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Ruiz de Martín Esteban S, Benito-Cuesta I, Terradillos I, Martínez-Relimpio AM, Arnanz MA, Ruiz-Pérez G, Korn C, Raposo C, Sarott RC, Westphal MV, Elezgarai I, Carreira EM, Hillard CJ, Grether U, Grandes P, Grande MT, Romero J. Cannabinoid CB 2 Receptors Modulate Microglia Function and Amyloid Dynamics in a Mouse Model of Alzheimer's Disease. Front Pharmacol 2022; 13:841766. [PMID: 35645832 PMCID: PMC9136843 DOI: 10.3389/fphar.2022.841766] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/30/2022] [Indexed: 12/23/2022] Open
Abstract
The distribution and roles of the cannabinoid CB2 receptor in the CNS are still a matter of debate. Recent data suggest that, in addition to its presence in microglial cells, the CB2 receptor may be also expressed at low levels, yet biologically relevant, in other cell types such as neurons. It is accepted that the expression of CB2 receptors in the CNS is low under physiological conditions and is significantly elevated in chronic neuroinflammatory states associated with neurodegenerative diseases such as Alzheimer's disease. By using a novel mouse model (CB2 EGFP/f/f), we studied the distribution of cannabinoid CB2 receptors in the 5xFAD mouse model of Alzheimer's disease (by generating 5xFAD/CB2 EGFP/f/f mice) and explored the roles of CB2 receptors in microglial function. We used a novel selective and brain penetrant CB2 receptor agonist (RO6866945) as well as mice lacking the CB2 receptor (5xFAD/CB2 -/-) for these studies. We found that CB2 receptors are expressed in dystrophic neurite-associated microglia and that their modulation modifies the number and activity of microglial cells as well as the metabolism of the insoluble form of the amyloid peptide. These results support microglial CB2 receptors as potential targets for the development of amyloid-modulating therapies.
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Guberman M, Kosar M, Omran A, Carreira EM, Nazaré M, Grether U. Reverse-Design toward Optimized Labeled Chemical Probes – Examples from the Endocannabinoid System. Chimia (Aarau) 2022. [DOI: 10.2533/chimia.2022.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Labeled chemical probes are of utmost importance to bring drugs from the laboratory through the clinic and ultimately to market. They support and impact all research and discovery phases: target verification and validation; assay development; lead optimization; and biomarker engagement in the context of preclinical studies and human trials. Probes should display high potency and selectivity as well as fulfill specific criteria in connection with absorption, distribution, metabolism, excretion and toxicology (ADMET) profile. Progress in fields such as imaging and proteomics increased the need for specialized probes to support drug discovery. Labeled probes carrying an additional reporter group are valuable tools to meet specific application requirements, but pose significant challenges in design and construction. In the reverse-design approach, small molecules previously optimized in medicinal chemistry programs form the basis for the generation of such high-quality probes. We discuss the reverse design concept for the generation of labeled probes targeting the endocannabinoid system (ECS), a complex lipid signaling network that plays a key role in many human health and disease conditions. The examples highlighted include diverse reporter units for a range of applications. In several cases the reported probes were the product of mutually rewarding and highly cross-fertilizing collaborations among academic and industry research programs, a strategy that can serve as a blueprint for future probe generation efforts.
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Fischer D, Balkenhohl M, Carreira EM. Cobalt-Catalyzed Cyclization of Unsaturated N-Acyl Sulfonamides: a Diverted Mukaiyama Hydration Reaction. JACS AU 2022; 2:1071-1077. [PMID: 35647594 PMCID: PMC9131372 DOI: 10.1021/jacsau.2c00186] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
The cycloisomerization of β-, γ-, and δ-unsaturated N-acyl sulfonamides to N-sulfonyl lactams and imidates is reported. This transformation is effected in the presence of a CoIII(salen) catalyst using t-BuOOH or air as the oxidant. The method shows good functional group tolerance (alkyl, aryl, heteroaryl, ether, N-Boc) and furnishes an underexplored class of cyclic building blocks. The strong solvent dependence of the transformation is investigated, and the synthetic versatility of the N-sulfonyl imidate product class is highlighted.
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Gazzi T, Brennecke B, Atz K, Korn C, Sykes D, Forn-Cuni G, Pfaff P, Sarott RC, Westphal MV, Mostinski Y, Mach L, Wasinska-Kalwa M, Weise M, Hoare BL, Miljuš T, Mexi M, Roth N, Koers EJ, Guba W, Alker A, Rufer AC, Kusznir EA, Huber S, Raposo C, Zirwes EA, Osterwald A, Pavlovic A, Moes S, Beck J, Nettekoven M, Benito-Cuesta I, Grande T, Drawnel F, Widmer G, Holzer D, van der Wel T, Mandhair H, Honer M, Fingerle J, Scheffel J, Broichhagen J, Gawrisch K, Romero J, Hillard CJ, Varga ZV, van der Stelt M, Pacher P, Gertsch J, Ullmer C, McCormick PJ, Oddi S, Spaink HP, Maccarrone M, Veprintsev DB, Carreira EM, Grether U, Nazaré M. Detection of cannabinoid receptor type 2 in native cells and zebrafish with a highly potent, cell-permeable fluorescent probe. Chem Sci 2022; 13:5539-5545. [PMID: 35694350 PMCID: PMC9116301 DOI: 10.1039/d1sc06659e] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/22/2022] [Indexed: 12/16/2022] Open
Abstract
Despite its essential role in the (patho)physiology of several diseases, CB2R tissue expression profiles and signaling mechanisms are not yet fully understood. We report the development of a highly potent, fluorescent CB2R agonist probe employing structure-based reverse design. It commences with a highly potent, preclinically validated ligand, which is conjugated to a silicon-rhodamine fluorophore, enabling cell permeability. The probe is the first to preserve interspecies affinity and selectivity for both mouse and human CB2R. Extensive cross-validation (FACS, TR-FRET and confocal microscopy) set the stage for CB2R detection in endogenously expressing living cells along with zebrafish larvae. Together, these findings will benefit clinical translatability of CB2R based drugs. Detection and visualization of the cannabinoid receptor type 2 by a cell-permeable high affinity fluorescent probe platform enables tracing receptor trafficking in live cells and in zebrafish.![]()
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Hauser N, Imhof MA, Eichenberger SS, Kündig T, Carreira EM. Total Synthesis of Shearinines D and G: A Convergent Approach to Indole Diterpenoids. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202112838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Carreira EM. JACS 2021: In Review. J Am Chem Soc 2022; 144:1-2. [PMID: 35016510 DOI: 10.1021/jacs.1c13452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Grigolon G, Araldi E, Erni R, Wu JY, Thomas C, La Fortezza M, Laube B, Pöhlmann D, Stoffel M, Zarse K, Carreira EM, Ristow M, Fischer F. Grainyhead 1 acts as a drug-inducible conserved transcriptional regulator linked to insulin signaling and lifespan. Nat Commun 2022; 13:107. [PMID: 35013237 PMCID: PMC8748497 DOI: 10.1038/s41467-021-27732-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 12/06/2021] [Indexed: 12/13/2022] Open
Abstract
Aging is impacted by interventions across species, often converging on metabolic pathways. Transcription factors regulate longevity yet approaches for their pharmacological modulation to exert geroprotection remain sparse. We show that increased expression of the transcription factor Grainyhead 1 (GRH-1) promotes lifespan and pathogen resistance in Caenorhabditis elegans. A compound screen identifies FDA-approved drugs able to activate human GRHL1 and promote nematodal GRH-1-dependent longevity. GRHL1 activity is regulated by post-translational lysine methylation and the phosphoinositide (PI) 3-kinase C2A. Consistently, nematodal longevity following impairment of the PI 3-kinase or insulin/IGF-1 receptor requires grh-1. In BXD mice, Grhl1 expression is positively correlated with lifespan and insulin sensitivity. In humans, GRHL1 expression positively correlates with insulin receptor signaling and also with lifespan. Fasting blood glucose levels, including in individuals with type 2 diabetes, are negatively correlated with GRHL1 expression. Thereby, GRH-1/GRHL1 is identified as a pharmacologically malleable transcription factor impacting insulin signaling and lifespan. Life- and healthspan of organisms can be modulated by dietary, genetic, or pharmacological interventions, which often affect metabolic pathways. Here the authors report that Grainyhead 1 is an evolutionarily conserved, drug-inducible transcription factor that promotes longevity in C. elegans, and thus a potential target for the development of geroprotective drugs.
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Schreib BS, Son M, Aouane FA, Baik MH, Carreira EM. Allene C(sp 2)-H Activation and Alkenylation Catalyzed by Palladium. J Am Chem Soc 2021; 143:21705-21712. [PMID: 34914882 DOI: 10.1021/jacs.1c11528] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The selective transition-metal-mediated activation of C(sp2)-H bonds of allenes is a formidable challenge because of the competitive, intrinsic reactivity of cumulated double bonds. Herein, we report a Pd-catalyzed C-H alkenylation of electronically unbiased allenes, affording penta-1,2,4-triene products in up to 94% yield. A picolinamide directing group enables the formation of putative allenyl-palladacycles, which subsequently participate in a turnover-limiting Heck-type reaction with electron-deficient alkene coupling partners. This mechanistic proposal is consistent with experimental and computational investigations. Additionally, we report for the first time the use of picolinamide N,O-acetals as readily removable auxiliaries for C-H activation reactions, allowing the efficient alkenylation of allenyl carbinol derivatives. Successful removal of the directing groups without affecting the reactive penta-1,2,4-triene substructure of the products is demonstrated.
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Müller M, Gräbnitz F, Barandun N, Shen Y, Wendt F, Steiner SN, Severin Y, Vetterli SU, Mondal M, Prudent JR, Hofmann R, van Oostrum M, Sarott RC, Nesvizhskii AI, Carreira EM, Bode JW, Snijder B, Robinson JA, Loessner MJ, Oxenius A, Wollscheid B. Light-mediated discovery of surfaceome nanoscale organization and intercellular receptor interaction networks. Nat Commun 2021; 12:7036. [PMID: 34857745 PMCID: PMC8639842 DOI: 10.1038/s41467-021-27280-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 11/09/2021] [Indexed: 12/18/2022] Open
Abstract
The molecular nanoscale organization of the surfaceome is a fundamental regulator of cellular signaling in health and disease. Technologies for mapping the spatial relationships of cell surface receptors and their extracellular signaling synapses would unlock theranostic opportunities to target protein communities and the possibility to engineer extracellular signaling. Here, we develop an optoproteomic technology termed LUX-MS that enables the targeted elucidation of acute protein interactions on and in between living cells using light-controlled singlet oxygen generators (SOG). By using SOG-coupled antibodies, small molecule drugs, biologics and intact viral particles, we demonstrate the ability of LUX-MS to decode ligand receptor interactions across organisms and to discover surfaceome receptor nanoscale organization with direct implications for drug action. Furthermore, by coupling SOG to antigens we achieved light-controlled molecular mapping of intercellular signaling within functional immune synapses between antigen-presenting cells and CD8+ T cells providing insights into T cell activation with spatiotemporal specificity. LUX-MS based decoding of surfaceome signaling architectures thereby provides a molecular framework for the rational development of theranostic strategies. The spatial organization of cell surface receptors is critical for cell signaling and drug action. Here, the authors develop an optoproteomic method for mapping surface protein interactions, revealing cellular responses to antibodies, drugs and viral particles as well as immunosynapse signaling events.
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Schafroth MA, Mazzoccanti G, Reynoso-Moreno I, Erni R, Pollastro F, Caprioglio D, Botta B, Allegrone G, Grassi G, Chicca A, Gasparrini F, Gertsch J, Carreira EM, Appendino G. Δ 9- cis-Tetrahydrocannabinol: Natural Occurrence, Chirality, and Pharmacology. JOURNAL OF NATURAL PRODUCTS 2021; 84:2502-2510. [PMID: 34304557 DOI: 10.1021/acs.jnatprod.1c00513] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The cis-stereoisomers of Δ9-THC [(-)-3 and (+)-3] were identified and quantified in a series of low-THC-containing varieties of Cannabis sativa registered in Europe as fiber hemp and in research accessions of cannabis. While Δ9-cis-THC (3) occurs in cannabis fiber hemp in the concentration range of (-)-Δ9-trans-THC [(-)-1], it was undetectable in a sample of high-THC-containing medicinal cannabis. Natural Δ9-cis-THC (3) is scalemic (ca. 80-90% enantiomeric purity), and the absolute configuration of the major enantiomer was established as 6aS,10aR [(-)-3] by chiral chromatographic comparison with a sample available by asymmetric synthesis. The major enantiomer, (-)-Δ9-cis-THC [(-)-3], was characterized as a partial cannabinoid agonist in vitro and elicited a full tetrad response in mice at 50 mg/kg doses. The current legal discrimination between narcotic and non-narcotic cannabis varieties centers on the contents of "Δ9-THC and isomers" and needs therefore revision, or at least a more specific wording, to account for the presence of Δ9-cis-THCs [(+)-3 and (-)-3] in cannabis fiber hemp varieties.
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Pfaff P, Anderl F, Fink M, Balkenhohl M, Carreira EM. Azoacetylenes for the Synthesis of Arylazotriazole Photoswitches. J Am Chem Soc 2021; 143:14495-14501. [PMID: 34478268 PMCID: PMC8447256 DOI: 10.1021/jacs.1c06014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We report a modular approach toward novel arylazotriazole photoswitches and their photophysical characterization. Addition of lithiated TIPS-acetylene to aryldiazonium tetrafluoroborate salts gives a wide range of azoacetylenes, constituting an underexplored class of stable intermediates. In situ desilylation transiently leads to terminal arylazoacetylenes that undergo copper-catalyzed cycloadditions (CuAAC) with a diverse collection of organoazides. These include complex molecules derived from natural products or drugs, such as colchicine, taxol, tamiflu, and arachidonic acid. The arylazotriazoles display near-quantitative photoisomerization and long thermal Z-half-lives. Using the method, we introduce for the first time the design and synthesis of a diacetylene platform. It permits implementation of consecutive and diversity-oriented approaches linking two different conjugants to independently addressable acetylenes within a common photoswitchable azotriazole. This is showcased in the synthesis of several photoswitchable conjugates, with potential applications as photoPROTACs and biotin conjugates.
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Balkenhohl M, Kölbl S, Georgiev T, Carreira EM. Mn- and Co-Catalyzed Aminocyclizations of Unsaturated Hydrazones Providing a Broad Range of Functionalized Pyrazolines. JACS AU 2021; 1:919-924. [PMID: 34337605 PMCID: PMC8317158 DOI: 10.1021/jacsau.1c00176] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Manganese- and cobalt-catalyzed aminocyclization reactions of unsaturated hydrazones are reported. Whereas manganese catalysis provides access to pyrazoline and tetrahydropyridazine alcohols, cobalt catalysis for the first time paves the way for the selective formation of pyrazoline aldehydes. Furthermore, various functional groups including hydroperoxide, thiol derivatives, iodide, and bicyclopentane may be introduced via manganese-catalyzed ring-forming aminofunctionalization. A progesterone receptor antagonist was prepared using the aminocyclization protocol.
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Pultar F, Hansen ME, Wolfrum S, Böselt L, Fróis-Martins R, Bloch S, Kravina AG, Pehlivanoglu D, Schäffer C, LeibundGut-Landmann S, Riniker S, Carreira EM. Mutanobactin D from the Human Microbiome: Total Synthesis, Configurational Assignment, and Biological Evaluation. J Am Chem Soc 2021; 143:10389-10402. [PMID: 34212720 DOI: 10.1021/jacs.1c04825] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mutanobactin D is a non-ribosomal, cyclic peptide isolated from Streptococcus mutans and shows activity reducing yeast-to-hyphae transition as well as biofilm formation of the pathogenic yeast Candida albicans. We report the first total synthesis of this natural product, which relies on enantioselective, zinc-mediated 1,3-dipolar cycloaddition and a sequence of cascading reactions, providing the key lipidated γ-amino acid found in mutanobactin D. The synthesis enables configurational assignment, determination of the dominant solution-state structure, and studies to assess the stability of the lipopeptide substructure found in the natural product. The information stored in the fingerprint region of the IR spectra in combination with quantum chemical calculations proved key to distinguishing between epimers of the α-substituted β-keto amide. Synthetic mutanobactin D drives discovery and analysis of its effect on growth of other members of the human oral consortium. Our results showcase how total synthesis is central for elucidating the complex network of interspecies communications of human colonizers.
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Richter MJR, Schneider M, Brandstätter M, Krautwald S, Carreira EM. Correction to "Total Synthesis of (-)-Mitrephorone A". J Am Chem Soc 2021; 143:9694. [PMID: 34156866 DOI: 10.1021/jacs.1c05408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Classen MJ, Böcker MNA, Roth R, Amberg WM, Carreira EM. Enantioselective Total Synthesis of (+)-Euphorikanin A. J Am Chem Soc 2021; 143:8261-8265. [PMID: 34043906 DOI: 10.1021/jacs.1c04210] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We disclose the first total synthesis of (+)-euphorikanin A, an ingenane-derived natural product featuring an unprecedented 5/6/7/3-fused tetracyclic skeleton. Key to the approach is a SmI2-mediated ketyl-enoate reaction that leads to the formation of two rings in a single step. The polarity-reversed cyclization proceeds in excellent yield and high diastereoselectivity. Access to ring B is effected late in the synthesis by implementation of a number of chemoselective transformations, including in situ generation of a vinyl lithium species and subsequent intramolecular attack onto an α-ketolactone.
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Sandmeier T, Carreira EM. Enantioselective Synthesis of Cyclic Nitrones by Chemoselective Intramolecular Allylic Alkylation of Oximes. Angew Chem Int Ed Engl 2021; 60:9913-9918. [PMID: 33555650 DOI: 10.1002/anie.202100150] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/04/2021] [Indexed: 12/14/2022]
Abstract
The enantio- and chemoselective iridium-catalyzed N-allylation of oximes is described for the first time. Intramolecular kinetic resolution provides access to cyclic nitrones and enantioenriched aliphatic allylic alcohols. Salient features of this transformation are its ability to employ E/Z-isomeric mixtures of oxime starting materials convergently and high functional group tolerance. The implementation of N-allylation/1,3-dipolar cycloaddition reaction sequences furnishes tricyclic isoxazolidines in highly enantio- and diastereoselective fashion. The synthetic utility of the approach is demonstrated by the efficient, formal synthesis of the marine natural product (+)-halichlorine.
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Sandmeier T, Carreira EM. Enantioselective Synthesis of Cyclic Nitrones by Chemoselective Intramolecular Allylic Alkylation of Oximes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Carreira EM. Addition to "Enantiospecific Response in Cross-Polarization Solid-State Nuclear Magnetic Resonance of Optically Active Metal Organic Frameworks". J Am Chem Soc 2021; 143:5565. [PMID: 33794096 DOI: 10.1021/jacs.1c02989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sandmeier T, Carreira EM. Enantio- and Chemoselective Intramolecular Iridium-Catalyzed O-Allylation of Oximes. Org Lett 2021; 23:2643-2647. [PMID: 33749284 DOI: 10.1021/acs.orglett.1c00559] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A method for the enantio- and chemoselective iridium-catalyzed O-allylation of oximes is described. Kinetic resolution in an intramolecular setting provides enantioenriched oxime ethers and aliphatic allylic alcohols. The synthetic potential of the products generated with this method is showcased by their elaboration into a series of heterocyclic compounds and the formal synthesis of glycoprotein GP IIb-IIIa receptor antagonist (-)-roxifiban. Preliminary mechanistic experiments and computational data shed light on the remarkable chemoselectivity of the reaction.
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Muri J, Feng Q, Wolleb H, Shamshiev A, Ebner C, Tortola L, Broz P, Carreira EM, Kopf M. Cyclopentenone Prostaglandins and Structurally Related Oxidized Lipid Species Instigate and Share Distinct Pro- and Anti-inflammatory Pathways. Cell Rep 2021; 30:4399-4417.e7. [PMID: 32234476 DOI: 10.1016/j.celrep.2020.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/11/2019] [Accepted: 03/05/2020] [Indexed: 01/06/2023] Open
Abstract
Oxidized lipids play a critical role in a variety of diseases with two faces: pro- and anti-inflammatory. The molecular mechanisms of this Janus-faced activity remain largely unknown. Here, we have identified that cyclopentenone-containing prostaglandins such as 15d-PGJ2 and structurally related oxidized phospholipid species possess a dual and opposing bioactivity in inflammation, depending on their concentration. Exposure of dendritic cells (DCs)/macrophages to low concentrations of such lipids before Toll-like receptor (TLR) stimulation instigates an anti-inflammatory response mediated by nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent inhibition of nuclear factor κB (NF-κB) activation and downstream targets. By contrast, high concentrations of such lipids upon TLR activation of DCs/macrophages result in inflammatory apoptosis characterized by mitochondrial depolarization and caspase-8-mediated interleukin (IL)-1β maturation independently of Nrf2 and the classical inflammasome pathway. These results uncover unexpected pro- and anti-inflammatory activities of physiologically relevant lipid species generated by enzymatic and non-enzymatic oxidation dependent on their concentration, a phenomenon known as hormesis.
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Isomura M, Petrone DA, Carreira EM. Construction of Vicinal Quaternary Centers via Iridium-Catalyzed Asymmetric Allenylic Alkylation of Racemic Tertiary Alcohols. J Am Chem Soc 2021; 143:3323-3329. [DOI: 10.1021/jacs.1c00609] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Hugentobler KM, Carreira EM. Discovery and Surprises with Cyclizations, Cycloadditions, Fragmentations, and Rearrangements in Complex Settings. Acc Chem Res 2021; 54:890-902. [PMID: 33533583 DOI: 10.1021/acs.accounts.0c00814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We discuss a number of synthesis routes to complex natural products recently reported from our group. Although the structures are quite varied, we demonstrate the research endeavor as a setting to examine the implementation of cyclizations, cycloadditions, rearrangements, and fragmentations. We showcase how the various transformations enabled access to key core structures and thereby allowed the rapid introduction of complexity. Two different routes to (-)-mitrephorone A, the first case discussed, led to the use of Koser's reagent to effect oxetane formation from diosphenol derivatives. Even though the Diels-Alder cycloaddition reaction represents one of the workhorses of complex molecule synthesis, there are opportunities provided by the complexity of secondary metabolites for discovery, study, and development. In our first approach to (-)-mitrephorone A, Diels-Alder cycloaddition provided access to fused cyclopropanes, while the second synthesis underscored the power of diastereoselective nitrile oxide cycloadditions to access hydroxy ketones. The successful implementation of the second approach required the rigorous stereocontrolled synthesis of tetrasubstituted olefins; this was accomplished by a highly stereoselective Cr-mediated reduction of dienes. The diterpenoid (+)-sarcophytin provided a stage for examining the Diels-Alder cycloaddition of two electron-deficient partners. The study revealed that in the system this unusual combination works optimally with the E,Z-dienoate and proceeds through an exo transition state to provide the desired cycloadduct. Our reported pallambin synthesis showcased the use of fulvene as a versatile building block for the core structure. Fulvene decomposition could be outcompeted by employing it as a diene and using a highly reactive dienophile, which affords a bicyclic product that can in turn be subjected to chemo- and stereoselective manipulations. The synthesis route proceeds with a C-H insertion providing the core structure en route to pallambin A and B. The studies resulting in our synthesis of gelsemoxonine highlight the use of the acid-catalyzed rearrangement/chelotropic extrusion of oxazaspiro[2.4]heptanes to access complex β-lactams, which are otherwise not readily prepared by extant methods in common use. Mechanistic investigations of the intriguing ring contraction supported by computational studies indicate that the reaction involves a concerted cleavage of the N-O bond and cyclopropane ring opening under the extrusion of ethylene. The synthesis of guanacastepenes focused on the use of cyclohexyne in [2+2]-cycloadditions with enolates. The resulting cyclobutene can be enticed to undergo ring opening to give a fused six-seven ring system. The cycloinsertion reaction of cyclohexyne developed for the first time proves useful as a general approach to complex fused ring systems.
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Sarott RC, Viray AEG, Pfaff P, Sadybekov A, Rajic G, Katritch V, Carreira EM, Frank JA. Optical Control of Cannabinoid Receptor 2-Mediated Ca2+ Release Enabled by Synthesis of Photoswitchable Probes. J Am Chem Soc 2021; 143:736-743. [DOI: 10.1021/jacs.0c08926] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Carreira EM, Chiu P. Challenges and More Challenges. Org Lett 2021; 23:1. [PMID: 33383990 DOI: 10.1021/acs.orglett.0c03811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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