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Dramatic influence of ester steric hindrance on the diastereoselectivity of a Michael addition towards the synthesis of the ABC tricycle of hexacyclinic acid. Tetrahedron 2021. [DOI: 10.1016/j.tet.2020.131843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Design and synthesis of new antitumor agents with the 1,7-epoxycyclononane framework. Study of their anticancer action mechanism by a model compound. Bioorg Med Chem 2018; 26:3379-3398. [PMID: 29784272 DOI: 10.1016/j.bmc.2018.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/13/2018] [Accepted: 05/08/2018] [Indexed: 11/23/2022]
Abstract
This article describes the design, synthesis and biological evaluation of a new family of antitumor agents having the 1,7-epoxycyclononane framework. We have developed a versatile synthetic methodology that allows the preparation of a chemical library with structural diversity and in good yield. The synthetic methodology has been scaled up to the multigram level and can be developed in an enantioselective fashion. The study in vitro of a model compound, in front of the cancer cell lines HL-60 and MCF-7, showed a growth inhibitory effect better than that of cisplatin. The observation of cancer cells by fluorescence microscopy showed the presence of apoptotic bodies and a degradation of microtubules. The study of cell cycle and mechanism of death of cancer cells by flow cytometry indicates that the cell cycle arrested at the G0/G1 phase and that the cells died by apoptosis preferably over necrosis. A high percentage of apoptotic cells at the subG0/G1 level was observed. This indicates that our model compound does not behave as an antimitotic agent like nocodazole, used as a reference, which arrests the cell cycle at G2/M phase. The interaction of anticancer agents with DNA molecules was evaluated by atomic force microscopy, circular dichroism and electrophoresis on agarose gel. The results indicate that the model compound has not DNA as a target molecule. The in silico study of the model compound showed a potential good oral bioavailability.
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Montaña ÁM, Ponzano S, Sanasi MF, Kociok-Köhn G. Synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products. Org Biomol Chem 2018; 16:1557-1580. [PMID: 29437174 DOI: 10.1039/c8ob00194d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The present work deals with the synthesis of the 10-oxabicyclo[5.2.1]decane framework present in bioactive natural products like physalins, with potential as antitumor agents. This synthetic methodology involves several key reactions: (a) synthesis of polyfunctionalized cycloheptenones by [4 + 3] cycloaddition reactions of furan precursors with oxyallyl cations; (b) Nicholas reaction with propargyl cations stabilized as dicobalt hexacarbonyl complexes; (c) demetallation and hydration of the resulting acetylenes; (d) stereoconvergent aldol cyclization to generate a key oxatricyclic intermediate and (e) a β-fragmentation process that affords, under hypoiodite photolysis, the desired product with moderate to good yield. The final compounds are the result of a radicalary β-fragmentation at the level of C2-C6 with respect to the tertiary hydroxyl group on C6, with an unexpected contraction from a ten- to a nine-membered ring system, via a radical addition to the carbonyl group on C4. The synthetic methodology has been scaled up to multigram level with good overall yield. Further biological, biochemical and biophysical studies are being carried out in our laboratory on these 1,7-epoxycyclononane derivatives to determine the potential of this kind of oxabicyclic compound as future hits and/or leads for the development of new anticancer drugs. The preliminary evaluation of the anticancer activity of the representative synthesized compounds, against the leukaemia cancer cell lines K-562 and SR, shows a promising activity with a GI50 = 0.01 μM and a LC50 = 7.4 μM for a conveniently functionalized 10-oxabicyclo[5.2.1]decane.
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Affiliation(s)
- Ángel M Montaña
- Industrial and Applied Organic Chemistry Research Unity, Department of Inorganic and Organic Chemistry, Universidad de Barcelona, Martí Franquès 1-11, 08028-Barcelona, Spain.
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Hilinski GJ, Kim YW, Hong J, Kutchukian PS, Crenshaw CM, Berkovitch SS, Chang A, Ham S, Verdine GL. Stitched α-helical peptides via bis ring-closing metathesis. J Am Chem Soc 2014; 136:12314-22. [PMID: 25105213 DOI: 10.1021/ja505141j] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Conformationally stabilized α-helical peptides are capable of inhibiting disease-relevant intracellular or extracellular protein-protein interactions in vivo. We have previously reported that the employment of ring-closing metathesis to introduce a single all-hydrocarbon staple along one face of an α-helical peptide greatly increases α-helical content, binding affinity to a target protein, cell penetration through active transport, and resistance to proteolytic degradation. In an effort to improve upon this technology for stabilizing a peptide in a bioactive α-helical conformation, we report the discovery of an efficient and selective bis ring-closing metathesis reaction leading to peptides bearing multiple contiguous staples connected by a central spiro ring junction. Circular dichroism spectroscopy, NMR, and computational analyses have been used to investigate the conformation of these "stitched" peptides, which are shown to exhibit remarkable thermal stabilities. Likewise, trypsin proteolysis assays confirm the achievement of a structural rigidity unmatched by peptides bearing a single staple. Furthermore, fluorescence-activated cell sorting (FACS) and confocal microscopy assays demonstrate that stitched peptides display superior cell penetrating ability compared to their stapled counterparts, suggesting that this technology may be useful not only in the context of enhancing the drug-like properties of α-helical peptides but also in producing potent agents for the intracellular delivery of proteins and oligonucleotides.
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Affiliation(s)
- Gerard J Hilinski
- Department of Chemistry and Chemical Biology and Department of Stem Cell and Regenerative Biology, Harvard University , Cambridge, Massachusetts 02138, United States
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Zheng H, Shi QY, Du K, Mei YJ, Zhang PF. One-pot Synthesis of 2,4,5-trisubstituted Imidazoles Catalyzed by Lipase. Catal Letters 2012. [DOI: 10.1007/s10562-012-0920-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Holan M, Pohl R, Císařová I, Jahn U. Polyfunctional β-Dicarbonyl Compounds by Michael Addition Reactions of Ester Enolates to α-Benzylidene and α-Alkylidene-β-dicarbonyl Compounds. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Clarke PA, Winn J. Synthesis of an austrodorane sesquiterpenoid core via a transannular Prins cyclization. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.01.093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Iqbal M, Black RJG, Winn J, Reeder AT, Blake AJ, Clarke PA. Studies on transannulation reactions across a nine-membered ring: the synthesis of natural product-like structures. Org Biomol Chem 2011; 9:5062-78. [DOI: 10.1039/c1ob05448a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tanaka Suzuki N, Suzuki T, Matsumura T, Hosoya Y, Nakazato T, Nakada M. Enantioselective Total Synthesis of (-)-FR182877. J SYN ORG CHEM JPN 2011. [DOI: 10.5059/yukigoseikyokaishi.69.646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Clarke PA, Cridland AP, Rolla GA, Iqbal M, Bainbridge NP, Whitwood AC, Wilson C. Studies on the synthesis of the ABC rings of (+/-)-hexacyclinic acid. J Org Chem 2009; 74:7812-21. [PMID: 19813768 DOI: 10.1021/jo901547k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A synthesis of the ABC-rings of the polyketide natural product hexacyclinic acid has been achieved. The B-ring was formed first via an intramolecular ester-tethered Diels-Alder reaction, and the A-ring was annulated to this by means of a SmI(2) mediated reductive 5-exo-trig cyclization of a samarium-ketyl radical onto a vinyl group. Finally, the C-ring was closed using olefin metathesis. Interestingly, use of enyne metathesis resulted in the synthesis of a more functionalized 5-membered C-ring in a model system, but an undesired 6-membered C-ring in the actual system. An investigation of this change in selectivity is discussed.
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Affiliation(s)
- Paul A Clarke
- Department of Chemistry, University of York, Heslington, York, North Yorks YO10 5DD, UK.
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Synthesis of six-membered oxygenated heterocycles through carbon–oxygen bond-forming reactions. Tetrahedron 2008. [DOI: 10.1016/j.tet.2007.11.092] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Suzuki T, Tanaka N, Matsumura T, Hosoya Y, Nakada M. Synthetic studies on (–)-FR182877: construction of the ABCD ring system via the intramolecular cycloadditions (1). Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.07.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Clarke PA, Santos S. Strategies for the Formation of Tetrahydropyran Rings in the Synthesis of Natural Products. European J Org Chem 2006. [DOI: 10.1002/ejoc.200500964] [Citation(s) in RCA: 280] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Paul A. Clarke
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
- Address from January 1, 2006: Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Soraia Santos
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
- Address from January 1, 2006: Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
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Studies on the diastereoselectivity in the IMDA reactions of terminally activated (E,E,E)-nona-1,6,8-trienes. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2005.12.118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Clarke PA, Black RJ, Blake AJ. Enantioselective synthesis of the bicyclo[4.3.0]nonane ring system of the pinguisane-type sesquiterpenoids via a Brønsted acid promoted transannular enol alkylation. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2005.12.084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
[structure: see text] An AB-ring system of the polyketide natural product hexacyclinic acid has been synthesized in racemic form. The key steps were an intramolecular Diels-Alder cyclization of an ester tethered 1,3-nonadiene-8-yne, which generated the B-ring, and a samarium diiodide mediated reductive annulation, which was used to form the A-ring.
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Affiliation(s)
- Paul A Clarke
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
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Synthesis of the B-ring of FR182877. Investigation of the reactions of 6-fumaryl 1,3,8-nonatrienes. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.01.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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