReprecursorwithtitaniaandthenofthePtcomplexwithdepositedlow-valentrheniumoxideclusters.Thesize,chargeandchemicalcompositionwerecharacterizedbymeansofHRTEM/STEMwithEDXmapping,XPS,andFTIRS.ThesesiteswithRe/Pt=2wereshowntobehighlyactiveandselectiveinthehydrogenationofcarboxylicacidtoalcoholunderverymildconditions(T=130°C,P=50bar).ThereactionrateconstantforthehydrogenationofhexanoicacidincreasedlinearlywiththePtcontent.Asforthehomogeneouspincer-typeRu-organiccomplexes,theactivePt–ReOXsitescandissociateheterolyticallythemolecularhydrogenwiththeformationofhydroxylgroupsandPthydrideforhydrogenationofthecarboxylicgroup.Indeed,TOFof20h-1andselectivityof98%–99%areapproachingthevaluestypicalofhomogeneouscatalysts.Thefirstorderkineticsdescribedwelltheexperimentaldataobtainedinawiderangeofreactionconditions.

简介：Ginkgoditerpenelactonesmeglumineinjection(GDLI)isacommerciallyavailableproductusedforneuroprotection.However,thepharmacokineticpropertiesoftheprototypesandhydrolyzedcarboxylicformsoftheprimarycomponentsinGDLI,i.e.,ginkgolideA(GA),ginkgolideB(GB),andginkgolideK(GK),haveneverbeenfullyevaluatedinbeagledogs.Inthiswork,asimple,sensitive,andreliablemethodbasedonultra-fastliquidchromatography-tandemmassspectrometry(UFLC-MS/MS)wasdeveloped,andtheprototypesandtotalamountsofGA,GB,andGKweredeterminedinbeagledogplasma.Theplasmaconcentrationsofthehydrolyzedcarboxylicformswerecalculatedbysubtractingtheprototypeconcentrationsfromthetotallactoneconcentrations.Forthefirsttime,thepharmacokineticsofGA,GB,andGKwerefullyassessedinthreeforms,i.e.,theprototypes,thehydrolyzedcarboxylicforms,andthetotalamounts,afterintravenousadministrationofGDLIinbeagledogs.Itwasshownthatginkgolidesprimarilyexistedinthehydrolyzedforminplasma,andtheratioofhydrolysatestoprototypeformsofGAandGBdecreasedgraduallytoahomeostaticratio.AllofthethreeformsofthethreeginkgolidesshowedlinearexposureofAUCtothedosages.GA,GB,andGKshowedaconstanthalf-lifeapproximately2.7,3.4,and1.2h,respectively,whichwereconsistentfortheformsatthreedoselevels(0.3,1.0,and3.0mg·kg~(-1))andafteraconsecutiveinjectionofGDLIfor7days(1.0mg·kg~(-1)).