1
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Dianat M, Straaten S, Maritato A, Wibberg D, Busche T, Blank LM, Ebert BE. Exploration of In Situ Extraction for Enhanced Triterpenoid Production by Saccharomyces cerevisiae. Microb Biotechnol 2024; 17:e70061. [PMID: 39696809 DOI: 10.1111/1751-7915.70061] [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: 06/10/2024] [Revised: 11/06/2024] [Accepted: 11/14/2024] [Indexed: 12/20/2024] Open
Abstract
Plant-derived triterpenoids are in high demand due to their valuable applications in cosmetic, nutraceutical, and pharmaceutical industries. To meet this demand, microbial production of triterpenoids is being developed for large-scale production. However, a prominent limitation of microbial synthesis is the intracellular accumulation, requiring cell disruption during downstream processing. Destroying the whole-cell catalyst drives up production costs and limits productivity and product yield per cell. Here, in situ product extraction of triterpenoids into a second organic phase was researched to address this limitation. An organic solvent screening identified water-immiscible isopropyl myristate as a suitable in situ extractant, enabling extraction of up to 90% of total triterpenoids from engineered Saccharomyces cerevisiae. Combining isopropyl myristate and β-cyclodextrins improved extraction efficiency. In a first configuration, repeated batch fermentation with sequential product extraction and cell recycling resulted in 1.8 times higher production than a reference fermentation without in situ product extraction. In the second configuration, yeast cells were in contact with the second organic phase throughout a fed-batch fermentation to continuously extract triterpenoids. This resulted in 90% product extraction and an extended production phase. Further improvement of triterpenoid production was not achieved due to microbial host limitations uncovered through omics analyses.
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Affiliation(s)
- Mariam Dianat
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Sarah Straaten
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Aldo Maritato
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Daniel Wibberg
- Center for Biotechnology (CeBiTec), Bielefeld University Institute of Bio, and Geosciences - Computational Metagenomics (IBG-5), Forschungszentrum Jülich GmbH - Branch Office Bielefeld University, Forschungszentrum Jülich GmbH, Bielefeld, Germany
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Tobias Busche
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Birgitta E Ebert
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, Queensland, Australia
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2
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Ancajas CMF, Oyedele AS, Butt CM, Walker AS. Advances, opportunities, and challenges in methods for interrogating the structure activity relationships of natural products. Nat Prod Rep 2024; 41:1543-1578. [PMID: 38912779 PMCID: PMC11484176 DOI: 10.1039/d4np00009a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Indexed: 06/25/2024]
Abstract
Time span in literature: 1985-early 2024Natural products play a key role in drug discovery, both as a direct source of drugs and as a starting point for the development of synthetic compounds. Most natural products are not suitable to be used as drugs without further modification due to insufficient activity or poor pharmacokinetic properties. Choosing what modifications to make requires an understanding of the compound's structure-activity relationships. Use of structure-activity relationships is commonplace and essential in medicinal chemistry campaigns applied to human-designed synthetic compounds. Structure-activity relationships have also been used to improve the properties of natural products, but several challenges still limit these efforts. Here, we review methods for studying the structure-activity relationships of natural products and their limitations. Specifically, we will discuss how synthesis, including total synthesis, late-stage derivatization, chemoenzymatic synthetic pathways, and engineering and genome mining of biosynthetic pathways can be used to produce natural product analogs and discuss the challenges of each of these approaches. Finally, we will discuss computational methods including machine learning methods for analyzing the relationship between biosynthetic genes and product activity, computer aided drug design techniques, and interpretable artificial intelligence approaches towards elucidating structure-activity relationships from models trained to predict bioactivity from chemical structure. Our focus will be on these latter topics as their applications for natural products have not been extensively reviewed. We suggest that these methods are all complementary to each other, and that only collaborative efforts using a combination of these techniques will result in a full understanding of the structure-activity relationships of natural products.
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Affiliation(s)
| | | | - Caitlin M Butt
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
| | - Allison S Walker
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA.
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
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3
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Watanabe A, Hikone Y, Nagatomo M, Inoue M. Conversion of Phorbol into Des-D-Ring Tricycle and Crotonianoid B via Peroxidation Reaction. Org Lett 2024; 26:4335-4339. [PMID: 38738923 DOI: 10.1021/acs.orglett.4c01363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Phorbol (1) has a tetracyclic ABCD-ring and is readily isolable from a natural source. We previously synthesized 1 and 16 structurally related natural products using common ABC-ring intermediate 2. Here we report a new synthetic route to 2 using 1 as a starting material. Key features of the synthesis are chemoselective removal of the D-ring via cyclopropane opening, peroxidation, and retro-aldol reactions. The high utility of the peroxidation was further demonstrated in the first synthesis of crotonianoid B (9).
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Affiliation(s)
- Ayumu Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuto Hikone
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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4
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Wang H, Abe I. Recent developments in the enzymatic modifications of steroid scaffolds. Org Biomol Chem 2024; 22:3559-3583. [PMID: 38639195 DOI: 10.1039/d4ob00327f] [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: 04/20/2024]
Abstract
Steroids are an important family of bioactive compounds. Steroid drugs are renowned for their multifaceted pharmacological activities and are the second-largest category in the global pharmaceutical market. Recent developments in biocatalysis and biosynthesis have led to the increased use of enzymes to enhance the selectivity, efficiency, and sustainability for diverse modifications of steroids. This review discusses the advancements achieved over the past five years in the enzymatic modifications of steroid scaffolds, focusing on enzymatic hydroxylation, reduction, dehydrogenation, cascade reactions, and other modifications for future research on the synthesis of novel steroid compounds and related drugs, and new therapeutic possibilities.
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Affiliation(s)
- Huibin Wang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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5
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Reese PB. Remote functionalization reactions in steroids: discovery and application. Steroids 2024; 204:109362. [PMID: 38278283 DOI: 10.1016/j.steroids.2023.109362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/23/2023] [Accepted: 12/30/2023] [Indexed: 01/28/2024]
Abstract
Research published between 2001 and 2022 on the functionalization of remote positions of steroids, as well as the use of this technique in the generation of biologically active compounds has been reviewed. In the first section of the analysis established and novel methods for activation of sites deemed to be remote were reported. A series of manganese- (mainly), rhodium-, ruthenium- and osmium-centered porphyrins as catalysts in the presence of PIDA as oxidant have effected hydroxylation at C-1, -5, -6, -7, -11, -14, -15, -16, -17, -20, -24 and -25. Dioxiranes have been utilized in inserting hydroxyl groups at the 5, 12, 14, 15, 16, 17, 20, 24 and 25 positions (tertiary centers for the most part). Alcohols at C-12 and -16 were oxidized further to ketones. The Schönecker oxidation, discovered and developed during the period, has revolutionized the selective functionalization at C-12 of steroids possessing a 17-keto group. In the presence of iron-centered PDP- and MCP-based catalysts, hydrogen peroxide and acetic acid, substrates tended to be hydroxylated at C-6 and -12, with further oxidation to ketones often accompanying this reaction. The hypohalite reaction, utilizing the more modern Suarez conditions (irradiation in the presence of iodine and PIDA), was reported to facilitate the insertion of a hydroxyl moiety five atoms away from an existing alcohol oxygen. Steroidal-3β-diazoacetates tend to decompose on heating with di-rhodium-centered catalysts while activating carbons four or five atoms away. Chromium- and iron-based acetates were observed to functionalize C-5 and -25. Other reactions involving ring cleavage and halogenation, ketone irradiation and α-hydroxylation of ethers were also covered. The syntheses of compounds with marked biological activity from readily available steroids is described in the second section of the study. Cyclopamine, cephalostatin-1, ritterazine B and three polyhydroxypregnanaes (pergularin, utendin and tomentogenin) were generated in sequences in which a key step required hydroxylation at C-12 using the Schönecker reaction. A crucial stage in the preparation of cortistatin A, the saundersioside core, eurysterol A, 5,6-dihydroglaucogenin C, as well as clinostatins A and B involved the functionalization of C-18 or -19 utilizing hypohalite chemistry. The synthetic route to xestobergsterol A, pavonin-4-aglycone and ouagabagenin included a transformation where ketone irradiation played a part in either producing a Δ14 or a C-19 activated steroid. The radical relay reaction, where a 17α-chloro-steroid was formed, was central in the generation of pythocholic acid. The lead tetraacetate reaction was pivotal in the functionalization of C-19 during the synthesis of cyclocitrinol.
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Affiliation(s)
- Paul B Reese
- Department of Chemistry, The University of the West Indies, Mona, Kingston 7, Jamaica.
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6
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Fay N, Kouklovsky C, de la Torre A. Natural Product Synthesis: The Endless Quest for Unreachable Perfection. ACS ORGANIC & INORGANIC AU 2023; 3:350-363. [PMID: 38075446 PMCID: PMC10704578 DOI: 10.1021/acsorginorgau.3c00040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/24/2023] [Accepted: 09/25/2023] [Indexed: 06/13/2024]
Abstract
Total synthesis is a field in constant progress. Its practitioners aim to develop ideal synthetic strategies to build complex molecules. As such, they are both a driving force and a showcase of the progress of organic synthesis. In this Perspective, we discuss recent notable total syntheses. The syntheses selected herein are classified according to the key strategic considerations for each approach.
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Affiliation(s)
- Nicolas Fay
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
| | - Cyrille Kouklovsky
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
| | - Aurélien de la Torre
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
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7
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Dembitsky VM. Bioactive Steroids Bearing Oxirane Ring. Biomedicines 2023; 11:2237. [PMID: 37626733 PMCID: PMC10452232 DOI: 10.3390/biomedicines11082237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 07/24/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.
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Affiliation(s)
- Valery M Dembitsky
- Centre for Applied Research, Innovation and Entrepreneurship, Lethbridge College, 3000 College Drive South, Lethbridge, AB T1K 1L6, Canada
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8
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Synthesis and cytotoxic activity of triterpenoids with N,O-heterocyclic fragments based on 2-formyl-1(2)-ene derivative of methyldihydrobetulonate. CHEMICAL PAPERS 2023. [DOI: 10.1007/s11696-022-02624-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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9
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Kõllo M, Rõuk K, Järving I, Pehk T, Lopp M. Towards the total synthesis of 9,11-secosterol: Linking A,B- and D-rings with Michael addition to sulfone-activated cyclopentanone. Tetrahedron 2023. [DOI: 10.1016/j.tet.2023.133363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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10
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Wender PA, Gentry ZO, Fanelli DJ, Luu-Nguyen QH, McAteer OD, Njoo E. Practical synthesis of the therapeutic leads tigilanol tiglate and its analogues. Nat Chem 2022; 14:1421-1426. [PMID: 36192432 PMCID: PMC10079359 DOI: 10.1038/s41557-022-01048-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023]
Abstract
Tigilanol tiglate is a natural product diterpenoid in clinical trials for the treatment of a broad range of cancers. Its unprecedented protein kinase C isoform selectivity make it and its analogues exceptional leads for PKC-related clinical indications, which include human immunodeficiency virus and AIDS eradication, antigen-enhanced cancer immunotherapy, Alzheimer's disease and multiple sclerosis. Currently, the only source of tigilanol tiglate is a rain forest tree, Fontainea picrosperma, whose limited number and restricted distribution (northeastern Australia) has prompted consideration of designed tree plantations to address supply needs. Here we report a practical laboratory synthesis of tigilanol tiglate that proceeds in 12 steps (12% overall yield, >80% average yield per step) and can be used to sustainably supply tigilanol tiglate and its analogues, the latter otherwise inaccessible from the natural source. The success of this synthesis is based on a unique strategy for the installation of an oxidation pattern common to many biologically active tiglianes, daphnanes and their analogues.
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Affiliation(s)
- Paul A Wender
- Department of Chemistry, Stanford University, Stanford, CA, USA.
- Department of Systems and Chemical Biology, Stanford University, Stanford, CA, USA.
| | | | - David J Fanelli
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | | | - Owen D McAteer
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Edward Njoo
- Department of Chemistry, Stanford University, Stanford, CA, USA
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11
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Millham AB, Micalizio GC. Toward the Asymmetric Synthesis of Cardenolides and Related Steroidal Systems: syn-S N2' of Organometallics with C14-C17 Vinylepoxides. Org Lett 2022; 24:7058-7061. [PMID: 36154235 PMCID: PMC9637385 DOI: 10.1021/acs.orglett.2c02455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In a program aimed at establishing a common sequence of C-C bond-forming reactions for asymmetric construction of tetracyclic triterpenoid natural products and related synthetic systems, effort has been directed toward introducing C17β-substitution by late-stage functionalization of stereodefined "steroidal" D-ring vinylepoxides (spanning C14-C17). It has been found that cyanocuprates participate in syn-SN2' reactions that result in products bearing various C17β-substituents and containing a β-OH at C14.
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Affiliation(s)
- Adam B. Millham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, NH 03755, United States
| | - Glenn C. Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, NH 03755, United States
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12
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Nicholson JM, Millham AB, Bucknam AR, Markham LE, Sailors XI, Micalizio GC. General Enantioselective and Stereochemically Divergent Four-Stage Approach to Fused Tetracyclic Terpenoid Systems. J Org Chem 2022; 87:3352-3362. [PMID: 35175755 PMCID: PMC9438405 DOI: 10.1021/acs.joc.1c02979] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Tetracyclic terpenoid-derived natural products are a broad class of medically relevant agents that include well-known steroid hormones and related structures, as well as more synthetically challenging congeners such as limonoids, cardenolides, lanostanes, and cucurbitanes, among others. These structurally related compound classes present synthetically disparate challenges based, in part, on the position and stereochemistry of the numerous quaternary carbon centers that are common to their tetracyclic skeletons. While de novo syntheses of such targets have been a topic of great interest for over 50 years, semisynthesis is often how synthetic variants of these natural products are explored as biologically relevant materials and how such agents are further matured as therapeutics. Here, focus was directed at establishing an efficient, stereoselective, and molecularly flexible de novo synthetic approach that could offer what semisynthetic approaches do not. In short, a unified strategy to access common molecular features of these natural product families is described that proceeds in four stages: (1) conversion of epichlorohydrin to stereodefined enynes, (2) metallacycle-mediated annulative cross-coupling to generate highly substituted hydrindanes, (3) tetracycle formation by stereoselective forging of the C9-C10 bond, and (4) group-selective oxidative rearrangement that repositions a quaternary center from C9 to C10. These studies have defined the structural features required for highly stereoselective C9-C10 bond formation and document the generality of this four-stage synthetic strategy to access a range of unique stereodefined systems, many of which bear stereochemistry/substitution/functionality not readily accessible from semisynthesis.
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Affiliation(s)
- Joshua M. Nicholson
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Adam B. Millham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Andrea R. Bucknam
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Lauren E. Markham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Xenia Ivanna Sailors
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C. Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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13
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Vorontsova SK, Zavarzin IV, Shirinian VZ, Bozhenko EI, Andreeva OE, Sorokin DV, Scherbakov AM, Minyaev ME. Synthesis and crystal structures of D-annulated pentacyclic steroids: looking within and beyond AR signalling in prostate cancer. CrystEngComm 2022. [DOI: 10.1039/d1ce01417j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbocyclic steroids D-annulated at 16α and 17α positions with a 5-membered ring E are easily accessible via the interrupted Nazarov cyclization. Three steroid series have been structurally studied: chlorine-containing D-annulated...
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14
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Wang Y, Tian H, Gui J. Gram-Scale Synthesis of Bufospirostenin A by a Biomimetic Skeletal Rearrangement Approach. J Am Chem Soc 2021; 143:19576-19586. [PMID: 34762408 DOI: 10.1021/jacs.1c10067] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bufospirostenin A, which was the first spirostanol to be isolated from an animal, possesses an unprecedented 5/7/6/5/5/6 hexacyclic framework. Herein, we report two biomimetic syntheses of this natural product in just seven or nine steps from a readily available steroidal lactone. Key features of the syntheses include a photosantonin rearrangement and a Wagner-Meerwein rearrangement for rapid construction of the rearranged A/B ring system, as well as a cobalt-mediated olefin hydroselenylation and a selenide E2 reaction to accomplish a challenging olefin transposition. Our syntheses provide experimental support for the biogenetic pathway to 5(10→1)abeo-steroids that we have proposed.
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Affiliation(s)
- Yu Wang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai200032, China
| | - Hailong Tian
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai200032, China
| | - Jinghan Gui
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai200032, China
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15
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Ronnebaum TA, Eaton SA, Brackhahn EAE, Christianson DW. Engineering the Prenyltransferase Domain of a Bifunctional Assembly-Line Terpene Synthase. Biochemistry 2021; 60:3162-3172. [PMID: 34609847 DOI: 10.1021/acs.biochem.1c00600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Copalyl diphosphate (CPP) synthase from Penicillium verruculosum (PvCPS) is a bifunctional diterpene synthase with both prenyltransferase and class II cyclase activities. The prenyltransferase α domain catalyzes the condensation of C5 dimethylallyl diphosphate with three successively added C5 isopentenyl diphosphates (IPPs) to form C20 geranylgeranyl diphosphate (GGPP), which then undergoes a class II cyclization reaction at the βγ domain interface to generate CPP. The prenyltransferase α domain mediates oligomerization to form a 648-kD (αβγ)6 hexamer. In the current study, we explore prenyltransferase structure-function relationships in this oligomeric assembly-line platform with the goal of generating alternative linear isoprenoid products. Specifically, we report steady-state enzyme kinetics, product analysis, and crystal structures of various site-specific variants of the prenyltransferase α domain. Crystal structures of the H786A, F760A, S723Y, S723F, and S723T variants have been determined at resolutions of 2.80, 3.10, 3.15, 2.65, and 2.00 Å, respectively. The substitution of S723 with bulky aromatic amino acids in the S723Y and S723F variants constricts the active site, thereby directing the formation of the shorter C15 isoprenoid, farnesyl diphosphate. While the S723T substitution only subtly alters enzyme kinetics and does not compromise GGPP biosynthesis, the crystal structure of this variant reveals a nonproductive binding mode for IPP that likely accounts for substrate inhibition at high concentrations. Finally, mutagenesis of the catalytic general acid in the class II cyclase domain, D313A, significantly compromises prenyltransferase activity. This result suggests molecular communication between the prenyltransferase and cyclase domains despite their distant connection by a flexible polypeptide linker.
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Affiliation(s)
- Trey A Ronnebaum
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Samuel A Eaton
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Emily A E Brackhahn
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - David W Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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