1
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Methods for substitution of the thioxo group with the oxo group in imidazolidine-2-thione derivatives. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3488-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Abstract
This review deals with the synthesis of naturally occurring alkaloids containing partially or completely saturated pyrimidine nuclei. The interest in these compounds is associated with their structural diversity, high biological activity and toxicity. The review is divided into four parts, each of which describes a number of synthetic methodologies toward structurally different naturally occurring alkaloids containing saturated cyclic six-membered amidine, guanidine, aminal and urea (thiourea) moieties, respectively. The development of various synthetic strategies for the preparation of these compounds has remarkably increased during the past few decades. This is primarily due to the fact that some of these compounds are isolated only in limited quantities, which makes it practically impossible to study their full structural characteristics and biological activity.
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3
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Wang SQ, Qi WY, Yin XS, Shi BF. Formal total synthesis of (±)-7-deoxycylindrospermopsin and its 8- epi isomer. Org Chem Front 2021. [DOI: 10.1039/d1qo00381j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A concise formal synthesis of (±)-7-deoxycylindrospermopsin in 14 steps was reported.
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Affiliation(s)
- Si-Qing Wang
- Center of Chemistry for Frontier Technologies
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China
| | - Wei-Yi Qi
- Center of Chemistry for Frontier Technologies
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China
| | - Xue-Song Yin
- Center of Chemistry for Frontier Technologies
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China
| | - Bing-Feng Shi
- Center of Chemistry for Frontier Technologies
- Department of Chemistry
- Zhejiang University
- Hangzhou 310027
- China
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4
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González-Blanco C, Dörr FA, Albuquerque R, Onuki J, Pinto E. Alternative Isolation Protocol for Desulfo and Zwitterionic Cylindrospermopsin Alkaloids and Comparison of Their Toxicity in HepG2 Cells. Molecules 2020; 25:molecules25133027. [PMID: 32630766 PMCID: PMC7412431 DOI: 10.3390/molecules25133027] [Citation(s) in RCA: 4] [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: 06/04/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022] Open
Abstract
The term cylindrospermopsins (CYNs) refers to a structurally related class of cyanobacterial metabolites comprised of a tricyclic guanidine group and a hydroxymethyluracil moiety. Most reports in environmental aquatic samples refer to cylindrospermopsin (CYN), and reports on other CYN alkaloids are scarce, due, in part, to a lack of versatile isolation protocols. Thus, using commercially available solid phase extraction (SPE) cartridges, we optimized an isolation protocol for the complete recovery of CYN, 7-deoxy-cylindrospermopsin (7D-CYN) and 7-deoxy-desulfo-cylindrospermopsin (7D-desulfo-CYN) from the same aliquot. The isolation protocol was adaptable depending on the nature of the sample (solid biomass, culture broth or environmental water sample) and tolerates up to 4 L of dense culture broth or 400 mg of lyophilized biomass. To quantitate the CYN alkaloids, we validated an LC-DAD-MS2 method, which takes advantage of the UV absorption of the uracil group (λ 262 nm). Using electrospray ionization (ESI) in a positive ion mode, the high-resolution MS1 data confirms the presence of the protonated alkaloids, and the MS2 fragment assignment is reported as complementary proof of the molecular structure of the CYNs. We isolated three CYN alkaloids with different water solubility using the same lyophilized sample, with a purity that ranged from 95% to 99%. The biological activity of the purified CYNs, along with a synthetic degradation product of CYN (desulfo-cylindrospermopsin), was evaluated by assessing necrosis and apoptosis in vitro using flow cytometry. CYN’s lethal potency in HepG2 cells was greater than the other analogs, due to the presence of all four functional groups: guanidine, uracil, C-7 hydroxyl and the sulfate residue.
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Affiliation(s)
- Carlos González-Blanco
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
- Laboratory of Development and Innovation, Butantan Institute, Av. Vital Brasil, 1500, São Paulo 05503-900, SP, Brazil;
- Sección de Toxicología, Departamento de Ciencias Forenses, Organismo de Investigación Judicial, Heredia 40801, Costa Rica
| | - Felipe Augusto Dörr
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
| | - Renata Albuquerque
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
| | - Janice Onuki
- Laboratory of Development and Innovation, Butantan Institute, Av. Vital Brasil, 1500, São Paulo 05503-900, SP, Brazil;
| | - Ernani Pinto
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
- Centre for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba 13416-000, SP, Brazil
- Correspondence: ; Tel.: +55-193429-4779
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5
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Mailyan AK, Chen JL, Li W, Keller AA, Sternisha SM, Miller BG, Zakarian A. Short Total Synthesis of [ 15N 5]-Cylindrospermopsins from 15NH 4Cl Enables Precise Quantification of Freshwater Cyanobacterial Contamination. J Am Chem Soc 2018; 140:6027-6032. [PMID: 29672038 PMCID: PMC6312099 DOI: 10.1021/jacs.8b03071] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fresh water cyanobacterial algal blooms represent a major health risk because these organisms produce cylindrospermopsin, a toxic, structurally complex, zwitterionic uracil-guanidine alkaloid recognized by the EPA as a dangerous drinking water contaminant. At present, the ability to detect and quantify the presence of cylindrospermospin in water samples is severely hampered by the lack of an isotopically labeled standard for analytical mass spectrometry. Herein, we present a concise, scaled total synthesis of 15N cylindrospermosin from 15N ammonium chloride, which leverages a unique stereoselective intramolecular double conjugate addition step to assemble the tricyclic guanidine core. In addition to providing the first pure isotopically labeled probe for precise quantification of this potent biotoxin in fresh water sources, our results demonstrate how unique constraints associated with isotope incorporation compel novel solutions to synthesis design.
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Affiliation(s)
- Artur K Mailyan
- Department of Chemistry and Biochemistry , University of California , Santa Barbara , California 93110 , United States
| | - Joanna L Chen
- Department of Chemistry and Biochemistry , University of California , Santa Barbara , California 93110 , United States
| | - Weiwei Li
- Bren School of Environmental Science and Management , University of California , Santa Barbara , California 93106 , United States
| | - Arturo A Keller
- Bren School of Environmental Science and Management , University of California , Santa Barbara , California 93106 , United States
| | - Shawn M Sternisha
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32310 , United States
| | - Brian G Miller
- Department of Chemistry and Biochemistry , Florida State University , Tallahassee , Florida 32310 , United States
| | - Armen Zakarian
- Department of Chemistry and Biochemistry , University of California , Santa Barbara , California 93110 , United States
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6
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Kabala K, Grzeszczyk B, Stecko S, Furman B, Chmielewski M. Approach to Monobactams and Nocardicins via Diastereoselective Kinugasa Reaction. J Org Chem 2015; 80:12038-46. [DOI: 10.1021/acs.joc.5b01979] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kamil Kabala
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka
44/52, 01-224 Warsaw, Poland
| | - Barbara Grzeszczyk
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka
44/52, 01-224 Warsaw, Poland
| | - Sebastian Stecko
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka
44/52, 01-224 Warsaw, Poland
| | - Bartłomiej Furman
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka
44/52, 01-224 Warsaw, Poland
| | - Marek Chmielewski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka
44/52, 01-224 Warsaw, Poland
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7
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Shpak-Kraievskyi P, Mankou Makaya A, Beauchard A, Martel A, Laurent MY, Dujardin G. [3+2] Route to Quaternary Oxaprolinol Derivatives as Masked Precursors of Disubstituted β3,β3-Amino Aldehyde. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500339] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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8
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Shaw JW, Grayson DH, Rozas I. Synthesis of Guanidines and Some of Their Biological Applications. TOPICS IN HETEROCYCLIC CHEMISTRY 2015. [DOI: 10.1007/7081_2015_174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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9
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Evans DM, Horton PN, Hursthouse MB, Murphy PJ. Preparation of an ABC tricyclic model of the cylindrospermopsin alkaloids via a biomimetically inspired pathway. RSC Adv 2014. [DOI: 10.1039/c4ra03031a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The protected guanidine18was convertedviaa 4-step sequence (Boc-deprotection, tethered Biginelli condensation, deallylation/decarboxylation and reduction) to give the tricyclic guanidines26and27, models of the tricyclic core of cylindrospermopsin1.
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10
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de la Cruz AA, Hiskia A, Kaloudis T, Chernoff N, Hill D, Antoniou MG, He X, Loftin K, O'Shea K, Zhao C, Pelaez M, Han C, Lynch TJ, Dionysiou DD. A review on cylindrospermopsin: the global occurrence, detection, toxicity and degradation of a potent cyanotoxin. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2013; 15:1979-2003. [PMID: 24056894 DOI: 10.1039/c3em00353a] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Cylindrospermopsin is an important cyanobacterial toxin found in water bodies worldwide. The ever-increasing and global occurrence of massive and prolonged blooms of cylindrospermopsin-producing cyanobacteria poses a potential threat to both human and ecosystem health. Its toxicity is associated with metabolic activation and may involve mechanisms that adversely affect a wide variety of targets in an organism. Cylindrospermopsin has been shown to be cytotoxic, dermatotoxic, genotoxic, hepatotoxic in vivo, developmentally toxic, and may be carcinogenic. Human exposure may occur through drinking water, during recreational activities and by consuming foods in which the toxin may have bioaccumulated. Drinking water shortages of sufficient quality coupled with growing human pressures and climate variability and change necessitate an integrated and sustainable water management program. This review presents an overview of the importance of cylindrospermopsin, its detection, toxicity, worldwide distribution, and lastly, its chemical and biological degradation and removal by natural processes and drinking water treatment processes.
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Affiliation(s)
- Armah A de la Cruz
- Office of Research and Development, US Environmental Protection Agency, Cincinnati, Ohio, USA
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11
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Williams RM. Natural products synthesis: enabling tools to penetrate Nature's secrets of biogenesis and biomechanism. J Org Chem 2011; 76:4221-59. [PMID: 21438619 PMCID: PMC3174107 DOI: 10.1021/jo2003693] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Selected examples from our laboratory of how synthetic technology platforms developed for the total synthesis of several disparate families of natural products was harnessed to penetrate biomechanistic and/or biosynthetic queries is discussed. Unexpected discoveries of biomechanistic reactivity and/or penetrating the biogenesis of naturally occurring substances were made possible through access to substances available only through chemical synthesis. Hypothesis-driven total synthesis programs are emerging as very useful conceptual templates for penetrating and exploiting the inherent reactivity of biologically active natural substances. In many instances, new enabling synthetic technologies were required to be developed. The examples demonstrate the often untapped richness of complex molecule synthesis to provide powerful tools to understand, manipulate and exploit Nature's vast and creative palette of secondary metabolites.
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Affiliation(s)
- Robert M Williams
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.
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12
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Mazmouz R, Chapuis-Hugon F, Pichon V, Méjean A, Ploux O. The Last Step of the Biosynthesis of the Cyanotoxins Cylindrospermopsin and 7-epi-Cylindrospermopsin is Catalysed by CyrI, a 2-Oxoglutarate-Dependent Iron Oxygenase. Chembiochem 2011; 12:858-62. [DOI: 10.1002/cbic.201000726] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Indexed: 11/11/2022]
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13
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Evans DM, Murphy PJ. A biomimetic approach to the cylindrospermopsin alkaloids. Chem Commun (Camb) 2011; 47:3225-6. [DOI: 10.1039/c0cc05034b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Affiliation(s)
- Daniel M Evans
- School of Chemistry, Bangor University, Bangor, Gwynedd, UK
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15
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Plé K, Haudrechy A, Probst NP. Use of the Claisen/metathesis reaction sequence for the synthesis of enantiomerically pure 1-aminocycloalkene-1-carboxylic acids. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Kielland N, Catti F, Bello D, Isambert N, Soteras I, Luque F, Lavilla R. Boron-Based Dipolar Multicomponent Reactions: Simple Generation of Substituted Aziridines, Oxazolidines and Pyrrolidines. Chemistry 2010; 16:7904-15. [DOI: 10.1002/chem.201000349] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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18
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Stewart I, Carmichael WW, Sadler R, McGregor GB, Reardon K, Eaglesham GK, Wickramasinghe WA, Seawright AA, Shaw GR. Occupational and environmental hazard assessments for the isolation, purification and toxicity testing of cyanobacterial toxins. Environ Health 2009; 8:52. [PMID: 19925679 PMCID: PMC2785771 DOI: 10.1186/1476-069x-8-52] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 11/19/2009] [Indexed: 05/16/2023]
Abstract
Cyanobacteria can produce groups of structurally and functionally unrelated but highly potent toxins. Cyanotoxins are used in multiple research endeavours, either for direct investigation of their toxicologic properties, or as functional analogues for various biochemical and physiological processes. This paper presents occupational safety guidelines and recommendations for personnel working in field, laboratory or industrial settings to produce and use purified cyanotoxins and toxic cyanobacteria, from bulk harvesting of bloom material, mass culture of laboratory isolates, through routine extraction, isolation and purification. Oral, inhalational, dermal and parenteral routes are all potential occupational exposure pathways during the various stages of cyanotoxin production and application. Investigation of toxicologic or pharmacologic properties using in vivo models may present specific risks if radiolabelled cyanotoxins are employed, and the potential for occupational exposure via the dermal route is heightened with the use of organic solvents as vehicles. Inter- and intra-national transport of living cyanobacteria for research purposes risks establishing feral microalgal populations, so disinfection of culture equipment and destruction of cells by autoclaving, incineration and/or chlorination is recommended in order to prevent viable cyanobacteria from escaping research or production facilities.
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Affiliation(s)
- Ian Stewart
- Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia
- School of Public Health, Griffith University, Logan Campus, University Drive, Meadowbrook, Queensland 4131, Australia
| | - Wayne W Carmichael
- Department of Biological Sciences, Wright State University, 3640 Colonel Glen Highway, Dayton, Ohio 45435, USA
| | - Ross Sadler
- School of Public Health, Griffith University, Logan Campus, University Drive, Meadowbrook, Queensland 4131, Australia
| | - Glenn B McGregor
- Queensland Department of Environment and Resource Management, 120 Meiers Road, Indooroopilly, Queensland 4068, Australia
| | - Karen Reardon
- Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia
| | - Geoffrey K Eaglesham
- Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia
| | - Wasantha A Wickramasinghe
- The University of Queensland, National Research Centre for Environmental Toxicology, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia
| | - Alan A Seawright
- The University of Queensland, National Research Centre for Environmental Toxicology, 39 Kessels Road, Coopers Plains, Queensland 4108, Australia
| | - Glen R Shaw
- School of Public Health, Griffith University, Gold Coast Campus, Parklands Drive, Southport, Queensland 4222, Australia
- Australian Rivers Institute, Griffith University, Gold Coast Campus, Parklands Drive, Southport, Queensland 4222, Australia
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19
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Pal U, Ranatunga S, Ariyarathna Y, Del Valle JR. Total Synthesis of the Putative Structure of Lucentamycin A. Org Lett 2009; 11:5298-301. [DOI: 10.1021/ol902251c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ujjwal Pal
- Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Sujeewa Ranatunga
- Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Yamuna Ariyarathna
- Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
| | - Juan R. Del Valle
- Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, and Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003
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20
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21
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Miyabe H, Yoshida K, Reddy VK, Takemoto Y. Palladium- or Iridium-Catalyzed Allylic Substitution of Guanidines: Convenient and Direct Modification of Guanidines. J Org Chem 2008; 74:305-11. [DOI: 10.1021/jo802271d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hideto Miyabe
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, and School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Kazumasa Yoshida
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, and School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Valluru Krishna Reddy
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, and School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Yoshiji Takemoto
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, and School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
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22
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Merino P, Mannucci V, Tejero T. Exploring Nitrone Chemistry: Towards the Enantiodivergent Synthesis of 6-Substituted 4-Hydroxypipecolic Acid Derivatives. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800348] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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New values of molecular extinction coefficient and specific rotation for cyanobacterial toxin cylindrospermopsin. Toxicon 2008; 51:717-9. [DOI: 10.1016/j.toxicon.2007.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 11/15/2007] [Accepted: 11/15/2007] [Indexed: 10/22/2022]
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24
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Schade D, Töpker-Lehmann K, Kotthaus J, Clement B. Synthetic approaches to N(delta)-methylated L-arginine, N(omega)-hydroxy-L-arginine, L-citrulline, and N(delta)-cyano-L-ornithine. J Org Chem 2008; 73:1025-30. [PMID: 18179234 DOI: 10.1021/jo702150d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nomega-Methylated arginines such as asymmetric dimethyl-L-arginine (ADMA) and monomethyl-l-arginine (NMMA) are known as potent physiological inhibitors of nitric oxide synthases (NOSs). To explore a possible physiological and pharmaceutical relevance of N(delta)-methylated analogues, a synthetic scheme had to be developed that would not lead to N(delta)-methyl-L-arginine only but also to its presumed metabolites of NOS catalysis. Two basic synthetic approaches have been pursued to obtain N(delta)-methylated derivatives of L-ornithine, L-citrulline, L-arginine, and N(omega)-hydroxy-L-arginine. A first attempt utilized conventionally protected L-ornithine, i.e., the tert-butyl ester and Boc-amine, and led to three end compounds in excellent yields. Simultaneous protection of the alpha-amino acid moiety by formation of boroxazolidinones, particularly by employing 9-borabicyclo[3.3.1]nonane (9-BBN-H), proved to be a convenient option to perform side chain modifications and led to all of the desired end compounds. Additionally, enantiomeric excess (ee, %) of crucial synthetic intermediates and end compounds was determined by chiral HPLC.
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Affiliation(s)
- Dennis Schade
- Department of Pharmaceutical Chemistry, Pharmaceutical Institute, Christian-Albrechts-University of Kiel, Gutenbergstrasse 76-78, D-24118 Kiel, Germany
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25
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Berlinck RGS, Burtoloso ACB, Kossuga MH. The chemistry and biology of organic guanidine derivatives. Nat Prod Rep 2008; 25:919-54. [DOI: 10.1039/b507874c] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Shalev-Malul G, Lieman-Hurwitz J, Viner-Mozzini Y, Sukenik A, Gaathon A, Lebendiker M, Kaplan A. An AbrB-like protein might be involved in the regulation of cylindrospermopsin production by Aphanizomenon ovalisporum. Environ Microbiol 2007; 10:988-99. [PMID: 18093160 DOI: 10.1111/j.1462-2920.2007.01519.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Certain filamentous cyanobacteria, including Aphanizomenon ovalisporum, are potentially toxic owing to the formation of the hepatotoxin cylindrospermopsin. We previously identified a gene cluster in A. ovalisporum likely to be involved in cylindrospermopsin biosynthesis, including amidinotransferase (aoaA) and polyketide-synthase (aoaC), transcribed on the reverse strands. Analysis of the genomic region between aoaA and aoaC identified two transcription start points for each of these genes, differentially expressed under nitrogen and light stress conditions. The transcript abundances of these genes and the cylindrospermopsin level were both affected by nitrogen availability and light intensity. Gel shift assays and DNA affinity columns isolated a protein that specifically binds to a 150 bp DNA fragment from the region between aoaA and aoaC, and MS/MS analyses identified similarity to AbrB in other cyanobacteria and in Bacillus sp. Comparison of the native AbrB isolated from A. ovalisporum with that obtained after cloning and overexpression of abrB in Escherichia coli identified specific post-translational modifications in the native cyanobacterial protein. These modifications, which are missing in the protein expressed in E. coli, include N-acetylation and methylation of specific residues. We discuss the possible role of these modifications in the regulation of cylindrospermopsin production in Aphanizomenon.
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Affiliation(s)
- Gali Shalev-Malul
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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27
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28
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Neumann C, Bain P, Shaw G. Studies of the comparative in vitro toxicology of the cyanobacterial metabolite deoxycylindrospermopsin. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1679-86. [PMID: 17763086 DOI: 10.1080/15287390701434869] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Cyanobacteria are capable of producing metabolites that are in some cases toxic to humans and other animals. Of these metabolites, the toxin cylindrospermopsin (CYN) is produced by a number of species of cyanobacteria including Cylindrospermopsis raciborskii, and its toxicity has been documented. The CYN analog deoxycylindrospermopsin (deoxyCYN) is commonly produced in varying proportions by the cyanobacteria that produce CYN. The toxicological profile of CYN suggests that it is primarily a hepatotoxin, but with the capacity to damage other organs and tissues. Limited in vivo information is available on the toxicity of deoxyCYN and suggests it to be of low potency. The aim of this research was to determine the comparative toxicology of deoxyCYN using in vitro systems. Using cell viability assays, it was shown that deoxyCYN had inhibitory effects on cell viability and proliferation of a similar magnitude to that of CYN. Morphological changes in deoxyCYN-treated cells were similar to those of CYN. Investigation of protein synthesis inhibition demonstrated that deoxyCYN was of similar potency to CYN. Inhibition of protein synthesis is an acknowledged mechanism of toxicity for CYN, and the results produced here suggest that deoxyCYN operates by similar toxicological mechanisms to CYN and that in vivo animal testing should be undertaken to clarify the potential for risk to humans from this toxin.
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Affiliation(s)
- Carolin Neumann
- Department of Anatomy II, Friedrich Alexander University, Erlangen, Germany
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Kikuchi S, Kubo T, Kaya K. Cylindrospermopsin determination using 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) as the internal standard. Anal Chim Acta 2007; 583:124-7. [PMID: 17386536 DOI: 10.1016/j.aca.2006.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 09/27/2006] [Accepted: 10/02/2006] [Indexed: 10/24/2022]
Abstract
Cylindrospermopsin (CYN) was determined by liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS) using 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) as the internal standard. In the selected ion monitoring of LC/ESI-MS, m/z 414 for CYN and 237 for HEPES were monitored using the negative mode; the retention times of CYN and HEPES were 12.41 and 14.21 min, respectively. CYN was determined from peak area ratios of m/z 414/237. By the treatment of an anion exchange cartridge using a buffer at pH 10.5, CYN was isolated and condensed. No interfering peak was observed. Linearity of this method was observed at the range of 0.10-31.12 ng. Total coefficients of variation were 5.1 and 2.9% at 104 and 1038 microg CYN L(-1). The quantitative limit at a signal-to-noise (S/N) ratio of 10 was 0.16 ng. CYN concentration in natural waters is low. CYN in waters should be condensed for determination. This method including the treatment for isolation and condensation of CYN is useful for determination of CYN in environmental and/or drinking waters.
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Affiliation(s)
- Sachiko Kikuchi
- Graduate School of Environmental Studies, Tohoku University, 6-6-20, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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