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Bowen JI, Zhong X, Gao K, Reed B, Crump MP, Wang L, Willis CL. Combining total synthesis and genetic engineering to probe dihydropyran formation in ambruticin biosynthesis. Chem Sci 2024; 15:5319-5326. [PMID: 38577359 PMCID: PMC10988584 DOI: 10.1039/d4sc00720d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/27/2024] [Indexed: 04/06/2024] Open
Abstract
The ambruticins are a family of potent antifungal polyketide derived natural products isolated from the myxobacterium Sorangium cellulosum. Their unusual structures include a trisubstituted cyclopropyl group and two oxygen heterocycles, a tetrahydropyran (THP) and dihydropyran (DHP). Herein we report a flexible modular approach for the total synthesis of ambruticins which is used to prepare ambruticins F and S as well as in the first total synthesis of 20,21-dihydroambruticin F. The flexible strategy unites 3 fragments via Julia-Kocienski olefinations and provides important standards for investigation of dihydropyran formation in ambruticin biosynthesis. Cultures of wild-type S. cellulosum So ce10 produce mainly ambruticin S and the VS series of metabolites. An efficient electroporation method enabled gene knockout experiments which revealed that the ΔambP-S mutant of S. cellulosum accumulated the bisTHP polyketide 20,21-dihydroambruticin F. In contrast, the ΔambN-S mutant gave ambruticin F with the 20,21-alkene as the major metabolite confirming that AmbP and AmbO (a Rieske enzyme and flavin-dependent monooxygenase respectively) are implicated in 20,21-alkene formation. The results of feeding studies to a Sorangium strain containing only ambP and ambO are in accord with formation of the 20,21-alkene occurring prior to generation of the C3 to C7 dihydroxylated tetrahydropyran in ambruticin biosynthesis.
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Affiliation(s)
- James I Bowen
- School of Chemistry, University of Bristol Bristol BS8 1TS UK
| | - Xiaotong Zhong
- Institute of Microbiology, Chinese Academy of Sciences No. 1 Beichen West Road, Chaoyang District Beijing 100101 China
| | - Kaining Gao
- Institute of Microbiology, Chinese Academy of Sciences No. 1 Beichen West Road, Chaoyang District Beijing 100101 China
- School of Life Sciences, Yunnan University Kunming 650500 China
| | - Benjamin Reed
- School of Chemistry, University of Bristol Bristol BS8 1TS UK
| | - Matthew P Crump
- School of Chemistry, University of Bristol Bristol BS8 1TS UK
| | - Luoyi Wang
- Institute of Microbiology, Chinese Academy of Sciences No. 1 Beichen West Road, Chaoyang District Beijing 100101 China
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Guth FM, Lindner F, Rydzek S, Peil A, Friedrich S, Hauer B, Hahn F. Rieske Oxygenase-Catalyzed Oxidative Late-Stage Functionalization during Complex Antifungal Polyketide Biosynthesis. ACS Chem Biol 2023; 18:2450-2456. [PMID: 37948749 DOI: 10.1021/acschembio.3c00498] [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: 11/12/2023]
Abstract
Rieske oxygenases (ROs) from natural product biosynthetic pathways are a poorly studied group of enzymes with significant potential as oxidative functionalization biocatalysts. A study on the ROs JerL, JerP, and AmbP from the biosynthetic pathways of jerangolid A and ambruticin VS-3 is described. Their activity was successfully reconstituted using whole-cell bioconversion systems coexpressing the ROs and their respective natural flavin-dependent reductase (FDR) partners. Feeding authentic biosynthetic intermediates and synthetic surrogates to these strains confirmed the involvement of the ROs in hydroxymethylpyrone and dihydropyran formation and revealed crucial information about the RO's substrate specificity. The pronounced dependence of JerL and JerP on the presence of a methylenolether allowed the precise temporal assignment of RO catalysis to the ultimate steps of jerangolid biosynthesis. JerP and AmbP stand out among the biosynthetic ROs studied so far for their ability to catalyze clean tetrahydropyran desaturation without further functionalizing the formed electron-rich double bonds. This work highlights the remarkable ability of ROs to highly selectively oxidize complex molecular scaffolds.
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Affiliation(s)
- Florian M Guth
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Frederick Lindner
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Simon Rydzek
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Andreas Peil
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Steffen Friedrich
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Bernhard Hauer
- Institute of Technical Biochemistry, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Frank Hahn
- Professur für Organische Chemie (Lebensmittelchemie), Fakultät für Biologie, Chemie und Geowissenschaften, Department of Chemistry, Universität Bayreuth, 95447 Bayreuth, Germany
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Karaj E, Sindi SH, Kuganesan N, Perera L, Taylor W, Viranga Tillekeratne LM. Tunable Cysteine-Targeting Electrophilic Heteroaromatic Warheads Induce Ferroptosis. J Med Chem 2022; 65:11788-11817. [PMID: 35984756 PMCID: PMC10408038 DOI: 10.1021/acs.jmedchem.2c00909] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Once considered potential liabilities, the modern era witnesses a renaissance of interest in covalent inhibitors in drug discovery. The available toolbox of electrophilic warheads is limited by constraints on tuning reactivity and selectivity. Following our work on a class of ferroptotic agents termed CETZOLEs, we discovered new tunable heterocyclic electrophiles which are capable of inducing ferroptosis. The biological evaluation demonstrated that thiazoles with an alkyne electrophile at the 2-position selectively induce ferroptosis with high potency. Density functional theory calculations and NMR kinetic studies demonstrated the ability of our heterocycles to undergo thiol addition, an apparent prerequisite for cytotoxicity. Chemoproteomic analysis indicated several potential targets, the most prominent among them being GPX4 protein. These results were further validated by western blot analysis and the cellular thermal shift assay. Incorporation of these heterocycles into appropriate pharmacophores generated highly cytotoxic agents such as the analogue BCP-T.A, with low nM IC50 values in ferroptosis-sensitive cell lines.
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Affiliation(s)
- Endri Karaj
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH 43606
| | - Shaimaa H. Sindi
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH 43606
| | - Nishanth Kuganesan
- Department of Biological Sciences, College of Natural Sciences and Mathematics, University of Toledo, Toledo, OH 43606
| | - Lalith Perera
- Laboratory of Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - William Taylor
- Department of Biological Sciences, College of Natural Sciences and Mathematics, University of Toledo, Toledo, OH 43606
| | - L. M. Viranga Tillekeratne
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH 43606
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Rinu PXT, Radhika S, Anilkumar G. Recent Applications and Trends in the Julia‐Kocienski Olefination. ChemistrySelect 2022. [DOI: 10.1002/slct.202200760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Sankaran Radhika
- School of Chemical Sciences Mahatma Gandhi University Priyadarsini Hills P O. Kottayam Kerala INDIA 686560
| | - Gopinathan Anilkumar
- School of Chemical Sciences Mahatma Gandhi University Priyadarsini Hills P O. Kottayam Kerala INDIA 686560
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Bowen JI, Wang L, Crump MP, Willis CL. Synthetic and biosynthetic methods for selective cyclisations of 4,5-epoxy alcohols to tetrahydropyrans. Org Biomol Chem 2022; 20:1150-1175. [PMID: 35029626 PMCID: PMC8827043 DOI: 10.1039/d1ob01905h] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/21/2021] [Indexed: 12/20/2022]
Abstract
Tetrahydropyrans (THPs) are common structural motifs found in natural products and synthetic therapeutic molecules. In Nature these 6-membered oxygen heterocycles are often assembled via intramolecular reactions involving either oxy-Michael additions or ring opening of epoxy-alcohols. Indeed, the polyether natural products have been particularly widely studied due to their fascinating structures and important biological properties; these are commonly formed via endo-selective epoxide-opening cascades. In this review we outline synthetic approaches for endo-selective intramolecular epoxide ring opening (IERO) of 4,5-epoxy-alcohols and their applications in natural product synthesis. In addition, the biosynthesis of THP-containing natural products which utilise IERO reactions are reviewed.
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Affiliation(s)
- James I Bowen
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - Luoyi Wang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Matthew P Crump
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| | - Christine L Willis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
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