1
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Golliher AE, Tenorio AJ, Cornali BM, Monroy EY, Tello-Aburto R, Holguin FO, Maio WA. The synthesis and use of γ-chloro-enamides for the subsequent construction of novel enamide-containing small molecules. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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2
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Shrestha UK, Golliher AE, Newar TD, Holguin FO, Maio WA. Asymmetric Total Synthesis and Revision of Absolute Stereochemistry for (+)-Taumycin A: An Approach that Exploits Orthogonally Protected Quasienantiomers. J Org Chem 2021; 86:11086-11099. [PMID: 33444024 DOI: 10.1021/acs.joc.0c02820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first asymmetric total synthesis of C(9)-S-(+)-taumycin A is now reported using an approach that targeted both C(9) diastereomers concurrently. To facilitate this work, we called upon the symmetrical nature of a C(5)-C(13) side-chain intermediate and exploited orthogonal protecting groups as a tactic to access both stereoisomers from a single chiral, nonracemic intermediate. In addition to our successful approach, several minor detours that helped refine our strategy and a detailed analysis of 1H NMR data will be discussed. Select compounds included in this work were screened against the NCI60 cell line panel and displayed modest growth inhibition activity.
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Affiliation(s)
| | | | | | | | - William A Maio
- New Mexico State University, Department of Chemistry and Biochemistry, Las Cruces, New Mexico 88003, United States
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3
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Total Synthesis and Structural Reassignment of Laingolide A. Mar Drugs 2021; 19:md19050247. [PMID: 33925490 PMCID: PMC8145716 DOI: 10.3390/md19050247] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/24/2021] [Accepted: 04/24/2021] [Indexed: 11/24/2022] Open
Abstract
The asymmetric total synthesis of four diastereomers of laingolide A was achieved, which led to the unambiguous assignment of the stereochemistry of the natural product. The salient features of the convergent, fully stereocontrolled approach were a copper-catalysed stereospecific Kumada-type coupling, a Julia-Kocienski olefination and an RCM/alkene migration sequence to access the desired macrocyclic enamide.
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4
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Golliher AE, Tenorio AJ, Dimauro NO, Mairata NR, Holguin FO, Maio W. Using (+)-Carvone to access novel derivatives of (+)- ent-Cannabidiol: the first asymmetric syntheses of (+)- ent-CBDP and (+)- ent-CBDV. Tetrahedron Lett 2021; 67:152891. [PMID: 34658452 PMCID: PMC8513745 DOI: 10.1016/j.tetlet.2021.152891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
(-)-Cannabidiol [(-)-CBD] has recently gained prominence as a treatment for neuro-inflammation and other neurodegenerative disorders; interest is also developing in its synthetic enantiomer, (+)-CBD, which has a higher affinity to CB1 / CB2 receptors than the natural stereoisomer. We have developed an inexpensive, stereoselective route to access ent-CBD derivatives using (+)-carvone as a starting material. In addition to (+)-CBD, we report the first syntheses of (+)-cannabidivarin, (+)-cannabidiphorol as well as C-6 / C-8 homologues.
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Affiliation(s)
- Alexandra E. Golliher
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
| | - Antonio J. Tenorio
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
| | - Nina O. Dimauro
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
| | - Nicolas R. Mairata
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
| | - F. Omar Holguin
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM 88003
| | - William Maio
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
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5
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Lai Y, Dai W. Modular Total Synthesis of (–)‐Palmyrolide A and (+)‐(
5
S
,
7
S
)‐Palmyrolide A via
Ring‐Closing
Metathesis and Alkene Isomerization†. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.202000458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yecai Lai
- Laboratory of Advanced Catalysis and Synthesis, Department of Chemistry and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Clear Water Bay Kowloon Hong Kong SAR China
| | - Wei‐Min Dai
- Laboratory of Advanced Catalysis and Synthesis, Department of Chemistry and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Clear Water Bay Kowloon Hong Kong SAR China
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6
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Li Y, Naman CB, Alexander KL, Guan H, Gerwick WH. The Chemistry, Biochemistry and Pharmacology of Marine Natural Products from Leptolyngbya, a Chemically Endowed Genus of Cyanobacteria. Mar Drugs 2020; 18:E508. [PMID: 33036172 PMCID: PMC7600079 DOI: 10.3390/md18100508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/21/2020] [Accepted: 10/02/2020] [Indexed: 12/23/2022] Open
Abstract
Leptolyngbya, a well-known genus of cyanobacteria, is found in various ecological habitats including marine, fresh water, swamps, and rice fields. Species of this genus are associated with many ecological phenomena such as nitrogen fixation, primary productivity through photosynthesis and algal blooms. As a result, there have been a number of investigations of the ecology, natural product chemistry, and biological characteristics of members of this genus. In general, the secondary metabolites of cyanobacteria are considered to be rich sources for drug discovery and development. In this review, the secondary metabolites reported in marine Leptolyngbya with their associated biological activities or interesting biosynthetic pathways are reviewed, and new insights and perspectives on their metabolic capacities are gained.
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Affiliation(s)
- Yueying Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China;
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA; (C.B.N.); (K.L.A.)
| | - C. Benjamin Naman
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA; (C.B.N.); (K.L.A.)
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China
| | - Kelsey L. Alexander
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA; (C.B.N.); (K.L.A.)
- Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA
| | - Huashi Guan
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China;
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA; (C.B.N.); (K.L.A.)
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
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7
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Chen J, Liu B. Remote Chirality Transfer through Medium Cycle Formation/Intramolecular Hydride Transfer Cascade. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.201900471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Juan Chen
- Analytical & Testing Center, Sichuan University Chengdu Sichuan 610064 China
| | - Bo Liu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University Chengdu Sichuan 610064 China
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8
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Li J, Preinfalk A, Maulide N. Enantioselective Redox-Neutral Coupling of Aldehydes and Alkenes by an Iron-Catalyzed "Catch-Release" Tethering Approach. J Am Chem Soc 2019; 141:143-147. [PMID: 30576130 PMCID: PMC6342409 DOI: 10.1021/jacs.8b12242] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Indexed: 12/19/2022]
Abstract
The reductive coupling of aldehydes and alkenes is an emerging technology that holds the potential to reinvent carbonyl addition chemistry. However, existing enantioselective methods are limited to form "branched" products. Herein, we present a directed enantio- and diastereoselective alkylation of aldehydes with simple olefins to selectively yield linear coupling products. This is achieved by redox-neutral remote functionalization, whereby a tethering "catch-release" strategy decisively solves the key problems of reactivity and selectivity.
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Affiliation(s)
| | | | - Nuno Maulide
- Institute of Organic Chemistry, University
of Vienna, Währinger Strasse 38, 1090 Vienna, Austria
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9
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Bailey SJ, Sapkota RR, Golliher AE, Dungan B, Talipov M, Holguin FO, Maio WA. Lewis-Acid-Mediated Union of Epoxy-Carvone Diastereomers with Anisole Derivatives: Mechanistic Insight and Application to the Synthesis of Non-natural CBD Analogues. Org Lett 2018; 20:4618-4621. [PMID: 30033728 DOI: 10.1021/acs.orglett.8b01909] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of trimethylsilyl trifluoromethanesulfonate as a mild means to unite epoxy-carvone silyl ethers with anisole derivatives to yield products that are structurally similar to the CBD scaffold is reported. Importantly, unlike related methods, this process can utilize both epoxy-carvone diastereomers and does not require the use of air/moisture-sensitive organometallic reagents. Several examples of aryl nucleophiles as well as mechanistic insight based on in silico computational analysis are presented.
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10
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Cui C, Dai WM. Total Synthesis of Laingolide B Stereoisomers and Assignment of Absolute Configuration. Org Lett 2018; 20:3358-3361. [PMID: 29781266 DOI: 10.1021/acs.orglett.8b01269] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Total synthesis of (-)-(2 R,9 S)- and (+)-(2 S,9 S)-stereoisomers of laingolide B has been accomplished by using sequential ring-closing metathesis (RCM) and alkene isomerization to construct the macrocyclic trans- N-methyl enamide moiety. The Myers alkylation was used to secure the C2 stereochemistry of the two RCM precursors from a common (9 S)-C3-C9 alkyl iodide. The absolute configuration of laingolide B has been assigned as (2 S,9 R) by comparison of the optical rotation data.
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Affiliation(s)
- Chengsen Cui
- Laboratory of Advanced Catalysis and Synthesis, Department of Chemistry , The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon , Hong Kong SAR , P. R. China
| | - Wei-Min Dai
- Laboratory of Advanced Catalysis and Synthesis, Department of Chemistry , The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon , Hong Kong SAR , P. R. China
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11
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Borra S, Amrutapu SK, Pabbaraja S, Singh YJ. Stereoselective total synthesis of palmyrolide A via intramolecular trans N-methyl enamide formation. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.08.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Nitelet A, Jouvin K, Evano G. Development of a general copper-catalyzed vinylic Finkelstein reaction—application to the synthesis of the C1–C9 fragment of laingolide B. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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13
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Philkhana SC, Mehrotra S, Murray TF, Reddy DS. Synthesis and biological evaluation of palmyrolide A macrocycles as sodium channel blockers towards neuroprotection. Org Biomol Chem 2016; 14:8457-73. [PMID: 27536802 DOI: 10.1039/c6ob01372d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Palmyrolide A is a neuroprotective macrolide isolated by Gerwick and coworkers in 2010. This natural product is known to suppress neuronal spontaneous calcium ion oscillations through its voltage-gated sodium channel blocking ability which is of significant interest in CNS drug discovery. Herein, we give a detailed account on total synthesis of (+)-palmyrolide A and synthesis of a focused library of macrocycles around the scaffold, followed by their biological evaluation. Use of the chiral pool approach, Zhu's oxidative homologation, access to unnatural cis-palmyrolide A, preparation of 18 new analogues and identification of macrolides with improved sodium channel blocking activity are the important features of the present paper. As a measure of potency as voltage-gated sodium channel blockers, all the synthesized analogues were profiled for their ability to inhibit the veratridine-stimulated Na(+) influx in murine primary neuronal cultures. Four macrocycles were found to be more potent or comparable to that of the natural product (-)-palmyrolide A. The most potent compound from this series 20 was structurally simplified and readily accessible in good quantities for further biological profiling.
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14
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Eno MS, Lu A, Morken JP. Nickel-Catalyzed Asymmetric Kumada Cross-Coupling of Symmetric Cyclic Sulfates. J Am Chem Soc 2016; 138:7824-7. [PMID: 27276235 DOI: 10.1021/jacs.6b03384] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nickel-catalyzed enantioselective cross-couplings between symmetric cyclic sulfates and aromatic Grignard reagents are described. These reactions are effective with a broad range of substituted cyclic sulfates and deliver products with asymmetric tertiary carbon centers. Mechanistic experiments point to a stereoinvertive SN2-like oxidative addition of a nickel complex to the electrophilic substrate.
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Affiliation(s)
- Meredith S Eno
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Alexander Lu
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - James P Morken
- Department of Chemistry, Merkert Chemistry Center, Boston College , Chestnut Hill, Massachusetts 02467, United States
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15
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Yadav JS, Suresh B, Srihari P. Expedient Synthesis of Large-Ringtrans-Enamide Macrolides by CuI-Mediated Intramolecular Coupling of Vinyl Iodide with Amide: Total Synthesis of Palmyrolide A. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600325] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Lai Y, Sun L, Sit MK, Wang Y, Dai WM. Diastereoselective synthesis of trans-3,5-disubstituted dihydrofuran-2(3H)-ones via SmI2-mediated reductive coupling of 2-alkylacrylates of N,N-diisopropyl-2-hydroxybenzamide with aldehydes. Tetrahedron 2016. [DOI: 10.1016/j.tet.2015.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Mehrotra S, Duggan BM, Tello-Aburto R, Newar TD, Gerwick W, Murray TF, Maio WA. Detailed analysis of (-)-palmyrolide a and some synthetic derivatives as voltage-gated sodium channel antagonists. JOURNAL OF NATURAL PRODUCTS 2014; 77:2553-2560. [PMID: 25343669 PMCID: PMC4251536 DOI: 10.1021/np500644k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Indexed: 06/04/2023]
Abstract
A small library of synthetic (-)-palmyrolide A diastereomers, analogues, and acyclic precursors have been examined with respect to their interaction with voltage-gated sodium channels (VGSCs). Toward this goal, the ability of (-)-palmyrolide A and analogues to antagonize veratridine-stimulated Na(+) influx in primary cultures of mouse cerebrocortical neurons was assessed. We found that synthetic (-)-palmyrolide A and its enantiomer functioned as VGSC antagonists to block veratridine-induced sodium influx. A detailed NMR and computational analysis of four diastereomers revealed that none had the same combination of shape and electrostatic potential as exhibited by natural (-)-palmyrolide A. These data indicate that the relative configuration about the tert-butyl and methyl substituents appears to be a prerequisite for biological function. Additional testing revealed that the enamide double bond was not necessary for blocking veratridine-induced sodium influx, whereas the acyclic analogues and other macrolide diastereomers tested were inactive as inhibitors of VGSCs, suggesting that the intact macrolide was required.
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Affiliation(s)
- Suneet Mehrotra
- Department
of Pharmacology, Creighton University School
of Medicine, Omaha, Nebraska 68178, United
States
| | - Brendan M. Duggan
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography
and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92037, United States
| | - Rodolfo Tello-Aburto
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
| | - Tara D. Newar
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
| | - William
H. Gerwick
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography
and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92037, United States
| | - Thomas F. Murray
- Department
of Pharmacology, Creighton University School
of Medicine, Omaha, Nebraska 68178, United
States
| | - William A. Maio
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
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18
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Wadsworth AD, Furkert DP, Brimble MA. Total synthesis of the macrocyclic N-Methyl enamides palmyrolide A and 2S-sanctolide A. J Org Chem 2014; 79:11179-93. [PMID: 25369466 DOI: 10.1021/jo502238r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Full details of the total syntheses of the initially reported and revised structures of the neuroprotective agent palmyrolide A are reported. The key macrocyclization step was achieved using a sequential ring-closing metathesis/olefin isomerization reaction. Furthermore, the total synthesis of the related macrolide (2S)-sanctolide A is reported. The synthesis used key elements from the synthesis of palmyrolide A, including the RCM/olefin isomerization sequence. The synthetic work described herein serves to facilitate the assignment of stereochemistry of the natural product sanctolide A and demonstrates the utility of this approach for the synthesis of macrocyclic tertiary enamide natural products.
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Affiliation(s)
- Andrew D Wadsworth
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Chemical Sciences, University of Auckland , 23 Symonds Street, Auckland 1142, New Zealand
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19
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Saicic RN. Protecting group-free syntheses of natural products and biologically active compounds. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.06.025] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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20
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2012. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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21
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Huguenot F, Delalande C, Vidal M. Metal-free 5-exo-dig cyclization of propargyl urea using TBAF. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.06.098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Chen QY, Liu Y, Cai W, Luesch H. Improved total synthesis and biological evaluation of potent apratoxin S4 based anticancer agents with differential stability and further enhanced activity. J Med Chem 2014; 57:3011-29. [PMID: 24660812 PMCID: PMC3993931 DOI: 10.1021/jm4019965] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Apratoxins are cytotoxic natural products originally isolated from marine cyanobacteria that act by preventing cotranslational translocation early in the secretory pathway to downregulate receptor levels and inhibit growth factor secretion, leading to potent antiproliferative activity. Through rational design and total synthesis of an apratoxin A/E hybrid, apratoxin S4 (1a), we have previously improved the antitumor activity and tolerability in vivo. Compound 1a and newly designed analogues apratoxins S7-S9 (1b-d), with various degrees of methylation at C34 (1b,c) or epimeric configuration at C30 (1d), were efficiently synthesized utilizing improved procedures. Optimizations have been applied to the synthesis of key intermediate aldehyde 7 and further include the application of Leighton's silanes and modifications of Kelly's methods to induce thiazoline ring formation in other crucial steps of the apratoxin synthesis. Apratoxin S9 (1d) exhibited increased activity with subnanomolar potency. Apratoxin S8 (1c) lacks the propensity to be deactivated by dehydration and showed efficacy in a human HCT116 xenograft mouse model.
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Affiliation(s)
- Qi-Yin Chen
- Department of Medicinal Chemistry and ‡Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida , Gainesville, Florida, United States
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23
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Abstract
This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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24
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Zhang F, Xu X, Li T, Liu Z. Shellfish toxins targeting voltage-gated sodium channels. Mar Drugs 2013; 11:4698-723. [PMID: 24287955 PMCID: PMC3877881 DOI: 10.3390/md11124698] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/10/2013] [Accepted: 11/12/2013] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) play a central role in the generation and propagation of action potentials in excitable neurons and other cells and are targeted by commonly used local anesthetics, antiarrhythmics, and anticonvulsants. They are also common targets of neurotoxins including shellfish toxins. Shellfish toxins are a variety of toxic secondary metabolites produced by prokaryotic cyanobacteria and eukaryotic dinoflagellates in both marine and fresh water systems, which can accumulate in marine animals via the food chain. Consumption of shellfish toxin-contaminated seafood may result in potentially fatal human shellfish poisoning. This article provides an overview of the structure, bioactivity, and pharmacology of shellfish toxins that act on VGSCs, along with a brief discussion on their pharmaceutical potential for pain management.
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Affiliation(s)
- Fan Zhang
- Cooperative Innovation Center of Engineering and New Products for Developmental Biology, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.
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25
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Philkhana SC, Seetharamsingh B, Dangat YB, Vanka K, Reddy DS. Synthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle. Chem Commun (Camb) 2013; 49:3342-4. [PMID: 23503336 DOI: 10.1039/c3cc40541a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, "(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide", which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.
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Affiliation(s)
- Satish Chandra Philkhana
- Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. HomiBhabha Road, Pune, 411008, India
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26
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De Gussem E, Cornelus J, Pieters S, Van den Bossche D, Van der Eycken J, Herrebout W, Bultinck P. Synthesis of the Natural Product Building Block 5‐(3‐Bromophenyl)‐4‐hydroxy‐5‐methylhexan‐2‐one and its Chiral Characterization by Using Chiroptical Spectroscopy. Chemphyschem 2013; 14:3255-62. [DOI: 10.1002/cphc.201300551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Ewoud De Gussem
- Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281‐S3, 9000 Gent (Belgium)
- The European Centre for Chirality (EC2), Groenenborgerlaan 171, 2020 Antwerp (Belgium)
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)
| | - Jelle Cornelus
- Department of Organic Chemistry, Ghent University, Krijgslaan 281‐S4, 9000 Gent (Belgium)
| | - Sam Pieters
- Department of Organic Chemistry, Ghent University, Krijgslaan 281‐S4, 9000 Gent (Belgium)
| | - Dries Van den Bossche
- Department of Organic Chemistry, Ghent University, Krijgslaan 281‐S4, 9000 Gent (Belgium)
| | - Johan Van der Eycken
- Department of Organic Chemistry, Ghent University, Krijgslaan 281‐S4, 9000 Gent (Belgium)
| | - Wouter Herrebout
- The European Centre for Chirality (EC2), Groenenborgerlaan 171, 2020 Antwerp (Belgium)
- Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)
| | - Patrick Bultinck
- Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281‐S3, 9000 Gent (Belgium)
- The European Centre for Chirality (EC2), Groenenborgerlaan 171, 2020 Antwerp (Belgium)
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Evano G, Theunissen C, Pradal A. Impact of copper-catalyzed cross-coupling reactions in natural product synthesis: the emergence of new retrosynthetic paradigms. Nat Prod Rep 2013; 30:1467-89. [DOI: 10.1039/c3np70071b] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Wadsworth AD, Furkert DP, Sperry J, Brimble MA. Total synthesis of the initially reported and revised structures of the neuroprotective agent palmyrolide A. Org Lett 2012; 14:5374-7. [PMID: 23046111 DOI: 10.1021/ol3025956] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The total syntheses of the initially reported and revised structures of the neuroprotective agent palmyrolide A are reported. The key macrocyclization step was achieved using a sequential ring closing metathesis/olefin isomerization reaction. The synthetic work described herein serves to confirm the recent structural revision of this unusual natural product.
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Affiliation(s)
- Andrew D Wadsworth
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland, 1010, New Zealand
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