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Scarpi D, Capanni C, Visi S, Faggi C, Occhiato EG. Gold(I)-Catalyzed Rautenstrauch/Hetero-Diels-Alder/Retro-aza-Michael Cascade Reaction for the Synthesis of α-Hydrazineyl-2-cyclopentenones. J Org Chem 2024; 89:14108-14119. [PMID: 39267288 DOI: 10.1021/acs.joc.4c01518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2024]
Abstract
A one-pot synthesis of ring-fused, α-hydrazineyl-2-cyclopentenone derivatives is achieved by a gold(I)-catalyzed Rautenstrauch/hetero Diels-Alder/ring opening tandem reaction of suitable propargyl esters. By mixing the latter with a dialkylazodicarboxylate in the presence of a gold(I) catalyst, the 1,2-acyloxy migration/cyclization process (Rautenstrauch reaction) leads to cyclopentadienyl ester intermediates which are trapped by the heterodienophile present in situ. This provides strained intermediates which spontaneously undergo highly regioselective ring opening by a retro aza-Michael reaction promoted by the gold(I) catalyst, eventually yielding the target compounds. Six- and seven-membered ring-fused cyclopentenones bearing a pendant α-hydrazineyl moiety can be obtained in moderate to excellent yield (50-98%) by this approach, with a minimal erosion of the initial optical purity when using enantioenriched substrates.
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Affiliation(s)
- Dina Scarpi
- Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Italy
| | - Claudia Capanni
- Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Italy
| | - Samuele Visi
- Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Italy
| | - Cristina Faggi
- Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Italy
| | - Ernesto G Occhiato
- Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Italy
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Sabec MH, Savage QR, Wood JL, Maskos U. Targeting high-affinity nicotinic receptors protects against the functional consequences of β-amyloid in mouse hippocampus. Mol Psychiatry 2024:10.1038/s41380-024-02666-7. [PMID: 39164528 DOI: 10.1038/s41380-024-02666-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 06/29/2024] [Accepted: 07/04/2024] [Indexed: 08/22/2024]
Abstract
The accumulation of β-amyloid oligomers is a hallmark of Alzheimer's disease, inducing neural and network dysfunction in the early stages of pathology. The hippocampus is affected early in the pathogenesis of AD, however the impact of soluble β-amyloid on the dentate gyrus (DG) subregion of the hippocampus and its interaction with nicotinic acetylcholine receptors (nAChRs) within this region are not known. Using a localized model of over-expression, we show that β-amyloid induces early-onset neuronal hyperactivity and hippocampal-dependent memory deficits in mice. Further, we find the DG region to be under potent and sub-type specific nicotinic control in both healthy and pathophysiological conditions, with targeted receptor inhibition leading to a mnemonic rescue against localized amyloidosis. We show that while neurogenesis and synaptic functions are not severely affected in our model, reducing β2-containing nAChR function is associated with the promotion of young adult-born neurons within the pathological network, suggesting a possible protective mechanism. Our data thus reveal the DG network level changes which occur in the early-stages of β-amyloid accumulation and highlight the downstream consequences of targeted nicotinic neuromodulation.
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Affiliation(s)
- Marie H Sabec
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems, 75015, Paris, France.
- Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, BS8 1TD, UK.
| | - Quentin R Savage
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - John L Wood
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Uwe Maskos
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems, 75015, Paris, France.
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Lin B, Liu T, Luo T. Gold-catalyzed cyclization and cycloaddition in natural product synthesis. Nat Prod Rep 2024; 41:1091-1112. [PMID: 38456472 DOI: 10.1039/d3np00056g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Covering: 2016 to mid 2023Transition metal catalysis, known for its remarkable capacity to expedite the assembly of molecular complexity from readily available starting materials in a single operation, occupies a central position in contemporary chemical synthesis. Within this landscape, gold-catalyzed reactions present a novel and versatile paradigm, offering robust frameworks for accessing diverse structural motifs. In this review, we highlighted a curated selection of publications in the past 8 years, focusing on the deployment of homogeneous gold catalysis in the ring-forming step for the total synthesis of natural products. These investigations are categorized based on the specific ring formations they engender, accentuating the prevailing gold-catalyzed methodologies applied to surmount intricate challenges in natural products synthesis.
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Affiliation(s)
- Boxu Lin
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Tianran Liu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Tuoping Luo
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518055, China
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Crespo Monteiro M, Vale JR, Siopa F. 2-Azabicyclo[3.2.1]octane scaffold: synthesis and applications. Org Biomol Chem 2024; 22:2902-2915. [PMID: 38526533 DOI: 10.1039/d4ob00199k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
2-Azabicyclo[3.2.1]octanes are nitrogen containing heterocycles with significant potential in the field of drug discovery. This core has been applied as key synthetic intermediate in several total synthesis, while their unique structure can make them a challenging scaffold to acquire. This Minireview summarizes the synthetic approaches to access this bicyclic architecture and highlights its presence in the total synthesis of several target molecules.
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Affiliation(s)
- Mariana Crespo Monteiro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - João Rafael Vale
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal.
| | - Filipa Siopa
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003, Lisbon, Portugal.
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Zhang J, Yan X, Zhang Q, Wang F, Yang B, Yang Y. Total Syntheses of Hosieines A-C. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308164. [PMID: 38326080 PMCID: PMC11005691 DOI: 10.1002/advs.202308164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/21/2024] [Indexed: 02/09/2024]
Abstract
The collective total syntheses of (±)-hosieines A-C with a cage-like tetracyclic framework have been realized, which includes the first syntheses of hosieines B-C. The key strategy of the synthesis employs a one-pot domino reaction that involves Cu-catalyzed [3+2] cycloaddition, 1,6-enone formation, and 1,6-aza-Michael addition forming the 5/6/6-aza-tricyclic skeleton. Other salient synthetic tactics comprise a challenging double bond migration and a 1,4-aza-Michael addition reaction to afford the tetracyclic framework.
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Affiliation(s)
- Jiayang Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource EvaluationSchool of PharmacyHuazhong University of Science and Technology13 Hangkong RoadWuhan430030China
| | - Xu Yan
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource EvaluationSchool of PharmacyHuazhong University of Science and Technology13 Hangkong RoadWuhan430030China
| | - Qing‐Bao Zhang
- Shandong Peninsula Engineering Research Center of Comprehensive Brine UtilizationWeifang University of Science and TechnologyShouguang262700China
| | - Fang Wang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource EvaluationSchool of PharmacyHuazhong University of Science and Technology13 Hangkong RoadWuhan430030China
| | - Bin Yang
- Baylor College of MedicineHoustonTX77030USA
| | - Yang Yang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource EvaluationSchool of PharmacyHuazhong University of Science and Technology13 Hangkong RoadWuhan430030China
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Matera C, Papotto C, Dallanoce C, De Amici M. Advances in small molecule selective ligands for heteromeric nicotinic acetylcholine receptors. Pharmacol Res 2023; 194:106813. [PMID: 37302724 DOI: 10.1016/j.phrs.2023.106813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/26/2023] [Accepted: 06/02/2023] [Indexed: 06/13/2023]
Abstract
The study of nicotinic acetylcholine receptors (nAChRs) has significantly progressed in the last decade, due to a) the improved techniques available for structural studies; b) the identification of ligands interacting at orthosteric and allosteric recognition sites on the nAChR proteins, able to tune channel conformational states; c) the better functional characterization of receptor subtypes/subunits and their therapeutic potential; d) the availability of novel pharmacological agents able to activate or block nicotinic-mediated cholinergic responses with subtype or stoichiometry selectivity. The copious literature on nAChRs is related to the pharmacological profile of new, promising subtype selective derivatives as well as the encouraging preclinical and early clinical evaluation of known ligands. However, recently approved therapeutic derivatives are still missing, and examples of ligands discontinued in advanced CNS clinical trials include drug candidates acting at both neuronal homomeric and heteromeric receptors. In this review, we have selected heteromeric nAChRs as the target and comment on literature reports of the past five years dealing with the discovery of new small molecule ligands or the advanced pharmacological/preclinical investigation of more promising compounds. The results obtained with bifunctional nicotinic ligands and a light-activated ligand as well as the applications of promising radiopharmaceuticals for heteromeric subtypes are also discussed.
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Affiliation(s)
- Carlo Matera
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section "Pietro Pratesi", University of Milan, Via Luigi Mangiagalli 25, 20133 Milan, Italy
| | - Claudio Papotto
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section "Pietro Pratesi", University of Milan, Via Luigi Mangiagalli 25, 20133 Milan, Italy
| | - Clelia Dallanoce
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section "Pietro Pratesi", University of Milan, Via Luigi Mangiagalli 25, 20133 Milan, Italy
| | - Marco De Amici
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section "Pietro Pratesi", University of Milan, Via Luigi Mangiagalli 25, 20133 Milan, Italy.
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Scott KA, Groch JR, Bao J, Marshall CM, Allen RA, Nick SJ, Lauta NR, Williams RE, Qureshi MH, Delost MD, Njardarson JT. Minimalistic graphical presentation approach for total syntheses. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.133062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Parker HP, Dawson A, Jones MJ, Yan R, Ouyang J, Hong R, Hunter WN. Delineating the activity of the potent nicotinic acetylcholine receptor agonists (+)-anatoxin-a and (−)-hosieine-A. Acta Crystallogr F Struct Biol Commun 2022; 78:313-323. [PMID: 36048081 PMCID: PMC9435674 DOI: 10.1107/s2053230x22007762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/01/2022] [Indexed: 11/10/2022] Open
Abstract
The affinity and thermodynamic parameters for the interactions of two naturally occurring neurotoxins, (+)-anatoxin-a and (−)-hosieine-A, with acetylcholine-binding protein were investigated using a fluorescence-quenching assay and isothermal titration calorimetry. The crystal structures of their complexes with acetylcholine-binding protein from Aplysia californica (AcAChBP) were determined and reveal details of molecular recognition in the orthosteric binding site. Comparisons treating AcAChBP as a surrogate for human α4β2 and α7 nicotinic acetylcholine receptors (nAChRs) suggest that the molecular features involved in ligand recognition and affinity for the protein targets are conserved. The ligands exploit interactions with similar residues as the archetypal nAChR agonist nicotine, but with greater affinity. (−)-Hosieine-A in particular has a high affinity for AcAChBP driven by a favorable entropic contribution to binding. The ligand affinities help to rationalize the potent biological activity of these alkaloids. The structural data, together with comparisons with related molecules, suggest that there may be opportunities to extend the hosieine-A scaffold to incorporate new interactions with the complementary side of the orthosteric binding site. Such a strategy may guide the design of new entities to target human α4β2 nAChR that may have therapeutic benefit.
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Zhai L, Tang Y, Zhang Y, Huang SH, Zhu L, Hong R. A Bridge to Alkaloid Synthesis. CHEM REC 2021; 22:e202100197. [PMID: 34473401 DOI: 10.1002/tcr.202100197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/23/2021] [Indexed: 11/07/2022]
Abstract
The construction of a structurally rigid architecture with chiral complexity, necessary to enhance the interaction with binding sites of drug targets, has been adapted as an intriguing approach in drug development. In the past few years, we have been interested in the synthesis of biologically significant and bridged alkaloids via novel synthetic methods and strategies based on recognition of the privileged pattern. Therefore, nitroso-ene and aza-Wacker cyclizations were elevated for the first time to construct bridged alkaloids, such as hosieine A, kopsone, melinonine-E and strychnoxanthine. Mechanistic investigations, including computational calculations for nitroso-ene reaction and deuterated experiments for aza-Wacker reaction, enable us to gain more insights into the chemical reactivity and selectivity of specific functional groups in developing viable synthetic methods.
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Affiliation(s)
- Li Zhai
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
- University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 101419, PR China, CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, PR China
| | - Ye Tang
- University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 101419, PR China, CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, PR China
| | - Yan Zhang
- University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 101419, PR China, CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, PR China
| | - Sha-Hua Huang
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, PR China
| | - Lili Zhu
- University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 101419, PR China, CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, PR China
| | - Ran Hong
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
- University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing 101419, PR China, CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, PR China
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Wang W, Zhou S, Li L, He Y, Dong X, Gao L, Wang Q, Song Z. 3-Silaazetidine: An Unexplored yet Versatile Organosilane Species for Ring Expansion toward Silaazacycles. J Am Chem Soc 2021; 143:11141-11151. [PMID: 34279908 DOI: 10.1021/jacs.1c04667] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Small-ring silacycles are important organosilane species in main-group chemistry and have found numerous applications in organic synthesis. 3-Silaazetidine, a unique small silacycle bearing silicon and nitrogen atoms, has not been adequately explored due to the lack of a general synthetic scheme and its sensitivity to air. Here, we describe that 3-silaazetidine can be easily prepared in situ from diverse air-stable precursors (RSO2NHCH2SiR12CH2Cl). 3-Silaazetidine shows excellent functional group tolerance in a palladium-catalyzed ring expansion reaction with terminal alkynes, giving 3-silatetrahydropyridines and diverse silaazacycle derivatives, which are promising ring frameworks for the discovery of Si-containing functional molecules.
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Affiliation(s)
- Wanshu Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Song Zhou
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Linjie Li
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Yuanhang He
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Xue Dong
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Lu Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Qiantao Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
| | - Zhenlei Song
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China
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Huck CJ, Boyko YD, Sarlah D. Total Synthesis of Stelletins through an Unconventional Annulation Strategy. Acc Chem Res 2021; 54:1597-1609. [PMID: 33635622 DOI: 10.1021/acs.accounts.0c00840] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Marine ecosystems present the largest source of biodiversity on the planet and an immense reservoir of novel chemical entities. Sessile marine organisms such as sponges produce a wide range of complex secondary metabolites, many of these with potent biological activity engineered for chemical defense. That such compounds exert dynamic effects outside of their native context is perhaps not surprising, and the realm of marine natural products has attracted considerable attention as a largely untapped repository of potential candidates for drug development. Only a handful of the more than 15 000 marine natural products that have been isolated to date have advanced to the clinic, and more are to be expected. The rich chemical information encoded in the intricate three-dimensional structures of many marine natural products facilitates highly discriminating interactions with cell signaling pathways, and especially within cancer cells such nuanced effects offer an exciting opportunity for the development of targeted therapies that lack the side effects and general toxicity of conventional chemotherapeutics. The isomalabaricanes are a rare class of marine triterpenoids that have been hailed as promising cytotoxic lead compounds for the treatment of cancer, and they have attracted a flurry of excitement from researchers because of their potent cytotoxicity in certain human cancer cell lines along with a range of other antineoplastic effects. Most notably, their inhibitory activity is highly cell-selective, characterized by large deviations from their mean GI50 concentrations across 3 orders of magnitude in the NCI-60 Human Tumor Cell Lines screen, suggesting mechanistic specificity rather than general and unbridled toxicity. Despite these auspicious preliminary reports, the isomalabaricane scaffold remains largely unexplored as a potential anticancer lead because of lack of material. This Account describes our recent efforts to develop a general, modular synthesis of the isomalabaricanes, as exemplified by the successful total syntheses of rhabdastrellic acid A, stelletin E, and stelletin A. The unorthodox trans-syn-trans configuration of their perhydrobenz[e]indene core severely circumscribes the synthetic methods available for its construction and required several generations of strategy to assemble. Ultimately, a series of unconventional transformations were identified that were capable of building this highly strained motif, and the syntheses of rhabdastrellic acid A and stelletin E were completed in racemic fashion. Subsequently, a second-generation approach to these natural products was developed, rendering the synthesis enantioselective as well as providing access to stelletin A. These synthetic efforts were greatly assisted by computational techniques such as 13C NMR prediction, which enabled structural assignments of hydrocarbon diastereomers, as well as relaxed surface scan conformational analysis, which informed a campaign for directed hydrogenation of an alkene. High-throughput experimentation methods were brought to bear during optimization of a late-stage Suzuki coupling on stelletin A. Finally, preliminary structure-activity relationship studies in glioblastoma and nonsmall cell lung cancer cell lines were conducted on stelletin A, revealing that the singular trans-syn-trans perhydrobenz[e]indene core is essential for the cytotoxic activity of the isomalabaricane triterpenoids.
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Affiliation(s)
- Christopher J. Huck
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois, Urbana, Illinois 61801, United States
| | - Yaroslav D. Boyko
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois, Urbana, Illinois 61801, United States
| | - David Sarlah
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois, Urbana, Illinois 61801, United States
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Fernandes RA, Kumar P, Choudhary P. Advances in catalytic and protecting-group-free total synthesis of natural products: a recent update. Chem Commun (Camb) 2020; 56:8569-8590. [PMID: 32537619 DOI: 10.1039/d0cc02659j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Catalytic processes in protecting-group-free syntheses of natural products are fast emerging towards achieving the goal of efficiency and economy in total synthesis. Present day sustainable development in synthesis of natural products does not permit the luxury of using stoichiometric reagents and protecting groups. Catalysis and step-economy can contribute significantly toward economy and efficiency of synthesis. This feature article details the ingenious efforts by many researchers in the last couple of years toward concise total syntheses, based on catalytic steps and protecting-group-free-strategies. These would again serve as guidelines in future development of reagents and catalysts aimed at achieving higher efficiency and chemoselectivity to the point that catalysis and protecting-group-free synthesis will be an accepted common practice.
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Affiliation(s)
- Rodney A Fernandes
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, Maharashtra, India.
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13
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2018. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.213051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Ni L, Chen J, Zhang X, Wu M, Zhang L, Wu Z, Huang M, Xu H. Hositisines A and B, new alkaloids from the stems of Ormosia hosiei Hemsl. et Wils. Nat Prod Res 2019; 35:2184-2189. [PMID: 31523982 DOI: 10.1080/14786419.2019.1666387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Two new alkaloids, named hositisines A (1) and B (2), with two known alkaloids (3 and 4) were isolated from the stems of Ormosia hosiei Hemsl. et Wils. Their structures were confirmed by UV, HRESIMS, NMR spectra. The absolute configurations of 1 and 2 were determined by quantum ECD calculation and ECD, respectively. Compounds 1-3 could significantly reduce the LDH release at the concentration 50 μM, which showed they could strongly protect the PC12 cells exposed to oxygen and glucose deprivation/reoxygenation (OGD/R) injury.
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Affiliation(s)
- Lin Ni
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China.,Fujian Colleges and University Engineering Research Institute of Conservation & Utilization of Natural Bioresources, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
| | - Jingxin Chen
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
| | - Xiaoqin Zhang
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, People's Republic of China
| | - Meiting Wu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
| | - Linjing Zhang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
| | - Zujian Wu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
| | - Mingqing Huang
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, People's Republic of China
| | - Huiyou Xu
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, People's Republic of China
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Boyko YD, Huck CJ, Sarlah D. Total Synthesis of Isomalabaricane Triterpenoids. J Am Chem Soc 2019; 141:14131-14135. [DOI: 10.1021/jacs.9b08487] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yaroslav D. Boyko
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Christopher J. Huck
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - David Sarlah
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
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