1
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Schatz DJ, Kuenstner EJ, George DT, Pronin SV. Synthesis of rearranged indole diterpenes of the paxilline type. Nat Prod Rep 2022; 39:946-968. [PMID: 34931646 PMCID: PMC10122275 DOI: 10.1039/d1np00062d] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Covering: up to 2021Rearranged indole diterpenes of the paxilline type comprise a large group of fungal metabolites that possess diverse structural features and potentially useful biological effects. The unique indoloterpenoid motif, which is common to all congeners, was first confirmed by crystallographic studies of paxilline. This family of natural products has fascinated organic chemists for the past four decades and has inspired numerous syntheses and synthetic approaches. The present review highlights efforts that have laid the foundation and introduced new directions to this field of natural product synthesis. The introduction includes a summary of biosynthetic considerations and biological activities, the main body of the manuscript provides a detailed discussion of selected syntheses, and the review concludes with a brief outlook on the future of the field.
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Affiliation(s)
- Devon J Schatz
- Department of Chemistry, University of California, Irvine, California, 92697-2025, USA.
| | - Eric J Kuenstner
- Department of Chemistry, University of California, Irvine, California, 92697-2025, USA.
| | - David T George
- Department of Chemistry, University of California, Irvine, California, 92697-2025, USA.
| | - Sergey V Pronin
- Department of Chemistry, University of California, Irvine, California, 92697-2025, USA.
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2
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Guo L, Xu Z, Tong R. Asymmetric Total Synthesis of Indole Diterpenes Paspalicine, Paspalinine, and Paspalinine‐13‐ene. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lian‐Dong Guo
- Department of Chemistry The Hong Kong University of Science and Technology Clearwater Bay Kowloon, Hong Kong China
| | - Zejun Xu
- Department of Chemistry The Hong Kong University of Science and Technology Clearwater Bay Kowloon, Hong Kong China
| | - Rongbiao Tong
- Department of Chemistry The Hong Kong University of Science and Technology Clearwater Bay Kowloon, Hong Kong China
- Hong Kong Branch of the Guangdong Southern Marine Science and Engineering Laboratory (Guangzhou) The Hong Kong University of Science and Technology Clearwater Bay Kowloon, Hong Kong China
- HKUST Shenzhen Research Institute Shenzhen 518057 China
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3
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Kundu S, Munda M, Nandi R, Bisai A. Pd(0)-Catalyzed Deacylative Allylations (DaA) Strategy and Application in the Total Synthesis of Alkaloids. CHEM REC 2021; 21:3818-3838. [PMID: 34796643 DOI: 10.1002/tcr.202100267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/12/2022]
Abstract
Natural product synthesis has been the prime focus for the development of new carbon-carbon bond forming transformations. In particular, the construction of molecules with all-carbon quaternary centers remain one of the most facinating targets. In this regard, transition-metal catalyzed processes have gained imporatnce owing to their mild nature. Towards this, Pd(0)-catalyzed decarboxylative allylations (DcA) is worth mentioning and has emerged as a convenient method for synthesis of molecules even in their enantioenriched form. However, in order to have a flexible approach that facilitate rapid production of derivatives by utilizing commercially available allyl alcohols, the concept of Pd(0)-catalyzed deacylative allylations (DaA) methodology gains popularity. In these reactions, the transfer of an acyl group has a functional role in activating the allylic alcohol (proelectrophile) toward reaction with Pd(0)-catalysts. We present here an Account on newly conceptualized deacylative allylations (DaA) methodology and its applications in the synthesis of various intermediates and building blocks. Further, its potential in the total synthesis of naturally occurring alkaloids have been summarized in this personal account.
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Affiliation(s)
- Sourav Kundu
- Department of Chemistry, Indian Institution of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462 066, MP, India
| | - Mintu Munda
- Department of Chemistry, Indian Institution of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462 066, MP, India
| | - Rhituparna Nandi
- Department of Chemistry, Indian Institution of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462 066, MP, India
| | - Alakesh Bisai
- Department of Chemical Sciences, Indian Institution of Science Education and Research Kolkata Mohanpur Campus, Kalyani, Nadia, 741 246, WB, India
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4
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Guo LD, Xu Z, Tong R. Asymmetric Total Synthesis of Indole Diterpenes Paspalicine, Paspalinine, and Paspalinine-13-ene. Angew Chem Int Ed Engl 2021; 61:e202115384. [PMID: 34784090 DOI: 10.1002/anie.202115384] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Indexed: 11/08/2022]
Abstract
Paspaline-derived indole diterpenes (IDTs) are structurally complex mycotoxins with unique tremorgenic activity. Reported are asymmetric total syntheses of three paspaline-derived IDTs paspalicine, paspalinine and paspalinine-13-ene. Our synthesis features a green Achmatowicz rearrangement/bicycloketalization for the efficient construction of FG rings (75 % yield) and a cascade ring-closing metathesis of dienyne for highly regioselective formation of CD rings (72 % yield). Other highlights include four palladium-mediated reactions (Stille, aza-Wacker, Suzuki, and Heck) to forge the BE rings and the installation of two continuous all-carbon quaternary stereocenters via reductive ring-opening of cyclopropane and α-methylation of the conjugate ester. Our new synthetic strategy is expected to be applicable to the chemical synthesis of other paspaline-derived IDTs and will facilitate the bioactivity studies of these agriculturally and pharmacologically important IDTs.
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Affiliation(s)
- Lian-Dong Guo
- Department of Chemistry, The Hong Kong University of Science and Technology Clearwater Bay, Kowloon, Hong Kong, China
| | - Zejun Xu
- Department of Chemistry, The Hong Kong University of Science and Technology Clearwater Bay, Kowloon, Hong Kong, China
| | - Rongbiao Tong
- Department of Chemistry, The Hong Kong University of Science and Technology Clearwater Bay, Kowloon, Hong Kong, China.,Hong Kong Branch of the Guangdong Southern Marine Science and Engineering Laboratory (Guangzhou), The Hong Kong University of Science and Technology Clearwater Bay, Kowloon, Hong Kong, China.,HKUST Shenzhen Research Institute, Shenzhen, 518057, China
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5
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Kozák L, Szilágyi Z, Tóth L, Pócsi I, Molnár I. Tremorgenic and neurotoxic paspaline-derived indole-diterpenes: biosynthetic diversity, threats and applications. Appl Microbiol Biotechnol 2019; 103:1599-1616. [PMID: 30613899 DOI: 10.1007/s00253-018-09594-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/15/2018] [Accepted: 12/20/2018] [Indexed: 12/18/2022]
Abstract
Indole-diterpenes (IDTs) such as the aflatrems, janthitrems, lolitrems, paspalitrems, penitrems, shearinines, sulpinines, and terpendoles are biogenetically related but structurally varied tremorgenic and neurotoxic mycotoxins produced by fungi. All these metabolites derive from the biosynthetic intermediate paspaline, a frequently occurring IDT on its own right. In this comprehensive review, we highlight the similarities and differences of the IDT biosynthetic pathways that lead to the generation of the main paspaline-derived IDT subgroups. We survey the taxonomic distribution and the regulation of IDT production in various fungi and compare the organization of the known IDT biosynthetic gene clusters. A detailed assessment of the highly diverse biological activities of these mycotoxins leads us to emphasize the significant losses that paspaline-derived IDTs cause in agriculture, and compels us to warn about the various hazards they represent towards human and livestock health. Conversely, we also describe the potential utility of these versatile molecules as lead compounds for pharmaceutical drug discovery, and examine the prospects for their industrial scale manufacture in genetically manipulated IDT producers or domesticated host microorganisms in synthetic biological production systems.
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Affiliation(s)
- László Kozák
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Teva Pharmaceutical Works Ltd., Debrecen, Hungary
| | | | - László Tóth
- Teva Pharmaceutical Works Ltd., Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
| | - István Molnár
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
- Southwest Center for Natural Products Research, School of Natural Resources and the Environment, University of Arizona, Tucson, USA.
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6
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Zhou M, Zhou J, Liu J, Liang JJ, Peng XG, Duan FF, Ruan HL. Parasubindoles A-G, Seven Eremophilanyl Indoles from the Whole Plant of Parasenecio albus. J Org Chem 2018; 83:12122-12128. [PMID: 30198718 DOI: 10.1021/acs.joc.8b02089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Parasubindoles A-G (1-7), seven eremophilanyl indoles with an unprecedented 12 H-cyclopentane[ b]naphthalenespiro-1,3'-indole skeleton, were isolated from the whole plant of Parasenecio albus. Their structures with absolute configurations were elucidated by spectroscopic methods, single-crystal X-ray diffraction, and ECD analyses. Plausible biosynthetic pathways of 1-7 were postulated.
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Affiliation(s)
- Ming Zhou
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Jia Zhou
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Junjun Liu
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Jing-Jing Liang
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Xiao-Gang Peng
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Fang-Fang Duan
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
| | - Han-Li Ruan
- School of Pharmacy, Tongji Medical College, Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , Huazhong University of Science and Technology , Wuhan 430030 , P. R. China
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7
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Heine D, Holmes NA, Worsley SF, Santos ACA, Innocent TM, Scherlach K, Patrick EH, Yu DW, Murrell JC, Vieria PC, Boomsma JJ, Hertweck C, Hutchings MI, Wilkinson B. Chemical warfare between leafcutter ant symbionts and a co-evolved pathogen. Nat Commun 2018; 9:2208. [PMID: 29880868 PMCID: PMC5992151 DOI: 10.1038/s41467-018-04520-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/24/2018] [Indexed: 11/14/2022] Open
Abstract
Acromyrmex leafcutter ants form a mutually beneficial symbiosis with the fungus Leucoagaricus gongylophorus and with Pseudonocardia bacteria. Both are vertically transmitted and actively maintained by the ants. The fungus garden is manured with freshly cut leaves and provides the sole food for the ant larvae, while Pseudonocardia cultures are reared on the ant-cuticle and make antifungal metabolites to help protect the cultivar against disease. If left unchecked, specialized parasitic Escovopsis fungi can overrun the fungus garden and lead to colony collapse. We report that Escovopsis upregulates the production of two specialized metabolites when it infects the cultivar. These compounds inhibit Pseudonocardia and one, shearinine D, also reduces worker behavioral defenses and is ultimately lethal when it accumulates in ant tissues. Our results are consistent with an active evolutionary arms race between Pseudonocardia and Escovopsis, which modifies both bacterial and behavioral defenses such that colony collapse is unavoidable once Escovopsis infections escalate. Acromyrmex ants cultivate fungus gardens that can be parasitized by Escovopsis sp., leading to colony collapse. Here, Heine et al. identify two secondary metabolites produced by Escovopsis that accumulate in Acromyrmex tissue, reduce behavioural defenses and suppress symbiotic Pseudonocardia bacteria.
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Affiliation(s)
- Daniel Heine
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, NR4 7UH, UK
| | - Neil A Holmes
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Sarah F Worsley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Ana Carolina A Santos
- Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstraße 11a, Jena, 07745, Germany.,Friedrich Schiller University, Jena, Germany.,Departmento de Química, Universidade Federal de São Carlos, UFSCar, Via Washington Luiz KM 235, CP 676, São Carlos, SP, Brazil
| | - Tabitha M Innocent
- Department of Biology, Centre for Social Evolution, University of Copenhagen, Universitetsparken 15, Copenhagen, 2100, Denmark
| | - Kirstin Scherlach
- Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstraße 11a, Jena, 07745, Germany
| | - Elaine H Patrick
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Douglas W Yu
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Paulo C Vieria
- Departmento de Química, Universidade Federal de São Carlos, UFSCar, Via Washington Luiz KM 235, CP 676, São Carlos, SP, Brazil
| | - Jacobus J Boomsma
- Department of Biology, Centre for Social Evolution, University of Copenhagen, Universitetsparken 15, Copenhagen, 2100, Denmark
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstraße 11a, Jena, 07745, Germany.,Friedrich Schiller University, Jena, Germany
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK.
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, NR4 7UH, UK.
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8
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Goda AA, Siddique AB, Mohyeldin M, Ayoub NM, El Sayed KA. The Maxi-K (BK) Channel Antagonist Penitrem A as a Novel Breast Cancer-Targeted Therapeutic. Mar Drugs 2018; 16:md16050157. [PMID: 29751615 PMCID: PMC5983288 DOI: 10.3390/md16050157] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/06/2018] [Accepted: 05/09/2018] [Indexed: 12/24/2022] Open
Abstract
Breast cancer (BC) is a heterogeneous disease with different molecular subtypes. The high conductance calcium-activated potassium channels (BK, Maxi-K channels) play an important role in the survival of some BC phenotypes, via membrane hyperpolarization and regulation of cell cycle. BK channels have been implicated in BC cell proliferation and invasion. Penitrems are indole diterpene alkaloids produced by various terrestrial and marine Penicillium species. Penitrem A (1) is a selective BK channel antagonist with reported antiproliferative and anti-invasive activities against multiple malignancies, including BC. This study reports the high expression of BK channel in different BC subtypes. In silico BK channel binding affinity correlates with the antiproliferative activities of selected penitrem analogs. 1 showed the best binding fitting at multiple BK channel crystal structures, targeting the calcium-sensing aspartic acid moieties at the calcium bowel and calcium binding sites. Further, 1 reduced the levels of BK channel expression and increased expression of TNF-α in different BC cell types. Penitrem A (1) induced G1 cell cycle arrest of BC cells, and induced upregulation of the arrest protein p27. Combination treatment of 1 with targeted anti-HER drugs resulted in synergistic antiproliferative activity, which was associated with reduced EGFR and HER2 receptor activation, as well as reduced active forms of AKT and STAT3. Collectively, the BK channel antagonists represented by penitrem A can be novel sensitizing, chemotherapeutics synergizing, and therapeutic agents for targeted BC therapy.
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Affiliation(s)
- Amira A Goda
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
| | - Abu Bakar Siddique
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
| | - Mohamed Mohyeldin
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
- Department of Pharmacognosy, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt.
| | - Nehad M Ayoub
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan.
| | - Khalid A El Sayed
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
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9
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Marine-Derived Penicillium Species as Producers of Cytotoxic Metabolites. Mar Drugs 2017; 15:md15100329. [PMID: 29064452 PMCID: PMC5666435 DOI: 10.3390/md15100329] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/30/2017] [Accepted: 10/09/2017] [Indexed: 12/16/2022] Open
Abstract
Since the discovery of penicillin, Penicillium has become one of the most attractive fungal genera for the production of bioactive molecules. Marine-derived Penicillium has provided numerous excellent pharmaceutical leads over the past decades. In this review, we focused on the cytotoxic metabolites * (* Cytotoxic potency was referred to five different levels in this review, extraordinary (IC50/LD50: <1 μM or 0.5 μg/mL); significant (IC50/LD50: 1~10 μM or 0.5~5 μg/mL); moderate (IC50/LD50: 10~30 μM or 5~15 μg/mL); mild (IC50/LD50: 30~50 μM or 15~25 μg/mL); weak (IC50/LD50: 50~100 μM or 25~50 μg/mL). The comparative potencies of positive controls were referred when they were available). produced by marine-derived Penicillium species, and on their cytotoxicity mechanisms, biosyntheses, and chemical syntheses.
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10
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Total synthesis of architecturally complex indole terpenoids: strategic and tactical evolution. J Antibiot (Tokyo) 2017; 71:185-204. [PMID: 28852179 DOI: 10.1038/ja.2017.94] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/01/2017] [Accepted: 07/08/2017] [Indexed: 02/07/2023]
Abstract
Indole terpenes have attracted the interests of synthetic chemists due to their complex architectures and potent biological activities. Examples of total syntheses of several indole terpenes were reviewed in this article to honor Professor KC Nicolaou.
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11
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Abstract
An enantioselective synthesis of the indole diterpenoid natural product paspaline is disclosed. Critical to this approach was the implementation of stereoselective desymmetrization reactions to assemble key stereocenters of the molecule. The design and execution of these tactics are described in detail, and a thorough analysis of observed outcomes is presented, ultimately providing the title compound in high stereopurity. This synthesis provides a novel template for preparing key stereocenters in this family of molecules, and the reactions developed en route to paspaline present a series of new synthetic disconnections in preparing steroidal natural products.
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Affiliation(s)
- Robert J. Sharpe
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Jeffrey S. Johnson
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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12
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Maragos CM. Development and Evaluation of Monoclonal Antibodies for Paxilline. Toxins (Basel) 2015; 7:3903-15. [PMID: 26426046 PMCID: PMC4626710 DOI: 10.3390/toxins7103903] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/08/2015] [Accepted: 09/22/2015] [Indexed: 11/16/2022] Open
Abstract
Paxilline (PAX) is a tremorgenic mycotoxin that has been found in perennial ryegrass infected with Acremonium lolii. To facilitate screening for this toxin, four murine monoclonal antibodies (mAbs) were developed. In competitive indirect enzyme-linked immunosorbent assays (CI-ELISAs) the concentrations of PAX required to inhibit signal development by 50% (IC50s) ranged from 1.2 to 2.5 ng/mL. One mAb (2-9) was applied to the detection of PAX in maize silage. The assay was sensitive to the effects of solvents, with 5% acetonitrile or 20% methanol causing a two-fold or greater increase in IC50. For analysis of silage samples, extracts were cleaned up by adsorbing potential matrix interferences onto a solid phase extraction column. The non-retained extract was then diluted with buffer to reduce solvent content prior to assay. Using this method, the limit of detection for PAX in dried silage was 15 µg/kg and the limit of quantification was 90 µg/kg. Recovery from samples spiked over the range of 100 to 1000 µg/kg averaged 106% ± 18%. The assay was applied to 86 maize silage samples, with many having detectable, but none having quantifiable, levels of PAX. The results suggest the CI-ELISA can be applied as a sensitive technique for the screening of PAX in maize silage.
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Affiliation(s)
- Chris M Maragos
- Bacterial Foodborne Pathogens and Mycology Research Unit, USDA-ARS-NCAUR, 1815 North University Street, Peoria, IL 61604, USA.
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13
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de Bekker C, Ohm RA, Loreto RG, Sebastian A, Albert I, Merrow M, Brachmann A, Hughes DP. Gene expression during zombie ant biting behavior reflects the complexity underlying fungal parasitic behavioral manipulation. BMC Genomics 2015; 16:620. [PMID: 26285697 PMCID: PMC4545319 DOI: 10.1186/s12864-015-1812-x] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/03/2015] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Adaptive manipulation of animal behavior by parasites functions to increase parasite transmission through changes in host behavior. These changes can range from slight alterations in existing behaviors of the host to the establishment of wholly novel behaviors. The biting behavior observed in Carpenter ants infected by the specialized fungus Ophiocordyceps unilateralis s.l. is an example of the latter. Though parasitic manipulation of host behavior is generally assumed to be due to the parasite's gene expression, few studies have set out to test this. RESULTS We experimentally infected Carpenter ants to collect tissue from both parasite and host during the time period when manipulated biting behavior is experienced. Upon observation of synchronized biting, samples were collected and subjected to mixed RNA-Seq analysis. We also sequenced and annotated the O. unilateralis s.l. genome as a reference for the fungal sequencing reads. CONCLUSIONS Our mixed transcriptomics approach, together with a comparative genomics study, shows that the majority of the fungal genes that are up-regulated during manipulated biting behavior are unique to the O. unilateralis s.l. genome. This study furthermore reveals that the fungal parasite might be regulating immune- and neuronal stress responses in the host during manipulated biting, as well as impairing its chemosensory communication and causing apoptosis. Moreover, we found genes up-regulated during manipulation that putatively encode for proteins with reported effects on behavioral outputs, proteins involved in various neuropathologies and proteins involved in the biosynthesis of secondary metabolites such as alkaloids.
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Affiliation(s)
- Charissa de Bekker
- Institute of Medical Psychology, Faculty of Medicine, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336, Munich, Germany.
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA.
| | - Robin A Ohm
- Microbiology, Faculty of Science, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Raquel G Loreto
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
- CAPES Foundation, Ministry of Education of Brazil, Brasília, 70040-020, DF, Brazil
| | - Aswathy Sebastian
- Bioinformatics Consulting Center, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
| | - Istvan Albert
- Bioinformatics Consulting Center, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
- Department of Biochemistry and Molecular Biology, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA
| | - Martha Merrow
- Institute of Medical Psychology, Faculty of Medicine, Ludwig-Maximilians-University Munich, Goethestrasse 31, 80336, Munich, Germany
| | - Andreas Brachmann
- Faculty of Biology, Section Genetics, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Martinsried, Germany
| | - David P Hughes
- Department of Entomology and Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, State College, Pennsylvania, 16802, PA, USA.
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14
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Nicholson MJ, Eaton CJ, Stärkel C, Tapper BA, Cox MP, Scott B. Molecular Cloning and Functional Analysis of Gene Clusters for the Biosynthesis of Indole-Diterpenes in Penicillium crustosum and P. janthinellum. Toxins (Basel) 2015. [PMID: 26213965 PMCID: PMC4549719 DOI: 10.3390/toxins7082701] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The penitremane and janthitremane families of indole-diterpenes are abundant natural products synthesized by Penicillium crustosum and P. janthinellum. Using a combination of PCR, cosmid library screening, and Illumina sequencing we have identified gene clusters encoding enzymes for the synthesis of these compounds. Targeted deletion of penP in P. crustosum abolished the synthesis of penitrems A, B, D, E, and F, and led to accumulation of paspaline, a key intermediate for paxilline biosynthesis in P. paxilli. Similarly, deletion of janP and janD in P. janthinellum abolished the synthesis of prenyl-elaborated indole-diterpenes, and led to accumulation in the latter of 13-desoxypaxilline, a key intermediate for the synthesis of the structurally related aflatremanes synthesized by Aspergillus flavus. This study helps resolve the genetic basis for the complexity of indole-diterpene natural products found within the Penicillium and Aspergillus species. All indole-diterpene gene clusters identified to date have a core set of genes for the synthesis of paspaline and a suite of genes encoding multi-functional cytochrome P450 monooxygenases, FAD dependent monooxygenases, and prenyl transferases that catalyse various regio- and stereo- specific oxidations that give rise to the diversity of indole-diterpene products synthesized by this group of fungi.
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Affiliation(s)
- Matthew J Nicholson
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Carla J Eaton
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Cornelia Stärkel
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Brian A Tapper
- AgResearch, Grasslands Research Centre, Private Bag 11 008, Palmerston North 4442, New Zealand.
| | - Murray P Cox
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Barry Scott
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
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Feldman KS, Gonzalez IY, Glinkerman CM. Intramolecular [3 + 2] Cyclocondensations of Alkenes with Indolidenes and Indolidenium Cations. J Am Chem Soc 2014; 136:15138-41. [DOI: 10.1021/ja508421e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ken S. Feldman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Inanllely Y. Gonzalez
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Christopher M. Glinkerman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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16
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Sallam AA, Ayoub NM, Foudah AI, Gissendanner CR, Meyer SA, El Sayed KA. Indole diterpene alkaloids as novel inhibitors of the Wnt/β-catenin pathway in breast cancer cells. Eur J Med Chem 2013; 70:594-606. [PMID: 24211635 PMCID: PMC3884952 DOI: 10.1016/j.ejmech.2013.09.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 09/24/2013] [Accepted: 09/28/2013] [Indexed: 10/26/2022]
Abstract
Penitrems are indole diterpene alkaloids best known for their BK channel inhibition and tremorgenic effects in mammals. In a previous study, penitrems A-F (1-5), their biosynthetic precursors, paspaline (6) and emindole SB (7), and two brominated penitrem analogs 8 and 9 demonstrated promising in vitro antiproliferative, antimigratory, and anti-invasive effects in the MTT (MCF-7 and MDA-MB-231), wound-healing, and Cultrex BME cell invasion (MDA-MB-231) assays, respectively. The study herein reports the novel ability of penitrem A to suppress total β-catenin levels in MDA-MB-231 mammary cancer cells. Nine new penitrem analogs (10-18) were semisynthetically prepared, in an attempt to identify pharmacophores correlated with BK channel inhibition and tremorgenicity of penitrems and decrease their toxicity. The degree of BK channel inhibition was assessed using the nematode Caenorhabditis elegans, and in vivo tremorgenic EC₅₀ was calculated using CD-1 male mice following an Up-and-Down Procedure (UDP). Although new analogs were generally less active than parent compound 1, some showed no BK channel inhibition or tremorgenicity and retained the ability of penitrem A (1) to suppress total β-catenin levels in MDA-MB-231 cells. Paspaline (6) and emindole SB (7), both lacking BK channel inhibition and tremorgenicity, represent the simplest indole diterpene skeleton that retains the antiproliferative, antimigratory and total β-catenin suppressing effects shown by the more complex penitrem A (1).
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Affiliation(s)
- Asmaa A. Sallam
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, USA
| | - Nehad M. Ayoub
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, USA
- Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
| | - Ahmed I. Foudah
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, USA
| | - Chris R. Gissendanner
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, USA
| | - Sharon A. Meyer
- Department of Toxicology, College of Pharmacy, University of Louisiana at Monroe, USA
| | - Khalid A. El Sayed
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, USA
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17
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Pockrandt D, Li SM. Geranylation of Cyclic Dipeptides by the Dimethylallyl Transferase AnaPT Resulting in a Shift of Prenylation Position on the Indole Ring. Chembiochem 2013; 14:2023-8. [DOI: 10.1002/cbic.201300372] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Indexed: 01/28/2023]
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18
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Gao H, Zhu T, Li D, Gu Q, Liu W. Prenylated indole diketopiperazine alkaloids from a mangrove rhizosphere soil derived fungus Aspergillus effuses H1-1. Arch Pharm Res 2013; 36:952-6. [DOI: 10.1007/s12272-013-0107-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 03/20/2013] [Indexed: 10/27/2022]
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19
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Zhang J, Halm ST, Halm DR. Role of the BK channel (KCa1.1) during activation of electrogenic K+ secretion in guinea pig distal colon. Am J Physiol Gastrointest Liver Physiol 2012; 303:G1322-34. [PMID: 23064759 PMCID: PMC3532550 DOI: 10.1152/ajpgi.00325.2012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Secretagogues acting at a variety of receptor types activate electrogenic K(+) secretion in guinea pig distal colon, often accompanied by Cl(-) secretion. Distinct blockers of K(Ca)1.1 (BK, Kcnma1), iberiotoxin (IbTx), and paxilline inhibited the negative short-circuit current (I(sc)) associated with K(+) secretion. Mucosal addition of IbTx inhibited epinephrine-activated I(sc) ((epi)I(sc)) and transepithelial conductance ((epi)G(t)) consistent with K(+) secretion occurring via apical membrane K(Ca)1.1. The concentration dependence of IbTx inhibition of (epi)I(sc) yielded an IC(50) of 193 nM, with a maximal inhibition of 51%. Similarly, IbTx inhibited (epi)G(t) with an IC(50) of 220 nM and maximal inhibition of 48%. Mucosally added paxilline (10 μM) inhibited (epi)I(sc) and (epi)G(t) by ∼50%. IbTx and paxilline also inhibited I(sc) activated by mucosal ATP, supporting apical K(Ca)1.1 as a requirement for this K(+) secretagogue. Responses to IbTx and paxilline indicated that a component of K(+) secretion occurred during activation of Cl(-) secretion by prostaglandin-E(2) and cholinergic stimulation. Analysis of K(Ca)1.1α mRNA expression in distal colonic epithelial cells indicated the presence of the ZERO splice variant and three splice variants for the COOH terminus. The presence of the regulatory β-subunits K(Ca)β1 and K(Ca)β4 also was demonstrated. Immunolocalization supported the presence of K(Ca)1.1α in apical and basolateral membranes of surface and crypt cells. Together these results support a cellular mechanism for electrogenic K(+) secretion involving apical membrane K(Ca)1.1 during activation by several secretagogue types, but the observed K(+) secretion likely required the activity of additional K(+) channel types in the apical membrane.
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Affiliation(s)
- Jin Zhang
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Susan T. Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - Dan R. Halm
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine, Dayton, Ohio
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20
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Enomoto M, Morita A, Kuwahara S. Total Synthesis of the Tremorgenic Indole Diterpene Paspalinine. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201206299] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Enomoto M, Morita A, Kuwahara S. Total synthesis of the tremorgenic indole diterpene paspalinine. Angew Chem Int Ed Engl 2012; 51:12833-6. [PMID: 23135880 DOI: 10.1002/anie.201206299] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/10/2012] [Indexed: 11/05/2022]
Affiliation(s)
- Masaru Enomoto
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan
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22
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Yu X, Liu Y, Xie X, Zheng XD, Li SM. Biochemical characterization of indole prenyltransferases: filling the last gap of prenylation positions by a 5-dimethylallyltryptophan synthase from Aspergillus clavatus. J Biol Chem 2011; 287:1371-80. [PMID: 22123822 DOI: 10.1074/jbc.m111.317982] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The putative prenyltransferase gene ACLA_031240 belonging to the dimethylallyltryptophan synthase superfamily was identified in the genome sequence of Aspergillus clavatus and overexpressed in Escherichia coli. The soluble His-tagged protein EAW08391 was purified to near homogeneity and used for biochemical investigation with diverse aromatic substrates in the presence of different prenyl diphosphates. It has shown that in the presence of dimethylallyl diphosphate (DMAPP), the recombinant enzyme accepted very well simple indole derivatives with L-tryptophan as the best substrate. Product formation was also observed for tryptophan-containing cyclic dipeptides but with much lower conversion yields. In contrast, no product formation was detected in the reaction mixtures of L-tryptophan with geranyl or farnesyl diphosphate. Structure elucidation of the enzyme products by NMR and MS analyses proved unequivocally the highly regiospecific regular prenylation at C-5 of the indole nucleus of the simple indole derivatives. EAW08391 was therefore termed 5-dimethylallyltryptophan synthase, and it filled the last gap in the toolbox of indole prenyltransferases regarding their prenylation positions. K(m) values of 5-dimethylallyltryptophan synthase were determined for L-tryptophan and DMAPP at 34 and 76 μM, respectively. Average turnover number (k(cat)) at 1.1 s(-1) was calculated from kinetic data of L-tryptophan and DMAPP. Catalytic efficiencies of 5-dimethylallyltryptophan synthase for L-tryptophan at 25,588 s(-1)·M(-1) and for other 11 simple indole derivatives up to 1538 s(-1)·M(-1) provided evidence for its potential usage as a catalyst for chemoenzymatic synthesis.
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Affiliation(s)
- Xia Yu
- Institut für Pharmazeutische Biologie und Biotechnologie, Philipps-Universität Marburg, Deutschhausstrasse 17A, 35037 Marburg, Germany
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23
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Stec E, Pistorius D, Müller R, Li SM. AuaA, a Membrane-Bound Farnesyltransferase from Stigmatella aurantiaca, Catalyzes the Prenylation of 2-Methyl-4-hydroxyquinoline in the Biosynthesis of Aurachins. Chembiochem 2011; 12:1724-30. [DOI: 10.1002/cbic.201100188] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Indexed: 01/05/2023]
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24
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Substrate promiscuity of secondary metabolite enzymes: prenylation of hydroxynaphthalenes by fungal indole prenyltransferases. Appl Microbiol Biotechnol 2011; 92:737-48. [DOI: 10.1007/s00253-011-3351-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 04/09/2011] [Accepted: 04/20/2011] [Indexed: 11/26/2022]
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25
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Genovese S, Curini M, Epifano F. Chemistry and biological activity of azoprenylated secondary metabolites. PHYTOCHEMISTRY 2009; 70:1082-1091. [PMID: 19660768 DOI: 10.1016/j.phytochem.2009.06.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 06/15/2009] [Accepted: 06/16/2009] [Indexed: 05/28/2023]
Abstract
N-Prenyl secondary metabolites (isopentenylazo-, geranylazo-, farnesylazo- and their biosynthetic derivatives) represent a family of extremely rare natural products. Only in recent years have these alkaloids been recognized as interesting and valuable biologically active secondary metabolites. To date about 35 alkaloids have been isolated from plants mainly belonging to the Rutaceae family, and from fungi, bacteria, and/or obtained by chemical synthesis. These metabolites comprise anthranilic acid derivatives, diazepinones, and indole, and xanthine alkaloids. Many of the isolated prenylazo secondary metabolites and their semisynthetic derivatives are shown to exert valuable in vitro and in vivo anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, and anti-fungal effects. The aim of this comprehensive review is to examine the different types of prenylazo natural products from a chemical, phytochemical and biological perspective.
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Affiliation(s)
- Salvatore Genovese
- Dipartimento di Scienze del Farmaco, Università "G. D'Annunzio" di Chieti-Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy.
| | - Massimo Curini
- Dipartimento di Chimica e Tecnologia del Farmaco, Sezione di Chimica Organica, Università degli Studi di Perugia, Via del Liceo, 06123 Perugia, Italy
| | - Francesco Epifano
- Dipartimento di Scienze del Farmaco, Università "G. D'Annunzio" di Chieti-Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy
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26
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Smith AB, Davulcu AH, Cho YS, Ohmoto K, Kürti L, Ishiyama H. Indole diterpene synthetic studies. Total synthesis of (+)-nodulisporic acid F and construction of the heptacyclic cores of (+)-nodulisporic acids A and B and (-)-nodulisporic acid D. J Org Chem 2007; 72:4596-610. [PMID: 17511507 DOI: 10.1021/jo062422i] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A first-generation strategy for construction of (+)-nodulisporic acids A (1) and B (2) is described. The strategy entails union of the eastern and western hemisphere subtargets via the indole synthesis protocol developed in our laboratory. Subsequent elaboration of rings E and F, however, revealed the considerable acid instability of the C(24) hydroxyl, thereby preventing further advancement. Nonetheless, preparation of the heptacyclic core of (+)-nodulisporic acids A and B, the total synthesis of (+)-nodulisporic acid F, the simplest member of the nodulisporic acid family, and elaboration of the heptacyclic core of (-)-nodulisporic acid D were achieved.
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Affiliation(s)
- Amos B Smith
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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27
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Smith AB, Kürti L, Davulcu AH, Cho YS. Development of a Scalable Synthesis of a Common Eastern Tricyclic Lactone for Construction of the Nodulisporic Acids. Org Process Res Dev 2006. [DOI: 10.1021/op060204l] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amos B. Smith
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
| | - László Kürti
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
| | - Akin H. Davulcu
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
| | - Young Shin Cho
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A
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28
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Smith AB, Kürti L, Davulcu AH. A New Modular Indole Synthesis. Construction of the Highly Strained CDEF Parent Tetracycle of Nodulisporic Acids A and B. Org Lett 2006; 8:2167-70. [PMID: 16671808 DOI: 10.1021/ol0606536] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Construction of the highly strained CDEF parent tetracycle, a structural motif found only in the potent ectoparasiticidal agents (+)-nodulisporic acids A and B and related congeners, has been achieved via a new modular indole synthesis, exploiting a sequential Stille cross-coupling/Buchwald-Hartwig union/cyclization tactic. The new indole synthesis holds the promise of rapid assembly of diverse, highly substituted indoles possessing uncommon substitution patterns.
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Affiliation(s)
- Amos B Smith
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, 19104, USA.
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29
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Smith AB, Davulcu AH, Kürti L. Indole Diterpenoid Synthetic Studies. Construction of the Heptacyclic Core of (−)-Nodulisporic Acid D. Org Lett 2006; 8:1669-72. [PMID: 16597137 DOI: 10.1021/ol0602912] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text] Construction of the heptacyclic core of (-)-nodulisporic acid D, a representative member of a recently discovered class of architecturally complex, ectoparasiticidal indole alkaloids, has been achieved. The modular synthetic strategy comprises an expedient, stereocontrolled synthesis of a tricyclic western hemisphere, in conjunction with union of an eastern hemisphere, exploiting the 2-substituted indole synthetic protocol introduced and developed in our laboratory.
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Affiliation(s)
- Amos B Smith
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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30
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Smith AB, Davulcu AH, Kürti L. Indole Diterpenoid Synthetic Studies. The Total Synthesis of (+)-Nodulisporic Acid F. Org Lett 2006; 8:1665-8. [PMID: 16597136 DOI: 10.1021/ol060290+] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text] A stereocontrolled total synthesis of (+)-nodulisporic acid F, the simplest member of a family of novel ectoparasiticidal agents, has been achieved. Highlights of the effective modular synthetic strategy include anionic union of a tricyclic lactone with o-toluidine via our 2-substituted indole synthetic protocol, an optimized C-ring construction protocol, and a late-stage installation of the alpha,beta-unsaturated carboxylic acid side chain via the B-alkyl Suzuki-Miyaura cross-coupling tactic.
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Affiliation(s)
- Amos B Smith
- Department of Chemistry, Monell Chemical Senses Center and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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31
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Singh SB, Ondeyka JG, Jayasuriya H, Zink DL, Ha SN, Dahl-Roshak A, Greene J, Kim JA, Smith MM, Shoop W, Tkacz JS. Nodulisporic acids D-F: structure, biological activities, and biogenetic relationships. JOURNAL OF NATURAL PRODUCTS 2004; 67:1496-1506. [PMID: 15387649 DOI: 10.1021/np0498455] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nodulisporic acids D, E, and F are the newest members of a family of nontremorogenic indole-diterpenoids that are potent, orally bioavailable, antiflea agents derived from a fungus belonging to the genus Nodulisporium. The four members of the D series are each devoid of an isoprene residue that is present at C-26 in the three nodulisporic acids described originally (the A series). Nodulisporic acid E (11a) has a simpler structure, which lacks not only the isoprene residue at C-26 but also two that form the A/B rings. Nodulisporic acid F is the simplest of all nodulisporic acids and is devoid of all three isoprene residues of the indole unit; as such, it represents the earliest biosynthetic intermediate in this series. A biogenetic grid based on mutation studies is proposed that encompasses all the known nodulisporic acids. Structure-activity relationships of the known natural nodulisporic acids have been elucidated. Within a series the most active compound possesses a dienoic acid chain, and overall, the end product of the biogenetic grid, i.e., nodulisporic acid A, exhibits the most potent antiflea activity. Additionally, the stereochemistries of C-3' ' and C-4' ' of nodulisporic acid D(2) and therefore of nodulisporic acids A(2), B(2), and C(2) have been assigned.
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Affiliation(s)
- Sheo B Singh
- Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, USA.
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