1
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Hess SN, Fürstner A. An Efficient and Scalable "Second Generation" Total Synthesis of the Marine Polyketide Limaol Endowed with Antiparasitic Activity. Chemistry 2024; 30:e202401429. [PMID: 38716817 DOI: 10.1002/chem.202401429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Indexed: 06/20/2024]
Abstract
The cluster of four skipped exo-methylene substituents on the "northern" wing of limaol renders this dinoflagellate-derived marine natural product unique in structural terms. This arguably non-thermodynamic array gains kinetic stability by virtue of populating local conformations which impede isomerization to a partly or fully conjugated polyene. This analysis suggested that the difficulties encountered during the late stages of our first total synthesis of this polyketide had not been caused by an overly fragile character of this unusual substructure; rather, an unfavorable steric microenvironment about the spirotricyclic core was identified as the likely cause. To remedy the issue, the protecting groups on this central fragment were changed; in effect, this amendment allowed all strategic and practical problems to be addressed. As a result, the overall yield over the longest linear sequence was multiplied by a factor of almost five and the material throughput increased more than eighty-fold per run. Key-to-success was a gold-catalyzed spirocyclization reaction; the reasons why a Brønsted acid cocatalyst is needed and the origin of the excellent levels of selectivity were delineated. The change of the protecting groups also allowed for much improved fragment coupling processes; most notably, the sequence of a substrate-controlled carbonyl addition reaction followed by Mitsunobu inversion that had originally been necessary to affix the southern tail to the core could be replaced by a reagent controlled asymmetric allylation. Finally, a much-improved route to the "northern" sector was established by leveraging the power of asymmetric hydrogenation of a 2-pyrone derivative. Limaol was found to combine appreciable antiparasitic activity with very modest cytotoxicity.
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Affiliation(s)
- Stephan N Hess
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
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2
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Siebert A, Kazmaier U. Chemical Ligation-Mediated Total Synthesis of Corramycin. Org Lett 2024; 26:3169-3173. [PMID: 38564715 DOI: 10.1021/acs.orglett.4c00774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The ligation-mediated total synthesis of corramycin, a myxobacterial natural product of the strain Corallococcus coralloides, is presented. The synthetic strategy included using two consecutive chemical ligations for a modular and efficient preparation. Finally, the synthesis employed a Ser/Thr ligation (STL) at a new ligation site combined with classical fragment coupling. This study provides the total synthesis of corramycin and enhances the preparative toolbox of STL in organic synthesis.
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Affiliation(s)
- Andreas Siebert
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Campus, C8.1, 66123 Saarbrücken, Germany
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3
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Bérubé C, Guay LD, Fraser T, Lapointe V, Cardinal S, Biron É. Convenient route to Fmoc-homotyrosine via metallaphotoredox catalysis and its use in the total synthesis of anabaenopeptin cyclic peptides. Org Biomol Chem 2023; 21:9011-9020. [PMID: 37921761 DOI: 10.1039/d3ob01608k] [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: 11/04/2023]
Abstract
Herein, we report the first solid-phase total synthesis of the natural cyclic peptide anabaenopeptin F and the use of metallaphotoredox catalysis to overcome the key challenges associated with the preparation of the non-proteinogenic amino acid homotyrosine contained in these peptides. Starting from L-homoserine, enantiopure Fmoc-protected homotyrosine was prepared in a straightforward manner by metallaphotoredox catalysis with N-Fmoc-(S)-2-amino-4-bromobutanoic acid and 4-tert-butoxybromobenzene partners. The prepared protected amino acid was used in solid-phase peptide synthesis to achieve the total synthesis of anabaenopeptin F and establish the stereochemistry of the isoleucine residue. Protease inhibition studies with the synthesized anabaenopeptin F showed inhibitory activities against carboxypeptidase B in the low nanomolar range. The high convergency of the synthetic methodologies paves the way for the rapid access to N-Fmoc-protected non-proteinogenic and unnatural amino acids and the total synthesis of complex bioactive peptides containing these amino acids.
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Affiliation(s)
- Christopher Bérubé
- Faculté de Pharmacie, Université Laval, Québec, Québec, Canada, G1 V 0A6.
- Laboratory of Medicinal Chemistry, Centre de Recherche du CHU de Québec-Université Laval, 2705 Boulevard Laurier, Québec, Québec, Canada, G1 V 0A6
| | - Louis-David Guay
- Faculté de Pharmacie, Université Laval, Québec, Québec, Canada, G1 V 0A6.
- Laboratory of Medicinal Chemistry, Centre de Recherche du CHU de Québec-Université Laval, 2705 Boulevard Laurier, Québec, Québec, Canada, G1 V 0A6
| | - Tommy Fraser
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Québec, Canada, G5L 3A1
| | - Victor Lapointe
- Faculté de Pharmacie, Université Laval, Québec, Québec, Canada, G1 V 0A6.
- Laboratory of Medicinal Chemistry, Centre de Recherche du CHU de Québec-Université Laval, 2705 Boulevard Laurier, Québec, Québec, Canada, G1 V 0A6
| | - Sébastien Cardinal
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Québec, Canada, G5L 3A1
| | - Éric Biron
- Faculté de Pharmacie, Université Laval, Québec, Québec, Canada, G1 V 0A6.
- Laboratory of Medicinal Chemistry, Centre de Recherche du CHU de Québec-Université Laval, 2705 Boulevard Laurier, Québec, Québec, Canada, G1 V 0A6
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4
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Holland DC, Schroder WA, Calcott MJ, Kaemmerer E, Avery VM, Ekins MG, Carroll AR. Cyclotheonellazoles D-I, Potent Elastase Inhibitory Thiazole-Containing Cyclic Peptides from Theonella sp. (2131). JOURNAL OF NATURAL PRODUCTS 2023; 86:2216-2227. [PMID: 37609780 DOI: 10.1021/acs.jnatprod.3c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Six new thiazole-containing cyclic peptides, the cyclotheonellazoles D-I (1-6), were isolated from the Australian marine sponge Theonella sp. (2131) with their structures assigned by comprehensive 1D and 2D NMR spectroscopic and MS spectrometric analyses, Marfey's derivatization studies, and comparison with time-dependent density functional theory (TDDFT) calculated ECD data. The Type 2 azole-homologated peptides herein comprise up to five nonproteinogenic amino acids, including the protease transition state mimic α-keto-β-amino acid residue 3-amino-4-methyl-2-oxohexanoic acid (Amoha), while 1-3 also contain a terminal hydantoin residue not previously found in cyclotheonellazoles. The keramamides A (7) and L (8) were reisolated affording expanded exploration of their biological activities. The peptides were examined for protease inhibitory activities against two mammalian serine proteases (elastase and chymotrypsin) and SARS-CoV-2 3-chymotrypsin-like protease (3CLpro), a validated antiviral therapeutic target for COVID-19. Peptides 1-6 and keramamide A (7) displayed potent nanomolar inhibition of elastase (IC50 16.0 to 61.8 nM), while 7 also contained modest inhibition of chymotrypsin and SARS-CoV-2 3CLpro (IC50 0.73 and 1.1 μM, respectively). The cyclotheonellazoles D-E (1-3) do not affect the viability of human breast, ovarian, and colon cancer cells (>100 μM), with the cytotoxicity previously reported for keramamide L (8) not replicated (inactive >20 μM).
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Affiliation(s)
- Darren C Holland
- School of Environment and Science, Griffith University, Gold Coast, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University,Nathan, Queensland 4111, Australia
| | - Wayne A Schroder
- School of Environment and Science, Griffith University, Gold Coast, Queensland 4222, Australia
| | - Mark J Calcott
- School of Biological Sciences, Victoria University of Wellington, Wellington 6102, New Zealand
| | - Elke Kaemmerer
- Discovery Biology, Griffith University, Nathan, Queensland 4111, Australia
| | - Vicky M Avery
- School of Environment and Science, Griffith University, Gold Coast, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University,Nathan, Queensland 4111, Australia
- Discovery Biology, Griffith University, Nathan, Queensland 4111, Australia
| | - Merrick G Ekins
- Queensland Museum, South Brisbane BC, Queensland 4101, Australia
| | - Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University,Nathan, Queensland 4111, Australia
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5
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Absolute Stereochemistry Determination of Bioactive Marine-Derived Cyclopeptides by Liquid Chromatography Methods: An Update Review (2018-2022). MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020615. [PMID: 36677673 PMCID: PMC9867211 DOI: 10.3390/molecules28020615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023]
Abstract
Cyclopeptides are considered as one of the most important classes of compounds derived from marine sources, due to their structural diversity and a myriad of their biological and pharmacological activities. Since marine-derived cyclopeptides consist of different amino acids, many of which are non-proteinogenic, they possess various stereogenic centers. In this respect, the structure elucidation of new molecular scaffolds obtained from natural sources, including marine-derived cyclopeptides, can become a very challenging task. The determination of the absolute configurations of the amino acid residues is accomplished, in most cases, by performing acidic hydrolysis, followed by analyses by liquid chromatography (LC). In a continuation with the authors' previous publication, and to analyze the current trends, the present review covers recently published works (from January 2018 to November 2022) regarding new cyclopeptides from marine organisms, with a special focus on their biological/pharmacological activities and the absolute stereochemical assignment of the amino acid residues. Ninety-one unreported marine-derived cyclopeptides were identified during this period, most of which displayed anticancer or antimicrobial activities. Marfey's method, which involves LC, was found to be the most frequently used for this purpose.
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6
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Gribble GW. Naturally Occurring Organohalogen Compounds-A Comprehensive Review. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2023; 121:1-546. [PMID: 37488466 DOI: 10.1007/978-3-031-26629-4_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.
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Affiliation(s)
- Gordon W Gribble
- Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA.
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7
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Ha MW, Kim J, Paek SM. Recent Achievements in Total Synthesis for Integral Structural Revisions of Marine Natural Products. Mar Drugs 2022; 20:md20030171. [PMID: 35323470 PMCID: PMC8951824 DOI: 10.3390/md20030171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 02/01/2023] Open
Abstract
A great effort to discover new therapeutic ingredients is often initiated through the discovery of the existence of novel marine natural products. Since substances produced by the marine environment might be structurally more complex and unique than terrestrial natural products, there have been cases of misassignments of their structures despite the availability of modern spectroscopic and computational chemistry techniques. When it comes to refutation to erroneously or tentatively proposed structures empirical preparations through organic chemical synthesis has the greatest contribution along with close and sophiscated inspection of spectroscopic data. Herein, we analyzed the total synthetic studies that have decisively achieved in revelation of errors, ambiguities, or incompleteness of the isolated structures of marine natural products covering the period from 2018 to 2021.
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Affiliation(s)
- Min Woo Ha
- Jeju Research Institute of Pharmaceutical Sciences, College of Pharmacy, Jeju National University, 102 Jejudaehak-ro, Jeju 63243, Jeju-do, Korea;
- Interdisciplinary Graduate Program in Advanced Convergence Technology & Science, Jeju National University, 102 Jejudaehak-ro, Jeju 63243, Jeju-do, Korea
| | - Jonghoon Kim
- Department of Chemistry, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Korea;
| | - Seung-Mann Paek
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Gyeongnam-do, Korea
- Correspondence: ; Tel.: +82-55-772-2424
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8
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Abstract
Protected dipeptides can be converted into cyclic ketoaminals, which can be subjected to palladium-catalyzed regioselective C-H functionalization. The best results are obtained using the 2-(methylthio)aniline (MTA) directing group, which is superior to the commonly used 8-aminoquinoline (AQ) group. No epimerization of stereogenic centers is observed. Subsequent cleavage of the directing and protecting groups allows the incorporation of a modified dipeptide into larger peptide chains.
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Affiliation(s)
- Michael Kohr
- Saarland University, Organic Chemistry I, Campus, Building C4.2, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Saarland University, Organic Chemistry I, Campus, Building C4.2, D-66123 Saarbrücken, Germany
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9
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Kanki D, Nakamukai S, Ogura Y, Takikawa H, Ise Y, Morii Y, Yamawaki N, Takatani T, Arakawa O, Okada S, Matsunaga S. Homophymamide A, Heterodetic Cyclic Tetrapeptide from a Homophymia sp. Marine Sponge: A Cautionary Note on Configurational Assignment of Peptides That Contain a Ureido Linkage. JOURNAL OF NATURAL PRODUCTS 2021; 84:1848-1853. [PMID: 34081460 DOI: 10.1021/acs.jnatprod.1c00336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A previously unreported heterodetic cyclic peptide, homophymamide A (1), was isolated from a Homophymia sp. marine sponge. The structure of homophymamide A was determined to be a lower homologue of anabaenopeptins by spectroscopic analysis, chemical degradation, and chemical synthesis. Analysis of the acidic hydrolysate showed that the racemization of Lys took place, leading us to pose a cautionary note on the configurational assignment of peptides that contain a ureido bond.
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Affiliation(s)
- Daichi Kanki
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shohei Nakamukai
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yusuke Ogura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hirosato Takikawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Ise
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
| | - Yasuhiro Morii
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan
| | - Nobuhiro Yamawaki
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan
| | - Tomohiro Takatani
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan
| | - Osamu Arakawa
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521, Japan
| | - Shigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigeki Matsunaga
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Bunkyo-ku, Tokyo 113-8657, Japan
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10
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Andler O, Kazmaier U. Total synthesis of apratoxin A and B using Matteson's homologation approach. Org Biomol Chem 2021; 19:4866-4870. [PMID: 33998628 DOI: 10.1039/d1ob00713k] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Apratoxin A and B, two members of an interesting class of marine cyclodepsipeptides are synthesized in a straightforward manner via Matteson homologation. Starting from a chiral boronic ester, the polyketide fragment of the apratoxins was obtained via five successive homologation steps in an overall yield of 27% and very good diastereoselectivity. This approach is highly flexible and should allow modification also of this part of the natural products, while previous modifications have been carried out mainly in the peptide fragment.
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Affiliation(s)
- Oliver Andler
- Organic Chemistry, Saarland University, P.O. Box 151150, 66041 Saarbrücken, Germany.
| | - Uli Kazmaier
- Organic Chemistry, Saarland University, P.O. Box 151150, 66041 Saarbrücken, Germany.
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11
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Zhang JN, Xia YX, Zhang HJ. Natural Cyclopeptides as Anticancer Agents in the Last 20 Years. Int J Mol Sci 2021; 22:3973. [PMID: 33921480 PMCID: PMC8068844 DOI: 10.3390/ijms22083973] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/24/2022] Open
Abstract
Cyclopeptides or cyclic peptides are polypeptides formed by ring closing of terminal amino acids. A large number of natural cyclopeptides have been reported to be highly effective against different cancer cells, some of which are renowned for their clinical uses. Compared to linear peptides, cyclopeptides have absolute advantages of structural rigidity, biochemical stability, binding affinity as well as membrane permeability, which contribute greatly to their anticancer potency. Therefore, the discovery and development of natural cyclopeptides as anticancer agents remains attractive to academic researchers and pharmaceutical companies. Herein, we provide an overview of anticancer cyclopeptides that were discovered in the past 20 years. The present review mainly focuses on the anticancer efficacies, mechanisms of action and chemical structures of cyclopeptides with natural origins. Additionally, studies of the structure-activity relationship, total synthetic strategies as well as bioactivities of natural cyclopeptides are also included in this article. In conclusion, due to their characteristic structural features, natural cyclopeptides have great potential to be developed as anticancer agents. Indeed, they can also serve as excellent scaffolds for the synthesis of novel derivatives for combating cancerous pathologies.
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Affiliation(s)
| | | | - Hong-Jie Zhang
- Teaching and Research Division, School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong SAR, China; (J.-N.Z.); (Y.-X.X.)
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12
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Abstract
This review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) 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 (1554 in 469 papers for 2018), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.
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Affiliation(s)
- Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Australia. and Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia
| | - Brent R Copp
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia and School of Environment and Science, Griffith University, Brisbane, Australia
| | - Robert A Keyzers
- Centre for Biodiscovery, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Michèle R Prinsep
- Chemistry, School of Science, University of Waikato, Hamilton, New Zealand
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13
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Andler O, Kazmaier U. A Straightforward Synthesis of Polyketides via Ester Dienolate Matteson Homologation. Chemistry 2021; 27:949-953. [PMID: 33089903 PMCID: PMC7839490 DOI: 10.1002/chem.202004650] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Indexed: 12/22/2022]
Abstract
Application of ester dienolates as nucleophiles in Matteson homologations allows for the stereoselective synthesis of highly substituted α,β-unsaturated δ-hydroxy carboxyl acids, structural motifs widespread found in polyketide natural products. The protocol is rather flexible and permits the introduction of substituents and functionalities also at those positions which are not accessible by the commonly used aldol reaction. Therefore, this ester dienolate Matteson approach is an interesting alternative to the "classical" polyketide syntheses.
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Affiliation(s)
- Oliver Andler
- Institut für Organische ChemieUniversität des SaarlandesCampus C4.266123SaarbrückenGermany
| | - Uli Kazmaier
- Institut für Organische ChemieUniversität des SaarlandesCampus C4.266123SaarbrückenGermany
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14
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Kiefer A, Bader CD, Held J, Esser A, Rybniker J, Empting M, Müller R, Kazmaier U. Synthesis of New Cyclomarin Derivatives and Their Biological Evaluation towards
Mycobacterium Tuberculosis
and
Plasmodium Falciparum. Chemistry 2019; 25:8894-8902. [DOI: 10.1002/chem.201901640] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Indexed: 01/03/2023]
Affiliation(s)
- Alexander Kiefer
- Organic ChemistrySaarland University Campus C4.2 66123 Saarbrücken Germany
| | - Chantal D. Bader
- Department Microbial Natural Products (MINS)Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)–Helmholtz Centre for Infection Research (HZI) Campus E8.1 66123 Saarbrücken Germany
| | - Jana Held
- Department of Tropical MedicineUniversity of Tübingen Wilhelmstraße 27 72074 Tübingen Germany
| | - Anna Esser
- Center for Molecular Medicine CologneUniversity of Cologne Robert Koch Str. 21 50931 Cologne Germany
| | - Jan Rybniker
- Department I of Internal MedicineUniversity of Cologne 50937 Cologne (Germany) and German Center for Infection Research (DZIF), Partner Site Bonn-Cologne Germany
| | - Martin Empting
- Department of Drug Design and Optimization (DDOP)Helmholtz-Institute for Pharmaceutical Research Saarland, (HIPS)–Helmholtz Centre for Infection Research (HZI) Campus E8.1 66123 Saarbrücken Germany
| | - Rolf Müller
- Department Microbial Natural Products (MINS)Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)–Helmholtz Centre for Infection Research (HZI) Campus E8.1 66123 Saarbrücken Germany
- Department of PharmacySaarland University Campus E8.1 66123 Saarbrücken Germany
| | - Uli Kazmaier
- Organic ChemistrySaarland University Campus C4.2 66123 Saarbrücken Germany
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15
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Horn A, Kazmaier U. Stereoselective Modification of N-(α-Hydroxyacyl)-glycinesters via Palladium-Catalyzed Allylic Alkylation. Org Lett 2019; 21:4595-4599. [DOI: 10.1021/acs.orglett.9b01497] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander Horn
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
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16
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Servatius P, Stach T, Kazmaier U. Total Synthesis of Luminmycin A, a Cryptic Natural Product from Photorhabdus Luminescens. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900460] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Phil Servatius
- Organic Chemistry; Saarland University; P.O. Box 151150 66041 Saarbrücken Germany
| | - Tanja Stach
- Organic Chemistry; Saarland University; P.O. Box 151150 66041 Saarbrücken Germany
| | - Uli Kazmaier
- Organic Chemistry; Saarland University; P.O. Box 151150 66041 Saarbrücken Germany
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17
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Kohr M, Kazmaier U. Halogenated Allyl Alcohol Derivatives - Versatile Electrophiles for Palladium-Catalyzed Allylic Alkylations. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Michael Kohr
- Organic Chemistry; Saarland University; P.O. Box 151150 66041 Saarbrücken Germany
| | - Uli Kazmaier
- Organic Chemistry; Saarland University; P.O. Box 151150 66041 Saarbrücken Germany
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18
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Junk L, Kazmaier U. Total Synthesis and Configurational Revision of Mozamide A, a Hydroxy-Brunsvicamide. J Org Chem 2019; 84:2489-2500. [DOI: 10.1021/acs.joc.8b02836] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lukas Junk
- Organic Chemistry I, Saarland University, Campus Building C4.2, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Organic Chemistry I, Saarland University, Campus Building C4.2, D-66123 Saarbrücken, Germany
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19
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Kinsinger T, Kazmaier U. Mono-selective β-C–H arylation of N-methylated amino acids and peptides promoted by the 2-(methylthio)aniline directing group. Org Biomol Chem 2019; 17:5595-5600. [DOI: 10.1039/c9ob00966c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
2-(Methylthio)aniline (MTA) directed C(sp3)–H functionalisations are efficient and straightforward protocols for the selective β-modification of N-methylated amino acids.
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Affiliation(s)
- Thorsten Kinsinger
- Institute of Organic Chemistry
- Saarland University
- 66041 Saarbrücken
- Germany
| | - Uli Kazmaier
- Institute of Organic Chemistry
- Saarland University
- 66041 Saarbrücken
- Germany
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20
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Kinsinger T, Kazmaier U. C–H Functionalization of N-Methylated Amino Acids and Peptides as Tool in Natural Product Synthesis: Synthesis of Abyssenine A and Mucronine E. Org Lett 2018; 20:7726-7730. [DOI: 10.1021/acs.orglett.8b03475] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Thorsten Kinsinger
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
| | - Uli Kazmaier
- Organic Chemistry I, Saarland University, Campus, Building C4.2, D-66123 Saarbrücken, Germany
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