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Chan HSS, Thompson AL, Christensen KE, Burton JW. Forwards and backwards - synthesis of Laurencia natural products using a biomimetic and retrobiomimetic strategy incorporating structural reassignment of laurefurenynes C-F. Chem Sci 2020; 11:11592-11600. [PMID: 34094406 PMCID: PMC8162873 DOI: 10.1039/d0sc04120c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/25/2020] [Indexed: 11/26/2022] Open
Abstract
Laurefurenynes C-F are four natural products isolated from Laurencia species whose structures were originally determined on the basis of extensive nuclear magnetic resonance experiments. On the basis of a proposed biogenesis, involving a tricyclic oxonium ion as a key intermediate, we have reassigned the structures of these four natural products and synthesized the four reassigned structures using a biomimetic approach demonstrating that they are the actual structures of the natural products. In addition, we have developed a synthesis of the enantiomers of the natural products laurencin and deacetyllaurencin from the enantiomer of (E)-laurefucin using an unusual retrobiomimetic strategy. All of these syntheses have been enabled by the use of tricyclic oxonium ions as pivotal synthetic intermediates.
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Affiliation(s)
- Hau Sun Sam Chan
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Amber L Thompson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Kirsten E Christensen
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Jonathan W Burton
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
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2
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Taylor CA, Zhang YA, Snyder SA. The enantioselective total synthesis of laurendecumallene B. Chem Sci 2020; 11:3036-3041. [PMID: 34122807 PMCID: PMC8157515 DOI: 10.1039/c9sc06116a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/05/2020] [Indexed: 02/04/2023] Open
Abstract
For decades, the Laurencia family of halogenated C15-acetogenins has served as a valuable testing ground for the prowess of chemical synthesis, particularly as it relates to generating functionalized 8-membered bromoethers. Herein, we show that a readily modified and predictable approach that generates such rings and an array of attendant stereocenters via a bromenium-induced cyclization/ring-expansion process can be used to synthesize laurendecumallene B and determine the configuration of two of its previously unassigned stereocenters. In particular, this work highlights how the use of the bromenium source BDSB (Et2SBr·SbCl5Br) in non-conventional solvents is essential in generating much of the target's complexity in optimal yields and stereoselectivity. Moreover, the final structural assignment of laurendecumallene B reveals that it has one element of bromine-based chirality that, to the best of our knowledge, is not shared with any other member of the class.
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Affiliation(s)
- Cooper A Taylor
- Department of Chemistry, University of Chicago 5735 S. Ellis Avenue Chicago IL 60637 USA
| | - Yu-An Zhang
- Department of Chemistry, University of Chicago 5735 S. Ellis Avenue Chicago IL 60637 USA
| | - Scott A Snyder
- Department of Chemistry, University of Chicago 5735 S. Ellis Avenue Chicago IL 60637 USA
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3
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Sam Chan HS, Nguyen QNN, Paton RS, Burton JW. Synthesis, Characterization, and Reactivity of Complex Tricyclic Oxonium Ions, Proposed Intermediates in Natural Product Biosynthesis. J Am Chem Soc 2019; 141:15951-15962. [PMID: 31560524 DOI: 10.1021/jacs.9b07438] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Reactive intermediates frequently play significant roles in the biosynthesis of numerous classes of natural products although the direct observation of these biosynthetically relevant species is rare. We present here direct evidence for the existence of complex, thermally unstable, tricyclic oxonium ions that have been postulated as key reactive intermediates in the biosynthesis of numerous halogenated natural products from Laurencia species. Evidence for their existence comes from full characterization of these oxonium ions by low-temperature NMR spectroscopy supported by density functional theory (DFT) calculations, coupled with the direct generation of 10 natural products on exposure of the oxonium ions to various nucleophiles.
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Affiliation(s)
- Hau Sun Sam Chan
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Q Nhu N Nguyen
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
| | - Robert S Paton
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K.,Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States
| | - Jonathan W Burton
- Chemistry Research Laboratory , University of Oxford , Mansfield Road , Oxford OX1 3TA , U.K
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4
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Scinto SL, Ekanayake O, Seneviratne U, Pigga JE, Boyd SJ, Taylor MT, Liu J, Am Ende CW, Rozovsky S, Fox JM. Dual-Reactivity trans-Cyclooctenol Probes for Sulfenylation in Live Cells Enable Temporal Control via Bioorthogonal Quenching. J Am Chem Soc 2019; 141:10932-10937. [PMID: 31246462 DOI: 10.1021/jacs.9b01164] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Sulfenylation (RSH → RSOH) is a post-translational protein modification associated with cellular mechanisms for signal transduction and the regulation of reactive oxygen species. Protein sulfenic acids are challenging to identify and study due to their electrophilic and transient nature. Described here are sulfenic acid modifying trans-cycloocten-5-ol (SAM-TCO) probes for labeling sulfenic acid functionality in live cells. These probes enable a new mode of capturing sulfenic acids via transannular thioetherification, whereas "ordinary" trans-cyclooctenes react only slowly with sulfenic acids. SAM-TCOs combine with sulfenic acid forms of a model peptide and proteins to form stable adducts. Analogously, SAM-TCO with the selenenic acid form of a model protein leads to a selenoetherification product. Control experiments illustrate the need for the transannulation process coupled with the activated trans-cycloalkene functionality. Bioorthogonal quenching of excess unreacted SAM-TCOs with tetrazines in live cells provides both temporal control and a means of preventing artifacts caused by cellular-lysis. A SAM-TCO biotin conjugate was used to label protein sulfenic acids in live cells, and subsequent quenching by tetrazine prevented further labeling even under harshly oxidizing conditions. A cell-based proteomic study validates the ability of SAM-TCO probes to identify and quantify known sulfenic acid redox proteins as well as targets not captured by dimedone-based probes.
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Affiliation(s)
- Samuel L Scinto
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Oshini Ekanayake
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Uthpala Seneviratne
- Pfizer Worldwide Research and Development , Cambridge , Massachusetts 02139 , United States
| | - Jessica E Pigga
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Samantha J Boyd
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Michael T Taylor
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Jun Liu
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Christopher W Am Ende
- Pfizer Worldwide Research and Development , Groton , Connecticut 06340 , United States
| | - Sharon Rozovsky
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
| | - Joseph M Fox
- Department of Chemistry and Biochemistry , University of Delaware , Newark , Delaware 19716 , United States
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5
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Zhang YA, Yaw N, Snyder SA. General Synthetic Approach for the Laurencia Family of Natural Products Empowered by a Potentially Biomimetic Ring Expansion. J Am Chem Soc 2019; 141:7776-7788. [DOI: 10.1021/jacs.9b01088] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Yu-An Zhang
- Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Natalie Yaw
- Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Scott A. Snyder
- Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
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6
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Lambert WD, Scinto SL, Dmitrenko O, Boyd SJ, Magboo R, Mehl RA, Chin JW, Fox JM, Wallace S. Computationally guided discovery of a reactive, hydrophilic trans-5-oxocene dienophile for bioorthogonal labeling. Org Biomol Chem 2018; 15:6640-6644. [PMID: 28752889 PMCID: PMC5708333 DOI: 10.1039/c7ob01707c] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The use of organic chemistry principles and prediction techniques has enabled the development of new bioorthogonal reactions. As this "toolbox" expands to include new reaction manifolds and orthogonal reaction pairings, the continued development of existing reactions remains an important objective. This is particularly important in cellular imaging, where non-specific background fluorescence has been linked to the hydrophobicity of the bioorthogonal moiety. Here we report that trans-5-oxocene (oxoTCO) displays enhanced reactivity and hydrophilicity compared to trans-cyclooctene (TCO) in the tetrazine ligation reaction. Aided by ab initio calculations we show that the insertion of a single oxygen atom into the trans-cyclooctene (TCO) ring system is sufficient to impart aqueous solubility and also results in significant rate acceleration by increasing angle strain. We demonstrate the rapid and quantitative cycloaddition of oxoTCO using a water-soluble tetrazine derivative and a protein substrate containing a site-specific genetically encoded tetrazine moiety both in vitro and in vivo. We anticipate that oxoTCO will find use in studies where hydrophilicity and fast bioconjugation kinetics are paramount.
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Affiliation(s)
- William D Lambert
- Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
| | - Samuel L Scinto
- Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
| | - Olga Dmitrenko
- Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
| | - Samantha J Boyd
- Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
| | | | - Ryan A Mehl
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, USA
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Joseph M Fox
- Brown Laboratory, Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
| | - Stephen Wallace
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK and Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, UK
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Clarke J, Bonney KJ, Yaqoob M, Solanki S, Rzepa HS, White AJP, Millan DS, Braddock DC. Epimeric Face-Selective Oxidations and Diastereodivergent Transannular Oxonium Ion Formation Fragmentations: Computational Modeling and Total Syntheses of 12-Epoxyobtusallene IV, 12-Epoxyobtusallene II, Obtusallene X, Marilzabicycloallene C, and Marilzabicycloallene D. J Org Chem 2016; 81:9539-9552. [PMID: 27704814 DOI: 10.1021/acs.joc.6b02008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The total syntheses of 12-epoxyobtusallene IV, 12-epoxyobtusallene II, obtusallene X, marilzabicycloallene C, and marilzabicycloallene D as halogenated C15-acetogenin 12-membered bicyclic and tricyclic ether bromoallene-containing marine metabolites from Laurencia species are described. Two enantiomerically pure C4-epimeric dioxabicyclo[8.2.1]tridecenes were synthesized by E-selective ring-closing metathesis where their absolute stereochemistry was previously set via catalytic asymmetric homoallylic epoxidation and elaborated via regioselective epoxide-ring opening and diastereoselective bromoetherification. Epimeric face-selective oxidation of their Δ12,13 olefins followed by bromoallene installation allowed access to the oppositely configured 12,13-epoxides of 12-epoxyobtusallene II and 12-epoxyobtusallene IV. Subsequent exploration of their putative biomimetic oxonium ion formation-fragmentations reactions revealed diastereodivergent pathways giving marilzabicycloallene C and obtusallene X, respectively. The original configurations of the substrates evidently control oxonium ion formation and their subsequent preferred mode of fragmentation by nucleophilic attack at C9 or C12. Quantum modeling of this stereoselectivity at the ωB97X-D/Def2-TZVPPD/SCRF = methanol level revealed that in addition to direction resulting from hydrogen bonding, the dipole moment of the ion-pair transition state is an important factor. Marilzabicycloallene D as a pentahalogenated 12-membered bicyclic ether bromoallene was synthesized by a face-selective chloronium ion initiated oxonium ion formation-fragmentation process followed by subsequent bromoallene installation.
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Affiliation(s)
- James Clarke
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - Karl J Bonney
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - Muhammad Yaqoob
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - Savade Solanki
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - Henry S Rzepa
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - Andrew J P White
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
| | - David S Millan
- Sandwich Laboratories, Pfizer Global Research and Development, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - D Christopher Braddock
- Department of Chemistry, Imperial College London , South Kensington, London, SW7 2AZ, U.K
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