1
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Dissanayake I, Hart JD, Becroft EC, Sumby CJ, Newton CG. Bisketene Equivalents as Diels–Alder Dienes. J Am Chem Soc 2020; 142:13328-13333. [DOI: 10.1021/jacs.0c06306] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Isuru Dissanayake
- Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Jacob D. Hart
- Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Emma C. Becroft
- Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Christopher J. Sumby
- Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia
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2
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Zheng YF, Lin JD, Li CP, Li JH. Friedel–Crafts allylation of 2-(benzyloxy)-3,4,5-trimethoxytoluene Catalysed by a Metal Trifluoromethanesulfonic Salt: Synthesis of Coenzyme Q10. JOURNAL OF CHEMICAL RESEARCH 2019. [DOI: 10.3184/030823407x270338] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the presence of a catalytic amount of scandium triflate, 2-benzyloxy-3,4,5-trimethoxytoluene reacted with allylic derivatives 4, giving the key intermediate 3 (R = benzyl) which was used for preparing coenzyme Q10, in moderate to high yields.
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Affiliation(s)
- Yun-Feng Zheng
- College of Pharmaceutical Sciences, Zhejiang University of Technology, 310032, P. R. China
| | - Jing-Du Lin
- College of Pharmaceutical Sciences, Zhejiang University of Technology, 310032, P. R. China
| | - Cheng-Ping Li
- College of Biology and Environmental Engineering, Zhejiang Shuren University, 310015, P. R. China
| | - Jing-Hua Li
- College of Pharmaceutical Sciences, Zhejiang University of Technology, 310032, P. R. China
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3
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Taguchi AT, O’Malley PJ, Wraight CA, Dikanov SA. Determination of the Complete Spin Density Distribution in 13C-Labeled Protein-Bound Radical Intermediates Using Advanced 2D Electron Paramagnetic Resonance Spectroscopy and Density Functional Theory. J Phys Chem B 2017; 121:10256-10268. [DOI: 10.1021/acs.jpcb.7b10036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander T. Taguchi
- Center
for Biophysics and Computational Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Veterinary Clinical Medicine, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | | | - Colin A. Wraight
- Center
for Biophysics and Computational Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Biochemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Sergei A. Dikanov
- Department
of Veterinary Clinical Medicine, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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4
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Lee SW, Lee HB, Kim BC, Sadaiah K, Lee K, Shin H. A Large Scale Formal Synthesis of CoQ 10: Highly Stereoselective Friedel-Crafts Allylation Reaction of Tetramethoxytoluene with (E)-4-Chloro-2-methyl-1-phenylsulfonyl-2-butene in the Presence of Montmorillonite K-10. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.4.1257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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5
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Oh ET, Jin Kim H, Taek Oh J, Su L, Yun I, Nam K, Min JH, Woo Kim J, Koo S. Synthesis of Coenzyme Q10. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Abstract
(2’E)-1-(3-methyl-4-p-toluenesulfonyl-2-butene)-6-methyl-2,3,4,5-tetramethoxybenzene (4) is the key intermediate in the synthesis of coenzyme Q10via a coupling reaction with solanesyl bromide. In this paper, we report a simple and effective synthesis of compound 4, starting with the readily available and inexpensive precursors p-toluenesulfonyl chloride (TsCl) and isoprene to obtain (2E)-1-p-toluenesulfonyl-2-methyl-4-hydroxy-2-butene (3) by addition, esterification and hydrolysis. Application of the Friedel-Crafts alkylation to compound 3, followed by the addition of 2,3,4,5-tetramethoxytoluene (TeMT), assembled the two parts into compound 4. The key parameters of each reaction were optimized at the same time, and the four total operations needed to produced compound 4 had a 27.9% overall yield under the optimized conditions. The structures of the compounds were characterized by 1H-NMR, IR and MS. This alternative process has the potential to be used for large-scale process.
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Affiliation(s)
- Fan-Song Mu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Meng Luo
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
- Authors to whom correspondence should be addressed; E-Mails: (M.L.); (Y.-G.Z.); Tel.: +86-451-8219-0535; Fax: +86-451-8219-0535
| | - Yu-Jie Fu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Xuan Zhang
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Ping Yu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Yuan-Gang Zu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; E-Mails: (F.-S.M.); (Y.-J.F.); (X.Z.); (P.Y.)
- Engineering Research Center of Forestry Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China
- Authors to whom correspondence should be addressed; E-Mails: (M.L.); (Y.-G.Z.); Tel.: +86-451-8219-0535; Fax: +86-451-8219-0535
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7
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Lin MT, Shubin AA, Samoilova RI, Narasimhulu KV, Baldansuren A, Gennis RB, Dikanov SA. Exploring by pulsed EPR the electronic structure of ubisemiquinone bound at the QH site of cytochrome bo3 from Escherichia coli with in vivo 13C-labeled methyl and methoxy substituents. J Biol Chem 2011; 286:10105-14. [PMID: 21247900 PMCID: PMC3060462 DOI: 10.1074/jbc.m110.206821] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 01/13/2011] [Indexed: 11/06/2022] Open
Abstract
The cytochrome bo(3) ubiquinol oxidase from Escherichia coli resides in the bacterial cytoplasmic membrane and catalyzes the two-electron oxidation of ubiquinol-8 and four-electron reduction of O(2) to water. The one-electron reduced semiquinone forms transiently during the reaction, and the enzyme has been demonstrated to stabilize the semiquinone. The semiquinone is also formed in the D75E mutant, where the mutation has little influence on the catalytic activity, and in the D75H mutant, which is virtually inactive. In this work, wild-type cytochrome bo(3) as well as the D75E and D75H mutant proteins were prepared with ubiquinone-8 (13)C-labeled selectively at the methyl and two methoxy groups. This was accomplished by expressing the proteins in a methionine auxotroph in the presence of l-methionine with the side chain methyl group (13)C-labeled. The (13)C-labeled quinone isolated from cytochrome bo(3) was also used for the generation of model anion radicals in alcohol. Two-dimensional pulsed EPR and ENDOR were used for the study of the (13)C methyl and methoxy hyperfine couplings in the semiquinone generated in the three proteins indicated above and in the model system. The data were used to characterize the transferred unpaired spin densities on the methyl and methoxy substituents and the conformations of the methoxy groups. In the wild type and D75E mutant, the constraints on the configurations of the methoxy side chains are similar, but the D75H mutant appears to have altered methoxy configurations, which could be related to the perturbed electron distribution in the semiquinone and the loss of enzymatic activity.
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Affiliation(s)
| | | | - Rimma I. Samoilova
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Kuppala V. Narasimhulu
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and
| | | | | | - Sergei A. Dikanov
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and
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8
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Tang M, Sperling LJ, Berthold DA, Nesbitt AE, Gennis RB, Rienstra CM. Solid-state NMR study of the charge-transfer complex between ubiquinone-8 and disulfide bond generating membrane protein DsbB. J Am Chem Soc 2011; 133:4359-66. [PMID: 21375236 DOI: 10.1021/ja107775w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ubiquinone (Coenzyme Q) plays an important role in the mitochondrial respiratory chain and also acts as an antioxidant in its reduced form, protecting cellular membranes from peroxidation. De novo disulfide bond generation in the E. coli periplasm involves a transient complex consisting of DsbA, DsbB, and ubiquinone (UQ). It is hypothesized that a charge-transfer complex intermediate is formed between the UQ ring and the DsbB-C44 thiolate during the reoxidation of DsbA, which gives a distinctive ~500 nm absorbance band. No enzymological precedent exists for an UQ-protein thiolate charge-transfer complex, and definitive evidence of this unique reaction pathway for DsbB has not been fully demonstrated. In order to study the UQ-8-DsbB complex in the presence of native lipids, we have prepared isotopically labeled samples of precipitated DsbB (WT and C41S) with endogenous UQ-8 and lipids, and we have applied advanced multidimensional solid-state NMR methods. Double-quantum filter and dipolar dephasing experiments facilitated assignments of UQ isoprenoid chain resonances not previously observed and headgroup sites important for the characterization of the UQ redox states: methyls (~20 ppm), methoxys (~60 ppm), olefin carbons (120-140 ppm), and carbonyls (150-160 ppm). Upon increasing the DsbB(C41S) pH from 5.5 to 8.0, we observed a 10.8 ppm upfield shift for the UQ C1 and C4 carbonyls indicating an increase of electron density on the carbonyls. This observation is consistent with the deprotonation of the DsbB-C44 thiolate at pH 8.0 and provides direct evidence of the charge-transfer complex formation. A similar trend was noted for the UQ chemical shifts of the DsbA(C33S)-DsbB(WT) heterodimer, confirming that the charge-transfer complex is unperturbed by the DsbB(C41S) mutant used to mimic the intermediate state of the disulfide bond generating reaction pathway.
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Affiliation(s)
- Ming Tang
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
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9
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Sabatino MA, Filardo G, Galia A, Scialdone O. Electrochemical synthesis of coenzymes Q n by oxidation of tetramethoxy precursors. J APPL ELECTROCHEM 2009. [DOI: 10.1007/s10800-009-9947-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Electrochemical oxidation of tetramethoxy precursor as a key step for the synthesis of coenzyme Q10. Electrochem commun 2007. [DOI: 10.1016/j.elecom.2007.01.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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11
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12
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Afri M, Ehrenberg B, Talmon Y, Schmidt J, Cohen Y, Frimer AA. Active oxygen chemistry within the liposomal bilayer. Part III: Locating Vitamin E, ubiquinol and ubiquinone and their derivatives in the lipid bilayer. Chem Phys Lipids 2005; 131:107-21. [PMID: 15210369 DOI: 10.1016/j.chemphyslip.2004.04.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Revised: 04/02/2004] [Accepted: 04/13/2004] [Indexed: 12/26/2022]
Abstract
We have previously shown that the location and orientation of compounds intercalated within the lipid bilayer can be qualitatively determined using an NMR chemical shift-polarity correlation. We describe herein the results of our application of this method to analogs of Vitamin E, ubiquinol and ubiquinone. The results indicate that tocopherol--and presumably the corresponding tocopheroxyl radical--reside adjacent to the interface, and can, therefore, abstract a hydrogen atom from ascorbic acid. On the other hand, the decaprenyl substituted ubiquinol and ubiquinone lie substantially deeper within the lipid membrane. Yet, contrary to the prevailing literature, their location is far from being the same. Ubiquinone-10 is situated above the long-chain fatty acid "slab". Ubiquinol-10 dwells well within the lipid slab, presumably out of "striking range" of Vitamin C. Nevertheless, ubiquinol can act as an antioxidant by reducing C- or O-centered lipid radicals or by recycling the lipid-resident tocopheroxyl radical.
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Affiliation(s)
- Michal Afri
- Department of Chemistry, Bar-Ilan University, Ramat Gan 52900, Israel
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13
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Min JH, Lee JS, Yang JD, Koo S. The Friedel−Crafts Allylation of a Prenyl Group Stabilized by a Sulfone Moiety: Expeditious Syntheses of Ubiquinones and Menaquinones. J Org Chem 2003; 68:7925-7. [PMID: 14510583 DOI: 10.1021/jo0350155] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An efficient synthetic method for the protected p-hydroquinone compounds 4 containing the C5 trans allylic sulfone moiety has been developed by the direct Friedel-Crafts allylation of the protected dihydroquinone 2 with 4-chloro-2-methyl-1-phenylsulfonyl-2-butene (7a) or 4-hydroxy-2-methyl-1-phenylsulfonyl-2-butene (7b). Expeditious total syntheses of coenzyme Q-10 and vitamin K2(20) have been demonstrated from these valuable key compounds 4a and 4b.
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Affiliation(s)
- Jae-Hong Min
- Department of Chemistry, Myong Ji University, Yongin, Kyunggi-Do, 449-728, Korea
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14
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van der Klei A, de Jong R, Lugtenburg J, Tielens A. Synthesis and Spectroscopic Characterization of [1′-14C]Ubiquinone-2, [1′-14C]-5-Demethoxy-5-hydroxyubiquinone-2, and [1′-14C]-5-Demethoxyubiquinone-2. European J Org Chem 2002. [DOI: 10.1002/1099-0690(200209)2002:17<3015::aid-ejoc3015>3.0.co;2-g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Loreau O, Maret A, Poullain D, Chardigny JM, Sébédio JL, Beaufrère B, Noël JP. Large-scale preparation of (9Z,12E)-[1-(13)C]-octadeca-9,12-dienoic acid, (9Z,12Z,15E)-[1-(13)C]-octadeca-9,12,15-trienoic acid and their [1-(13)C] all-cis isomers. Chem Phys Lipids 2000; 106:65-78. [PMID: 10878236 DOI: 10.1016/s0009-3084(00)00137-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Several grams of labelled trans linoleic and linolenic acids with high chemical and isomeric purities (>97%) have been prepared for human metabolism studies. A total of 12.5 g of (9Z, 12E)-[1-(13)C]-octadeca-9,12-dienoic acid and 6.3 g of (9Z,12Z, 15E)-[1-(13)C]-octadeca-9,12,15-trienoic acid were obtained in, respectively, seven steps (7.8% overall yield) and 11 steps (7% overall yield) from 7-bromo-heptan-1-ol. The trans bromo precursors used for the labelling were synthesised by using copper-catalysed couplings. The trans fatty acids were then obtained via the nitrile derivatives. A total of 23.5 g of (9Z,12Z)-[1-(13)C]-octadeca-9, 12-dienoic acid and 10.4 g of (9Z,12Z,15Z)-[1-(13)C]-octadeca-9,12, 15-trienoic acid were prepared in five steps in, respectively, 32 and 18% overall yield. Large quantities of bromo and chloro precursors were synthesised from the commercially available acid according to Barton's procedure. In all cases, the main impurities (>0.5%) of each labelled fatty acid have been characterised.
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Affiliation(s)
- O Loreau
- CEA/Saclay, Service des Molécules Marquées, Bât. 547, F-91191 Cedex, Gif sur Yvette, France.
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16
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Boullais C, Rannou C, Réveillère E, Mioskowski C. Synthesis of [3-D3]-, [3-13C]-, and [1,2-13C2]Propynes and Their Use for the Synthesis of [5-D3-Methyl]-, [5-13C-Methyl]-, and [5,6-13C2-2,5-Cyclohexadienyl]ubiquinones 3. European J Org Chem 2000. [DOI: 10.1002/(sici)1099-0690(200003)2000:5<723::aid-ejoc723>3.0.co;2-q] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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18
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Sabin E, Boullais C. Synthesis of (2′Z,6′E) and (2′E,6′E)-[1′-13C] ubiquinone 3 by means of (2E,6E) and (2Z,6E)-[1-13C] farnesyltrimethyltin reagents. J Labelled Comp Radiopharm 1998. [DOI: 10.1002/(sici)1099-1344(1998100)41:10<899::aid-jlcr142>3.0.co;2-j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Stowell MHB, Wang G, Day MW, Chan SI. Design, Synthesis, and Photochemical Properties of a Photoreleasable Ubiquinol-2: A Novel Compound for Studying Rapid Electron-Transfer Kinetics in Ubiquinol-Oxidizing Enzymes. J Am Chem Soc 1998. [DOI: 10.1021/ja971079j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael H. B. Stowell
- Contribution from the Arthur Amos Noyes Laboratory of Chemical Physics, the Beckman Institute, and the Carl F. and Winifred H. Braun Laboratories, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Guangyang Wang
- Contribution from the Arthur Amos Noyes Laboratory of Chemical Physics, the Beckman Institute, and the Carl F. and Winifred H. Braun Laboratories, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Michael W. Day
- Contribution from the Arthur Amos Noyes Laboratory of Chemical Physics, the Beckman Institute, and the Carl F. and Winifred H. Braun Laboratories, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Sunney I. Chan
- Contribution from the Arthur Amos Noyes Laboratory of Chemical Physics, the Beckman Institute, and the Carl F. and Winifred H. Braun Laboratories, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
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20
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Lipshutz BH, Kim SK, Mollard P, Stevens KL. An expeditious route to CoQn, vitamins K1 and K2, and related allylated para-quinones utilizing Ni(0) catalysis. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(97)10222-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Burie JR, Boullais C, Nonella M, Mioskowski C, Nabedryk E, Breton J. Importance of the Conformation of Methoxy Groups on the Vibrational and Electrochemical Properties of Ubiquinones. J Phys Chem B 1997. [DOI: 10.1021/jp970640x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Kates MJ, Schauble JH. Total Synthesis of Chaetomellic Anhydrides A and B via a Novel Succinate to Maleate Oxidation. J Org Chem 1996; 61:4164-4167. [PMID: 11667302 DOI: 10.1021/jo9601977] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael J. Kates
- Department of Chemistry, Villanova University, Villanova, Pennsylvania 19085
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23
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Kropacheva TN, van Liemt WBS, Raap J, Lugtenburg J, Hoff AJ. Hydrogen-Bonding Effect on 13C and Proton Hyperfine Couplings of [4-13C]-Labeled Ubisemiquinones in Vitro. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960059l] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatyana N. Kropacheva
- Department of Chemistry, Udmurt State University, Izhevsk, 426037 Russia, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Willem B. S. van Liemt
- Department of Chemistry, Udmurt State University, Izhevsk, 426037 Russia, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Jan Raap
- Department of Chemistry, Udmurt State University, Izhevsk, 426037 Russia, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Johan Lugtenburg
- Department of Chemistry, Udmurt State University, Izhevsk, 426037 Russia, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - Arnold J. Hoff
- Department of Chemistry, Udmurt State University, Izhevsk, 426037 Russia, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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24
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Affiliation(s)
- Bruce H. Lipshutz
- Department of Chemistry, University of California Santa Barbara, California 93106-9510
| | - Gerd Bulow
- Department of Chemistry, University of California Santa Barbara, California 93106-9510
| | - Richard F. Lowe
- Department of Chemistry, University of California Santa Barbara, California 93106-9510
| | - Kirk L. Stevens
- Department of Chemistry, University of California Santa Barbara, California 93106-9510
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25
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26
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Brudler R, de Groot HJ, van Liemt WB, Gast P, Hoff AJ, Lugtenburg J, Gerwert K. FTIR spectroscopy shows weak symmetric hydrogen bonding of the QB carbonyl groups in Rhodobacter sphaeroides R26 reaction centres. FEBS Lett 1995; 370:88-92. [PMID: 7649310 DOI: 10.1016/0014-5793(95)00805-j] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The absorption frequencies of the C = O and C = C (neutral state) and of the C...O (semiquinone state) stretching vibrations of QB have been assigned by FTIR spectroscopy, using native and site-specifically 1-, 2-, 3- and 4-13C-labelled ubiquinone-10 (UQ10) reconstituted at the QB binding site of Rhodobacter sphaeroides R26 reaction centres. Besides the main C = O band at 1641 cm-1, two smaller bands are observed at 1664 and 1651 cm-1. The smaller bands at 1664 and 1651 cm-1 agree in frequencies with the 1- and 4-C = O vibrations of unbound UQ10, showing that a minor fraction is loosely and symmetrically bound to the protein. The larger band at 1641 cm-1 indicates symmetric H-bonding of the 1- and 4-C = O groups for the larger fraction of UQ10 but much weaker interaction as for the 4-C = O group of QA. The FTIR experiments show that different C = O protein interactions contribute to the factors determining the different functions of UQ10 at the QA and the QB binding sites.
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Affiliation(s)
- R Brudler
- Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Germany
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Breton J, Boullais C, Burie JR, Nabedryk E, Mioskowski C. Binding sites of quinones in photosynthetic bacterial reaction centers investigated by light-induced FTIR difference spectroscopy: assignment of the interactions of each carbonyl of QA in Rhodobacter sphaeroides using site-specific 13C-labeled ubiquinone. Biochemistry 1994; 33:14378-86. [PMID: 7981197 DOI: 10.1021/bi00252a002] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Light-induced QA-/QA FTIR difference spectra of the photoreduction of the primary quinone (QA) have been obtained for Rhodobacter sphaeroides reaction centers (RCs) reconstituted with ubiquinone (Q3) labeled selectively with 13C at the 1- or 4-position of the quinone ring, i.e., on either of the two carbonyls. The vibrational modes of the quinone in the QA site are compared to those in vitro. IR absorption spectra of films of the labeled quinones show that the two carbonyls contribute equally to the split C = O band at 1663-1650 cm-1. This splitting is assigned to the two different geometries of the methoxy group nearest to each carbonyl. The QA-/QA spectra of RCs reconstituted with either 13C1- or 13C4-labeled Q3 and with unlabeled Q3 as well as the double differences calculated from these spectra exhibit distinct isotopic shifts for the bands assigned to C = O and C = C vibrations of the neutral QA. For the unlabeled QA, these bands correspond to the bands at 1660, 1628, and 1601 cm-1 previously detected upon nonselective isotopic labeling [Breton, J., Burie, J.-R., Berthomieu, C., Berger, G., & Nabedryk, E. (1994) Biochemistry 33, 4953-4965]. The 1660-cm-1 band is unaffected upon selective labeling at C4 but shifts to approximately 1623 cm-1 upon 13C1 labeling, demonstrating that this band arises from the C1 carbonyl, proximal to the isoprenoid chain. The band at 1628 cm-1 shifts by 11 and 16 cm-1 upon 13C1 and 13C4 labeling, respectively, and is assigned to a C = C mode coupled to both carbonyls.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Breton
- Section de Bioénergétique, CEA-Saclay, Gif-sur-Yvette, France
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van den Brink JS, Spoyalov AP, Gast P, van Liemt WB, Raap J, Lugtenburg J, Hoff AJ. Asymmetric binding of the primary acceptor quinone in reaction centers of the photosynthetic bacterium Rhodobacter sphaeroides R26, probed with Q-band (35 GHz) EPR spectroscopy. FEBS Lett 1994; 353:273-6. [PMID: 7957873 DOI: 10.1016/0014-5793(94)01047-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The reaction center (RC)-bound primary acceptor quinone QA of the photosynthetic bacterium Rhodobacter sphaeroides R26 functions as a one-electron gate. The radical anion QA.- is proposed to have an asymmetric electron distribution, induced by the protein environment. We replace the native ubiquinone-10 (UQ10) with specifically 13C-labelled UQ10, and use Q-band (35 GHz) EPR spectroscopy to investigate this phenomenon in closer detail. The direct observation of the 13C-hyperfine splitting of the gz-component of UQ10A.- in the RC and in frozen isopropanol shows that the electron spin distribution is symmetric in the isopropanol glass, and asymmetric in the RC. Our results allow qualitative assessment of the spin and charge distribution for QA.- in the RC. The carbonyl oxygen of the semiquinone anion nearest to the S = 2 Fe(2+)-ion and QB is shown to acquire the highest (negative) charge density.
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Affiliation(s)
- J S van den Brink
- Department of Biophysics, Huygens Laboratory, Leiden University, The Netherlands
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