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Li T, Xi C, Yu Y, Wang N, Wang X, Iwasaki A, Fang F, Ding L, Li S, Zhang W, Yuan Y, Wang T, Yan X, He S, Cao Z, Naman CB. Targeted Discovery of Amantamide B, an Ion Channel Modulating Nonapeptide from a South China Sea Oscillatoria Cyanobacterium. J Nat Prod 2022; 85:493-500. [PMID: 34986303 DOI: 10.1021/acs.jnatprod.1c00983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amantamide B (1) is a new linear nonapeptide analogue of the cyanobacterial natural product amantamide A (2), and both have methyl ester and butanamide termini. These compounds were discovered in this study from the organic extract of a tropical marine filamentous cyanobacterium, Oscillatoria sp., collected around the Paracel Islands in the South China Sea. The use of LC-MS/MS molecular networking for sample prioritization and as an analytical dereplication tool facilitated the targeted isolation of 1 and 2. These molecules were characterized by spectroscopy and spectrometry, and configurational assignments were determined using chemical degradation and chiral-phase HPLC analysis. Compounds 1 and 2 modulated spontaneous calcium oscillations without notable cytotoxicity at 10 μM in short duration in vitro testing on primary cultured neocortical neurons, a model system that evaluates neuronal excitability and/or the potential activity on Ca2+ signaling. Both molecules were also found to be moderately cytotoxic in longer duration bioassays, with in vitro IC50 values of 1-10 μM against CCRF-CEM human T lymphoblastoid cells and U937 human histiocytic lymphoma cells. These formerly undiscovered bioactivities of known compound 2 expand upon its previously reported function as a selective CXCR7 agonist among 168 GPCR targets.
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Affiliation(s)
- Te Li
- School of Marine Science, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Chuchu Xi
- State Key Laboratory of Natural Medicines & Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, People's Republic of China
| | - Yiyi Yu
- State Key Laboratory of Natural Medicines & Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, People's Republic of China
| | - Ning Wang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Xiao Wang
- Department of Pathology and Pathogen Biology, College of Medicine, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Arihiro Iwasaki
- Department of Chemistry, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Fang Fang
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Lijian Ding
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Shuang Li
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Weiyan Zhang
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Ye Yuan
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Tingting Wang
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Xiaojun Yan
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Shan He
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines & Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, People's Republic of China
| | - C Benjamin Naman
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315800, People's Republic of China
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Abstract
7-Deoxy-desulfo-cylindrospermopsin was purified at small-scale from the supernatant of a culture of the cyanobacterium Oscillatoria sp. PCC 10702. This metabolite was obtained in a pure form using a three-step chromatographic procedure, and its identity was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). LC-MS quantification showed that this metabolite was excreted in the culture medium of Oscillatoria sp. PCC 10702. Isotopic incorporation studies using [2-13C,15N]glycine, a cylindrospermopsin precursor, and Oscillatoria sp. PCC 10702 cells showed that glycine was incorporated into 7-deoxy-desulfo-cylindrospermopsin, 7-deoxy-cylindrospermopsin, 7-epi-cylindrospermopsin, and cylindrospermopsin. The isotopic incorporation rate was consistent with the following metabolic flux: 7-deoxy-desulfo-cylindrospermopsin → 7-deoxy-cylindrospermopsin → 7-epi-cylindrospermopsin and cylindrospermopsin. We have cloned the cyrJ gene into an expression vector and overproduced the putative sulfotransferase CyrJ in Escherichia coli. The purified protein CyrJ catalyzed, in vitro, the transfer of a sulfonate group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to 7-deoxy-desulfo-cylindrospermopsin to give 7-deoxy-cylindrospermopsin. Kinetic analysis afforded the following apparent constants: KM app. (PAPS) = 0.12 μM, Vmax app. = 20 nM/min, KM app. (7-deoxy-desulfo-cylindrospermopsin) = 0.12 μM, and KI app. (7-deoxy-desulfo-cylindrospermopsin) = 4.1 μM. Preliminary data suggested that CyrJ catalyzed the reaction through a ternary-complex kinetic mechanism. All these data confirmed that CyrJ catalyzed a sulfotransfer during the penultimate step of the biosynthesis of cylindrospermopsin.
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Affiliation(s)
- Annick Méjean
- LIED, UMR 8236 CNRS, Université de Paris, 75205 Paris, Cedex 13, France
| | - Olivier Ploux
- LIED, UMR 8236 CNRS, Université de Paris, 75205 Paris, Cedex 13, France
- Chimie ParisTech, PSL, 75005 Paris, France
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Kust A, Méjean A, Ploux O. Biosynthesis of Anatoxins in Cyanobacteria: Identification of the Carboxy-anatoxins as the Penultimate Biosynthetic Intermediates. J Nat Prod 2020; 83:142-151. [PMID: 31899634 DOI: 10.1021/acs.jnatprod.9b01121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Anatoxin-a, homoanatoxin-a, and dihydroanatoxin-a are potent cyanobacterial neurotoxins. They are biosynthesized in cyanobacteria from proline and acetate by a pathway involving three polyketide synthases. We report the identification of carboxy-anatoxin-a, carboxy-homoanatoxin-a, and carboxy-dihydroanatoxin-a in acidic extracts of Cuspidothrix issatschenkoi CHARLIE-1, Oscillatoria sp. PCC 6506, and Cylindrospermum stagnale PCC 7417, respectively, using liquid chromatography coupled to mass spectrometry. The structure of these carboxy derivatives was confirmed by mass spectrometry and by isotopic incorporation experiments using labeled proline and acetate. Each of these three cyanobacteria only produce one carboxy-anatoxin, suggesting that these metabolites are the product of the hydrolysis by AnaA, the type II thioesterase, of the thioesters bound to AnaG, the last polyketide synthase of the pathway. By measuring the rate of isotopic incorporation of labeled proline into carboxy-homoanatoxin-a and homoanatoxin-a produced by Oscillatoria sp. PCC 6506, we show that carboxy-homoanatoxin-a is the intracellular precursor of homoanatoxin-a, and that homoanatoxin-a is then excreted into the extracellular medium. The transformation of carboxy-homoanatoxin-a into homoanatoxin-a is a very slow two-step process, with accumulation of carboxy-homoanatoxin-a, suggesting that the decarboxylation is spontaneous and not enzymatically catalyzed. However, an unidentified and extracellular catalyst accelerates the decarboxylation when the cell extracts are prepared at neutral pH.
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Affiliation(s)
- Andreja Kust
- LIED, UMR 8236 CNRS , Université Paris Diderot , 75205 Paris Cedex 13, France
- The Czech Academy of Sciences, Biology Centre , Institute of Hydrobiology , 370 05 České Budějovice , Czech Republic
- Institute of Microbiology CAS, Center Algatech , 37981 Třeboň , Czech Republic
| | - Annick Méjean
- LIED, UMR 8236 CNRS , Université Paris Diderot , 75205 Paris Cedex 13, France
| | - Olivier Ploux
- LIED, UMR 8236 CNRS , Université Paris Diderot , 75205 Paris Cedex 13, France
- Chimie ParisTech, PSL , 75005 Paris , France
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Ding CYG, Pang LM, Liang ZX, Goh KKK, Glukhov E, Gerwick WH, Tan LT. MS/MS-Based Molecular Networking Approach for the Detection of Aplysiatoxin-Related Compounds in Environmental Marine Cyanobacteria. Mar Drugs 2018; 16:md16120505. [PMID: 30551660 PMCID: PMC6315786 DOI: 10.3390/md16120505] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/05/2018] [Accepted: 12/10/2018] [Indexed: 12/20/2022] Open
Abstract
Certain strains of cyanobacteria produce a wide array of cyanotoxins, such as microcystins, lyngbyatoxins and aplysiatoxins, that are associated with public health issues. In this pilot study, an approach combining LC-MS/MS and molecular networking was employed as a rapid analytical method to detect aplysiatoxins present in four environmental marine cyanobacterial samples collected from intertidal areas in Singapore. Based on 16S-ITS rRNA gene sequences, these filamentous cyanobacterial samples collected from Pulau Hantu were determined as Trichodesmium erythraeum, Oscillatoria sp. PAB-2 and Okeania sp. PNG05-4. Organic extracts were prepared and analyzed on LC-HRMS/MS and Global Natural Product Social Molecular Networking (GNPS) for the presence of aplysiatoxin-related molecules. From the molecular networking, six known compounds, debromoaplysiatoxin (1), anhydrodebromoaplysiatoxin (2), 3-methoxydebromoaplysiatoxin (3), aplysiatoxin (4), oscillatoxin A (5) and 31-noroscillatoxin B (6), as well as potential new analogues, were detected in these samples. In addition, differences and similarities in molecular networking clusters related to the aplysiatoxin molecular family were observed in extracts of Trichodesmium erythraeum collected from two different locations and from different cyanobacterial species found at Pulau Hantu, respectively.
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Affiliation(s)
- Chi Ying Gary Ding
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore 637616, Singapore.
| | - Li Mei Pang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
| | - Zhao-Xun Liang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
| | - Kau Kiat Kelvin Goh
- Singapore Phenome Centre, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, (K.K.K.G.).
| | - Evgenia Glukhov
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA.
| | - William H Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA.
| | - Lik Tong Tan
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore 637616, Singapore.
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Bouma-Gregson K, Kudela RM, Power ME. Widespread anatoxin-a detection in benthic cyanobacterial mats throughout a river network. PLoS One 2018; 13:e0197669. [PMID: 29775481 PMCID: PMC5959195 DOI: 10.1371/journal.pone.0197669] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [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: 01/04/2018] [Accepted: 05/07/2018] [Indexed: 11/20/2022] Open
Abstract
Benthic algae fuel summer food webs in many sunlit rivers, and are hotspots for primary and secondary production and biogeochemical cycling. Concerningly, riverine benthic algal assemblages can become dominated by toxic cyanobacteria, threatening water quality and public health. In the Eel River in Northern California, over a dozen dog deaths have been attributed to cyanotoxin poisonings since 2000. During the summers of 2013–2015, we documented spatial and temporal patterns of cyanotoxin concentrations in the watershed, showing widespread distribution of anatoxin-a in benthic cyanobacterial mats. Solid phase adsorption toxin tracking (SPATT) samplers were deployed weekly to record dissolved microcystin and anatoxin-a levels at 10 sites throughout the watershed, and 187 Anabaena-dominated or Phormidium-dominated cyanobacterial mat samples were collected from 27 locations to measure intracellular anatoxin-a (ATX) and microcystins (MCY). Anatoxin-a levels were higher than microcystin for both SPATT (mean MCY = 0.8 and ATX = 4.8 ng g resin-1 day-1) and cyanobacterial mat samples (mean MCY = 0.074 and ATX = 1.89 μg g-1 DW). Of the benthic mats sampled, 58.9% had detectable anatoxin-a (max = 70.93 μg g-1 DW), while 37.6% had detectable microcystins (max = 2.29 μg g-1 DW). SPATT cyanotoxin levels peaked in mid-summer in warm mainstem reaches of the watershed. This is one of the first documentations of widespread anatoxin-a occurrence in benthic cyanobacterial mats in a North American watershed.
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Affiliation(s)
- Keith Bouma-Gregson
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Raphael M. Kudela
- Ocean Sciences Department, University of California, Santa Cruz, California, United States of America
| | - Mary E. Power
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
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Cai F, Yu G, Zhang K, Chen Y, Li Q, Yang Y, Xie J, Wang Y, Li R. Geosmin production and polyphasic characterization of Oscillatoria limosa Agardh ex Gomont isolated from the open canal of a large drinking water system in Tianjin City, China. Harmful Algae 2017; 69:28-37. [PMID: 29122240 DOI: 10.1016/j.hal.2017.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 03/21/2017] [Revised: 09/25/2017] [Accepted: 09/30/2017] [Indexed: 06/07/2023]
Abstract
Taste and odor (T & O) episodes always cause strong effects on drinking water supply system. Luanhe River diversion into Tianjin City in China is an important drinking water resource. Massive growth of a benthic filamentous cyanobacterium with geosmin production in the open canal caused a strong earthy odor episode in Tianjin. On the basis of the morphological and molecular identification of this cyanobacterium as Oscillatoria limosa Agardh ex Gomont, the genetic basis for geosmin biosynthesis and factors influencing growth and geosmin production of O. limosa CHAB 7000 were studied in this work. A 2268-bp open reading frame, encoding 755 amino acids, was amplified and characterized as the geosmin synthase gene (geo), followed by a cyclic nucleotide-binding protein gene (cnb). Phylogenetic analysis implied that the evolution of the geosmin genes in O. limosa CHAB 7000 might involve a horizontal gene transfer event. Examination on the growth and geosmin production of O. limosa CHAB 7000 at different light intensities showed that the maximum geosmin production was observed at 10μmol photons m-2s-1, while the optimum growth was at 60μmol photons m-2s-1. Under three temperature conditions (15°C, 25°C, and 35°C), the maximum growth and geosmin production were observed at 25°C. Most amounts of geosmin were retained in cells during the growth phase, but high temperature and low light intensity increased the release of geosmin into the medium, implying that O. limosa CHAB 7000 had a high potential harm for the release of geosmin from its cells at these adverse conditions.
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Affiliation(s)
- Fangfang Cai
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Gongliang Yu
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Kai Zhang
- Tianjin Hydraulic Research Institute, Tianjin 300061, People's Republic of China
| | - Youxin Chen
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Qiang Li
- Tianjin Hydraulic Research Institute, Tianjin 300061, People's Republic of China
| | - Yiming Yang
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jinlin Xie
- College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Yilang Wang
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Renhui Li
- Key Laboratory of Algal Biology, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
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Méjean A, Dalle K, Paci G, Bouchonnet S, Mann S, Pichon V, Ploux O. Dihydroanatoxin-a Is Biosynthesized from Proline in Cylindrospermum stagnale PCC 7417: Isotopic Incorporation Experiments and Mass Spectrometry Analysis. J Nat Prod 2016; 79:1775-1782. [PMID: 27340731 DOI: 10.1021/acs.jnatprod.6b00189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
LC-MS and GC-MS analytical conditions have been developed to detect the cis- and trans-epimers (relative configuration of the carbon bearing the acetyl or propionyl group) of dihydroanatoxin-a and dihydrohomoanatoxin-a, in biological samples. These compounds epimerize under acidic conditions, yielding a major species that was tentatively assigned as the cis-epimer. Cylindrospermum stagnale PCC 7417 was definitively shown to produce dihydroanatoxin-a (1.2 mg/g dried cells). Oscillatoria sp. PCC 9107, Oscillatoria sp. PCC 6506, and C. stagnale PCC 7417, which produce anatoxin-a, homoanatoxin-a, and dihydroanatoxin-a, respectively, were cultivated in the presence of isotopically labeled proline, and the toxins were extracted. Interpretation of the GC-MS electron ionization mass spectra of these labeled anatoxins showed that they are all biosynthesized from proline and that the positions of the labels in these molecules are identical. These data and the fact that the ana cluster of genes is conserved in these cyanobacteria suggest that dihydroanatoxin-a is formed by the reduction of either anatoxin-a or its precursor in a specific step involving AnaK, an F420-dependent oxido-reductase whose gene is found in the ana gene cluster in C. stagnale PCC 7417. This is the first report of a cyanobacterium producing dihydroanatoxin-a, suggesting that other producers are present in the environment.
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Affiliation(s)
- Annick Méjean
- LIED, UMR 8236 CNRS, Université Paris Diderot , 75205 Paris Cedex 13, France
| | - Klervi Dalle
- LIED, UMR 8236 CNRS, Université Paris Diderot , 75205 Paris Cedex 13, France
| | - Guillaume Paci
- LIED, UMR 8236 CNRS, Université Paris Diderot , 75205 Paris Cedex 13, France
| | | | - Stéphane Mann
- MCAM, UMR 7245, Sorbonne Université, Muséum National d'Histoire Naturelle, CNRS , 75005 Paris, France
| | - Valérie Pichon
- LSABM CBI, UMR 8231 ESPCI ParisTech, CNRS, PSL Research University , 75005 Paris, France
| | - Olivier Ploux
- LIED, UMR 8236 CNRS, Université Paris Diderot , 75205 Paris Cedex 13, France
- Chimie ParisTech, ENSCP , 75005 Paris, France
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Carneiro MG, Koharudin LMI, Griesinger C, Gronenborn AM, Lee D. (1)H, (13)C and (15)N resonance assignment of the anti-HIV lectin from Oscillatoria agardhii. Biomol NMR Assign 2015; 9:317-319. [PMID: 25680849 PMCID: PMC4537409 DOI: 10.1007/s12104-015-9600-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/09/2015] [Indexed: 06/04/2023]
Abstract
Lectins from different sources are known to interfere with HIV infection. The anti-viral activity is mediated by binding to high mannose sugars present on the viral envelope, thereby inhibiting cell entry. The lectin from Oscillatoria agardhii agglutinin (OAA) specifically recognizes a unique substructure of high mannose sugars and exhibits broad anti-HIV activity. Here we report the assignment of backbone and side-chain (1)H, (13)C and (15)N resonances of free OAA.
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Affiliation(s)
- Marta G Carneiro
- Department for NMR-based Structural Biology, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Leonardus M I Koharudin
- Department of Structural Biology, University of Pittsburgh School of Medicine, 1050 Biomedical Science Tower 3, 3501 5th Ave, Pittsburgh, PA, 15260, USA
| | - Christian Griesinger
- Department for NMR-based Structural Biology, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Angela M Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, 1050 Biomedical Science Tower 3, 3501 5th Ave, Pittsburgh, PA, 15260, USA
| | - Donghan Lee
- Department for NMR-based Structural Biology, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
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Vehovszky Á, Kovács AW, Farkas A, Győri J, Szabó H, Vasas G. Pharmacological studies confirm neurotoxic metabolite(s) produced by the bloom-forming Cylindrospermopsis raciborskii in Hungary. Environ Toxicol 2015; 30:501-512. [PMID: 24293352 DOI: 10.1002/tox.21927] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [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: 08/19/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 06/02/2023]
Abstract
A rapid cyanobacterial bloom of Cylindrospermopsis raciborskii (3.2 × 10(4) filaments/mL) was detected early November, 2012, in the Fancsika pond (East Hungary). The strong discoloration of water was accompanied by a substantial fish mortality (even dead cats were seen on the site), raising the possibility of some toxic metabolites in the water produced by the bloom-forming cyanobacteria (C. raciborskii). The potential neuronal targets of the toxic substances in the bloom sample were studied on identified neurons (RPas) in the central nervous system of Helix pomatia. The effects of the crude aqueous extracts of the Fancsika bloom sample (FBS) and the laboratory isolate of C. raciborskii from the pond (FLI) were compared with reference samples: C. raciborskii ACT 9505 (isolated in 1995 from Lake Balaton, Hungary), the cylindrospermopsin producer AQS, and the neurotoxin (anatoxin-a, homoanatoxin-a) producer Oscillatoria sp. (PCC 6506) strains. Electrophysiological tests showed that both FBS and FLI samples as well the ACT 9505 extracts modulate the acetylcholine receptors (AChRs) of the neurons, evoking ACh agonist effects, then inhibiting the ACh-evoked neuronal responses. Dose-response data suggested about the same range of toxicity of FBS and FLI samples (EC50 = 0.397 mg/mL and 0.917 mg/mL, respectively) and ACT 9505 extracts (EC50 = 0.734 mg/mL). The extract of the neurotoxin-producing PCC 6506 strain, however, proved to be the strongest inhibitor of the ACh responses on the same neurons (EC50 = 0.073 mg/mL). The presented results demonstrated an anatoxin-a-like cholinergic inhibitory effects of cyanobacterial extracts (both the environmental FBS sample, and the laboratory isolate, FLI) by some (yet unidentified) toxic components in the matrix of secondary metabolites. Previous pharmacological studies of cyanobacterial samples collected in other locations (Balaton, West Hungary) resulted in similar conclusions; therefore, we cannot exclude that this chemotype of C. raciborskii which produce anatoxin-a like neuroactive substances is more widely distributed in this region.
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Affiliation(s)
- Á Vehovszky
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237, Tihany, POB 35, Hungary
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Ban D, Mazur A, Carneiro MG, Sabo TM, Giller K, Koharudin LMI, Becker S, Gronenborn AM, Griesinger C, Lee D. Enhanced accuracy of kinetic information from CT-CPMG experiments by transverse rotating-frame spectroscopy. J Biomol NMR 2013; 57:73-82. [PMID: 23949308 DOI: 10.1007/s10858-013-9769-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/05/2013] [Indexed: 06/02/2023]
Abstract
Micro-to-millisecond motions of proteins transmit pivotal signals for protein function. A powerful technique for the measurement of these motions is nuclear magnetic resonance spectroscopy. One of the most widely used methodologies for this purpose is the constant-time Carr-Purcell-Meiboom-Gill (CT-CPMG) relaxation dispersion experiment where kinetic and structural information can be obtained at atomic resolution. Extraction of accurate kinetics determined from CT-CPMG data requires refocusing frequencies that are much larger than the nuclei's exchange rate between states. We investigated the effect when fast processes are probed by CT-CPMG experiments via simulation and show that if the intrinsic relaxation rate (R(CT-CPMG)(2,0)) is not known a priori the extraction of accurate kinetics is hindered. Errors on the order of 50 % in the exchange rate are attained when processes become fast, but are minimized to 5 % with a priori (CT-CPMG)(2,0)) information. To alleviate this shortcoming, we developed an experimental scheme probing (CT-CPMG)(2,0)) with large amplitude spin-lock fields, which specifically contains the intrinsic proton longitudinal Eigenrelaxation rate. Our approach was validated with ubiquitin and the Oscillatoria agardhii agglutinin (OAA). For OAA, an underestimation of 66 % in the kinetic rates was observed if (CT-CPMG)(2,0)) is not included during the analysis of CT-CPMG data and result in incorrect kinetics and imprecise amplitude information. This was overcome by combining CT-CPMG with (CT-CPMG)(2,0)) measured with a high power R1ρ experiment. In addition, the measurement of (CT-CPMG)(2,0)) removes the ambiguities in choosing between different models that describe CT-CPMG data.
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Affiliation(s)
- David Ban
- Department for NMR-Based Structural Biology, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
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11
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Gerasimenko LM, Orleanskiĭ VK, Zaĭtseva LV. [Accumulation and precipitation of Mn2+ by the cells of Oscillatoria terebriformis]. Mikrobiologiia 2013; 82:605-613. [PMID: 25509399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The cyanobacterium Oscillatoria terebriformis was shown to exhibit resistance to high manganese concentrations, remaining viable at 2.5 mM MnCl2 in the medium. Cyanobacterial cells were capable of considerable manganese consumption from the medium. Dynamics of Mn sorption by the cells was the same in all experimental variants, independent on the manganese concentration. Manganese concentration in the biomass peaked after 2-3 days and depended on Mn2+ concentration in the medium and on the amount of biomass introduced. In the case of O. terebriformis, manganese removed from the medium may be subdivided into Mn absorbed by the cell, Mn bound to the cell wall, Mn absorbed by the glycocalix, and chemically precipitated Mn. Of the total 21.25 ± 1.0 mg of consumed manganese, biological absorption and chemical precipitation were responsible for 11.78 ± 0.98 and 9.2 ± 0.8 mg, respectively. In the presence of cyanobacteria, Mn removal from the medium was 2.28 times higher than in the control. This process depended considerably on Mn sorption by exopolysaccharides. At 1.3 mM Mn2+, a lamellar mat was formed with interlayers of manganese carbonate.
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Engene N, Choi H, Esquenazi E, Byrum T, Villa FA, Cao Z, Murray TF, Dorrestein PC, Gerwick L, Gerwick WH. Phylogeny-guided isolation of ethyl tumonoate A from the marine cyanobacterium cf. Oscillatoria margaritifera. J Nat Prod 2011; 74:1737-1743. [PMID: 21751786 PMCID: PMC3163041 DOI: 10.1021/np200236c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The evolutionary relationships of cyanobacteria, as inferred by their SSU (16S) rRNA genes, were used as predictors of their potential to produce varied secondary metabolites. The evolutionary relatedness in geographically distant cyanobacterial specimens was then used as a guide for the detection and isolation of new variations of predicted molecules. This phylogeny-guided isolation approach for new secondary metabolites was tested in its capacity to direct the search for specific classes of new natural products from Curaçao marine cyanobacteria. As a result, we discovered ethyl tumonoate A (1), a new tumonoic acid derivative with anti-inflammatory activity and inhibitory activity of calcium oscillations in neocortical neurons.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - William H. Gerwick
- To whom correspondence should be addressed. Tel: (858) 534-0578. Fax: (858) 534-0529.
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13
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Mevers E, Liu WT, Engene N, Mohimani H, Byrum T, Pevzner PA, Dorrestein PC, Spadafora C, Gerwick WH. Cytotoxic veraguamides, alkynyl bromide-containing cyclic depsipeptides from the marine cyanobacterium cf. Oscillatoria margaritifera. J Nat Prod 2011; 74:928-36. [PMID: 21488639 PMCID: PMC3103610 DOI: 10.1021/np200077f] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A family of cancer cell cytotoxic cyclodepsipeptides, veraguamides A-C (1-3) and H-L (4-8), were isolated from a collection of cf. Oscillatoria margaritifera obtained from the Coiba National Park, Panama, as part of the Panama International Cooperative Biodiversity Group program. The planar structure of veraguamide A (1) was deduced by 2D NMR spectroscopy and mass spectrometry, whereas the structures of 2-8 were mainly determined by a combination of 1H NMR and MS2/MS3 techniques. These new compounds are analogous to the mollusk-derived kulomo'opunalide natural products, with two of the veraguamides (C and H) containing the same terminal alkyne moiety. However, four veraguamides, A, B, K, and L, also feature an alkynyl bromide, a functionality that has been previously observed in only one other marine natural product, jamaicamide A. Veraguamide A showed potent cytotoxicity to the H-460 human lung cancer cell line (LD50=141 nM).
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Affiliation(s)
- Emily Mevers
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography University of California San Diego, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Wei-Ting Liu
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Niclas Engene
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography University of California San Diego, La Jolla, California 92093, United States
| | - Hosein Mohimani
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California 92093, United States
| | - Tara Byrum
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography University of California San Diego, La Jolla, California 92093, United States
| | - Pavel A. Pevzner
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California 92093, United States
| | - Pieter C. Dorrestein
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - Carmenza Spadafora
- Instituto de Investigaciones Científicas Avanzados y Sevicios de Alta Tecnología, Center of Celluar and Molecular Biology of Diseases, Clayton, Bldg. 219 P.O. Box 7250, Panama 5, Republic of Panama
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography University of California San Diego, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093, United States
- To whom correspondence should be addressed. Tel: (858) 534-0578. Fax: (858) 534-0529.
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Koharudin LMI, Furey W, Gronenborn AM. Novel fold and carbohydrate specificity of the potent anti-HIV cyanobacterial lectin from Oscillatoria agardhii. J Biol Chem 2011; 286:1588-97. [PMID: 20961847 PMCID: PMC3020767 DOI: 10.1074/jbc.m110.173278] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [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: 08/06/2010] [Revised: 09/23/2010] [Indexed: 11/06/2022] Open
Abstract
Oscillatoria agardhii agglutinin (OAA) is a recently discovered cyanobacterial lectin that exhibits potent anti-HIV activity. Up to now, only its primary structure and carbohydrate binding data have been available. To elucidate the structural basis for the antiviral mechanism of OAA, we determined the structure of this lectin by x-ray crystallography at 1.2 Å resolution and mapped the specific carbohydrate recognition sites of OAA by NMR spectroscopy. The overall architecture of OAA comprises 10 β-strands that fold into a single, compact, β-barrel-like domain, creating a unique topology compared with all known protein structures in the Protein Data Bank. OAA sugar binding was tested against Man-9 and various disaccharide components of Man-9. Two symmetric carbohydrate-binding sites were located on the protein, and a preference for Manα(1-6)Man-linked sugars was found. Altogether, our structural results explain the antiviral activity OAA and add to the growing body of knowledge about antiviral lectins.
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Affiliation(s)
| | - William Furey
- Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260 and
- the Biocrystallography Laboratory, Veterans Affairs Medical Center, Pittsburgh, Pennsylvania 15240
| | - Angela M. Gronenborn
- From the Departments of Structural Biology and
- Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260 and
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15
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Hussain A, Krischke M, Roitsch T, Hasnain S. Rapid determination of cytokinins and auxin in cyanobacteria. Curr Microbiol 2010; 61:361-9. [PMID: 20339849 DOI: 10.1007/s00284-010-9620-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 03/10/2010] [Indexed: 11/27/2022]
Abstract
Five cyanobacterial strains, Anabaena sp. Ck1, Oscillatoria sp. Ck2, Phormidium sp. Ck3, Chroococcidiopsis sp. Ck4, and Synechosystis sp. Ck5 were selected for their positive cytokinins-like activity using cucumber cotyledon bioassay and GUS assay in Arabidopsis ARR5::GUS. Classical cucumber cotyledon bioassay was modified for direct screening of cyanobacteria avoiding need for extraction and purification. Cytokinins from cyanobacteria were absorbed onto filter paper which was then assayed for cytokinins-like activity. A rapid chromatographic method was developed for the simultaneous determination of cytokinins and indole-3-acetic acid (IAA). Cyanobacterial biomass (50-100 mg) and cell-free culture filtrate were extracted in Bieleski buffer and purified by solid-phase extraction. The extract was used to determine phytohormones by ultra performance liquid chromatography and electrospray ionization-tandem mass spectrometry in positive and negative modes, respectively, with multiple reactions monitoring. Stable isotope-labeled cytokinins and IAA standards were added in the samples to follow recovery of the compounds and method validation. Five cytokinins determined in the selected strains were Zeatin (cis and trans isomers), Zeatin riboside, Dihydrozeatin riboside, and zeatin-o-glucoside. The strains were shown to accumulate as well as release the phytohormones.
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Affiliation(s)
- Anwar Hussain
- Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
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Ferranti P, Fabbrocino S, Nasi A, Caira S, Bruno M, Serpe L, Gallo P. Liquid chromatography coupled to quadruple time-of-flight tandem mass spectrometry for microcystin analysis in freshwaters: method performances and characterisation of a novel variant of microcystin-RR. Rapid Commun Mass Spectrom 2009; 23:1328-1336. [PMID: 19337977 DOI: 10.1002/rcm.4006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cyanobacteria, also called blue-green algae, occur worldwide within water blooms in eutrophic lakes and drinking water reservoirs, producing several biotoxins (cyanotoxins). Among these, microcystins (MCs) are a group of cyclic heptapeptides showing potent hepatotoxicity and activity as tumour promoters. So far, at least 89 MCs from different cyanobacteria genera have been characterised. Herein, ion trap, matrix-assisted laser desorption/ionisation time-of-flight (MALDI-ToF) and quadruple time-of-flight (Q-ToF) mass spectrometry (MS)-based methods were tested and compared for analysing MCs in freshwaters. Method performances in terms of limit of detection, limit of quantification, mean recoveries, repeatability, and specificity were evaluated. In particular, a liquid chromatography/electrospray ionisation (LC/ESI)-Q-ToF-MS/MS method was firstly described to analyse MCs in freshwaters; this technique is highly selective and sensitive, and allowed us to characterise the molecular structure of an unknown compound. Indeed, the full structural characterisation of a novel microcystin variant from a bloom of Planktothrix rubescens in the Lake Averno, near Naples, was attained by the study of the fragmentation pattern. The new cyanotoxin was identified as the 9-acetyl-Adda variant of microcystin-RR.
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El Herry S, Fathalli A, Rejeb AJB, Bouaïcha N. Seasonal occurrence and toxicity of Microcystis spp. and Oscillatoria tenuis in the Lebna Dam, Tunisia. Water Res 2008; 42:1263-1273. [PMID: 17936328 DOI: 10.1016/j.watres.2007.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 08/17/2007] [Accepted: 09/20/2007] [Indexed: 05/25/2023]
Abstract
Physicochemical and biological water quality, including the total microcystin concentrations, was investigated for the first time from January to December 2005 in the Lebna Dam, Tunisia. Microcystin levels and characterization of the different microcystin variants present were measured by protein phosphatase (PP2A) inhibition assays and by LC/MS/MS, respectively. Nutrient values were high, with total inorganic nitrogen and phosphorus concentrations ranging from 0.05 to 8.4 mg L(-1) and from 0.03 to 1.37 mg L(-1), respectively. However, the chlorophyll-a concentrations were very low with a peak (5.32 microg L(-1)) on 20 September 2005 at 9 m depth water samples. Microscopic examination of the phytoplankton samples showed the dominance in the autumn of three morphospecies of the genus Microcystis and the species Oscillatoria tenuis. The total (particulate and dissolved) microcystin concentrations at the surface and at 9 m depth water samples ranged between 0.008 and 1.73, and 0.005 and 5.57 microg microcystin (MC)-LR equivalent L(-1), respectively, with a peak on 20 September. The presence of the microcystin synthetase genes (mcyA, -B, and -C) in the lysates of the three morphospecies of the genus Microcystis and the species O. tenuis indicated that these species were responsible for the microcystin production in this system. The analysis of the field cyanobacterial sample extract containing these species by LC/MS/MS revealed the presence of two microcystin variants: microcystin-LR (MC-LR) and microcystin-YR (MC-YR).
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Affiliation(s)
- Soumaya El Herry
- Laboratoire Santé Publique-Environnement, 5, Rue J.B. Clément, Université Paris-Sud 11, UFR de Pharmacie, 92296 Châtenay-Malabry, France
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