异构体
- 与 异构体 相关的网络例句 [注:此内容来源于网络,仅供参考]
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Cephalotaxine ester of 2-oxo-6-methylheptanoic acid was treated with lithium diisopropylamide and Me O-(1-methoxyisopropyl)glycolate to give a mixture of homoisoharringtonine and its stereoisomers with 56% yield. The four stereoisomers separated by TLC showed identical mass spectra and almost superimposed IR but with different 1H NMR spectra. The configuration of the 2'-C and 3'-C of the four isomers were postulated based upon their 1H NMR spectra as compared with the 1H NMR spectra of isoharringtonine and its stereoisomers.
2-氧代-6-甲基庚酰基三尖杉碱(3)与0-(1-甲氧基异丙基)羟基乙酸甲酯(4)在强碱性试剂二异丙胺锂存在下,起亲核加成反应,反应中间体5在室温用酸性丙酮水解,得到一种新的三尖杉酯类生物碱一一高异三尖杉酯碱(6c)及其立体异构体(6a、6b、6d)的混合物,产率56%、通过制备薄层层析分得这四个立体异构体,它们的1H NMR和异三尖杉酯碱及其立体异构体的1H NMR类似,推定了它们的绝对构型。
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The results indicate that thermal stabilities and decomposition mechanisms of the title compounds derived from the BDE, Ea and static electronic parameters are basically consistent. Homolysis of the N—NO2 bond is the initial step in the thermolysis of the title compounds, the meta-isomers are more stable than the para-isomers, and the ortho-isomers are the most sensitive.
结果表明,由BDE、Ea和静态电子结构参数推断的标题物热稳定性和热解机理的结论基本是一致的,N-NO2键均裂是标题物的热解引发步骤,间位取代异构体较对位取代异构体稳定,而邻位取代的异构体稳定性最差。
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It has been shown that tautomerism has a significant effect on the QSAR modelling, and the models obtained from 1H-indazol tautomeric form always represent higher quality than those from 2H-indazol tautomer, which indicates that 1H-indazol tautomer of the indazolyl urea is probably the active form when binding with the TRPV1 channel protein. It has also been demonstrated that the theoretical descriptors derived from electrostatic potentials on molecular surface together with the GETAWAY descriptors can be well used to express the quantitative structure-activity relationship of indazolyl urea TRPV1 channel antagonists.
结果表明:互变异构对QSAR结果具有一定的影响,采用1H-吲唑异构形式得到的模型,在质量上均高于采用2H-吲唑异构体,预示着1H-吲唑异构体更有可能是吲唑脲类分子的活性异构形式;分子表面静电势参数结合GETAWAY参数可以较好地用于描述TRPV1通道拮抗剂分子结构与其活性间的定量关系。
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A computational result of RHF/LANL2DZ optimized structure and total energy shows that the isomers with C H…π structure have lower total energy, and that stability and isomeric preference of isomer are related to the C H…π interaction in the isomer.
用 RHF/LANL2DZ对该体系可能的异构体进行结构、能量优化,可能形成C—H…π相互作用的异构体具有较好的稳定性。C—H…π相互作用对含吡啶环的[CoN5Cl]^2+系配合物的异构体的选择性形成及其稳定性具有重要作用。
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The calculated results show that the X3+ cations each has two stable structures: the regular trigon(D3h) and the line with the regular trigon(D3h) being the ground state, while for three neutral X3Cl clusters, Sc3Cl has three stable isomers: the trigon-pyramidal(C3v), bidentate(C2v-1), and C2v-2 structures, Y3Cl and La3Cl each has only two stable isomers: the trigon-pyramidal(C3v) and bidentate(C2v-1) structures.
计算结果表明,三个X3+阳离子有两个稳定异构体:正三角型(D3h)和线型,其中正三角型为基态;对于三个中性的X3Cl团簇,Sc3Cl 有三个稳定的异构体:三角金字塔型(C3v)、双齿型(C2v-1)和 C2v-2型(图 1 e);Y3Cl 和 La3Cl有2个稳定的异构体:三角金字塔型(C3v)和双齿型(C2v-1)。
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RESULT: 1.Ouabain act on lens sodium-pump,under the LM,lens anterior capsular membrane discontinuous,epithelium cells clustered,occluding zonule seperated,lens fiber layers fractured.Under the EM,cells totally hollowed,mitochondria swelling,myelin figure appeared.RT-PCR examine the expression condition of αsubunit of sodium pump on mRNA level,α1、α2 and α3-isoform are all decreased.2.Digoxin act on lens sodium-pump,under the LM,lens cell oedema,linkage distructed,extensive exfoliation.Under the EM,plasma appeared little half-transparant hollow region,mitochondria swelling and ridge disappeared. RT-PCR examine,α1、α2 and α3-isoform are all decreased.3.Amphotericin B act on lens sodium-pump,under the LM,lens epithelium cells linked tightly,arranged in-line,lens fiber layers arranged tightly and regularily.Under the EM,abbundant cellular organes,exuberant cells function indicated. RT-PCR examine the expression condition of αsubunit of sodium pump on mRNA level,α1 and α3-isoform are increased significantly,demonstrated isoform-specific action.4D-thyroxine act on lens sodium-pump,under the LM,lens plasmalemma integrated,cells arranged tightly and regularily.Under the EM,nucleus fission appeared,desmosome half-desmosome and tensile microfilaments linked the cells. RT-PCR examine,α2 and α3-isoform are increased, also demonstrated isoform-specific action.5.Vitamin E act on lens sodium-pump,under the LM,lens anterior capsular membrane continuous and smooth,epithelium cells tightly linked,lens fiber layers appearede hollow region occasionally.Under the EM,lateral membrane high density belt appeared,abundant nucleolus. RT-PCR examine,onlyα1-isoform are increased, demonstrated significantly isoform-specific action.6.DMSO act on lens sodium-pump,under the LM,lens anterior capsular membrane slightly thicker,cells linkage partly distructed.Under the EM,plasmalemma denaturation,mitochondria swelling.RT-PCR examine,α1、α2 and α3-isoform are all altered slightly and haven't significant meanning.
结果:1、哇巴因作用于晶状体钠泵后,光镜下晶状体前囊膜断裂、上皮细胞聚积、闭合连接分离、纤维板层裂隙,电镜下全层细胞空泡化、线粒体肿胀出现髓样结构,RT-PCR法检测晶状体钠泵α亚单位α1、α2及α3三种重整异构体在mRNA水平的表达均减弱。2、地高辛作用于晶状体钠泵后,光镜下晶状体细胞水肿、细胞连接破坏、广泛剥离,电镜下胞质见少许半透明空化区、线粒体肿胀嵴消失,RT-PCR法检测晶状体钠泵α亚单位α1、α2及α3三种重整异构体在mRNA水平的表达均减弱。3、两性霉素B作用于晶状体钠泵后,光镜下晶状体上皮细胞紧密连接、线状排列、纤维板层紧密规整,电镜下细胞器丰富、细胞功能旺盛,RT-PCR法检测α1及α3表达显著增强、具有一定的重整异构作用特异性。4、D甲状腺素作用于晶状体钠泵后,光镜下晶状体质膜完整、细胞排列紧密规整,电镜下胞核见分裂像、细胞间有桥粒、半桥粒及张力微丝,RT-PCR法检测α2及α3表达均增强、亦有一定的重整异构作用特异性。5、维生素E作用于晶状体钠泵后,光镜下晶状体前囊膜连续光滑、上皮细胞紧密连接、纤维板层偶见空化,电镜下囊侧膜内有高电子密度带、细胞核仁丰富,RT-PCR法检测仅有α1的表达显著增强、具有极强的重整异构作用特异性。6、二甲基亚砜作用于晶状体钠泵后,光镜下晶状体前囊膜轻度增厚、细胞连接部分破坏,电镜下质膜变性、线粒体肿胀,RT-PCR法检测晶状体钠泵α亚单位α1、α2及α3三种重整异构体在mRNA水平的表达无显著改变。
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In this thesis,the AM1,MNDO,MINDO/3(mainly AM1)and INDO/S-CI semiempirical MO methods were used toinvestigate the excited-state intramolecular protontransfer reactions of salicylic acid derivatives—salicylic acid,methyl salicylate,salicylaldehyde,o-hydroxyaceto-phenone,salicylamide and 3-hydroxy-picolinamide (6 conformers and 2-3 anion species);2-(2'-hydroxy-5' methylphenyl) benzotriazole(4 conformers),2-(2' hydroxyphenyl) benzimidazole (3 conformers and 3anion species),Bis-2,5-(2-benzoxazolyl)hydroquinone(3 conformers),2-(2'-hydroxyphenyl)benzothiazole(2conformers) and 7-azaindole dimer (2 conformers).Theinvestigations were described as follows.Geometry optimization,relative stability andhydrogen bonding energy First,for sylicylic acid derivative molecules,the AM1,MNDO and MINDO/3 methods were used toinvestigate ground-state geometry optimization,energies,relative stabilities and hydrogen-bondingenergies on the five kinds of the molecules(designing 6 conformers and 2-3 anion species).Comparing with experimental data,the optimizedgeometry,the order of stability,the hydrogen-bonding energies and the distances between O-O in O-H..O hydrogen bonds by AM1 method were in agreementwith the experimental data,however,the C-C bondlengths optimized by MNDO and MINDO/3 were longer,C-O and O-H bond lengths were shorter;for C-N bondlengths,the results opitimized by MNDO method werethe same as those by AM1 method,nevertheless the C-Nbond lengths given by MINDO/3 method were muchshorter.For some sylicylic acid derivatives(e.g.methyl salicylate,salicylamide),the order ofstabilities on the conformers given by MNDO andMINDO/3 methods were not in agreement with theexisting conformers deduced by experimental methods,and the hydrogen bonding energies calculated by MNDO.and MINDO/3 methods were smaller.Second,the studyon the other systems found that the optimizedgeometry of the proton-transfered product with INDOmethod could not be obtained,only could theoptimized geometry of reactant be obtained,and thecalculated hydrogen bonding energies were greater.Many results of calculation indicated that the studyon the excited-state intramolecular proton transferreaction system using AM1 method was suitable andreliable.
本论文用AM1、MNDO、MINDO/3(主要是AM1)和INDO/S-CI半经验分子轨道方法对水杨酸衍生物系列——水杨酸、水杨酸甲酯、水杨醛、O-羟基乙酰苯酮、水杨酰胺和3-羟基吡啶酰胺(6种异构体和2-3种阴离子);2-(2'-羟基-5'-甲基苯基)苯并三〓唑(4种异构体);2-(2'-羟基苯基)苯并咪唑(3种异构体和3种阴离子);2,5-二间氮杂氧茚氢醌(3种异构体);2-(2'-羟基苯基)间〓杂硫茚(2种异构体)和7-〓吲哚二体(2种异构体)的激发态分子内质子转移反应在以下几个方面进行了较系统的理论研究:几何构型优化和相对稳定性及氢键能首先以水杨酸衍生物系列分子为例,用AM1、MNDO和MINDO/3方法考察了5种分子(每种分子设计6种异构体和2-3种阴离子)的基态几何构型优化,能量、相对稳定性和氢键能计算,通过和实验数据进行比较,AM1方法给出的优化几何构型、稳定性次序、氢键能和O—H。。。O氢键的0—0距离与实验数据吻合最好,MNDO和MINDO/3方法优化的C-C键长偏长,C-O键和O-H键长偏短;对于C-N键长,MNDO和AM1优化结果差别不大,而MINDO/3给出了过短的C-N键长,MNDO和MINDO/3方法给出的有些水杨酸衍生物分子(如水杨酸甲酯和水杨酰胺)异构体的稳定性次序和实验上推测的可存在异构体结果不一致,MNDO和MINDO/3方法给出的氢键能偏低,对其他体系的研究发现INDO方法常常不能得到质子转移产物的优化几何构型,只能得到反应物的优化构型,并且估算的氢键能偏高,大量的计算结果表明AM1方法对本论文研究的激发态分子内质子转移反应体系是适宜和可靠的。
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In addition ,nine new O,O-dialkyl-[α-(1,3,4,6-tetraacetyl-2-deoxy-β-D-glucoamino)-p-methyl benzlidene] phosphonatesand eight O,O-dialkyl-α-(2-deoxy-D-glucoamino)-p-methyl benzylidene phosphonates were prepared. The 〓 and〓 spectra of Ⅰ-Ⅴ compounds indicated clearly that each of Ⅰ-Ⅴ compounds contains two diastereo-isomers.
我们对非对映异构体的分离方法进行了研究,并分离得到了五个单一构型的异构体〓、〓、〓、〓和〓,培养出了〓、〓和〓三个异构体的单晶,通过X-射线衍射分析,确定了〓、〓和〓三个异构体的绝对构型,反应过程中引入的手性原子的构型均为R构型。
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Keywords hypophosphorous acid;thiol isomer thione isomers;enantiomer;proton transfer;isomerization reaction
单硫代次膦酸;硫酮式异构体;硫醇式异构体;对映异构体;质子转移异构化
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Rresults from those studies can be summariazed as follow:(1) A preliminary study no correlationship between the UV-VIS reflection spectrum of tomato fruit surface and the lycopene amount of tomato fruit was undertaken. Based on observation from this study, a damage-free and in-situ detection technique of lycopene amount from tomato was developed with UV-VIS reflection spectroscopy;(2) The geometrical isomers of lycopene were separated successfully on C30-HPLC-PDA-ELSD. The absorption coefficients of Z-isomers were consequently dedermined. The geometrical isomer composition of lycopene could therefore be assessed. Those efforts formed a solid base to identify the natural product from synthetic compound of lycopene;(3) Lycopene resource from the fruit of Autumn oliver was proved to be available for industrial application. An extraction methos of lycopene from the fruit of Autumn oliver by supercritical carbon dioxide was developed at laboratory scale;(4) A method to extract lycopene by supercritical liquid with improved efficiency was developed; Data from this investigation suggested that a proper raw material pre-extraction process was important for a better extraction efficiency;(5) Variation in the geometrical isomer composition of lycopene during its metabolish in rat was assessed. A large amount of Z-isomers were observed. This variation took place in serum;(6) The absorption rate and accumulation in serum of natural lycopene in rat were assessed;(7) Ability to quench singlet oxygen by different geometrical isomers of lycopene was compared;(8) It was detected that whether natural lycopene had functions to regule blood-lipids and LDL antioxidation;(9) A C31 degradation piece of lycopene was found in the prostate gland of rat.
研究结果包括:[1]应用UV-VIS反射光谱法建立了番茄果实中番茄红素含量的无损伤、现场检测技术;[2]应用C30-HPLC-PDA-ELSD技术实现了对番茄红素几何异构体的分离,测定了不同顺式异构体的吸光系数,建立了天然番茄红素几何异构体组成的检测方法,为区分和鉴定人工合成品和天然产物奠定了基础;[3]证实了秋橄榄果实中的番茄红素资源具有工业开发价值,并建立了超临界CO_2萃取的实验室方法;[4]探索了提高番茄红素超临界流体萃取效率的方法,证明了物料前处理对提高萃取效率起了极其重要的作用;[5]观察了番茄红素在大鼠体内几何异构体组成的变化情况,发现了大量顺式异构体的存在,并证实了几何异构体组成在血清中发生了显著变化;[6]测定了天然番茄红素在大鼠体内的吸收率和在大鼠血清中的动态积累规律;[7]比较了不同番茄红素几何异构体淬灭单线态氧的能力;[8]检测了天然番茄红素是否具有调节血脂作用和抗低密度脂蛋白氧化的功能;[9]首次发现大鼠前列腺内存在番茄红素C31降解片段,并证实其仍具有淬灭单线态氧的能力。
- 推荐网络例句
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This one mode pays close attention to network credence foundation of the businessman very much.
这一模式非常关注商人的网络信用基础。
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Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.
扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。
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There is no differences of cell proliferation vitality between labeled and unlabeled NSCs.
双标记神经干细胞的增殖、分化活力与未标记神经干细胞相比无改变。