1
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El-Desoky AHH, Inada N, Maeyama Y, Kato H, Hitora Y, Sebe M, Nagaki M, Kai A, Eguchi K, Inazumi T, Sugimoto Y, Frisvad JC, Williams RM, Tsukamoto S. Taichunins E-T, Isopimarane Diterpenes and a 20- nor-Isopimarane, from Aspergillus taichungensis (IBT 19404): Structures and Inhibitory Effects on RANKL-Induced Formation of Multinuclear Osteoclasts. J Nat Prod 2021; 84:2475-2485. [PMID: 34464116 DOI: 10.1021/acs.jnatprod.1c00486] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fifteen new isopimarane-type diterpenes, taichunins E-S (1-15), and a new 20-nor-isopimarane, taichunin T (16), together with four known compounds were isolated from Aspergillus taichungensis (IBT 19404). The structures of these new compounds were determined by NMR and mass spectroscopy, and their absolute configurations were analyzed by NOESY and TDDFT calculations of ECD spectra. Taichunins G, K, and N (3, 7, and 10) completely inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinuclear osteoclasts in RAW264 cells at 5 μM, with 3 showing 92% inhibition at a concentration of 0.2 μM.
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Affiliation(s)
- Ahmed H H El-Desoky
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
- Pharmaceutical Industries Research Division, Pharmacognosy Department, National Research Centre, 33 El Bohouth Street (Former El Tahrir Street), Dokki, P.O. 12622, Giza, Egypt
| | - Natsumi Inada
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Yuka Maeyama
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Hikaru Kato
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Yuki Hitora
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Momona Sebe
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Mika Nagaki
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Aika Kai
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Keisuke Eguchi
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Tomoaki Inazumi
- Department of Pharmaceutical Biochemistry, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Yukihiko Sugimoto
- Department of Pharmaceutical Biochemistry, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Jens C Frisvad
- Section for Synthetic Biology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Soltofts Plads Building 221, 2800 Kongens Lyngby, Denmark
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, United States
| | - Sachiko Tsukamoto
- Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
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2
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Aoyagi Y, Nomura S, Horiba K, Shikano R, Omura Y, Omiya H, Fukuzawa S, Yano R, Williams RM, Takeya K, Hitotsuyanagi Y. Lipase TL®-mediated kinetic resolution of glycerol analogues: Efficient convergent route to both enantiomeric glycerol units. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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3
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Fraley AE, Tran HT, Kelly SP, Newmister SA, Tripathi A, Kato H, Tsukamoto S, Du L, Li S, Williams RM, Sherman DH. Flavin-Dependent Monooxygenases NotI and NotI' Mediate Spiro-Oxindole Formation in Biosynthesis of the Notoamides. Chembiochem 2020; 21:2449-2454. [PMID: 32246875 PMCID: PMC7483341 DOI: 10.1002/cbic.202000004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 04/04/2020] [Indexed: 11/08/2022]
Abstract
The fungal indole alkaloids are a unique class of complex molecules that have a characteristic bicyclo[2.2.2]diazaoctane ring and frequently contain a spiro-oxindole moiety. While various strains produce these compounds, an intriguing case involves the formation of individual antipodes by two unique species of fungi in the generation of the potent anticancer agents (+)- and (-)-notoamide A. NotI and NotI' have been characterized as flavin-dependent monooxygenases that catalyze epoxidation and semi-pinacol rearrangement to form the spiro-oxindole center within these molecules. This work elucidates a key step in the biosynthesis of the notoamides and provides an evolutionary hypothesis regarding a common ancestor for production of enantiopure notoamides.
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Affiliation(s)
- Amy E Fraley
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
- Department of Medicinal Chemistry, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
| | - Hong T Tran
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
- Program in Chemical Biology, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 48109, USA
| | - Samantha P Kelly
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
- Program in Chemical Biology, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 48109, USA
| | - Sean A Newmister
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
- Department of Medicinal Chemistry, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
| | - Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan
| | - Lei Du
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong, 266237, China
| | - Shengying Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong, 266237, China
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Ave., Fort Collins, CO 80523, USA
| | - David H Sherman
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI 28104, USA
- Department of Medicinal Chemistry, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150W. Medical Center Drive, Ann Arbor, MI 48109
- Department of Chemistry, University of Michigan, 930N. University Ave., Ann Arbor, MI 48109, USA
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4
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Fraley AE, Tran HT, Kelly SP, Newmister SA, Tripathi A, Kato H, Tsukamoto S, Du L, Li S, Williams RM, Sherman DH. Cover Feature: Flavin‐Dependent Monooxygenases NotI and NotI′ Mediate Spiro‐Oxindole Formation in Biosynthesis of the Notoamides (ChemBioChem 17/2020). Chembiochem 2020. [DOI: 10.1002/cbic.202000548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Amy E. Fraley
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
- Department of Medicinal ChemistryUniversity of Michigan 428 Church St. Ann Arbor MI 48109 USA
| | - Hong T. Tran
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
- Program in Chemical BiologyUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 48109 USA
| | - Samantha P. Kelly
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
- Program in Chemical BiologyUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 48109 USA
| | - Sean A. Newmister
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
| | - Ashootosh Tripathi
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
- Department of Medicinal ChemistryUniversity of Michigan 428 Church St. Ann Arbor MI 48109 USA
| | - Hikaru Kato
- Graduate School of Pharmaceutical SciencesKumamoto University 5-1 Oe-honmachi Kumamoto 862-0973 Japan
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical SciencesKumamoto University 5-1 Oe-honmachi Kumamoto 862-0973 Japan
| | - Lei Du
- State Key Laboratory of Microbial TechnologyShandong University Qingdao Shandong 266237 China
| | - Shengying Li
- State Key Laboratory of Microbial TechnologyShandong University Qingdao Shandong 266237 China
| | - Robert M. Williams
- Department of ChemistryColorado State University 1301 Center Ave. Fort Collins CO 80523 USA
| | - David H. Sherman
- Life Sciences InstituteUniversity of Michigan 210 Washtenaw Ave. Ann Arbor MI 28104 USA
- Department of Medicinal ChemistryUniversity of Michigan 428 Church St. Ann Arbor MI 48109 USA
- Department of Microbiology and ImmunologyUniversity of Michigan Medical School 1150W. Medical Center Drive Ann Arbor MI 48109
- Department of ChemistryUniversity of Michigan 930N. University Ave. Ann Arbor MI 48109 USA
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5
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Chaabane M, Williams RM, Stephens AT, Park JW. circDeep: deep learning approach for circular RNA classification from other long non-coding RNA. Bioinformatics 2020; 36:73-80. [PMID: 31268128 PMCID: PMC6956777 DOI: 10.1093/bioinformatics/btz537] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 06/13/2019] [Accepted: 07/01/2019] [Indexed: 01/17/2023] Open
Abstract
MOTIVATION Over the past two decades, a circular form of RNA (circular RNA), produced through alternative splicing, has become the focus of scientific studies due to its major role as a microRNA (miRNA) activity modulator and its association with various diseases including cancer. Therefore, the detection of circular RNAs is vital to understanding their biogenesis and purpose. Prediction of circular RNA can be achieved in three steps: distinguishing non-coding RNAs from protein coding gene transcripts, separating short and long non-coding RNAs and predicting circular RNAs from other long non-coding RNAs (lncRNAs). However, the available tools are less than 80 percent accurate for distinguishing circular RNAs from other lncRNAs due to difficulty of classification. Therefore, the availability of a more accurate and fast machine learning method for the identification of circular RNAs, which considers the specific features of circular RNA, is essential to the development of systematic annotation. RESULTS Here we present an End-to-End deep learning framework, circDeep, to classify circular RNA from other lncRNA. circDeep fuses an RCM descriptor, ACNN-BLSTM sequence descriptor and a conservation descriptor into high level abstraction descriptors, where the shared representations across different modalities are integrated. The experiments show that circDeep is not only faster than existing tools but also performs at an unprecedented level of accuracy by achieving a 12 percent increase in accuracy over the other tools. AVAILABILITY AND IMPLEMENTATION https://github.com/UofLBioinformatics/circDeep. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Mohamed Chaabane
- Department of Computer Engineering and Computer Science, Louisville, KY 40208, USA
| | - Robert M Williams
- Department of Computer Engineering and Computer Science, Louisville, KY 40208, USA
| | - Austin T Stephens
- Department of Computer Engineering and Computer Science, Louisville, KY 40208, USA
| | - Juw Won Park
- Department of Computer Engineering and Computer Science, Louisville, KY 40208, USA.,KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40208, USA
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6
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Sadahiro Y, Kato H, Williams RM, Tsukamoto S. Irpexine, an Isoindolinone Alkaloid Produced by Coculture of Endophytic Fungi, Irpex lacteus and Phaeosphaeria oryzae. J Nat Prod 2020; 83:1368-1373. [PMID: 32301614 DOI: 10.1021/acs.jnatprod.0c00047] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A new isoindolinone alkaloid, irpexine (1), was isolated as a racemate, along with a known green pigment, hypoxyxylerone (2), from the coculture of two endophytic fungi, Irpex lacteus and Phaeosphaeria oryzae. Compound 1 was found to be a newly produced metabolite of I. lacteus in the coculture with P. oryzae. Although 2 was produced in a monoculture of I. lacteus, its production was markedly enhanced by the coculture.
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Affiliation(s)
- Yusaku Sadahiro
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
| | - Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 301 West Pitkin Street, Fort Collins, Colorado 80523, United States
- University of Colorado Cancer Center, Aurora, Colorado 80045, United States
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
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7
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Li S, Newmister SA, Lowell AN, Zi J, Chappell CR, Yu F, Hohlman RM, Orjala J, Williams RM, Sherman DH. Control of Stereoselectivity in Diverse Hapalindole Metabolites is Mediated by Cofactor‐Induced Combinatorial Pairing of Stig Cyclases. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shasha Li
- Life Sciences InstituteDepartment of Medicinal ChemistryThe University of Michigan USA
| | | | - Andrew N. Lowell
- Life Science InstituteThe University of Michigan USA
- Department of ChemistryVirginia Tech Blacksburg VA 24061 USA
| | - Jiachen Zi
- Department of Pharmaceutical SciencesCollege of PharmacyUniversity of Illinois at Chicago Chicago IL 60612 USA
| | - Callie R. Chappell
- Department of Molecular, Cellular & Developmental BiologyThe University of Michigan USA
| | - Fengan Yu
- Life Science InstituteThe University of Michigan USA
| | - Robert M. Hohlman
- Life Sciences InstituteDepartment of Medicinal ChemistryThe University of Michigan USA
| | - Jimmy Orjala
- Department of Pharmaceutical SciencesCollege of PharmacyUniversity of Illinois at Chicago Chicago IL 60612 USA
| | - Robert M. Williams
- Department of ChemistryColorado State University Fort Collins CO 80523 USA
- University of Colorado Cancer Center Aurora CO 80045 USA
| | - David H. Sherman
- Life Sciences InstituteDepartments of Medicinal Chemistry, Chemistry, Microbiology & ImmunologyThe University of Michigan 210 Washtenaw Avenue Ann Arbor MI 48109-2216n USA
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8
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Li S, Newmister SA, Lowell AN, Zi J, Chappell CR, Yu F, Hohlman RM, Orjala J, Williams RM, Sherman DH. Control of Stereoselectivity in Diverse Hapalindole Metabolites is Mediated by Cofactor-Induced Combinatorial Pairing of Stig Cyclases. Angew Chem Int Ed Engl 2020; 59:8166-8172. [PMID: 32052896 PMCID: PMC7274885 DOI: 10.1002/anie.201913686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Indexed: 11/07/2022]
Abstract
Stereospecific polycyclic core formation of hapalindoles and fischerindoles is controlled by Stig cyclases through a three-step cascade involving Cope rearrangement, 6-exo-trig cyclization, and a final electrophilic aromatic substitution. Reported here is a comprehensive study of all currently annotated Stig cyclases, revealing that these proteins can assemble into heteromeric complexes, induced by Ca2+ , to cooperatively control the stereochemistry of hapalindole natural products.
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Affiliation(s)
- Shasha Li
- Life Sciences Institute, Department of Medicinal Chemistry, The University of Michigan, USA
| | | | - Andrew N Lowell
- Life Science Institute, The University of Michigan, USA
- Department of Chemistry, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jiachen Zi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Callie R Chappell
- Department of Molecular, Cellular & Developmental Biology, The University of Michigan, USA
| | - Fengan Yu
- Life Science Institute, The University of Michigan, USA
| | - Robert M Hohlman
- Life Sciences Institute, Department of Medicinal Chemistry, The University of Michigan, USA
| | - Jimmy Orjala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, USA
- University of Colorado Cancer Center, Aurora, CO, 80045, USA
| | - David H Sherman
- Life Sciences Institute, Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology, The University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI, 48109-2216n, USA
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9
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Abstract
New structural classes of antibiotics are rare, structurally novel broad-spectrum antibiotics exceptionally so. The recently discovered baulamycins constitute a remarkable example of these highly prized compounds and, as such, have attracted considerable attention in the form of both synthetic efforts and biological studies. For the first time, we report a gram-scale preparation of the common carbon framework of the baulamycin family, as well as the total synthesis of its most potent member, baulamycin A. Our approach employs highly stereoselective, catalyst-controlled asymmetric conjugate additions to thioesters to set key stereocenters, as well as the first reported use of "dry ozonolysis" to reveal a masked carboxylic acid in the total synthesis of a natural product.
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Affiliation(s)
- Jonathan R Thielman
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.,University of Colorado Cancer Center, Aurora, Colorado 80045, USA
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10
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Fraley AE, Caddell Haatveit K, Ye Y, Kelly SP, Newmister SA, Yu F, Williams RM, Smith JL, Houk KN, Sherman DH. Molecular Basis for Spirocycle Formation in the Paraherquamide Biosynthetic Pathway. J Am Chem Soc 2020; 142:2244-2252. [PMID: 31904957 DOI: 10.1021/jacs.9b09070] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The paraherquamides are potent anthelmintic natural products with complex heptacyclic scaffolds. One key feature of these molecules is the spiro-oxindole moiety that lends a strained three-dimensional architecture to these structures. The flavin monooxygenase PhqK was found to catalyze spirocycle formation through two parallel pathways in the biosynthesis of paraherquamides A and G. Two new paraherquamides (K and L) were isolated from a ΔphqK strain of Penicillium simplicissimum, and subsequent enzymatic reactions with these compounds generated two additional metabolites, paraherquamides M and N. Crystal structures of PhqK in complex with various substrates provided a foundation for mechanistic analyses and computational studies. While it is evident that PhqK can react with various substrates, reaction kinetics and molecular dynamics simulations indicated that the dioxepin-containing paraherquamide L is the favored substrate. Through this effort, we have elucidated a key step in the biosynthesis of the paraherquamides and provided a rationale for the selective spirocyclization of these powerful anthelmintic agents.
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Affiliation(s)
| | - Kersti Caddell Haatveit
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095 , United States
| | | | | | | | | | - Robert M Williams
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States.,University of Colorado Cancer Center , Aurora , Colorado 80045 , United States
| | | | - K N Houk
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095 , United States
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11
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Dan Q, Newmister SA, Klas KR, Fraley AE, McAfoos TJ, Somoza AD, Sunderhaus JD, Ye Y, Shende VV, Yu F, Sanders JN, Brown WC, Zhao L, Paton RS, Houk KN, Smith JL, Sherman DH, Williams RM. Fungal indole alkaloid biogenesis through evolution of a bifunctional reductase/Diels-Alderase. Nat Chem 2019; 11:972-980. [PMID: 31548667 PMCID: PMC6815239 DOI: 10.1038/s41557-019-0326-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 08/05/2019] [Indexed: 12/25/2022]
Abstract
Prenylated indole alkaloids such as the calmodulin-inhibitory malbrancheamides and anthelmintic paraherquamides possess great structural diversity and pharmaceutical utility. Here, we report complete elucidation of the malbrancheamide biosynthetic pathway accomplished through complementary approaches. These include a biomimetic total synthesis to access the natural alkaloid and biosynthetic intermediates in racemic form and in vitro enzymatic reconstitution to provide access to the natural antipode (+)-malbrancheamide. Reductive cleavage of an L-Pro-L-Trp dipeptide from the MalG non-ribosomal peptide synthetase (NRPS) followed by reverse prenylation and a cascade of post-NRPS reactions culminates in an intramolecular [4+2] hetero-Diels-Alder (IMDA) cyclization to furnish the bicyclo[2.2.2]diazaoctane scaffold. Enzymatic assembly of optically pure (+)-premalbrancheamide involves an unexpected zwitterionic intermediate where MalC catalyses enantioselective cycloaddition as a bifunctional NADPH-dependent reductase/Diels-Alderase. The crystal structures of substrate and product complexes together with site-directed mutagenesis and molecular dynamics simulations demonstrate how MalC and PhqE (its homologue from the paraherquamide pathway) catalyse diastereo- and enantioselective cyclization in the construction of this important class of secondary metabolites.
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Affiliation(s)
- Qingyun Dan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Sean A Newmister
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Kimberly R Klas
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Amy E Fraley
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Timothy J McAfoos
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Amber D Somoza
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - James D Sunderhaus
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Ying Ye
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Vikram V Shende
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, USA
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jacob N Sanders
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - W Clay Brown
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Le Zhao
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Robert S Paton
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Janet L Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA.
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, MI, USA.
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA.
- University of Colorado Cancer Center, Aurora, CO, USA.
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12
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Dan Q, Newmister SA, Klas KR, Fraley AE, Paton RS, Houk KN, Williams RM, Sherman DH, Smith JL. Evolution of a bifunctional reductase/Diels–Alderase for fungal indole alkaloid biosynthesis. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319097599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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13
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Kato H, Sebe M, Nagaki M, Eguchi K, Kagiyama I, Hitora Y, Frisvad JC, Williams RM, Tsukamoto S. Taichunins A-D, Norditerpenes from Aspergillus taichungensis (IBT 19404). J Nat Prod 2019; 82:1377-1381. [PMID: 30995043 DOI: 10.1021/acs.jnatprod.8b01032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Four new norditerpenes, taichunins A-D (1-4), were isolated from the fungus Aspergillus taichungensis (IBT 19404). Compound 1 has a new carbon framework. The absolute configurations were determined by the calculated ECD spectral method. Compound 1 was cytotoxic against HeLa cells with an IC50 value of 4.5 μM, whereas 2-4 were nontoxic at 50 μM.
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Affiliation(s)
- Hikaru Kato
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Momona Sebe
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Mika Nagaki
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Keisuke Eguchi
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Ippei Kagiyama
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Yuki Hitora
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
| | - Jens C Frisvad
- Section for Eukaryotic Biotechnology, Departments of System Biology , Technical University of Denmark , Building 221, 2800 Kongens Lyngby , Denmark
| | - Robert M Williams
- Department of Chemistry , Colorado State University , 301 West Pitkin Street , Fort Collins , Colorado 80523 , United States
- University of Colorado Cancer Center , Aurora , Colorado 80045 , United States
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences , Kumamoto University , 5-1 Oe-honmachi , Kumamoto 862-0973 , Japan
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14
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Klas KR, Kato H, Frisvad JC, Yu F, Newmister SA, Fraley AE, Sherman DH, Tsukamoto S, Williams RM. Structural and stereochemical diversity in prenylated indole alkaloids containing the bicyclo[2.2.2]diazaoctane ring system from marine and terrestrial fungi. Nat Prod Rep 2019; 35:532-558. [PMID: 29632911 DOI: 10.1039/c7np00042a] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Covering: up to February 2017 Various fungi of the genera Aspergillus, Penicillium, and Malbranchea produce prenylated indole alkaloids possessing a bicyclo[2.2.2]diazaoctane ring system. After the discovery of distinct enantiomers of the natural alkaloids stephacidin A and notoamide B, from A. protuberus MF297-2 and A. amoenus NRRL 35660, another fungi, A. taichungensis, was found to produce their diastereomers, 6-epi-stephacidin A and versicolamide B, as major metabolites. Distinct enantiomers of stephacidin A and 6-epi-stephacidin A may be derived from a common precursor, notoamide S, by enzymes that form a bicyclo[2.2.2]diazaoctane core via a putative intramolecular hetero-Diels-Alder cycloaddition. This review provides our current understanding of the structural and stereochemical homologies and disparities of these alkaloids. Through the deployment of biomimetic syntheses, whole-genome sequencing, and biochemical studies, a unified biogenesis of both the dioxopiperazine and the monooxopiperazine families of prenylated indole alkaloids constituted of bicyclo[2.2.2]diazaoctane ring systems is presented.
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Affiliation(s)
- Kimberly R Klas
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO 80523, USA.
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15
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Newmister SA, Romminger S, Schmidt JJ, Williams RM, Smith JL, Berlinck RGS, Sherman DH. Unveiling sequential late-stage methyltransferase reactions in the meleagrin/oxaline biosynthetic pathway. Org Biomol Chem 2019; 16:6450-6459. [PMID: 30141817 DOI: 10.1039/c8ob01565a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Antimicrobial and anti-proliferative meleagrin and oxaline are roquefortine C-derived alkaloids produced by fungi of the genus Penicillium. Tandem O-methylations complete the biosynthesis of oxaline from glandicoline B through meleagrin. Currently, little is known about the role of these methylation patterns in the bioactivity profile of meleagrin and oxaline. To establish the structural and mechanistic basis of methylation in these pathways, crystal structures were determined for two late-stage methyltransferases in the oxaline and meleagrin gene clusters from Penicillium oxalicum and Penicillium chrysogenum. The homologous enzymes OxaG and RoqN were shown to catalyze penultimate hydroxylamine O-methylation to generate meleagrin in vitro. Crystal structures of these enzymes in the presence of methyl donor S-adenosylmethionine revealed an open active site, which lacks an apparent base indicating that catalysis is driven by proximity effects. OxaC was shown to methylate meleagrin to form oxaline in vitro, the terminal pathway product. Crystal structures of OxaC in a pseudo-Michaelis complex containing sinefungin and meleagrin, and in a product complex containing S-adenosyl-homocysteine and oxaline, reveal key active site residues with His313 serving as a base that is activated by Glu369. These data provide structural insights into the enzymatic methylation of these alkaloids that include a rare hydroxylamine oxygen acceptor, and can be used to guide future efforts towards selective derivatization and structural diversification and establishing the role of methylation in bioactivity.
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Affiliation(s)
- Sean A Newmister
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
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16
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17
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Park C, Clark EM, R Williams B, Schulz E, Williams RM, Holt CL. MEANING PREDICTS DECLINES IN DEPRESSIVE SYMPTOMS BUT DOESN’T BUFFER STRESS IN A NATIONAL SAMPLE OF AFRICAN AMERICANS. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.1621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- C Park
- University of Connecticut, Storrs, Connecticut, United States
| | - E M Clark
- Saint Louis University, St. Louis, Missouri, USA
| | - B R Williams
- Birmingham/Atlanta Geriatric Research, Education and Clinical Center (GRECC) Birmingham VA Medical Center, Birmingham AL USA; Division of Gerontology, Geriatrics and Palliative Care, University of Alabama at Birmingham, Birmingham AL USA
| | - E Schulz
- OTR/L, CFLE, Department of Occupational Therapy, A.T. Still University, Arizona School of Health Sciences, Mesa, AZ, USA
| | - R M Williams
- University of Maryland College Park, College Park, Maryland, USA
| | - C L Holt
- University of Maryland, School of Public Health, Department of Behavioral and Community Health, College Park, MD USA
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18
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Kai A, Kato H, Sherman DH, Williams RM, Tsukamoto S. Isolation of a new indoxyl alkaloid, Amoenamide B, from Aspergillus amoenus NRRL 35600: biosynthetic implications and correction of the structure of Speramide B. Tetrahedron Lett 2018; 50:4236-4240. [PMID: 30765898 DOI: 10.1016/j.tetlet.2018.10.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A new prenylated indoxyl alkaloid, Amoenamide B (1), was isolated from Aspergillus amoenus NRRL 35600 along with Asperochramide A (2). Although many prenylated oxyindole alkaloids, containing bicyclo[2.2.2]diazaoctane cores, have been isolated from the fungus of the genera Aspergillus and Penicillium to date, 1 is the fourth compound with the indoxyl unit containing the cores. During the structure elucidation of 1, we found that the planar structure matched to that of Speramide A (3), isolated from A. ochraceus KM007, but the reported structure of 3 was incorrect and turned out to be that of Taichunamide H (4), recently isolated from A. versicolor HDN11-84.
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Affiliation(s)
- Aika Kai
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States.,Departments of Medicinal Chemistry, Microbiology & Immunology, and Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, United States.,University of Colorado Cancer Center, Aurora, Colorado 80045, United States
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
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19
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Kato H, Kai A, Kawabata T, Sunderhaus JD, McAfoos TJ, Finefield JM, Sugimoto Y, Williams RM, Tsukamoto S. Corrigendum to “Enantioselective inhibitory abilities of enantiomers of notoamides against RANKL-induced formation of multinuclear osteoclasts” [Bioorg. Med. Chem. Lett. 27 (22) (2017) 4975–4978]. Bioorg Med Chem Lett 2018; 28:2573. [DOI: 10.1016/j.bmcl.2018.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Sugimoto K, Sadahiro Y, Kagiyama I, Kato H, Sherman DH, Williams RM, Tsukamoto S. Corrigendum to “Isolation of amoenamide A and five antipodal prenylated alkaloids from Aspergillus amoenus NRRL 35600” [Tetrahedron Lett. 58 (2017) 2797–2800]. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.06.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Gollins S, Massalha S, Mullard A, Williams RM, Lloyd A, Morris J, Garcia-Alonso A. A Prospective Phase I/II Study of Docetaxel, Cisplatin and Continuous Capecitabine in Advanced Oesophago-Gastric Cancer (NWCOG-3). Clin Oncol (R Coll Radiol) 2018; 30:409-417. [PMID: 29573846 DOI: 10.1016/j.clon.2018.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 01/24/2018] [Indexed: 10/17/2022]
Abstract
AIMS This open-label prospective phase I/II dose-escalation study determined the maximum tolerated dose (MTD) and then evaluated response, safety and feasibility of a novel combination of docetaxel, cisplatinum and capecitabine (DCC) in chemotherapy-naive patients with advanced oesophago-gastric carcinoma. MATERIALS AND METHODS Patients with adenocarcinoma or squamous cell carcinoma of the oesophagus or stomach, of good performance status, deemed too advanced for curative treatment, were given systematically increasing doses of 3 weekly DCC to ascertain the MTD. Phase II administered up to six cycles of DCC at the MTD, assessing response and toxicity. RESULTS Between November 2007 and November 2012, 15 patients were recruited into phase I and 41 into phase II. The MDT was a 21 day cycle of docetaxel 60 mg/m2 IV day 1, cisplatinum 60 mg/m2 IV day 1 and oral capecitabine 1000 mg/m2 daily in two divided doses for days 1-21. The most common phase II grade 3-4 toxicities were neutropenia 88% (10% febrile neutropenia), fatigue 15%, sensory neuropathy 10% and non-neutropenic infection 10%. The overall response rate was 51%, median progression-free survival was 7.4 months (confidence interval 6.7-9.4) and median overall survival was 10.9 months (confidence interval 7.7-13.7). CONCLUSION DCC was tolerable and feasible with promising efficacy, and may be suitable for future investigation in both first-line metastatic and neoadjuvant settings.
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Affiliation(s)
- S Gollins
- North Wales Cancer Treatment Centre, Glan Clwyd Hospital, Bodelwyddan, UK.
| | - S Massalha
- Ysbyty Gwynedd, Penrhosgarnedd, Bangor, UK
| | - A Mullard
- Ysbyty Gwynedd, Penrhosgarnedd, Bangor, UK
| | | | - A Lloyd
- North Wales Cancer Treatment Centre, Glan Clwyd Hospital, Bodelwyddan, UK
| | - J Morris
- North Wales Cancer Treatment Centre, Glan Clwyd Hospital, Bodelwyddan, UK
| | - A Garcia-Alonso
- North Wales Cancer Treatment Centre, Glan Clwyd Hospital, Bodelwyddan, UK
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22
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Newmister SA, Li S, Garcia-Borràs M, Sanders JN, Yang S, Lowell AN, Yu F, Smith JL, Williams RM, Houk KN, Sherman DH. Structural basis of the Cope rearrangement and cyclization in hapalindole biogenesis. Nat Chem Biol 2018. [PMID: 29531360 DOI: 10.1038/s41589-018-0003-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hapalindole alkaloids are a structurally diverse class of cyanobacterial natural products defined by their varied polycyclic ring systems and diverse biological activities. These complex metabolites are generated from a common biosynthetic intermediate by the Stig cyclases in three mechanistic steps: a rare Cope rearrangement, 6-exo-trig cyclization, and electrophilic aromatic substitution. Here we report the structure of HpiC1, a Stig cyclase that catalyzes the formation of 12-epi-hapalindole U in vitro. The 1.5-Å structure revealed a dimeric assembly with two calcium ions per monomer and with the active sites located at the distal ends of the protein dimer. Mutational analysis and computational methods uncovered key residues for an acid-catalyzed [3,3]-sigmatropic rearrangement, as well as specific determinants that control the position of terminal electrophilic aromatic substitution, leading to a switch from hapalindole to fischerindole alkaloids.
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Affiliation(s)
- Sean A Newmister
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Shasha Li
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Marc Garcia-Borràs
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jacob N Sanders
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Song Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Andrew N Lowell
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Janet L Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA. .,University of Colorado Cancer Center, Aurora, CO, USA.
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA.
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA. .,Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA. .,Department of Chemistry, University of Michigan, Ann Arbor, MI, USA. .,Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
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23
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24
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Kato H, Nakahara T, Sugimoto K, Matsuo K, Kagiyama I, Frisvad JC, Sherman DH, Williams RM, Tsukamoto S. Correction to "Isolation of Notoamide S and Enantiomeric 6-epi-Stephacidin A from the Terrestrial Fungus Aspergillus amoenus: Biogenetic Implications". Org Lett 2017; 20:315. [PMID: 29235872 DOI: 10.1021/acs.orglett.7b03781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Fraley AE, Garcia-Borràs M, Tripathi A, Khare D, Mercado-Marin EV, Tran H, Dan Q, Webb GP, Watts KR, Crews P, Sarpong R, Williams RM, Smith JL, Houk KN, Sherman DH. Function and Structure of MalA/MalA', Iterative Halogenases for Late-Stage C-H Functionalization of Indole Alkaloids. J Am Chem Soc 2017; 139:12060-12068. [PMID: 28777910 PMCID: PMC5595095 DOI: 10.1021/jacs.7b06773] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Malbrancheamide is a dichlorinated fungal indole alkaloid isolated from both Malbranchea aurantiaca and Malbranchea graminicola that belongs to a family of natural products containing a characteristic bicyclo[2.2.2]diazaoctane core. The introduction of chlorine atoms on the indole ring of malbrancheamide differentiates it from other members of this family and contributes significantly to its biological activity. In this study, we characterized the two flavin-dependent halogenases involved in the late-stage halogenation of malbrancheamide in two different fungal strains. MalA and MalA' catalyze the iterative dichlorination and monobromination of the free substrate premalbrancheamide as the final steps in the malbrancheamide biosynthetic pathway. Two unnatural bromo-chloro-malbrancheamide analogues were generated through MalA-mediated chemoenzymatic synthesis. Structural analysis and computational studies of MalA' in complex with three substrates revealed that the enzyme represents a new class of zinc-binding flavin-dependent halogenases and provides new insights into a potentially unique reaction mechanism.
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Affiliation(s)
- Amy E. Fraley
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Marc Garcia-Borràs
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Dheeraj Khare
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Hong Tran
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Qingyun Dan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Gabrielle P. Webb
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Katharine R. Watts
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Phillip Crews
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Robert M. Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Janet L. Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan 48109, United States
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26
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Sugimoto K, Sadahiro Y, Kagiyama I, Kato H, Sherman DH, Williams RM, Tsukamoto S. Isolation of amoenamide A and five antipodal prenylated alkaloids from Aspergillus amoenus NRRL 35600. Tetrahedron Lett 2017; 58:2797-2800. [PMID: 29622844 DOI: 10.1016/j.tetlet.2017.05.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A new prenylated alkaloid, Amoenamide A (6), was isolated from the fungus Aspergillus amoenus NRRL 35600. Previously, 6 was postulated to be a precursor of Notoamide E4 (21) converted from Notoamide E (16), which was a key precursor of the prenylated indole alkaloids in the fungi of the genus Aspergillus. We previously succeeded in the isolation of two pairs of antipodes, Stephacidin A (1) and Notoamide B (2), from A. amoenus and A. protuberus MF297-2 and expected the presence of other antipodes in the culture of A. amoenus. We here report five new antipodes (7-11) along with a new metabolite (12), which was isolated as a natural compound for the first time, from A. amoenus.
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Affiliation(s)
- Kayo Sugimoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - Yusaku Sadahiro
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - Ippei Kagiyama
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
| | - David H Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology, The University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109-2216, United States
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, United States.,University of Colorado Cancer Center, Aurora, Colorado 80045
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Kumamoto, Japan
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27
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Li S, Lowell AN, Newmister SA, Yu F, Williams RM, Sherman DH. Decoding cyclase-dependent assembly of hapalindole and fischerindole alkaloids. Nat Chem Biol 2017; 13:467-469. [PMID: 28288107 PMCID: PMC5391265 DOI: 10.1038/nchembio.2327] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 12/22/2016] [Indexed: 11/25/2022]
Abstract
The formation of C-C bonds in an enantioselective fashion to create complex polycyclic scaffolds in the hapalindole- and fischerindole- type alkaloids from Stigonematales cyanobacteria represents a compelling and urgent challenge in adapting microbial biosynthesis as a catalytic platform in drug development. Here we determine the biochemical basis for tri- and tetracyclic core formation in these secondary metabolites, involving a new class of cyclases that catalyze a complex cyclization cascade.
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Affiliation(s)
- Shasha Li
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Andrew N Lowell
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Sean A Newmister
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
- University of Colorado Cancer Center, Aurora, Colorado, USA
| | - David H Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Department of Microbiology &Immunology, University of Michigan, Ann Arbor, Michigan, USA
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28
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Zhao L, Dunne CE, Clausen DJ, Roberts JM, Paulk J, Liu H, Wiest OG, Bradner JE, Williams RM. Synthesis and Biochemical Evaluation of Biotinylated Conjugates of Largazole Analogues: Selective Class I Histone Deacetylase Inhibitors. Isr J Chem 2017; 57:319-330. [PMID: 30760938 PMCID: PMC6370329 DOI: 10.1002/ijch.201600130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The synthesis of biotinylated conjugates of synthetic analogues of the potent and selective histone deacetylase (HDAC) inhibitor largazole is reported. The thiazole moiety of the parent compound's cap group was derivatized to allow the chemical conjugation to biotin. The derivatized largazole analogues were assayed across a panel of HDACs 1-9 and retained potent and selective inhibitory activity towards the class I HDAC isoforms. The biotinylated conjugate was further shown to pull down HDACs 1, 2, and 3.
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Affiliation(s)
- Le Zhao
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 (USA)
| | - Christine E. Dunne
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 (USA)
| | - Dane J. Clausen
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 (USA)
| | - Justin M. Roberts
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115 (USA)
| | - Joshiawa Paulk
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115 (USA)
| | - Haining Liu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670 (USA)
| | - Olaf G. Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670 (USA)
| | - James E. Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115 (USA)
| | - Robert M. Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 (USA)
- University of Colorado Cancer Center, Aurora, Colorado 80045 (USA)
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29
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Sherman DH, Li S, Lowell AN, Newmister SA, Yu F, Williams RM. Biocatalyst discovery from the secondary metabolome. FASEB J 2017. [DOI: 10.1096/fasebj.31.1_supplement.528.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Shasha Li
- Medicinal ChemistryUniversity of MichiganAnn ArborMI
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30
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Newmister SA, Gober CM, Romminger S, Yu F, Tripathi A, Parra LLL, Williams RM, Berlinck RG, Joullie MM, Sherman DH. OxaD: A Versatile Indolic Nitrone Synthase from the Marine-Derived Fungus Penicillium oxalicum F30. J Am Chem Soc 2016; 138:11176-84. [PMID: 27505044 PMCID: PMC5014723 DOI: 10.1021/jacs.6b04915] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Indole alkaloids are a diverse class of natural products known for their wide range of biological activities and complex chemical structures. Rarely observed in this class are indolic nitrones, such as avrainvillamide and waikialoid, which possess potent bioactivities. Herein the oxa gene cluster from the marine-derived fungus Penicillium oxalicum F30 is described along with the characterization of OxaD, a flavin-dependent oxidase that generates roquefortine L, a nitrone-bearing intermediate in the biosynthesis of oxaline. Nitrone functionality in roquefortine L was confirmed by spectroscopic methods and 1,3-dipolar cycloaddition with methyl acrylate. OxaD is a versatile biocatalyst that converts an array of semisynthetic roquefortine C derivatives bearing indoline systems to their respective nitrones. This work describes the first implementation of a nitrone synthase as a biocatalyst and establishes a novel platform for late-stage diversification of a range of complex natural products.
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Affiliation(s)
- Sean A. Newmister
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Claire M. Gober
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Stelamar Romminger
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Lizbeth Lorena L. Parra
- Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, CP 780, CEP 13560-970 Sao Carlos, SP, Brazil
| | - Robert M. Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- University of Colorado Cancer Center, Aurora, Colorado 80045, United States
| | - Roberto G.S. Berlinck
- Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, CP 780, CEP 13560-970 Sao Carlos, SP, Brazil
| | - Madeleine M. Joullie
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan 48109, United States
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Affiliation(s)
- Masashi Yokoya
- Graduate
School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Ryoko Toyoshima
- Graduate
School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Toshihiro Suzuki
- Graduate
School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Vy H. Le
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- The University of Colorado Cancer Center, Aurora, Colorado 80045, United States
| | - Robert M. Williams
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- The University of Colorado Cancer Center, Aurora, Colorado 80045, United States
| | - Naoki Saito
- Graduate
School of Pharmaceutical Sciences, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
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32
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Mace EK, Aalseth CE, Day AR, Hoppe EW, Keillor ME, Moran JJ, Panisko ME, Seifert A, Tatishvili G, Williams RM. First results of a simultaneous measurement of tritium and (14)C in an ultra-low-background proportional counter for environmental sources of methane. J Environ Radioact 2016; 155-156:122-129. [PMID: 26990077 DOI: 10.1016/j.jenvrad.2016.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 06/05/2023]
Abstract
Simultaneous measurement of tritium and (14)C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960's atmospheric tritium and (14)C have fallen dramatically as the isotopic injections from aboveground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and (14)C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and (14)C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. These first results show that the dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). However, for samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.
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Affiliation(s)
- E K Mace
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA.
| | - C E Aalseth
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - A R Day
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - E W Hoppe
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - M E Keillor
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - J J Moran
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - M E Panisko
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - A Seifert
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - G Tatishvili
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
| | - R M Williams
- Pacific Northwest National Laboratory, 902 Battelle Blvd, P.O. Box 999, MSIN J4-65, Richland, WA 99352, USA
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Abstract
Eight examples of biosynthetic pathways wherein a natural enzyme has been identified and claimed to function as a catalyst for the [4 + 2] cycloaddition reaction, namely, Diels-Alderases, are briefly reviewed. These are discussed in the context of the mechanistic challenges associated with the technical difficulty of proving that the net formal [4 + 2] cycloaddition under study indeed proceeds through a synchronous mechanism and that the putative biosynthetic enzyme deploys the pericyclic transition state required for a Diels-Alder cycloaddition reaction.
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Affiliation(s)
- Kimberly Klas
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80524, United States
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University , 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - David H Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Microbiology & Immunology, and Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Robert M Williams
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80524, United States.,University of Colorado Cancer Center , Aurora, Colorado 80045, United States
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Kagiyama I, Kato H, Nehira T, Frisvad JC, Sherman DH, Williams RM, Tsukamoto S. Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404). Angew Chem Int Ed Engl 2015; 55:1128-32. [PMID: 26644336 DOI: 10.1002/anie.201509462] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Indexed: 11/11/2022]
Abstract
Seven new prenylated indole alkaloids, taichunamides A-G, were isolated from the fungus Aspergillus taichungensis (IBT 19404). Taichunamides A and B contained an azetidine and 4-pyridone units, respectively, and are likely biosynthesized from notoamide S via (+)-6-epi-stephacidin A. Taichunamides C and D contain endoperoxide and methylsulfonyl units, respectively. This fungus produced indole alkaloids containing an anti-bicyclo[2.2.2]diazaoctane core, whereas A. protuberus and A. amoenus produced congeners with a syn-bicyclo[2.2.2]diazaoctane core. Plausible biosynthetic pathways to access these cores within the three species likely arise from an intramolecular hetero Diels-Alder reaction.
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Affiliation(s)
- Ippei Kagiyama
- Graduated School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan
| | - Hikaru Kato
- Graduated School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan
| | - Tatsuo Nehira
- Graduated School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-hiroshima, 739-8521, Japan
| | - Jens C Frisvad
- Section for Eukaryotic Biotechnology, Departments of System Biology, Technical University of Denmark, Building 221, 2800, Kongens Lyngby, Denmark
| | - David H Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology, The University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI, 48109-2216, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA.,Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, CO, 80523, USA
| | - Sachiko Tsukamoto
- Graduated School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto, 862-0973, Japan.
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Kagiyama I, Kato H, Nehira T, Frisvad JC, Sherman DH, Williams RM, Tsukamoto S. Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis
(IBT 19404). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509462] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ippei Kagiyama
- Graduated School of Pharmaceutical Sciences; Kumamoto University; 5-1 Oe-honmachi Kumamoto 862-0973 Japan
| | - Hikaru Kato
- Graduated School of Pharmaceutical Sciences; Kumamoto University; 5-1 Oe-honmachi Kumamoto 862-0973 Japan
| | - Tatsuo Nehira
- Graduated School of Integrated Arts and Sciences; Hiroshima University; 1-7-1 Kagamiyama Higashi-hiroshima 739-8521 Japan
| | - Jens C. Frisvad
- Section for Eukaryotic Biotechnology, Departments of System Biology; Technical University of Denmark; Building 221 2800 Kongens Lyngby Denmark
| | - David H. Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology; The University of Michigan; 210 Washtenaw Avenue Ann Arbor MI 48109-2216 USA
| | - Robert M. Williams
- Department of Chemistry; Colorado State University; 1301 Center Avenue Fort Collins CO 80523 USA
- Department of Chemistry; Colorado State University; 1301 Center Avenue Fort Collins CO 80523 USA
| | - Sachiko Tsukamoto
- Graduated School of Pharmaceutical Sciences; Kumamoto University; 5-1 Oe-honmachi Kumamoto 862-0973 Japan
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36
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Li S, Lowell AN, Yu F, Raveh A, Newmister SA, Bair N, Schaub JM, Williams RM, Sherman DH. Hapalindole/Ambiguine Biogenesis Is Mediated by a Cope Rearrangement, C-C Bond-Forming Cascade. J Am Chem Soc 2015; 137:15366-9. [PMID: 26629885 DOI: 10.1021/jacs.5b10136] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hapalindoles are bioactive indole alkaloids with fascinating polycyclic ring systems whose biosynthetic assembly mechanism has remained unknown since their initial discovery in the 1980s. In this study, we describe the fam gene cluster from the cyanobacterium Fischerella ambigua UTEX 1903 encoding hapalindole and ambiguine biosynthesis along with the characterization of two aromatic prenyltransferases, FamD1 and FamD2, and a previously undescribed cyclase, FamC1. These studies demonstrate that FamD2 and FamC1 act in concert to form the tetracyclic core ring system of the hapalindoles from cis-indole isonitrile and geranyl pyrophosphate through a presumed biosynthetic Cope rearrangement and subsequent 6-exo-trig cyclization/electrophilic aromatic substitution reaction.
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Affiliation(s)
| | | | | | | | | | - Nathan Bair
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States
| | | | - Robert M Williams
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.,University of Colorado Cancer Center , Aurora, Colorado 80045, United States
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37
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Sherman DH, Tsukamoto S, Williams RM. ORGANIC SYNTHESIS. Comment on "Asymmetric syntheses of sceptrin and massadine and evidence for biosynthetic enantiodivergence". Science 2015; 349:149. [PMID: 26160938 DOI: 10.1126/science.aaa9349] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/05/2015] [Indexed: 11/02/2022]
Abstract
Ma et al. (Reports, 10 October 2014, p. 219) report asymmetric syntheses of sceptrin and massadine and, through a stereochemical reassignment, claim to "uncover enantiodivergence as a new biosynthetic paradigm for natural products." We challenge and clarify this claim with relevant examples from the literature of this well-known phenomenon of enantiodivergent congener biosynthesis within the same producing organism.
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Affiliation(s)
- David H Sherman
- Life Sciences Institute and Departments of Medicinal Chemistry, Microbiology and Immunology, and Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA. The University of Colorado Cancer Center, Aurora, CO 80045, USA.
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38
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Clausen DJ, Smith WB, Haines BE, Wiest O, Bradner JE, Williams RM. Modular synthesis and biological activity of pyridyl-based analogs of the potent Class I Histone Deacetylase Inhibitor Largazole. Bioorg Med Chem 2015; 23:5061-5074. [PMID: 26054247 DOI: 10.1016/j.bmc.2015.03.063] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/26/2022]
Abstract
The formation of a series of analogs containing a pyridine moiety in place of the natural thiazole heterocycle, based on the potent, naturally occurring HDAC inhibitor Largazole has been accomplished. The synthetic strategy was designed modularly to access multiple inhibitors with different aryl functionalities containing both the natural depsipeptide and peptide isostere variant of the macrocycle. The cytotoxicity and biochemical activity of the library of HDAC inhibitors is described herein.
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Affiliation(s)
- Dane J Clausen
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
| | - William B Smith
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Brandon E Haines
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Olaf Wiest
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - James E Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; University of Colorado Cancer Center, Aurora, CO 80045, USA.
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39
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Decroos C, Clausen DJ, Haines BE, Wiest O, Williams RM, Christianson DW. Variable active site loop conformations accommodate the binding of macrocyclic largazole analogues to HDAC8. Biochemistry 2015; 54:2126-35. [PMID: 25793284 DOI: 10.1021/acs.biochem.5b00010] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The macrocyclic depsipeptide Largazole is a potent inhibitor of metal-dependent histone deacetylases (HDACs), some of which are drug targets for cancer chemotherapy. Indeed, Largazole partially resembles Romidepsin (FK228), a macrocyclic depsipeptide already approved for clinical use. Each inhibitor contains a pendant side chain thiol that coordinates to the active site Zn(2+) ion, as observed in the X-ray crystal structure of the HDAC8-Largazole complex [Cole, K. E., Dowling, D. P., Boone, M. A., Phillips, A. J., and Christianson, D. W. (2011) J. Am. Chem. Soc. 133, 12474]. Here, we report the X-ray crystal structures of HDAC8 complexed with three synthetic analogues of Largazole in which the depsipeptide ester is replaced with a rigid amide linkage. In two of these analogues, a six-membered pyridine ring is also substituted (with two different orientations) for the five-membered thiazole ring in the macrocycle skeleton. The side chain thiol group of each analogue coordinates to the active site Zn(2+) ion with nearly ideal geometry, thereby preserving the hallmark structural feature of inhibition by Largazole. Surprisingly, in comparison with the binding of Largazole, these analogues trigger alternative conformational changes in loops L1 and L2 flanking the active site. However, despite these structural differences, inhibitory potency is generally comparable to, or just moderately less than, the inhibitory potency of Largazole. Thus, this study reveals important new structure-affinity relationships for the binding of macrocyclic inhibitors to HDAC8.
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Affiliation(s)
- Christophe Decroos
- †Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Dane J Clausen
- ‡Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Brandon E Haines
- §Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Olaf Wiest
- §Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,∥Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Robert M Williams
- ‡Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.,⊥University of Colorado Cancer Center, Aurora, Colorado 80045, 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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40
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Le VH, Inai M, Williams RM, Kan T. Ecteinascidins. A review of the chemistry, biology and clinical utility of potent tetrahydroisoquinoline antitumor antibiotics. Nat Prod Rep 2015; 32:328-47. [PMID: 25273374 PMCID: PMC4806878 DOI: 10.1039/c4np00051j] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ecteinascidin family comprises a number of biologically active compounds, containing two to three tetrahydroisoquinoline subunits. Although isolated from marine tunicates, these compounds share a common pentacyclic core with several antimicrobial compounds found in terrestrial bacteria. Among the tetrahydroisoquinoline natural products, ecteinascidin 743 (Et-743) stands out as the most potent antitumor antibiotics that it is recently approved for treatment of a number of soft tissue sarcomas. In this article, we will review the backgrounds, the mechanism of action, the biosynthesis, and the synthetic studies of Et-743. Also, the development of Et-743 as an antitumor drug is discussed.
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Affiliation(s)
- V H Le
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
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41
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Pilon JL, Clausen DJ, Hansen RJ, Lunghofer PJ, Charles B, Rose BJ, Thamm DH, Gustafson DL, Bradner JE, Williams RM. Comparative pharmacokinetic properties and antitumor activity of the marine HDACi Largazole and Largazole peptide isostere. Cancer Chemother Pharmacol 2015; 75:671-82. [PMID: 25616967 DOI: 10.1007/s00280-015-2675-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 01/03/2015] [Indexed: 12/12/2022]
Abstract
PURPOSE Largazole is a potent class I-selective HDACi natural product isolated from the marine cyanobacteria Symploca sp. The purpose of this study was to test synthetic analogs of Largazole to identify potential scaffold structural modifications that would improve the drug-like properties of this clinically relevant natural product. METHODS The impact of Largazole scaffold replacements on in vitro growth inhibition, cell cycle arrest, induction of apoptosis, pharmacokinetic properties, and in vivo activity using a xenograft model was investigated. RESULTS In vitro studies in colon, lung, and pancreatic cancer cell lines showed that pyridyl-substituted Largazole analogs had low-nanomolar/high-picomolar antiproliferative activity, and induced apoptosis and cell cycle arrest at concentrations equivalent to or lower than the parent compound Largazole. Using IV bolus delivery at 5 mg/kg, two compartmental pharmacokinetic modeling on the peptide isostere analog of Largazole indicated improved pharmacokinetic parameters. In an A549 non-small cell lung carcinoma xenograft model using a dosage of 5 mg/kg administered intraperitoneally every other day, Largazole, Largazole thiol, and Largazole peptide isostere demonstrated tumor growth inhibition (TGI%) of 32, 44, and 66%, respectively. Largazole peptide isostere treatment was statistically superior to control (p = 0.002) and to Largazole (p = 0.006). Surprisingly, tumor growth inhibition was not observed with the potent pyridyl-based analogs. CONCLUSIONS These results establish that replacing the depsipeptide linkage in Largazole with an amide may impart pharmacokinetic and therapeutic advantage and that alternative prodrug forms of Largazole are feasible.
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Affiliation(s)
- John L Pilon
- Cetya Therapeutics, 1301 Center Avenue, Fort Collins, CO, 80523, USA
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42
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Kato H, Nakahara T, Sugimoto K, Matsuo K, Kagiyama I, Frisvad JC, Sherman DH, Williams RM, Tsukamoto S. Isolation of notoamide S and enantiomeric 6-epi-stephacidin A from the fungus Aspergillus amoenus: biogenetic implications. Org Lett 2015; 17:700-3. [PMID: 25615822 DOI: 10.1021/ol5037198] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Notoamide S has been hypothesized to be a key biosynthetic intermediate for characteristic metabolites stephacidin A, notoamide B, and versicolamide B in Aspergillus sp. but has not yet been isolated. The isolation of notoamide S and an enantiomeric mixture of 6-epi-stephacidin A enriched with the (-)-isomer from Aspergillus amoenus is reported. The presence of (+)-versicolamide B suggests that the fungus possesses only the oxidase, which converts (+)-6-epi-stephacidin A into (+)-Versicolamide B, but not for (-)-6-epi-Stephacidin A.
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Affiliation(s)
- Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University , 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
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43
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Kato H, Nakahara T, Yamaguchi M, Kagiyama I, Finefield JM, Sunderhaus JD, Sherman DH, Williams RM, Tsukamoto S. Bioconversion of 6- epi-Notoamide T Produces Metabolites of Unprecedented Structures in a Marine-derived Aspergillus sp. Tetrahedron Lett 2015; 56:247-251. [PMID: 25767298 DOI: 10.1016/j.tetlet.2014.11.083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We previously described the bioconversion of Notoamide T into (+)-Stephacidin A and (-)-Notoamide B, which suggested that Versicolamide B (8) is biosynthesized from 6-epi-Notoamide T (10) via 6-epi-Stephacidin A. Here we report that [13C]2-10 was incorporated into isotopically enriched 8 and seven new metabolites, which were not produced under normal culture conditions. The results suggest that the addition of excess precursor activated the expression of dormant tailoring genes giving rise to these structurally unprecedented metabolites.
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Affiliation(s)
- Hikaru Kato
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Takashi Nakahara
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Michitaka Yamaguchi
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Ippei Kagiyama
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Jennifer M Finefield
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, USA
| | - James D Sunderhaus
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, USA
| | - David H Sherman
- Life Sciences Institute and Department of Medicinal Chemistry, The University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109-2216, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, 1301 Center Avenue, Fort Collins, Colorado 80523, USA ; University of Colorado Cancer Center, Aurora, Colorado 80045, USA
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
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Takashima A, Chen Z, English B, Williams RM, Faller DV. Abstract B36: Targeting oncogenic RAS with small molecule PKC-delta inhibitors. Mol Cancer Res 2014. [DOI: 10.1158/1557-3125.rasonc14-b36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Somatic point mutations of RAS genes at codons 12, 13, and 61 are the most common dominant oncogenic lesions in human cancer, making aberrant RAS signaling an important therapeutic target. Unfortunately, the oncogenic RAS/GAP switch is an exceedingly difficult target for rational drug discovery. We have developed a novel, alternative strategy to circumvent this limitation of targeting RAS directly. Mutated, constitutively-activated RAS is lethal to the tumor cell unless a survival pathway, mediated by a novel PKC isozyme, PKC-delta, is also active. This ”non-oncogene” dependency of RAS-mutant cells on PKC-delta activity can be exploited therapeutically. We have demonstrated the selective susceptibility of human pancreatic, lung, colon, ovarian and neuroendocrine tumor cells with mutant K- or HRAS alleles to PKC-delta inhibition. Importantly, unlike the classical PKC isozymes, PKC-delta is not required for the survival of normal cells, and its inhibition or down-regulation in normal cells and organisms has no adverse effects.
Furthermore, we demonstrate that cancer stem-like cells derived from RAS-mutant tumor specimens and cell lines are equally or more susceptible to PKC-delta inhibition as the non-stem-like population, both in culture and in xenograft studies.
There is currently no treatment option that targets melanoma with NRAS mutations, which is the second most frequently mutated gene in melanoma. We report here that PKC-delta inhibition is cytotoxic in melanomas with primary NRAS mutations. Novel small-molecule inhibitors of PKC-delta were designed as chimeric hybrids of two naturally-occurring PKC-delta inhibitors, staurosporine and rottlerin. The specific hypothesis we have interrogated and validated is the concept that combining two domains of two naturally-occurring PKC-delta inhibitors into a chimeric or hybrid structure retains biochemical and biological activity, and improves selectivity for the specific PKC-delta isozyme. We have devised a potentially general synthetic protocol to make these chimeric species using Molander trifluorborate coupling chemistry. Inhibition of PKC-delta, by siRNA or small molecule inhibitors, suppressed the growth of multiple melanoma cell lines carrying NRAS mutations, mediated via caspase-dependent apoptosis. Following PKC-delta inhibition, the stress-responsive JNK pathway was activated, leading to the activation of H2AX. Consistent with recent reports on the apoptotic role of phospho-H2AX, knockdown of H2AX prior to PKC-delta inhibition mitigated the induction of caspase-dependent apoptosis. Furthermore, PKC-delta inhibition effectively induced cytotoxicity in BRAF-mutant melanoma cell lines that had evolved resistance to a BRAF inhibitor, suggesting the potential clinical application of targeting PKC-delta in patients who have relapsed following treatment with BRAF inhibitors.
Collectively, these findings demonstrate that inhibition of PKC-delta by novel small molecule inhibitors represents a novel and targeted therapeutic approach to tumors bearing mutant RAS alleles.
Citation Format: Asami Takashima, Zhihong Chen, Brandon English, Robert M. Williams, Douglas V. Faller. Targeting oncogenic RAS with small molecule PKC-delta inhibitors. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr B36. doi: 10.1158/1557-3125.RASONC14-B36
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Abstract
Epidithiodioxopiperazine alkaloids possess an astonishing array of molecular architecture and generally exhibit potent biological activity. Nearly twenty distinct families have been isolated and characterized since the seminal discovery of gliotoxin in 1936. Numerous biosynthetic investigations offer a glimpse at the relative ease with which Nature is able to assemble this class of molecules, while providing synthetic chemists inspiration for the development of more efficient syntheses. Herein, we discuss the isolation and characterization, proposed fungal biogeneses, and total syntheses of epidithiodioxopiperazines.
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Affiliation(s)
- Timothy R Welch
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
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Takashima A, English B, Chen Z, Cao J, Cui R, Williams RM, Faller DV. Protein kinase Cδ is a therapeutic target in malignant melanoma with NRAS mutation. ACS Chem Biol 2014; 9:1003-14. [PMID: 24506253 DOI: 10.1021/cb400837t] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
NRAS is the second most frequently mutated gene in melanoma. Previous reports have demonstrated the sensitivity of cancer cell lines carrying KRAS mutations to apoptosis initiated by inhibition of protein kinase Cδ (PKCδ). Here, we report that PKCδ inhibition is cytotoxic in melanomas with primary NRAS mutations. Novel small-molecule inhibitors of PKCδ were designed as chimeric hybrids of two naturally occurring PKCδ inhibitors, staurosporine and rottlerin. The specific hypothesis interrogated and validated is that combining two domains of two naturally occurring PKCδ inhibitors into a chimeric or hybrid structure retains biochemical and biological activity and improves PKCδ isozyme selectivity. We have devised a potentially general synthetic protocol to make these chimeric species using Molander trifluorborate coupling chemistry. Inhibition of PKCδ, by siRNA or small molecule inhibitors, suppressed the growth of multiple melanoma cell lines carrying NRAS mutations, mediated via caspase-dependent apoptosis. Following PKCδ inhibition, the stress-responsive JNK pathway was activated, leading to the activation of H2AX. Consistent with recent reports on the apoptotic role of phospho-H2AX, knockdown of H2AX prior to PKCδ inhibition mitigated the induction of caspase-dependent apoptosis. Furthermore, PKCδ inhibition effectively induced cytotoxicity in BRAF mutant melanoma cell lines that had evolved resistance to a BRAF inhibitor, suggesting the potential clinical application of targeting PKCδ in patients who have relapsed following treatment with BRAF inhibitors. Taken together, the present work demonstrates that inhibition of PKCδ by novel small molecule inhibitors causes caspase-dependent apoptosis mediated via the JNK-H2AX pathway in melanomas with NRAS mutations or BRAF inhibitor resistance.
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Affiliation(s)
| | - Brandon English
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | | | | | | | - Robert M. Williams
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- University of Colorado Cancer Center, Aurora, Colorado 80045, United States
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Chen Z, Forman LW, Williams RM, Faller DV. Protein kinase C-δ inactivation inhibits the proliferation and survival of cancer stem cells in culture and in vivo. BMC Cancer 2014; 14:90. [PMID: 24528676 PMCID: PMC3927586 DOI: 10.1186/1471-2407-14-90] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 02/06/2014] [Indexed: 12/18/2022] Open
Abstract
Background A subpopulation of tumor cells with distinct stem-like properties (cancer stem-like cells, CSCs) may be responsible for tumor initiation, invasive growth, and possibly dissemination to distant organ sites. CSCs exhibit a spectrum of biological, biochemical, and molecular features that are consistent with a stem-like phenotype, including growth as non-adherent spheres (clonogenic potential), ability to form a new tumor in xenograft assays, unlimited self-renewal, and the capacity for multipotency and lineage-specific differentiation. PKCδ is a novel class serine/threonine kinase of the PKC family, and functions in a number of cellular activities including cell proliferation, survival or apoptosis. PKCδ has previously been validated as a synthetic lethal target in cancer cells of multiple types with aberrant activation of Ras signaling, using both genetic (shRNA and dominant-negative PKCδ mutants) and small molecule inhibitors. In contrast, PKCδ is not required for the proliferation or survival of normal cells, suggesting the potential tumor-specificity of a PKCδ-targeted approach. Methods shRNA knockdown was used validate PKCδ as a target in primary cancer stem cell lines and stem-like cells derived from human tumor cell lines, including breast, pancreatic, prostate and melanoma tumor cells. Novel and potent small molecule PKCδ inhibitors were employed in assays monitoring apoptosis, proliferation and clonogenic capacity of these cancer stem-like populations. Significant differences among data sets were determined using two-tailed Student’s t tests or ANOVA. Results We demonstrate that CSC-like populations derived from multiple types of human primary tumors, from human cancer cell lines, and from transformed human cells, require PKCδ activity and are susceptible to agents which deplete PKCδ protein or activity. Inhibition of PKCδ by specific genetic strategies (shRNA) or by novel small molecule inhibitors is growth inhibitory and cytotoxic to multiple types of human CSCs in culture. PKCδ inhibition efficiently prevents tumor sphere outgrowth from tumor cell cultures, with exposure times as short as six hours. Small-molecule PKCδ inhibitors also inhibit human CSC growth in vivo in a mouse xenograft model. Conclusions These findings suggest that the novel PKC isozyme PKCδ may represent a new molecular target for cancer stem cell populations.
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Affiliation(s)
| | | | | | - Douglas V Faller
- Cancer Center, Boston University School of Medicine, K-712C, 72 E, Concord St,, Boston, MA 02118, USA.
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Thankamony A, Tossavainen PH, Sleigh A, Acerini C, Elleri D, Dalton RN, Jackson NC, Umpleby AM, Williams RM, Dunger DB. Short-term administration of pegvisomant improves hepatic insulin sensitivity and reduces soleus muscle intramyocellular lipid content in young adults with type 1 diabetes. J Clin Endocrinol Metab 2014; 99:639-47. [PMID: 24423298 DOI: 10.1210/jc.2013-3264] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Data on the metabolic effects of GH derived from studies using GH suppression by pharmacological agents may not reflect selective actions. OBJECTIVE The purpose of this study was to evaluate the effects of GH antagonism on glucose and lipid metabolism using pegvisomant, a selective GH receptor antagonist in patients with type 1 diabetes (T1D). DESIGN AND PARTICIPANTS In a randomized, placebo-controlled, crossover study, 10 young adults with T1D were evaluated at baseline and after 4 weeks of treatment with either 10 mg of pegvisomant or placebo. The assessments included an overnight euglycemic steady state followed by a hyperinsulinemic euglycemic clamp and used glucose and glycerol cold stable isotopes. OUTCOME MEASURES Hepatic and peripheral insulin sensitivity (IS), lipid turnover, and intramyocellular lipid (IMCL) were measured. RESULTS Compared with placebo, pegvisomant treatment resulted in lower IGF-I levels (P < .001). During the overnight steady state, insulin requirements for euglycemia (P = .019), insulin levels (P = .008), and glucose production rates (Ra) (P = .033) were reduced. During the clamp study, glucose infusion rates (P = .031) increased and glucose Ra (P = .015) decreased whereas glucose disposal rates were unchanged. Free fatty acid levels were similar during the steady state but were lower during the clamp (P = .040) after pegvisomant. Soleus muscle IMCL decreased after treatment (P = .024); however, no change in tibialis anterior muscle was observed. CONCLUSIONS The study demonstrates that GH antagonism in T1D results in improved hepatic insulin sensitivity. Lack of consistent changes in free fatty acid levels may suggest a direct effect of GH on IS. Unchanged peripheral IS despite reductions in IMCL indicate that GH-induced alterations in IMCL may not be causally linked to glucose metabolism.
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Affiliation(s)
- A Thankamony
- Department of Paediatrics (A.T., P.H.T., C.A., D.E., R.M.W., D.B.D.), University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; Wolfson Brain Imaging Centre (A.S.), University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; Department of Paediatrics (P.H.T.), University of Oulu, 90029 OYS, Oulu, Finland; WellChild Laboratory (R.N.D.), King's College London, Evelina Children's Hospital, London SE1 7EH, United Kingdom; Diabetes and Metabolic Medicine (N.C.J., A.M.U.), Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7WG, United Kingdom; and National Institute for Health Research Cambridge Comprehensive Biomedical Research Centre (D.B.D.), Cambridge, CB2 0QQ, United Kingdom
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Abstract
This paper describes the selective syntheses of two cis-isomer enriched cyclopentanone fragrances: (Z)-3-(2-oxopropyl)-2-(pent-2-en-1-yl)cyclopentanone (4 steps, 62% overall yield, 67% cis) and Magnolione® (5 steps, 60% overall yield, 55% cis). In addition, the asymmetric synthesis of (3aR,7aS)-5-methyl-2,3,3a,4,7,7a-hexahydro-1H-inden-1-one as well as (3a'R,7a'S)-5'-methyl-2',3',3a',4',7',7a'-hexahydrospiro[[1,3]dioxolane-2,1'-indene]) has been realized by an efficient kinetic resolution, which enables the selective synthesis of the 2S,3R-isomer-enriched 3 and 4.
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Affiliation(s)
- Guojun Pan
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
| | - Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA ; University of Colorado Cancer Center, Aurora, CO 80045, USA
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Kato H, Nakamura Y, Finefield JM, Umaoka H, Nakahara T, Williams RM, Tsukamoto S. Corrigendum to “Study on the biosynthesis of the notoamides: pinacol-type rearrangement of the isoprenyl unit in deoxybrevianamide E and 6-hydroxydeoxybrevianamide E” [Tetrahedron Lett. 52 (2011) 6923–6926]. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2013.11.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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