- Hydrogenation of plant polyalkoxybenzene derivatives: convenient access to coenzyme Q0 analogues
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A technologically advanced protocol has been developed for converting plant allyl(polyalkoxy)benzenes to methyl- and propyl(polyalkoxy)benzenes being intermediates in the syntheses of coenzyme Q0 analogues. The key stage of allyl and benzaldehyde moieties hydrogenation was carried out in a periodical autoclave mode on highly porous ceramic block Pd-catalysts. These catalysts possess large surface area, low hydraulic resistance, significant thermal and mechanical stabililty, multiple cycling and easy regeneration, which can dramatically reduce Pd consumption.
- Khrustalev, Victor N.,Muravsky, Egor A.,Semenov, Victor V.,Shinkarev, Ilia Yu.,Varakutin, Alexander E.
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p. 599 - 601
(2020/10/18)
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- Efficient synthesis of 5-bromo-2,3-dimethoxy-6-methyl-1,4-benzoquinone: key intermediate for preparing Coenzyme Q
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The title compound, a key intermediate for preparing Coenzyme Qn family, was prepared in an excellent yield by a reaction sequence starting from the commercially available 3,4,5-trimethoxytoluene 1 via bromination, methoxylation and oxidation reactions. A
- Qiu, Yong-Fu,Lu, Bin,Yan, Yi-Yu,Luo, Wan-Yue,Wang, Jin,Hu, Xiao
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p. 2745 - 2748
(2019/08/21)
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- Efficient synthesis and antioxidant activities of N-heterocyclyl substituted Coenzyme Q analogues
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A new strategy for the efficient synthesis of C-5 heterocyclyl substituted Coenzyme Q analogues was developed by N-alkylation of bromomethylated quinone 11 with a series of amines 12 under metal-free conditions. In vitro antioxidant activities of these Coenzyme Q analogues were evaluated and compared with commercial antioxidant Coenzyme Q10 by employing DPPH assay. All these N-heterocyclyl substituted Coenzyme Q analogues are found to be exhibiting good antioxidant properties and may be used as potent antioxidants for combating oxidative stress.
- Wang, Jin,Xia, Fei,Jin, Wen-Bin,Guan, Jin-Yan,Zhao, Hang
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p. 214 - 218
(2016/08/25)
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- QUINONE BASED NITRIC OXIDE DONATING COMPOUNDS
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The present invention relates to nitric oxide donor compounds having a quinone based structure, to processes for their preparation and to their use in the treatment and/or prophylaxis of glaucoma and ocular hypertension.
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Page/Page column 40
(2015/11/18)
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- Alkyne-tag Raman imaging for visualization of mobile small molecules in live cells
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Alkyne has a unique Raman band that does not overlap with Raman scattering from any endogenous molecule in live cells. Here, we show that alkyne-tag Raman imaging (ATRI) is a promising approach for visualizing nonimmobilized small molecules in live cells. An examination of structure-Raman shift/intensity relationships revealed that alkynes conjugated to an aromatic ring and/or to a second alkyne (conjugated diynes) have strong Raman signals in the cellular silent region and can be excellent tags. Using these design guidelines, we synthesized and imaged a series of alkyne-tagged coenzyme Q (CoQ) analogues in live cells. Cellular concentrations of diyne-tagged CoQ analogues could be semiquantitatively estimated. Finally, simultaneous imaging of two small molecules, 5-ethynyl-2′-deoxyuridine (EdU) and a CoQ analogue, with distinct Raman tags was demonstrated.
- Yamakoshi, Hiroyuki,Dodo, Kosuke,Palonpon, Almar,Ando, Jun,Fujita, Katsumasa,Kawata, Satoshi,Sodeoka, Mikiko
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supporting information
p. 20681 - 20689
(2013/02/23)
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- Bis-coenzyme Q0: Synthesis, characteristics, and application
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A methylene-bridged bis-coenzyme Q0, bis(2,3-dimethoxy-5-methyl- l,4-benzoquinone)methane (Bis-CoQ0), that shows intramolecular electronic communications has been synthesized for the first time. By employing electrochemical, in situ UV/Vis, and electron paramagnetic resonance (EPR) spectroelectrochemical techniques, the unstable reduced intermediate speciesa-monoradicals, diamagnetic dianions and tetraanions of Bis-CoQ 0a-have been observed. The electron-transfer process can be defined as a three-step reduction process with a total of four electrons in solution in CH3CN. The chemical reaction in the third redox step process was confirmed by variable temperature cyclic voltammetry. In an aprotic CH 3CN solution, the peak potential separation between electron-transfer steps diminished sequentially with increasing concentration of water. The hydrogen-bonding interactions between water and the electrochemically reduced intermediates of Bis-CoQ0 can be estimated by peak potential shifts. The electronic communications of Bis-CoQ0 may have been blocked when one reduction peak was observed with proper quantities of water in CH 3CN solution. The antioxidant defense capacity of Bis-CoQ 0-protected cells has also been assessed.
- Wang, Xiuwen,Ma, Wei,Ying, Yilun,Liang, Jie,Long, Yi-Tao
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supporting information; experimental part
p. 1064 - 1073
(2011/10/11)
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- In situ spectroeletrochemistry and cytotoxic activities of natural ubiquinone analogues
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Quinones are a group of potent antineoplastic agents. Here we described effective and facile routes to synthesize a series of ubiquinone analogues (UQAs). These unique compounds have been investigated by electrochemistry and in situ UV-vis spectroelectrochemistry to explore their electron-transfer processes and radical properties in aprotic media. The structure-activities relationships of inhibiting cancer cell proliferation of UQAs were examined in murine melanoma B16F10 cells using a 72 h continuous exposure MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Our results revealed that UQAs had improved antiproliferative activity and displayed better inhibitory effects than natural ubiquinone 10. The cytotoxic activities of UQAs were correlated to the semiubiquinone radicals, which were confirmed by in situ electron spin resonance (ESR). In the cytotoxicity test, 6-vinylubiquinone 5 and 6-(4′-fluorophenyl) ubiquinone 7 that possess half maximal inhibitory concentration value (IC50) of 6.1 μM and 6.2 μM. This would make them as valuable candidates for future pharmacological studies.
- Ma, Wei,Zhou, Hao,Ying, Yi-Lun,Li, Da-Wei,Chen, Guo-Rong,Long, Yi-Tao,Chen, Hong-Yuan
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experimental part
p. 5990 - 6000
(2011/09/19)
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- Reversible redox of NADH and NAD+ at a hybrid lipid bilayer membrane using ubiquinone
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Here, we report the reversible interconversion between NADH and NAD + at a low overpotential, which is in part mediated by ubiquinone embedded in a biomimetic membrane to mimic the initial stages of respiration. This system can be used as a platform to examine biologically relevant electroactive molecules embedded in a natural membrane environment and provide new insights into the mechanism of biological redox cycling.
- Ma, Wei,Li, Da-Wei,Sutherland, Todd C.,Li, Yang,Long, Yi-Tao,Chen, Hong-Yuan
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supporting information; experimental part
p. 12366 - 12369
(2011/10/02)
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- A green and efficient synthesis of 1-chloromethyl -2,3,4,5-tetramethoxy6- methylbenzene
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The title compound, a key intermediate for preparing coenzyme Q analogues, was prepared in excellent yield by a reaction sequence starting from the commercially available 3,4,5-trlmethoxybenzadehyde via Wolff-Kishner reduction, selective bromination, methoxylation and Blanc chloromethylation reaction.
- Wang, Jin,Yang, Jian,Yang, Bo,Hu, Xiao,Sun, Jia-Qiang,Yang, Tao
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experimental part
p. 717 - 718
(2011/04/22)
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- Design and synthesis of novel quinone inhibitors targeted to the redox function of apurinic/apyrimidinic endonuclease 1/redox enhancing factor-1 (Ape1/Ref-1)
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The multifunctional enzyme apurinic endonuclease 1/redox enhancing factor 1 (Ape1/ref-1) maintains genetic fidelity through the repair of apurinic sites and regulates transcription through redox-dependent activation of transcription factors. Ape1 can therefore serve as a therapeutic target in either a DNA repair or transcriptional context. Inhibitors of the redox function can be used as either therapeutics or novel tools for separating the two functions for in vitro study. Presently there exist only a few compounds that have been reported to inhibit Ape1 redox activity; here we describe a series of quinones that exhibit micromolar inhibition of the redox function of Ape1. Benzoquinone and naphthoquinone analogues of the Ape1-inhibitor E3330 were designed and synthesized to explore structural effects on redox function and inhibition of cell growth. Most of the naphthoquinones were low micromolar inhibitors of Ape1 redox activity, and the most potent analogues inhibited tumor cell growth with IC50 values in the 10-20 μM range.
- Nyland II, Rodney L.,Luo, Meihua,Kelley, Mark R.,Borch, Richard F.
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scheme or table
p. 1200 - 1210
(2010/07/18)
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- An alternative route for the synthesis of 2,3,4,5-tetramethoxytoluene
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The transformation of the commercially available 2,3,4- trimetho×ybenzaldehyde to 2,3,4,5-tetrametho×ytoluene using a Dakin reaction to insert the extra oxygen, formylation, reduction and methylation of the phenolic hydro×yl group is described.
- Vera, William J.,Chinea, Kimberly,Banerjee, Ajoy K.
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experimental part
p. 186 - 187
(2009/10/15)
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- Novel Intermediates Useful for the Preparation of Coenzymes, Process for the Preparation of Novel Intermediates and an Improved Process for the Preparation of Coenzymes
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The present invention relates to novel intermediates for the preparation of coenzymes, processes for the preparation of the intermediates and an improved process for the preparation of Coenzymes. The present invention particularly relates to an improved process for the preparation of Coenzyme Q, more particularly for Conenzyme Q9 and Coenzyme Q10. Still more particularly this invention relates to regio and stereo controlled process for the preparation of Coenzyme Q9 and Coenzyme Q10 of the formula I where n=9 (Coenzyme CoQ9), and where n=10. (Coenzyme CoQ10)
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Page/Page column 15
(2008/12/08)
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- Practical synthesis of 2,3,4,5-tetramethoxytoluene
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The title compound, a key material for synthesis of coenzyme Q 10 , was effectively prepared in high yield by a reaction sequence starting from 3,4,5-trimethoxybenzadehyde via Wolff-Kishner reduction, Vilsmeier-Haack reaction, Dakin reaction, and methylation. Copyright Taylor & Francis Group, LLC.
- Ji, Yafei,Xu, Wanmei,Jin, Wenhu,Weimin, Yue
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p. 1961 - 1965
(2007/10/03)
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- Alternative synthesis of 1,2,3,4-tetramethoxy-5-methylbenzene: A key intermediate for preparing coenzyme Q homologs and analogs
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Preparation of 1,2,3,4-tetramethoxy-5-methylbenzene (1) through a new process from pyrogallol is described. In the preparation, a modified mild brominating agent was employed, and a simple introduction of methyl group into aromatic ring through chloromethylation of the corresponding substrate (4), followed by reductive dehalogenation, was achieved successfully with good yields. Copyright Taylor & Francis Group, LLC.
- Yang, Jian,Weng, Lingling,Zheng, Hu
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p. 2401 - 2405
(2007/10/03)
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- MITOQUINONE DERIVATIVES USED AS MITOCHONDRIALLY TARGETED ANTIOXIDANTS
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This invention relates to pharmaceutically acceptable amphiphilic antioxidant compounds, compositions and dosage forms comprising said compounds, and methods and uses reliant on said compounds.The exemplified compounds are all mitoquinone derivatives, bei
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Page/Page column 52-53
(2010/02/11)
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- A new fluorogenic transformation: Development of an optical probe for coenzyme Q
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(Chemical Equation Presented) A new fluorogenic transformation based on a quinone reduction/lactonization sequence has been developed and evaluated as a tool for probing redox phenomena in a biochemical context. The probe presented herein is an irreversible redox probe and is reduced selectively by biologically relevant quinols such as ubiquinol but is inert to reduced nicotinamides (e.g., NADH). The ensuing cyclization is fast and quantitative and provides a measurable optical response.
- Tremblay, Matthew S.,Sames, Dalibor
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p. 2417 - 2420
(2007/10/03)
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- 2,3-Dimethoxy-5-methyl-1,4-benzoquinones and 2-methyl-1,4-naphthoquinones: Glycation inhibitors with lipid peroxidation activity
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Anti-glycation activity of our anti-oxidant quinone library was measured and several 2,3-dimethoxy-5-methyl-1,4-benzoquinones and 2-methyl-1,4- naphthoquinones were identified as novel inhibitors of glycation, of which 2,3-dimethoxy-5-methyl-1,4-benzoquinones 13b is the most potent glycation inhibitor with around 50 μM of the IC50 value.
- Jung, Young-Sik,Joe, Bo-Young,Cho, Sung Ju,Konishi, Yasuo
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p. 1125 - 1129
(2007/10/03)
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- Synthesis of 1,2,3,4-tetrahydroxybenzenes from biomass-derived carbon
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A bioengineered synthesis scheme for the production of 1,2,3,4-tetrahydroxybenzene from a carbon source is provided. Methods of producing 1,2,3,4-tetrahydroxybenzene acid from a carbon source based on the synthesis scheme are also provided. Methods are also provided for converting 1,2,3,4-tetrahydroxybenzene to 1,2,3-trihydroxybenzene by catalytic hydrogenation.
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- The preparation of side chain functionalized analogues of coenzyme Q for protein conjugation studies
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The synthesis of two analogues of CoQ (10 and 13) suitable for conjugation to a peptide or protein, and hence the development of an ELISA immunoassay, is presented. These analogues were synthesized from the protected quinone, 1-bromo-2-methyl-3,4,5,6-tetramethoxybenzene (1), itself prepared from commercially available CoQ-0 (3). Model coupling studies of one of the analogues (10) to N-acetyl-L-lysine methyl ester and a lysine containing dipeptide (N-acetylglycine-L-lysine methyl ester) were also undertaken as a first step to monoclonial antibody production.
- Daines, Alison M.,Abell, Andrew D.
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p. 2371 - 2375
(2007/10/03)
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- A convergent approach to coenzyme Q
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Syntheses of coenzyme Q3-8 are described, as well as related systems such as plastoquinone-5. Preparation of the higher homologues of the ubiquinones relies on two new conjunctive reagents, or "linchpins", each of which ultimately corresponds to two or three prenyl units. These allow for attachment of a polyprenyl halide at one end, followed by a Ni(0)-catalyzed cross-coupling at the other terminus with a chloromethylated p-quinone.
- Lipshutz, Bruce H.,Bulow, Gerd,Fernandez-Lazaro, Fernando,Kim, Sung-Kyu,Lowe, Richard,Mollard, Paul,Stevens, Kirk L.
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p. 11664 - 11673
(2007/10/03)
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- An expeditious route to CoQ(n), Vitamins K1 and K2, and related allylated para-quinones utilizing Ni(0) catalysis
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Coupling reactions between vynylalanes and chloromethylated para-quinones, mediated by catalytic amounts of Ni(0), lead directly to allylated products, including coenzyme Q, and vitamins K1 and K2.
- Lipshutz, Bruce H.,Kim, Sung-Kyu,Mollard, Paul,Stevens, Kirk L.
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p. 1241 - 1253
(2007/10/03)
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- Allylated aromatics via Ni-catalyzed couplings of benzylic chlorides and vinylic organometallics
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Hydroalumination and hydrozirconation of alkynes lead to vinylic organometallics which react with benzylic chlorides at room temperature under the influence of in situ-generated, catalytic quantities of (presumably) Ni(O), to afford allylated aromatics in good yields.
- Lipshutz, Bruce H.,Buelow, Gerd,Lowe, Richard F.,Stevens, Kirk L.
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p. 7265 - 7276
(2007/10/03)
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- Total Synthesis of Linear Polyprenoids. 2. Improved preparation of the Aromatic Nucleus of Ubiquinone
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Highly efficient copper-catalyzed polymethoxylation of tribromocresol is the key process in a three-step, practical approach to obtain ubiquinone 0 from p-cresol.Short syntheses of several ubiquinones were achieved via direct, copper-mediated coupling of 2-lithio-3,4,5,6-tetramethoxytoluene to the appropriate polyprenyl bromide.
- Keinan, Ehud,Eren, Doron
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p. 3872 - 3875
(2007/10/02)
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- Hydroquinone derivatives and preparation thereof
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The novel hydroquinone derivatives of the formula (I) are useful intermediates for the preparation of coenzyme Q, vitamin K and the polyprenyltrimethylquinones: STR1 wherein R1 is lower alkyl, lower alkoxy lower alkyl or methoxyethoxymethyl, R2 and R3 are each methyl or methoxy, or R2 and R3, taken together with the carbon atoms from which they depend, define a benzene ring, and R4 is a substituted or unsubstituted aromatic hydrocarbon. The compounds (I) are readily prepared either by reacting a Grignard reagent of the formula (II) with a halosulfone (III) in the presence of a copper compound, or by reacting a copper derivative (II') of the Grignard reagent (II) with a halo-sulfone (III), as follows: STR2 wherein R1, R2, R3 and R4 are defined as above, and X is a halogen atom or a tosyl group.
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- SYNTHESIS OF UBIQUINONE AND MENAQUINONE ANALOGUES BY OXIDATIVE DEMETHYLATION OF ALKENYLHYDROQUINONE ETHERS WITH ARGENTIC OXIDE OR CERIC AMMONIUM NITRATE IN THE PRESENCE OF 2,4,6-PYRIDINE-TRICARBOXYLIC ACID
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It was found that alkenylhydroquinone ethers demethylated with argentic oxide or ceric ammonium nitrate in the presence of 2,4,6-pyridinetricarboxylic acid as a catalyst and afforded ubiquinone-2, menaquinone-2 and their analogs in yields of 53 to 89 percent.The new approach to the synthesis of starting alkenylhydroquinone ethers as well as 2,4,6-pyridinetricarboxylic acid and its derivatives has been reported.
- Syper, L.,Kloc, K.,Mlochowski, J.
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p. 123 - 129
(2007/10/02)
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