1
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Ali S, Rani A, Khan S. Manganese-Catalyzed C-H Functionalizations Driven via Weak Coordination: Recent Developments and Perspectives. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Yang J, Fu X, Tang S, Deng K, Zhang L, Yang X, Ji Y. 2-Amino-5,6-difluorophenyl-1 H-pyrazole-Directed Pd II Catalysis: Arylation of Unactivated β-C(sp 3)-H Bonds. J Org Chem 2019; 84:10221-10236. [PMID: 31313581 DOI: 10.1021/acs.joc.9b01276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Palladium-catalyzed arylation of unactivated β-C(sp3)-H bonds in carboxylic acid derivatives with aryl iodides is described for the first time using 2-amino-5,6-difluorophenyl-1H-pyrazole as an efficient and readily removable directing group. Two fluoro groups are installed at the 5- and 6-position of the anilino moiety in 2-aminophenyl-1H-pyrazole, clearly enhancing the directing ability of the auxiliary. In addition, the protocol employs Cu(OAc)2/Ag3PO4 (1.2/0.3) as additives, evidently reducing the stoichiometric amount of expensive silver salts. Furthermore, this process exhibits high β-site selectivity, compatibility with diverse substrates containing α-hydrogen atoms, and excellent functional group tolerance.
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Affiliation(s)
| | | | | | | | | | - Xianjin Yang
- Key Laboratory of Organofluorine Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Science , 345 Lingling Road , Shanghai 200032 , P. R. China
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3
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Kianmehr E, Gholamhosseyni M. Visible-Light-Promoted Copper-Catalyzed Regioselective Benzylation of Pyridine N
-Oxides versus Thermal Acylation Reaction with Toluene Derivatives. European J Org Chem 2018. [DOI: 10.1002/ejoc.201701586] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ebrahim Kianmehr
- School of Chemistry; College of Science; University of Tehran; Tehran Iran
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4
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Zhang D, Qiao K, Hua J, Liu Z, Qi H, Yang Z, Zhu N, Fang Z, Guo K. Preparation of fluoroalkoxy or fluorophenoxy substituted N-heterocycles from heterocyclic N-oxides and polyfluoroalcohols. Org Chem Front 2018. [DOI: 10.1039/c8qo00499d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A novel and efficient approach to introduce fluorine-containing groups into N-heterocycles was reported.
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Affiliation(s)
- Dong Zhang
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Kai Qiao
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Jiawei Hua
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Zhuang Liu
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Hao Qi
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Zhao Yang
- School of Engineering
- China Pharmaceutical University
- Nanjing 211198
- China
| | - Ning Zhu
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Zheng Fang
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
| | - Kai Guo
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing 211816
- China
- State Key Laboratory of Materials-Oriented Chemical Engineering
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5
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Bakthadoss M, Kumar PV, Reddy TS. Ruthenium-Catalyzed, Keto-Directed, Site-Selective C-H Activation of Diverse Chromanones with Alkenes. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700513] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Polu Vijay Kumar
- Department of Chemistry; Pondicherry University; 605014 Puducherry India
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6
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Huang Z, Lim HN, Mo F, Young MC, Dong G. Transition metal-catalyzed ketone-directed or mediated C-H functionalization. Chem Soc Rev 2016; 44:7764-86. [PMID: 26185960 DOI: 10.1039/c5cs00272a] [Citation(s) in RCA: 432] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transition metal-catalyzed C-H functionalization has evolved into a prominent and indispensable tool in organic synthesis. While nitrogen, phosphorus and sulfur-based functional groups (FGs) are widely employed as effective directing groups (DGs) to control the site-selectivity of C-H activation, the use of common FGs (e.g. ketone, alcohol and amine) as DGs has been continuously pursued. Ketones are an especially attractive choice of DGs and substrates due to their prevalence in various molecules and versatile reactivity as synthetic intermediates. Over the last two decades, transition metal-catalyzed C-H functionalization that is directed or mediated by ketones has experienced vigorous growth. This review summarizes these advancements into three major categories: use of ketone carbonyls as DGs, direct β-functionalization, and α-alkylation/alkenylation with unactivated olefins and alkynes. Each of these subsections is discussed from the perspective of strategic design and reaction discovery.
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Affiliation(s)
- Zhongxing Huang
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Hee Nam Lim
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Fanyang Mo
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Michael C Young
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Guangbin Dong
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
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7
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Wan L, Qiao K, Sun XN, Di ZC, Fang Z, Li ZJ, Guo K. Benzylation of heterocyclic N-oxides via direct oxidative cross-dehydrogenative coupling with toluene derivatives. NEW J CHEM 2016. [DOI: 10.1039/c6nj02560a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel cross-dehydrogenative coupling (CDC) of heterocyclic N-oxides with toluene derivatives has been disclosed.
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Affiliation(s)
- L. Wan
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - K. Qiao
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - X. N. Sun
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - Z. C. Di
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - Z. Fang
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - Z. J. Li
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
| | - K. Guo
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- 30 Puzhu South Road
- Nanjing
- P. R. China
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8
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Pham TTM, Pino Rodriguez NJ, Hijri M, Sylvestre M. Optimizing Polychlorinated Biphenyl Degradation by Flavonoid-Induced Cells of the Rhizobacterium Rhodococcus erythropolis U23A. PLoS One 2015; 10:e0126033. [PMID: 25970559 PMCID: PMC4430277 DOI: 10.1371/journal.pone.0126033] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/27/2015] [Indexed: 01/11/2023] Open
Abstract
There is evidence that many plant secondary metabolites may act as signal molecules to trigger the bacterial ability to metabolize polychlorinated biphenyls (PCBs) during the rhizoremediation process. However, the bases for the PCB rhizoremediation process are still largely unknown. The rhizobacterium Rhodococcus erythropolis U23A is unable to use flavanone as a growth substrate. However, on the basis of an assay that monitors the amount of 4-chlorobenzoate produced from 4-chlorobiphenyl by cells grown co-metabolically on flavanone plus sodium acetate, this flavonoid was previously found to be a potential inducer of the U23A biphenyl catabolic pathway. In this work, and using the same assay, we identified ten other flavonoids that did not support growth, but that acted as inducers of the U23A biphenyl pathway, and we confirmed flavonoid induction of the biphenyl catabolic pathway using quantitative real-time polymerase chain reaction (RT-qPCR) on the bphA gene. We also examined the effect of the growth co-substrate on flavonoid induction. Sodium acetate was replaced by glucose, mannose, sucrose, or mannitol, which are sugars found in plant root exudates. The data showed that the level of induction of strain U23A biphenyl-degrading enzymes was significantly influenced by the nature and concentration of the flavonoid in the growth medium, as well as by the substrate used for growth. Sucrose allowed for an optimal induction response for most flavonoids. Some flavonoids, such as flavone and isoflavone, were better inducers of the biphenyl catabolic enzymes than biphenyl itself. We also found that all flavonoids tested in this work were metabolized by strain U23A during co-metabolic growth, but that the metabolite profiles, as well as the level of efficiency of degradation, differed for each flavonoid. To obtain insight into how flavonoids interact with strain U23A to promote polychlorinated biphenyl (PCB) degradation, we determined the concentration of flavanone at which optimal PCB-degrading performance of strain U23A was achieved. We showed that it corresponded to the concentration required to fully induce the biphenyl catabolic pathway of the strain. Together, our data demonstrate that optimal PCB degradation during the rhizoremediation process will require the adjustment of several parameters, including the presence of the appropriate flavonoids at the proper concentrations and the presence of proper growth substrates that positively influence the ability of flavonoids to induce the pathway.
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Affiliation(s)
- Thi Thanh My Pham
- Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Québec, Canada
| | | | - Mohamed Hijri
- Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
| | - Michel Sylvestre
- Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Québec, Canada
- * E-mail:
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9
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Kianmehr E, Faghih N, Khan KM. Palladium-Catalyzed Regioselective Benzylation–Annulation of Pyridine N-Oxides with Toluene Derivatives via Multiple C–H Bond Activations: Benzylation versus Arylation. Org Lett 2015; 17:414-7. [DOI: 10.1021/ol503238a] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Ebrahim Kianmehr
- School
of Chemistry, College of Science, University of Tehran, Tehran 1417614411, Iran
| | - Nasser Faghih
- School
of Chemistry, College of Science, University of Tehran, Tehran 1417614411, Iran
| | - Khalid Mohammed Khan
- H.
E. J. Research Institute of Chemistry, International Center for Chemical
and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
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10
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Catalytic CC bond forming transformations via direct β-CH functionalization of carbonyl compounds. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.09.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Has the bacterial biphenyl catabolic pathway evolved primarily to degrade biphenyl? The diphenylmethane case. J Bacteriol 2013; 195:3563-74. [PMID: 23749969 DOI: 10.1128/jb.00161-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this work, we have compared the ability of Pandoraea pnomenusa B356 and of Burkholderia xenovorans LB400 to metabolize diphenylmethane and benzophenone, two biphenyl analogs in which the phenyl rings are bonded to a single carbon. Both chemicals are of environmental concern. P. pnomenusa B356 grew well on diphenylmethane. On the basis of growth kinetics analyses, diphenylmethane and biphenyl were shown to induce the same catabolic pathway. The profile of metabolites produced during growth of strain B356 on diphenylmethane was the same as the one produced by isolated enzymes of the biphenyl catabolic pathway acting individually or in coupled reactions. The biphenyl dioxygenase oxidizes diphenylmethane to 3-benzylcyclohexa-3,5-diene-1,2-diol very efficiently, and ultimately this metabolite is transformed to phenylacetic acid, which is further metabolized by a lower pathway. Strain B356 was also able to cometabolize benzophenone through its biphenyl pathway, although in this case, this substrate was unable to induce the biphenyl catabolic pathway and the degradation was incomplete, with accumulation of 2-hydroxy-6,7-dioxo-7-phenylheptanoic acid. Unlike strain B356, B. xenovorans LB400 did not grow on diphenylmethane. Its biphenyl pathway enzymes metabolized diphenylmethane, but they poorly metabolize benzophenone. The fact that the biphenyl catabolic pathway of strain B356 metabolized diphenylmethane and benzophenone more efficiently than that of strain LB400 brings us to postulate that in strain B356, this pathway evolved divergently to serve other functions not related to biphenyl degradation.
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12
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Kumar P, Mohammadi M, Dhindwal S, Pham TTM, Bolin JT, Sylvestre M. Structural insights into the metabolism of 2-chlorodibenzofuran by an evolved biphenyl dioxygenase. Biochem Biophys Res Commun 2012; 421:757-62. [DOI: 10.1016/j.bbrc.2012.04.078] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 04/14/2012] [Indexed: 11/16/2022]
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13
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Remarkable ability of Pandoraea pnomenusa B356 biphenyl dioxygenase to metabolize simple flavonoids. Appl Environ Microbiol 2012; 78:3560-70. [PMID: 22427498 DOI: 10.1128/aem.00225-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many investigations have provided evidence that plant secondary metabolites, especially flavonoids, may serve as signal molecules to trigger the abilities of bacteria to degrade chlorobiphenyls in soil. However, the bases for this interaction are largely unknown. In this work, we found that BphAE(B356), the biphenyl/chlorobiphenyl dioxygenase from Pandoraea pnomenusa B356, is significantly better fitted to metabolize flavone, isoflavone, and flavanone than BphAE(LB400) from Burkholderia xenovorans LB400. Unlike those of BphAE(LB400), the kinetic parameters of BphAE(B356) toward these flavonoids were in the same range as for biphenyl. In addition, remarkably, the biphenyl catabolic pathway of strain B356 was strongly induced by isoflavone, whereas none of the three flavonoids induced the catabolic pathway of strain LB400. Docking experiments that replaced biphenyl in the biphenyl-bound form of the enzymes with flavone, isoflavone, or flavanone showed that the superior ability of BphAE(B356) over BphAE(LB400) is principally attributable to the replacement of Phe336 of BphAE(LB400) by Ile334 and of Thr335 of BphAE(LB400) by Gly333 of BphAE(B356). However, biochemical and structural comparison of BphAE(B356) with BphAE(p4), a mutant of BphAE(LB400) which was obtained in a previous work by the double substitution Phe336Met Thr335Ala of BphAE(LB400), provided evidence that other residues or structural features of BphAE(B356) whose precise identification the docking experiment did not allow are also responsible for the superior catalytic abilities of BphAE(B356). Together, these data provide supporting evidence that the biphenyl catabolic pathways have evolved divergently among proteobacteria, where some of them may serve ecological functions related to the metabolism of plant secondary metabolites in soil.
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14
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Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran. Biochem Biophys Res Commun 2012; 419:362-7. [PMID: 22342725 DOI: 10.1016/j.bbrc.2012.02.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/03/2012] [Indexed: 11/23/2022]
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15
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Bioconversion of substituted naphthalenes and β-eudesmol with the cytochrome P450 BM3 variant F87V. Appl Microbiol Biotechnol 2010; 90:147-57. [DOI: 10.1007/s00253-010-3064-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 12/05/2010] [Accepted: 12/06/2010] [Indexed: 10/18/2022]
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16
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Structural insight into the expanded PCB-degrading abilities of a biphenyl dioxygenase obtained by directed evolution. J Mol Biol 2010; 405:531-47. [PMID: 21073881 DOI: 10.1016/j.jmb.2010.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/01/2010] [Accepted: 11/02/2010] [Indexed: 11/23/2022]
Abstract
The biphenyl dioxygenase of Burkholderia xenovorans LB400 is a multicomponent Rieske-type oxygenase that catalyzes the dihydroxylation of biphenyl and many polychlorinated biphenyls (PCBs). The structural bases for the substrate specificity of the enzyme's oxygenase component (BphAE(LB400)) are largely unknown. BphAE(p4), a variant previously obtained through directed evolution, transforms several chlorobiphenyls, including 2,6-dichlorobiphenyl, more efficiently than BphAE(LB400), yet differs from the parent oxygenase at only two positions: T335A/F336M. Here, we compare the structures of BphAE(LB400) and BphAE(p4) and examine the biochemical properties of two BphAE(LB400) variants with single substitutions, T335A or F336M. Our data show that residue 336 contacts the biphenyl and influences the regiospecificity of the reaction, but does not enhance the enzyme's reactivity toward 2,6-dichlorobiphenyl. By contrast, residue 335 does not contact biphenyl but contributes significantly to expansion of the enzyme's substrate range. Crystal structures indicate that Thr335 imposes constraints through hydrogen bonds and nonbonded contacts to the segment from Val320 to Gln322. These contacts are lost when Thr is replaced by Ala, relieving intramolecular constraints and allowing for significant movement of this segment during binding of 2,6-dichlorobiphenyl, which increases the space available to accommodate the doubly ortho-chlorinated congener 2,6-dichlorobiphenyl. This study provides important insight about how Rieske-type oxygenases can expand substrate range through mutations that increase the plasticity and/or mobility of protein segments lining the catalytic cavity.
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17
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Novel antibacterial compounds specifically targeting the essential WalR response regulator. J Antibiot (Tokyo) 2010; 63:127-34. [PMID: 20111065 DOI: 10.1038/ja.2010.4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The WalK/WalR (YycG/YycF) two-component system, which is essential for cell viability, is highly conserved and specific to low-GC percentage of Gram-positive bacteria, making it an attractive target for novel antimicrobial compounds. Recent work has shown that WalK/WalR exerts an effect as a master regulatory system in controlling and coordinating cell wall metabolism with cell division in Bacillus subtilis and Staphylococcus aureus. In this paper, we develop a high-throughput screening system for WalR inhibitors and identify two novel inhibitors targeting the WalR response regulator (RR): walrycin A (4-methoxy-1-naphthol) and walrycin B (1,6-dimethyl-3-[4-(trifluoromethyl)phenyl]pyrimido[5,4-e][1,2,4]triazine-5,7-dione). Addition of these compounds simultaneously affects the expression of WalR regulon genes, leading to phenotypes consistent with those of cells starved for the WalK/WalR system and having a bactericidal effect. B. subtilis cells form extremely long aseptate filaments and S. aureus cells form large aggregates under these conditions. These results show that walrycins A and B are the first antibacterial agents targeting WalR in B. subtilis and S. aureus.
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18
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Sylvestre M, Macek T, Mackova M. Transgenic plants to improve rhizoremediation of polychlorinated biphenyls (PCBs). Curr Opin Biotechnol 2009; 20:242-7. [PMID: 19250817 DOI: 10.1016/j.copbio.2009.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 01/22/2009] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
Abstract
Recent investigations have shown that the three components of the biphenyl dioxygenase and the 2,3-dihydroxybiphenyl dioxygenase can be produced actively in transgenic plants. Both enzymes catalyze critical steps of the bacterial polychlorinated biphenyl (PCB) degrading pathway. On the basis of these observations, optimized plant-microbe bioremediation processes in which transgenic plants would initiate PCB metabolism and release the metabolites for further degradation by rhizobacteria has been proposed. Since this is still a relatively new approach for PCB remediation, its successful application will require efforts first, to engineer improved PCB-degrading enzymes; second, to co-ordinately express these enzymes' components in plants; and third, to better understand the mechanisms by which plants and rhizobacteria interact to degrade organic pollutants.
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Affiliation(s)
- Michel Sylvestre
- Institut national de la recherche scientifique, INRS-Institut Armand-Frappier, Laval, Québec, Canada.
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19
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Kagami O, Shindo K, Kyojima A, Takeda K, Ikenaga H, Furukawa K, Misawa N. Protein engineering on biphenyl dioxygenase for conferring activity to convert 7-hydroxyflavone and 5,7-dihydroxyflavone (chrysin). J Biosci Bioeng 2008; 106:121-7. [PMID: 18804053 DOI: 10.1263/jbb.106.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Accepted: 04/28/2008] [Indexed: 11/17/2022]
Abstract
A central part (amino-acid position 268-397 of 458 amino-acid residues) of the biphenyl dioxygenase large (alpha) subunit, BphA1, from Pseudomonas pseudoalcaligenes strain KF707 was exchanged with the corresponding part of BphA1 from another biphenyl-degrading bacterium, Pseudomonas putida strain KF715, to construct hybrid BphA1, BphA1 (715-707). When expressed in Escherichia coli together with the bphA2A3A4BC genes from strain KF707, this enzyme was shown to possess activity for degrading both 1-phenylnaphthalene and 2-phenylnaphthalene. Between central parts of BphA1 from strains KF707 and KF715, the difference of amino-acid residues resided only in position 324-325. An attempt was made to improve the substrate preference of BphA1 by applying random amino-acid substitutions at these positions to BphA1 (715-707). After screening the mutant library to bioconvert several flavonoids, BphA1 (1-22; T324A and I325L) and BphA1 (2-2; T324L and I325I) were selected. When expressed in E. coli together with bphA2A3A4B from strain KF707, both BphA1 (1-22) and BphA1 (2-2) bioconverted the refractory flavonoids, 7-hydroxyflavone and 5,7-dihydroxyflavone (chrysin), which were hardly converted by any unmodified and artificially-modified shuffled biphenyl dioxygeneses, into their vicinal diol forms, i.e., 2-(2,3-dihydroxyphenyl)-7-hydroxy-chromen-4-one and 2-(2,3-dihydroxyphenyl)-5,7-dihydroxy-chromen-4-one, respectively. In addition, trans-chalcone was converted into 3-(2,3-dihydroxyphenyl)-1-phenylpropan-1-one and further into 1,3-bis-(2,3-dihydroxyphenyl)-propan-1-one. The antioxidative activity of these generated compounds was markedly higher than that of the original substrates used.
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Affiliation(s)
- Osamu Kagami
- Marine Biotechnology Institute, Kamaishi, Iwate, Japan
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20
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Al Rahim M, Nakajima A, Misawa N, Shindo K, Adachi K, Shizuri Y, Ohizumi Y, Yamakuni T. A novel diol-derivative of chalcone produced by bioconversion, 3-(2,3-dihydroxyphenyl)-1-phenylpropan-1-one, activates PKA/MEK/ERK signaling and antagonizes Abeta-inhibition of the cascade in cultured rat CNS neurons. Eur J Pharmacol 2008; 600:10-7. [PMID: 18948095 DOI: 10.1016/j.ejphar.2008.09.046] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 09/25/2008] [Accepted: 09/29/2008] [Indexed: 10/21/2022]
Abstract
Chalcone compounds have been widely studied for their anti-inflammatory, anti-pyretic, anti-invasive and anti-proliferative activities in various cell lines. However, their effects on the central nervous system (CNS) are still largely unexplored. We have recently developed a bioconversion system using a recombinant Escherichia coli that enables us to produce chemical compounds that are naturally rare and usually difficult to chemically synthesize. One such compound is 3-(2,3-dihydroxyphenyl)-1-phenylpropan-1-one, a novel chalcone-diol. Here we show, for the first time, that the chalcone-diol enhanced the phosphorylation of extracellular signal-regulated kinase (ERK) in a time- and concentration-dependent manner in cultured cortical neurons. Also, this chalcone-diol increased intracellular cyclic AMP (cAMP) concentration, thereby enhancing phosphorylation of ERK and cAMP-response element-binding protein (CREB), and CRE-mediated transcription via the cAMP-dependent protein kinase (PKA)/mitogen-activated protein kinase/ERK kinase (MEK) pathway in cultured rat hippocampal neurons. Recent studies have demonstrated that PKA/CREB-dependent signaling, which is required for long-term potentiation, is inhibited by sublethal concentrations of amyloid beta-peptide (Abeta) in cultured hippocampal neurons. After treatment with the chalcone-diol at 50 muM prior to treatment with a sublethal concentration of Abeta(1-42), the Abeta(1-42)-induced inhibition of phosphorylation of PKA substrates and CREB was prevented in cultured hippocampal neurons, indicating the potential for protection against the Abeta-induced impairment of PKA/CREB signaling observed in Alzheimer's disease. Therefore, these results suggest that our present study provides a new approach for discovering novel lead compounds for the treatment of neurodegenerative CNS diseases associated with impaired PKA/CREB signaling, including Alzheimer's disease.
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Affiliation(s)
- Md Al Rahim
- Department of Pharmacotherapy, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Sendai, Japan
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21
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Furukawa K, Fujihara H. Microbial degradation of polychlorinated biphenyls: Biochemical and molecular features. J Biosci Bioeng 2008; 105:433-49. [PMID: 18558332 DOI: 10.1263/jbb.105.433] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Accepted: 02/04/2008] [Indexed: 11/17/2022]
Affiliation(s)
- Kensuke Furukawa
- Depatment of Food and Bioscience, Faculty of Food and Nutrition, Beppu University, Beppu, Ohita 874-8501, Japan.
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22
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Kobayashi K, Fukamachi S, Nakamura D, Morikawa O, Konishi H. Convenient Synthesis of 1,4-Dihydro-2H-3,1-benzoxazin-2-ones by Iodocyclization of t-Butyl 2-Vinylphenylcarbamate. HETEROCYCLES 2008. [DOI: 10.3987/com-07-11186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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23
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Kobayashi K, Fukamachi S, Konishi H. Synthesis of 1,4-Dihydro-2H-3,1-benzoxazin-2-ones by Hydriodic Acid Mediated Cyclization of tert-Butyl 2-Vinylphenylcarbamates. HETEROCYCLES 2008. [DOI: 10.3987/com-08-11399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Mohammadi M, Chalavi V, Novakova-Sura M, Laliberté JF, Sylvestre M. Expression of bacterial biphenyl-chlorobiphenyl dioxygenase genes in tobacco plants. Biotechnol Bioeng 2007; 97:496-505. [PMID: 17006888 DOI: 10.1002/bit.21188] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Optimized plant-microbe bioremediation processes in which the plant initiates the metabolism of xenobiotics and releases the metabolites in the rhizosphere to be further degraded by the rhizobacteria is a promising alternative to restore contaminated sites in situ. However, such processes require that plants produce the metabolites that bacteria can readily oxidize. The biphenyl dioxygenase is the first enzyme of the bacterial catabolic pathway involved in the degradation of polychlorinated biphenyls. This enzyme consists of three components: the two sub-unit oxygenase (BphAE) containing a Rieske-type iron-sulfur cluster and a mononuclear iron center, the Rieske-type ferredoxin (BphF), and the FAD-containing ferredoxin reductase (BphG). In this work, based on analyses with Nicotiana benthamiana plants transiently expressing the biphenyl dioxygenase genes from Burkholderia xenovorans LB400 and transgenic Nicotiana tabacum plants transformed with each of these four genes, we have shown that each of the three biphenyl dioxygenase components can be produced individually as active protein in tobacco plants. Therefore, when BphAE, BphF, and BphG purified from plant were used to catalyze the oxygenation of 4-chlorobiphenyl, detectable amounts of 2,3-dihydro-2, 3-dihydroxy-4'-chlorobiphenyl were produced. This suggests that creating transgenic plants expressing simultaneously all four genes required to produce active biphenyl dioxygenase is feasible.
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Affiliation(s)
- Mahmood Mohammadi
- Institut National de la Recherche Scientifique, INRS-Institut-Armand-Frappier, 531 Boul des Prairies, Laval, Quebec, Canada
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25
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Shindo K, Shindo Y, Hasegawa T, Osawa A, Kagami O, Furukawa K, Misawa N. Synthesis of highly hydroxylated aromatics by evolved biphenyl dioxygenase and subsequent dihydrodiol dehydrogenase. Appl Microbiol Biotechnol 2007; 75:1063-9. [PMID: 17401562 DOI: 10.1007/s00253-007-0928-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/05/2007] [Accepted: 03/06/2007] [Indexed: 11/28/2022]
Abstract
The evolved bphA1 (2049) gene, in which nine amino acids from the Pseudomonas pseudoalcaligenes KF707 BphA1 were changed to those from the Burkholderia xenovorans LB400 BphA1 (M247I, H255Q, V258I, G268A, D303E, -313G, S324T, V325I, and T376N), was expressed in Escherichia coli along with the bphA2A3A4 and bphB genes derived from strain KF707. This recombinant E. coli cells converted biphenyl and several heterocyclic aromatic compounds into the highly hydroxylated products such as biphenyl-2,3,2',3'-tetraol (from biphenyl), 2-(2,3-dihydroxyphenyl)benzoxazole-4,5-diol (from 2-phenylbenzoxazole), and 2-(2,5-dihydroxyphenyl)benzoxazole-4,5-diol [from 2-(2-hydroxyphenyl)benzoxazole]. The antioxidative activity of these generated compounds was markedly higher than that of the original substrate used.
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Affiliation(s)
- Kazutoshi Shindo
- Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan.
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26
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Biocatalytic synthesis of monocyclic arene-dihydrodiols and -diols by Escherichia coli cells expressing hybrid toluene/biphenyl dioxygenase and dihydrodiol dehydrogenase genes. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcatb.2005.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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