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Amewu RK, Spangenberg T. Detection of Mycolactone by Thin Layer Chromatography. Methods Mol Biol 2022; 2387:131-149. [PMID: 34643909 DOI: 10.1007/978-1-0716-1779-3_14] [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] [Indexed: 06/13/2023]
Abstract
By means of thin layer chromatography coupled to a fluorescence enhancer, a highly sensitive and operationally simple method to detect the mycolactones stemming from the human pathogen Mycobacterium ulcerans was developed and applied to various sample sources.
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Affiliation(s)
| | - Thomas Spangenberg
- Global Health Institute of Merck, Ares Trading S.A. (a subsidiary of Merck KGaA Darmstadt Germany), Eysins, Switzerland
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2
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Kubicek-Sutherland JZ, Vu DM, Anderson AS, Sanchez TC, Converse PJ, Martí-Arbona R, Nuermberger EL, Swanson BI, Mukundan H. Understanding the Significance of Biochemistry in the Storage, Handling, Purification, and Sampling of Amphiphilic Mycolactone. Toxins (Basel) 2019; 11:toxins11040202. [PMID: 30987300 PMCID: PMC6520765 DOI: 10.3390/toxins11040202] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/26/2019] [Accepted: 04/01/2019] [Indexed: 12/29/2022] Open
Abstract
Mycolactone, the amphiphilic macrolide toxin secreted by Mycobacterium ulcerans, plays a significant role in the pathology and manifestations of Buruli ulcer (BU). Consequently, it follows that the toxin is a suitable target for the development of diagnostics and therapeutics for this disease. Yet, several challenges have deterred such development. For one, the lipophilic nature of the toxin makes it difficult to handle and store and contributes to variability associated with laboratory experimentation and purification yields. In this manuscript, we have attempted to incorporate our understanding of the lipophilicity of mycolactone in order to define the optimal methods for the storage, handling, and purification of this toxin. We present a systematic correlation of variability associated with measurement techniques (thin-layer chromatography (TLC), mass spectrometry (MS), and UV-Vis spectrometry), storage conditions, choice of solvents, as well as the impact of each of these on toxin function as assessed by cellular cytotoxicity. We also compared natural mycolactone extracted from bacterial culture with synthesized toxins in laboratory (solvents, buffers) and physiologically relevant (serum) matrices. Our results point to the greater stability of mycolactone in organic, as well as detergent-containing, solvents, regardless of the container material (plastic, glass, or silanized tubes). They also highlight the presence of toxin in samples that may be undetectable by any one technique, suggesting that each detection approach captures different configurations of the molecule with varying specificity and sensitivity. Most importantly, our results demonstrate for the very first time that amphiphilic mycolactone associates with host lipoproteins in serum, and that this association will likely impact our ability to study, diagnose, and treat Buruli ulcers in patients.
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Affiliation(s)
| | - Dung M Vu
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Aaron S Anderson
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Timothy C Sanchez
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Paul J Converse
- Department of Medicine, Johns Hopkins University Center for Tuberculosis Research, Baltimore, MD 21218, USA.
| | | | - Eric L Nuermberger
- Department of Medicine, Johns Hopkins University Center for Tuberculosis Research, Baltimore, MD 21218, USA.
| | - Basil I Swanson
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - Harshini Mukundan
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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Dachavaram SS, Penthala NR, Calahan JL, Munson EJ, Crooks PA. Highly sulphated cellulose: a versatile, reusable and selective desilylating agent for deprotection of alcoholic TBDMS ethers. Org Biomol Chem 2018; 16:6057-6062. [PMID: 30090907 DOI: 10.1039/c8ob01438h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mild, efficient and rapid protocol was developed for the deprotection of alcoholic TBDMS ethers using a recyclable, eco-friendly highly sulphated cellulose sulphate acid catalyst in methanol. This acid catalyst selectively cleaves alcoholic TBDMS ethers in bis-TBDMS ethers containing both alcoholic and phenolic TBDMS ether moieties.
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Affiliation(s)
- Soma Shekar Dachavaram
- Department of Pharmaceutical Sciences College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Saint-Auret S, Abdelkafi H, Le Nouen D, Guenin-Macé L, Demangel C, Bisseret P, Blanchard N. Modular total syntheses of mycolactone A/B and its [ 2H]-isotopologue. Org Biomol Chem 2018; 15:7518-7522. [PMID: 28871293 DOI: 10.1039/c7ob01943b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A modular total synthesis of mycolactone A/B, the exotoxin produced by Mycobacterium ulcerans, has been achieved through the orchestration of several Pd-catalyzed key steps. While this route leads to a mixture of the natural product and its C12 epimer (4 : 1 ratio), this was inconsequential from the biological activity standpoint. Compared to the previously reported routes, this synthetic blueprint allows the late-stage modification of the toxin, as exemplified by the preparation of [22,22,22-2H3]-mycolactone A/B.
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Affiliation(s)
- Sarah Saint-Auret
- Université de Strasbourg, CNRS, Laboratoire de Chimie Moléculaire UMR 7509, 67000 Strasbourg, France.
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Gehringer M, Altmann KH. The chemistry and biology of mycolactones. Beilstein J Org Chem 2017; 13:1596-1660. [PMID: 28904608 PMCID: PMC5564285 DOI: 10.3762/bjoc.13.159] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/21/2017] [Indexed: 12/21/2022] Open
Abstract
Mycolactones are a group of macrolides excreted by the human pathogen Mycobacterium ulcerans, which exhibit cytotoxic, immunosuppressive and analgesic properties. As the virulence factor of M. ulcerans, mycolactones are central to the pathogenesis of the neglected disease Buruli ulcer, a chronic and debilitating medical condition characterized by necrotic skin ulcers. Due to their complex structure and fascinating biology, mycolactones have inspired various total synthesis endeavors and structure-activity relationship studies. Although this review intends to cover all synthesis efforts in the field, special emphasis is given to the comparison of conceptually different approaches and to the discussion of more recent contributions. Furthermore, a detailed discussion of molecular targets and structure-activity relationships is provided.
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Affiliation(s)
- Matthias Gehringer
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zürich, Vladimir-Prelog-Weg 4, 8093 Zürich, Switzerland
| | - Karl-Heinz Altmann
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zürich, Vladimir-Prelog-Weg 4, 8093 Zürich, Switzerland
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Babu VS, Zhou Y, Kishi Y. Design, synthesis, and cytotoxicity of stabilized mycolactone analogs. Bioorg Med Chem Lett 2017; 27:1274-1277. [PMID: 28159417 DOI: 10.1016/j.bmcl.2017.01.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/11/2017] [Accepted: 01/12/2017] [Indexed: 11/16/2022]
Abstract
On exposure to visible light, mycolactone A/B, the causative toxin of Buruli ulcer, rearranges to a mixture of four photo-mycolactones apparently via a rare photochemically-induced [4πs+2πa] cycloaddition. In order to prevent the rearrangement, two C6'-C7' dihydromycolactone analogs 6'α-15 and 6'β-15 were designed and synthesized. 6'α-15 and 6'β-15 were shown to be stable under not only photochemical, but also acidic and basic conditions. Cytotoxicity was tested against arbitrarily chosen four cell lines (human Hek-293, human lung carcinoma A-549, human melanoma LOX-IMVI, and mouse L-929), thereby revealing that: (1) both analogs maintain potent cytotoxicity; (2) 6'β-15 exhibits significantly higher potency against human cell lines than 6'α-15; (3) in comparison with parent mycolactone A/B, 6'β-15 exhibits equal potency against human Hek-293, whereas significantly lower potency against human lung carcinoma A-549 and human melanoma LOX-IMVI.
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Affiliation(s)
- Vaddela Sudheer Babu
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Ya Zhou
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
| | - Yoshito Kishi
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
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Saint-Auret S, Abdelkafi H, Le Nouen D, Bisseret P, Blanchard N. Synthetic strategies towards mycolactone A/B, an exotoxin secreted by Mycobacterium ulcerans. Org Chem Front 2017. [DOI: 10.1039/c7qo00608j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pitfalls and dead-ends pave the way to mycolactone A/B. This full account reports synthetic efforts towards this natural product that eventually culminated in a de novo total synthesis.
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Affiliation(s)
- Sarah Saint-Auret
- Université de Strasbourg
- CNRS
- Laboratoire de Chimie Moléculaire UMR 7509
- 67000 Strasbourg
- France
| | - Hajer Abdelkafi
- Université de Strasbourg
- CNRS
- Laboratoire de Chimie Moléculaire UMR 7509
- 67000 Strasbourg
- France
| | - Didier Le Nouen
- Université de Haute-Alsace
- Laboratoire de Chimie Organique et Bioorganique EA 4566
- 68093 Mulhouse Cedex
- France
| | - Philippe Bisseret
- Université de Strasbourg
- CNRS
- Laboratoire de Chimie Moléculaire UMR 7509
- 67000 Strasbourg
- France
| | - Nicolas Blanchard
- Université de Strasbourg
- CNRS
- Laboratoire de Chimie Moléculaire UMR 7509
- 67000 Strasbourg
- France
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Li X, Babu VS, Kishi Y. Stereoselective total synthesis and stereochemistry confirmation of photo-mycolactones. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2014.12.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chany AC, Tresse C, Casarotto V, Blanchard N. History, biology and chemistry of Mycobacterium ulcerans infections (Buruli ulcer disease). Nat Prod Rep 2014; 30:1527-67. [PMID: 24178858 DOI: 10.1039/c3np70068b] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mycobacterium ulcerans infections (Buruli ulcer disease) have a long history that can be traced back 150 years. The successive discoveries of the mycobacteria in 1948 and of mycolactone A/B in 1999, the toxin responsible for this dramatic necrotic skin disease, resulted in a paradigm shift concerning the disease itself and in a broader sense, delineated an entirely new role for bioactive polyketides as virulence factors. The fascinating history, biology and chemistry of M. ulcerans infections are discussed in this review.
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Affiliation(s)
- Anne-Caroline Chany
- Université de Haute Alsace, Laboratoire de Chimie Organique et Bioorganique, EA4566, Ecole Nationale Supérieure de Chimie de Mulhouse, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France
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