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辅酶NAD(P)H在生物体内起着重要的调节作用, 已引起了有机化学工作者极大的兴趣, 尤其是在还原反应的立体选择性上, 人们已经开展了大量的研究工作. 讨论了NAD(P)H模型分子进行立体专一性还原反应的影响因素, 并对NAD(P)H模型分子的研究工作做了总结. 相似文献
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报道了5种N-芳基芴亚胺在酸性条件下被烟酰胺辅酶模型(Hantzsch酯,BNAH)还原的反应。结果表明:亚胺的结构、酸的强度以及溶剂的不同均会影响亚胺的还原效率,本文结合反应的结构效应、溶剂效应和同位素效应,对其可能的酸催化氢负离子转移机理进行了讨论。 相似文献
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辅酶NAD(P)H在生物氧化还原反应中起着重要作用[1].1-苄基-1,4-二氢尼古丁酰胺(BNAH)作为其模型物,被广泛用于物理有机和生物化学的研究之中[2].虽然绝大多数的研究都集中于还原反应机理方面[3,4],BNAH作为还原剂在有机合成中的应用也是值得注意的.我们曾用BNAH还原2-溴-1-苯亚乙基丙二腈及其类似物合成取代环丙烷[5~7],方法简便.五元环结构广泛存在于萜类和甾体等天然产物中.对于茚等苯并五元环结构的合成已有许多方法[8~11]. 其中,2,2-双取代1,2-二氢茚(1)(吸电子取代基)是用邻-二溴甲基苯与丙二腈等活泼亚甲基化合物在DMSO中,NaH存在下双分子缩合制备的[12]. 相似文献
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A facile approach to chiral dihydroquinazolinone derivatives has been described via biomimetic asymmetric reduction of quinazolinones with chiral and regenerable NAD(P)H models. The utility of this method was demonstrated by a concise synthesis of the bromodomain protein divalent inhibitor. 相似文献
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合成了一系列3酰胺基氮取代的NAD(P)H模型物,测定了其与5硝基异喹啉正离子的二级反应速率常数,并与模型物的氧化还原电势进行了比较.实验结果表明,模型物3位酰基氧一方面可离域二氢吡啶环上N的电子;另一方面负电性的3位酰基氧在反应过渡态中又可引起分子内和分子间的两种静电作用;3位酰基的电子效应对模型物动力学反应性的影响是这两种效应综合作用的结果. 相似文献
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Oleg A. Raitman Andrei B. Kharitonov Maya Zayats Eugenii Katz Itamar Willner 《Analytica chimica acta》2004,504(1):101-111
Crosslinked films consisting of the acrylamide-acrylamidophenylboronic acid copolymer that are imprinted with recognition sites for β-nicotinamide adenine dinucleotide (NAD+), β-nicotinamide adenine dinucleotide phosphate NADP+, and their reduced forms (NAD(P)H), are assembled on Au-coated glass supports. The binding of the oxidized cofactors NAD+ or NADP+ or the reduced cofactors NADH or NADPH to the respective imprinted sites results in the swelling of the polymer films through the uptake of water. Surface plasmon resonance (SPR) spectroscopy is employed to follow the binding of the different cofactors to the respective imprinted sites. The imprinted recognition sites reveal selectivity towards the association of the imprinted cofactors. The method enables the analysis of the NAD(P)+ and NAD(P)H cofactors in the concentration range of 1×10−6 to 1×10−3 M. The cofactor-imprinted films associated with the Au-coated glass supports act as active interfaces for the characterization of biocatalyzed transformations that involve the cofactor-dependent enzymes. This is exemplified with the characterization of the biocatalyzed oxidation of lactate to pyruvate in the presence of NAD+ and lactate dehydrogenase using the NADH-imprinted polymer film. 相似文献
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Dr. Kaiqing Ma He Yang Dr. Xingkang Wu Fangjun Huo Prof. Fangqin Cheng Prof. Caixia Yin 《Angewandte Chemie (International ed. in English)》2023,62(19):e202301518
NAD(P)H is crucial for biosynthetic reactions and antioxidant functions. However, the current probes developed for detecting NAD(P)H in vivo require intratumoral injection, which limited their application for animal imaging. To address this issue, we have developed a liposoluble cationic probe, KC8 , which exhibits excellent tumor-targeting ability and near-infrared (NIR) fluorescence after reaction with NAD(P)H. By using KC8 , it was demonstrated for the first time that the level of NAD(P)H in the mitochondria of living colorectal cancer (CRC) cells was highly related to the abnormality of the p53. Furthermore, KC8 was successfully used to differentiate not only between tumor and normal tissue but also between tumors with p53 abnormality and normal tumors when administered intravenously. Finally, we evaluated tumor heterogeneity through two fluorescent channels after treating a tumor with 5-Fu. This study provides a new tool for real-time monitoring of the p53 abnormality of CRC cells. 相似文献
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An improved procedure for the preparation of chiral NAD(P)H model, (SS)-1-benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine, with satisfactary chemical yield and excellent enantiopurity is reported. 相似文献
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Ubiquinone‐Rhodol (UQ‐Rh) for Fluorescence Imaging of NAD(P)H through Intracellular Activation 下载免费PDF全文
Dr. Hirokazu Komatsu Dr. Yutaka Shindo Prof. Dr. Kotaro Oka Dr. Jonathan P. Hill Prof. Dr. Katsuhiko Ariga 《Angewandte Chemie (International ed. in English)》2014,53(15):3993-3995
The nicotinamide adenine dinucleotide (NAD) derivatives NADH and NADPH are critical components of cellular energy metabolism and operate as electron carriers. A novel fluorescent ubiquinone‐rhodol derivative (UQ‐Rh) was developed as a probe for NAD(P)H. By using the artificial promoter [(η5‐C5Me5)Ir(phen)(H2O)]2+, intracellular activation and imaging of NAD(P)H were successfully demonstrated. In contrast to bioorthogonal chemistry, this “bioparallel chemistry” approach involves interactions with native biological processes and could potentially be used to control or investigate cellular systems. 相似文献
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Chiral NAD(P)H models are important reduction reagents in asymmetric synthesis. (S,)l-Benzyl-3-(p-tolylsulfinyl)-1,4 1 is one of these models, which canreduce carbonyl and unsaturated compound under mild conditions with highenantioselectivity'. An impressive example is that methyl benzoylformate is reduced byl in the presence of Mg= or Zn' to methyl (R)-mandelate with up to 97% e.e. at roomtemperature'. Our investigation' has shown that the reduction of allylic bromide by Iwithout Mg:* o… 相似文献
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The calculation of H + H2 system by symplectic quasiclassical trajectory (SQCT) shows that there are two types of collision trajectories A and B, i.e., type A trajectory passes the saddle point of transition state (TS), whereas type B trajectory does not pass the saddle point of transition state. Not all the reactants of type A trajectory are reactive, while not all of type B trajectory are nonreactive. The partition and reactivity of these two types of trajectories are affected by reactant state(R), furthermore, the types of trajectories affect the state and angle distributions of products. Not only the rudiment framework for theoretical study on state(R)-state(TS)-state(P) is established, but also the further understanding of transition state theory (TST) of Eyring is investigated in this paper. 相似文献
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《Analytical letters》2012,45(18):2025-2034
Abstract A highly sensitive bioluminescent assay of dehydrogenases was performed. NADH was produced by the catalytic action of alcohol and glucose-6-phosphate dehydrogenases and subsequently measured with high sensitivity by a bioluminescent assay using NAD (P) H : FMN oxidoreductase and luciferase from Photobacterium fischeri. The minimal amount of dehydrogenases that could be measured was 0.0055 amol (5.5 × 10?-21 mol). 相似文献
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Helmut Goesmann Eberhard Matern Jolanta Olkowska‐Oetzel Jerzy Pikies Gerhard Fritz 《无机化学与普通化学杂志》2001,627(6):1181-1184
Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXIII. Reactions of tBu2P–P=P(Me)tBu2 with (Et3P)2NiCl2 and [{η2‐C2H4}Ni(PEt3)2] tBu2P–P=P(Me)tBu2 ( 1 ) forms with (Et3P)2NiCl2 ( 2 ) and Na(Nph) the [μ‐(1,3 : 2,3‐η‐tBu2P4tBu2){Ni(PEt3)Cl}2] ( 3 ) as main product. Using Na/Hg instead as reducing agent the Ni0 compounds [{η2‐tBu2P–P}Ni(PEt3)2] ( 4 ), [{η2‐tBu2P–P=P–PtBu2}Ni(PEt3)2] ( 5 ) and [(Et3P)Ni(μ‐PtBu2)]2 ( 6 ) with four‐membered Ni2P2 ring result. [{η2‐C2H4}Ni(PEt3)2] yields with 1 also 4 . The compounds were characterized by 1H and 31P{1H} NMR investigations and 3 also by a single crystal X‐ray analysis. It crystallizes triclinic in the space group P 1 with a = 1129.4(2), b = 1256.8(3), c = 1569.5(3) pm, α = 72.44(3)°, β = 70.52(3)° and γ = 74.20(3)°. 相似文献
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《Acta Crystallographica. Section C, Structural Chemistry》2017,73(7):531-535
3‐Aminocarbonyl‐1‐benzylpyridinium bromide (N‐benzylnicotinamide, BNA), C13H13N2O+·Br−, (I), and 1‐benzyl‐1,4‐dihydropyridine‐3‐carboxamide (N‐benzyl‐1,4‐dihydronicotinamide, rBNA), C13H14N2O, (II), are valuable model compounds used to study the enzymatic cofactors NAD(P)+ and NAD(P)H. BNA was crystallized successfully and its structure determined for the first time, while a low‐temperature high‐resolution structure of rBNA was obtained. Together, these structures provide the most detailed view of the reactive portions of NAD(P)+ and NAD(P)H. The amide group in BNA is rotated 8.4 (4)° out of the plane of the pyridine ring, while the two rings display a dihedral angle of 70.48 (17)°. In the rBNA structure, the dihydropyridine ring is essentially planar, indicating significant delocalization of the formal double bonds, and the amide group is coplanar with the ring [dihedral angle = 4.35 (9)°]. This rBNA conformation may lower the transition‐state energy of an ene reaction between a substrate double bond and the dihydropyridine ring. The transition state would involve one atom of the double bond binding to the carbon ortho to both the ring N atom and the amide substituent of the dihydropyridine ring, while the other end of the double bond accepts an H atom from the methylene group para to the N atom. 相似文献
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[t-Bu2P]3P7 and (t-Bu2Sb)3P7, as well as Investigations on the Formation of Heptaphosphanes (3) Containing PMe2, PF2, and P(CF3)2 Groups Tris(di-tert-butylphospha)heptaphosphanortricyclane (t-Bu2P)3P7 1 obtained by reacting Li3P7 · 3 DME with t-Bu2PF forms yellow crystals. (t-Bu2Sb)3P7 2 produced similarly from t-Bu2SbCl and Li3P7 · 3 DME didn't form crystals; it decomposes in a solution of toluene above ?10°C. Both compounds were identified by their 31P{1H} NMR spectra, and 1 also by elemental analysis and single crystal structure determination (space group) P21/a, a = 1 712.0(9) pm, b = 1 105.1(7) pm, c = 1 854.0(10) pm, β = 94.96(4)°, Z = 4 formula units in the elementary cell). Attempts to synthesize (Me2P)3P7 3 , (F2P)3P7 4 and [(F3C)2P]3P7 5 failed as dialkylchlorophosphanes as Me2PCl e. g. with Li3P7 · 3 DME react under Li/Cl exchange, dialkylfluorophosphanes (except t-Bu2PF) disproportionate, and neither PF3 nor (F3C)2PBr with Li3P7 · 3 DME give the desired products 4 or 5 , resp. 相似文献