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Bâlici Ș, Rusu D, Páll E, Filip M, Chirilă F, Nicula GZ, Vică ML, Ungur R, Matei HV, Fiț NI. In Vitro Antibacterial Susceptibility of Different Pathogens to Thirty Nano-Polyoxometalates. Pharmaceuticals (Basel) 2021; 15:ph15010033. [PMID: 35056090 PMCID: PMC8777622 DOI: 10.3390/ph15010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 11/16/2022] Open
Abstract
Due to their unique properties, nano-polyoxometalates (POMs) can be alternative chemotherapeutic agents instrumental in designing new antibiotics. In this research, we synthesized and characterized “smart” nanocompounds and validated their antibacterial effects in order to formulate and implement potential new drugs. We characterized thirty POMs in terms of antibacterial activity–structure relationship. The antibacterial effects of these compounds are directly dependent upon their structure and the type of bacterial strain tested. We identified three POMs that presented sound antibacterial activity against S. aureus, B. cereus, E. coli, S. enteritidis and P. aeruginosa strains. A newly synthesized compound K6[(VO)SiMo2W9O39]·11H2O (POM 7) presented antibacterial activity only against S. aureus (ATCC 6538P). Twelve POMs exerted antibacterial effects against both Gram-positive and Gram-negative strains. Only one POM (a cluster derivatized with organometallic fragments) exhibited a stronger effect compared to amoxicillin. New studies in terms of selectivity and specificity are required to clarify these extremely important aspects needed to be considered in drug design.
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Affiliation(s)
- Ștefana Bâlici
- Department of Cell and Molecular Biology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania; (Ș.B.); (G.Z.N.); (H.V.M.)
| | - Dan Rusu
- Department of Physical-Chemistry, Faculty of Pharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania;
| | - Emőke Páll
- Department of Reproduction, Obstetrics and Veterinary Gynecology, Faculty of Veterinary Medicine, University of Agricultural Science and Veterinary Medicine, 400372 Cluj-Napoca, Romania;
| | - Miuța Filip
- Analytical and Environmental Chemistry Laboratory, “Raluca Ripan” Institute for Research in Chemistry, “Babeș-Bolyai” University, 400294 Cluj-Napoca, Romania;
| | - Flore Chirilă
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Agricultural Science and Veterinary Medicine, 400372 Cluj-Napoca, Romania; (F.C.); (N.I.F.)
| | - Gheorghe Zsolt Nicula
- Department of Cell and Molecular Biology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania; (Ș.B.); (G.Z.N.); (H.V.M.)
| | - Mihaela Laura Vică
- Department of Cell and Molecular Biology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania; (Ș.B.); (G.Z.N.); (H.V.M.)
- Correspondence:
| | - Rodica Ungur
- Department of Medical Rehabilitation, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400347 Cluj-Napoca, Romania;
| | - Horea Vladi Matei
- Department of Cell and Molecular Biology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania; (Ș.B.); (G.Z.N.); (H.V.M.)
| | - Nicodim Iosif Fiț
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Agricultural Science and Veterinary Medicine, 400372 Cluj-Napoca, Romania; (F.C.); (N.I.F.)
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Dawood MFA, Azooz MM. Insights into the oxidative status and antioxidative responses of germinating broccoli (Brassica oleracea var. italica L.) seeds in tungstate contaminated water. CHEMOSPHERE 2020; 261:127585. [PMID: 32739687 DOI: 10.1016/j.chemosphere.2020.127585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 06/18/2020] [Accepted: 06/29/2020] [Indexed: 05/25/2023]
Abstract
The utilization of tungsten in traffic, smelting, mining, and other industrial applications allows its' accumulation in the environmental ecosystems. The present study included using a soluble form of tungsten (tungstate) at different levels (0, 1, 5, 10, 50, and 100 mg L-1) as a water contaminant. The germinating seeds experienced tungstate at 1-50 mg L-1 exhibited stimulation of seedling dry and fresh matter stress tolerance indices, whereas retardation of these traits at the level of 100 mg L-1 was manifested. The stimulation of seedling growth at the levels of 1-50 mg L-1 was associated with the regulation of reactive oxygen status, higher stability of cell membrane, and elevated level of antioxidative responses. Regarding the oxidative stress of the seedlings exposed to tungstate contaminated water, only the concentration of 100 mg L-1 induced accumulation of hydrogen peroxide, superoxide anion, and hydroxyl radical with apparent membrane deteriorations in terms of lipid peroxidation. Furthermore, reductions of phytochelatins, reduced glutathione, ascorbate, ascorbate peroxidase, glutathione peroxidase, as well as glutathione-S-transferase were the main symptoms of tungstate phytotoxicity at the same level. The accumulation of lignin, ionic peroxidase, soluble peroxidase, and lignin-related enzymes (phenylalanine ammonia-lyase and polyphenol oxidase) were the striking reasons for restricting seedlings growth at noxious tungstate level. The results could suggest that the elevated levels of defense systems, at least in part, were accountable for raising broccoli resistance against tungstate stress at low doses. Furthermore, these plants can grow in tungsten-polluted areas by modifying their physiological processes. However, this study shed the light to the eco-toxicity of tungstate and imparts evidence for the need to establishing environmental risk management of tungstate accumulation.
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Affiliation(s)
- Mona F A Dawood
- Botany and Microbiology Department, Faculty of Science, Assiut University, 71516, Assiut, Egypt.
| | - Mohamed M Azooz
- Botany and Microbiology Department, Faculty of Science, South Valley University, 83523, Qena, Egypt
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3
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Tanuhadi E, Al-Sayed E, Roller A, Čipčić-Paljetak H, Verbanac D, Rompel A. Synthesis, Characterization, and Phosphoesterase Activity of a Series of 4f- and 4d-Sandwich-Type Germanotungstates [( n-C 4H 9) 4N] l/mH 2[(M(H 2O) 3)(γ-GeW 10O 35) 2] (M = Ce III, Nd III, Gd III, Er III, l = 7; Zr IV, m = 6). Inorg Chem 2020; 59:14078-14084. [PMID: 32945651 PMCID: PMC7539296 DOI: 10.1021/acs.inorgchem.0c01852] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
We report on a family of five new
4f- and 4d-doped sandwich-type
germanotungstates with the general formula [(n-C4H9)4N]l/mH2[(M(H2O)3)(γ-GeW10O35)2]·3(CH3)2CO [M(H2O)3(GeW10)2] (M = CeIII, NdIII, GdIII, ErIII, l = 7; ZrIV, m = 6), which have been synthesized
at room temperature in an acetone–water mixture. Among the
compound series, [Zr(H2O)3(GeW10)2]8–, which has been obtained in the
presence of 30% H2O2, represents the first example
of a 4d-substituted germanotungstate incorporating the intact dilacunary
[γ-GeIVW10O36]8– building block. All compounds were characterized thoroughly in the
solid state by single-crystal and powder X-ray diffraction (XRD),
IR spectroscopy, thermogravimetric analysis (TGA), and elemental analysis
and in solution by NMR and UV–vis spectroscopy. The phosphoesterase
activity of [Ce(H2O)3(GeW10)2]9– and [Zr(H2O)3(GeW10)2]8– toward the model substrates 4-nitrophenyl phosphate (NPP)
and O,O-dimethyl O-(4-nitrophenyl) phosphate (DMNP) was monitored with 1H- and 31P-NMR spectroscopy revealing an acceleration
of the hydrolytic reaction by an order of magnitude (kcorr = 3.44 (±0.30) × 10–4 min–1 for [Ce(H2O)3(GeW10)2]9– and kcorr = 5.36 (±0.05) × 10–4 min–1 for [Zr(H2O)3(GeW10)2]8–) as compared to the uncatalyzed reaction (kuncat = 2.60 (±0.10) × 10–5 min–1). [Ce(H2O)3(GeW10)2]9– demonstrated improved antibacterial
activity toward Moraxella catarrhalis (MIC 32 μg/mL),
compared to the unsubstituted [GeW10O36]8– POM (MIC 64 μg/mL). We report on the synthesis and characterization of five
new monosubstituted 4f- and 4d-germanotungstates [(n-C4H9)4N]l/mH2[(M(H2O)3)(γ-GeW10O35)2]·3(CH3)2CO [M(H2O)3(GeW10)2] (M = CeIII, NdIII, GdIII, ErIII, l = 7; ZrIV; m = 6). The phosphoesterase properties of [Ce(H2O)3(GeW10)2]9− and [Zr(H2O)3(GeW10)2]8− were
investigated by probing the hydrolytic activity toward 4-nitrophenyl
phosphate (NPP) and O,O-dimethyl O-(4-nitrophenyl) phosphate (DMNP). Antibacterial tests
revealed inhibiting activity of [Ce(H2O)3(GeW10)2]9− against Moraxella
catarrhalis.
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Affiliation(s)
- Elias Tanuhadi
- Fakultät für Chemie, Institut für Biophysikalische Chemie, Universität Wien, 1090 Wien, Austria
| | - Emir Al-Sayed
- Fakultät für Chemie, Institut für Biophysikalische Chemie, Universität Wien, 1090 Wien, Austria
| | - Alexander Roller
- Fakultät für Chemie, Zentrum für Röntgenstrukturanalyse, Universität Wien, 1090 Wien, Austria
| | - Hana Čipčić-Paljetak
- Center for Translational and Clinical Research, Croatian Center of Excellence for Reproductive and Regenerative Medicine, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Donatella Verbanac
- Faculty of Pharmacy and Biochemistry, University of Zagreb, 10000 Zagreb, Croatia
| | - Annette Rompel
- Fakultät für Chemie, Institut für Biophysikalische Chemie, Universität Wien, 1090 Wien, Austria
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Mohammed GI, Ahmad W, Alwael H, Saigl ZM, Al-Eryani DA, Bashammakh AS, El-Shahawi MS. A quercetin based fluorescent chemical sensor for ultra-sensitive determination and speciation of tungsten species in water. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 229:117929. [PMID: 31918153 DOI: 10.1016/j.saa.2019.117929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
The current study explores the use of quercetin for developing a highly selective spectrofluorimetric methodology for trace determination, speciation and thermodynamic characterization of tungstate (WO42-) species in water. The study relies on the principle of chelate formation between WO42- and quercetin with subsequent increase in the emission intensity. The developed method could be applied successfully in a wide linear range (1.0-400.0 μg L-1) with a detection limit of 0.28 μg L-1 and quantification limit of 0.92 μg L-1 at λex/em = 400/492 nm. The developed method was successfully applied in real tap and waste water samples. The suitability of the proposed method was further validated by inductively coupled plasma-optical emission spectrometry (ICP-OES) in terms of student's t and F tests at 95% confidence. Characterization (NMR, FTIR and electronic spectra), stoichiometry, stability constant, fluorescence mechanism and thermodynamic parameters (ΔH, ΔS, and ΔG) of the produced complex species were evaluated and properly assigned. The fluorescence quenching mechanism of tungstate quercetin complex by Triton X-100 was also evaluated for computing Stern-Volmer quenching constant and approximating quenching sphere. The method showed a clear significance over most of the reported methods for tungsten in literature in terms of good accuracy, robustness, ruggedness, short analytical time and cost-effectiveness.
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Affiliation(s)
- G I Mohammed
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia; Department of Chemistry, Faculty of Applied Sciences, Umm AL-Qura University, Makkah, Saudi Arabia
| | - W Ahmad
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - H Alwael
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - Z M Saigl
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - D A Al-Eryani
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - A S Bashammakh
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
| | - M S El-Shahawi
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
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5
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Adusumalli VKB, Runowski M, Lis S. 3,5-Dihydroxy Benzoic Acid-Capped CaF 2:Tb 3+ Nanocrystals as Luminescent Probes for the WO 4 2- Ion in Aqueous Solution. ACS OMEGA 2020; 5:4568-4575. [PMID: 32175503 PMCID: PMC7066553 DOI: 10.1021/acsomega.9b03956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
We report a facile and effective luminescence method for the determination of the WO4 2- ion in aqueous medium at initial pH = 6.3. This is achieved using 3,5-dihydroxybenzoic acid-capped CaF2:Tb3+ (5%) nanocrystals (NCs) as a luminescent probe. This is accomplished based on the energy transfer luminescence from the WO4 2- ion to the Tb3+ ion in small-size CaF2:Tb3+ NCs. Hydroxyl groups on the surface ligand helps in binding the tungstate ion to the surface of the NCs. With the gradual addition of the WO4 2- ion, the intensity of the Tb3+ excitation and emission spectra significantly increased. The linear range of the detection was from 1 to 10 μM for the WO4 2- ion (R 2 = 0.99). The calculated detection limit was 0.4 μM (by applying the 3σ/K criterion).
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Affiliation(s)
- Venkata
N. K. B. Adusumalli
- Department of Rare Earths, Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61-614 Poznań, Poland
| | - Marcin Runowski
- Department of Rare Earths, Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61-614 Poznań, Poland
| | - Stefan Lis
- Department of Rare Earths, Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61-614 Poznań, Poland
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Gu J, Zhang L, Yuan X, Chen YG, Gao X, Li D. Synthesis and Antibacterial Activity of Polyoxometalates with Different Structures. Bioinorg Chem Appl 2018; 2018:9342326. [PMID: 30627139 PMCID: PMC6305049 DOI: 10.1155/2018/9342326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 09/13/2018] [Indexed: 11/24/2022] Open
Abstract
A new inorganic-organic hybrid compound, [{Cu(phen)2}2(H4W12O40)], was synthesized, and its crystal structure was determined. The Keggin anion H4W12O40 4- was grafted with two coordination units {Cu(phen)2}, forming an electrically neutral molecule. The antibacterial activity of several polyoxometalate compounds with different anionic structures including the new compound was studied. The results show that the compound 1 can inhibit the growth of Enterococcus faecalis FA2 strains and that antibacterial activity of the polyoxometalate compounds is dependent with component elements of POM but is less relative with the anion structures.
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Affiliation(s)
- Jingmin Gu
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Lei Zhang
- Animal Science and Technology College, Jilin Agricultural University, Changchun 130117, China
| | - Xiaofeng Yuan
- Department of Pediatrics, Affiliated Hospital of the Changchun University of Chinese Medicine, Changchun 130021, China
| | - Ya-Guang Chen
- Key Laboratory of Polyoxometalates Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, China
| | - Xiuzhu Gao
- Department of Hepatology, The First Hospital, Jilin University, Changchun 130021, China
| | - Dong Li
- Department of Hepatology, The First Hospital, Jilin University, Changchun 130021, China
- Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
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7
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Oburger E, Vergara Cid C, Preiner J, Hu J, Hann S, Wanek W, Richter A. pH-Dependent Bioavailability, Speciation, and Phytotoxicity of Tungsten (W) in Soil Affect Growth and Molybdoenzyme Activity of Nodulated Soybeans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:6146-6156. [PMID: 29701969 PMCID: PMC5990931 DOI: 10.1021/acs.est.7b06500] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/08/2018] [Accepted: 04/27/2018] [Indexed: 05/15/2023]
Abstract
Increasing use of tungsten (W)-based products opened new pathways for W into environmental systems. Due to its chemical alikeness with molybdenum (Mo), W is expected to behave similarly to its "twin element", Mo; however, our knowledge of the behavior of W in the plant-soil environment remains inadequate. The aim of this study was to investigate plant growth as well as W and nutrient uptake depending on soil chemical properties such as soil pH and texture. Soybean ( Glycine max cv. Primus) was grown on two acidic soils differing in soil texture that were either kept at their natural soil pH (pH of 4.5-5) or limed (pH of ≥7) and amended with increasing concentrations of metallic W (control and 500 and 5000 mg kg-1). In addition, the activity of molybdoenzymes involved in N assimilation (nitrate reductase) and symbiotic N2 fixation (nitrogenase) was also investigated. Our results showed that the risk of W entering the food web was significantly greater in high-pH soils due to increased solubility of mainly monomeric W. The effect of soil texture on W solubility and phytoavailability was less pronounced compared to soil pH. Particularly at intermediate W additions (W 500 mg kg-1), symbiotic nitrogen fixation was able to compensate for reduced leaf nitrate reductase activity. When W soil solution concentrations became too toxic (W 5000 mg kg-1), nodulation was more strongly inhibited than nitrogenase activity in the few nodules formed, suggesting a more-efficient detoxification and compartmentalization mechanism in nodules than in soybean leaves. The increasing presence of polymeric W species observed in low-pH soils spiked with high W concentrations resulted in decreased W uptake. Simultaneously, polymeric W species had an overall negative effect on nutrient assimilation and plant growth, suggesting a greater phytotoxicity of W polymers. Our study demonstrates the importance of accounting for soil pH in risk assessment studies of W in the plant-soil environment, something that has been completely neglected in the past.
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Affiliation(s)
- Eva Oburger
- Department of Microbiology and Ecosystem Science, Division of Terrestrial
Ecosystem Research and Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
- BOKU,
Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz Strasse 24, A-3430 Tulln, Austria
| | - Carolina Vergara Cid
- BOKU,
Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz Strasse 24, A-3430 Tulln, Austria
- Faculty
of Physical and Natural Sciences, Multidisciplinary Institute of Plant
Biology, Pollution and Bioindicator Section, National University of Cordoba, Avenida Velez Sarsfield 1611, X5016CGA Cordoba, Argentina
| | - Julian Preiner
- Department of Microbiology and Ecosystem Science, Division of Terrestrial
Ecosystem Research and Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
- BOKU,
Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Konrad-Lorenz Strasse 24, A-3430 Tulln, Austria
| | - Junjian Hu
- BOKU,
Department of Chemistry, University of Natural
Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Stephan Hann
- BOKU,
Department of Chemistry, University of Natural
Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Wolfgang Wanek
- Department of Microbiology and Ecosystem Science, Division of Terrestrial
Ecosystem Research and Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
| | - Andreas Richter
- Department of Microbiology and Ecosystem Science, Division of Terrestrial
Ecosystem Research and Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
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Bostick BC, Sun J, Landis JD, Clausen JL. Tungsten Speciation and Solubility in Munitions-Impacted Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1045-1053. [PMID: 29307178 DOI: 10.1021/acs.est.7b05406] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Considerable questions persist regarding tungsten geochemistry in natural systems, including which forms of tungsten are found in soils and how adsorption regulates dissolved tungsten concentrations. In this study, we examine tungsten speciation and solubility in a series of soils at firing ranges in which tungsten rounds were used. The metallic, mineral, and adsorbed forms of tungsten were characterized using X-ray absorption spectroscopy and X-ray microprobe, and desorption isotherms for tungsten in these soils were used to characterize its solid-solution partitioning behavior. Data revealed the complete and rapid oxidation of tungsten metal to hexavalent tungsten(VI) and the prevalence of adsorbed polymeric tungstates in the soils rather than discrete mineral phases. These polymeric complexes were only weakly retained in the soils, and porewaters in equilibrium with contaminated soils had 850 mg L-1 tungsten, considerably in excess of predicted solubility. We attribute the high solubility and limited adsorption of tungsten to the formation of polyoxometalates such as W12SiO404-, an α-Keggin cluster, in soil solutions. Although more research is needed to confirm which of such polyoxometalates are present in soils, their formation may not only increase the solubility of tungsten but also facilitate its transport and influence its toxicity.
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Affiliation(s)
- Benjamín C Bostick
- Lamont-Doherty Earth Observatory, Columbia University , Palisades, New York 10964, United States
| | - Jing Sun
- School of Earth Sciences, University of Western Australia , 35 Stirling Highway, Perth, West Australia 6009, Australia
| | - Joshua D Landis
- Department of Earth Sciences, Dartmouth College , Hanover, New Hampshire 03755, United States
| | - Jay L Clausen
- Research and Development Center, Cold Regions Research and Engineering Laboratory , 72 Lyme Road, Hanover, New Hampshire 03755, United States
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James B, Zhang W, Sun P, Wu M, Li HH, Khaliq MA, Jayasuriya P, James S, Wang G. Tungsten (W) bioavailability in paddy rice soils and its accumulation in rice (Oryza sativa). INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2017; 27:487-497. [PMID: 28994318 DOI: 10.1080/09603123.2017.1386768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/16/2017] [Indexed: 06/07/2023]
Abstract
The aim of this study was to investigate the accumulation characteristics of tungsten (W) by different indica rice cultivars from the soil and to assess the potential risks to human health via dietary intake of W in rice consumption. A total of 153 rice (ear) samples of 15 cultivars and the corresponding surface soil samples were collected from 7 cities in Fujian Province of southeastern China. The available soil W were extracted using H2C2O4·2H2O-(NH4)2C2O4·H2O at pH 3.3). Results showed that the total soil W ranged from 2.03 mg kg-1 to 15.34 mg kg-1 and available soil W ranged from 0.03 mg kg-1 to 1.61 mg kg-1. The W concentration in brown rice varied from 7 μg kg-1 to 283 μg kg-1 and was significantly correlated with the available soil W. The highest mean TFavail (transfer factor based on available soil W) was 0.91 for Te-you 627 (hybrid, indica rice), whereas the lowest was 0.08 for Yi-you 673 (hybrid, indica rice). The TFavail decreased with the increase in available soil W, clay content, and cation exchange capacity. The consumption of the brown rice produced from the investigated areas in some cultivars by the present study may cause risks to human health.
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Affiliation(s)
- Blessing James
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Weili Zhang
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Pei Sun
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Mingyan Wu
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Hong Hong Li
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Muhammad Athar Khaliq
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Pathmamali Jayasuriya
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Swithin James
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
| | - Guo Wang
- a College of Resources and Environmental Science, Key Laboratory of Soil Environmental Health and Regulation in Fujian Province , Fujian Agriculture and Forestry University , Fuzhou , China
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Krivoshiev BV, Dardenne F, Blust R, Covaci A, Husson SJ. Elucidating toxicological mechanisms of current flame retardants using a bacterial gene profiling assay. Toxicol In Vitro 2015; 29:2124-32. [DOI: 10.1016/j.tiv.2015.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/31/2015] [Accepted: 09/01/2015] [Indexed: 11/24/2022]
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Alvarado-Gámez AL, Alonso-Lomillo MA, Domínguez-Renedo O, Arcos-Martínez MJ. A chronoamperometric screen printed carbon biosensor based on alkaline phosphatase inhibition for W(IV) determination in water, using 2-phospho-L-ascorbic acid trisodium salt as a substrate. SENSORS (BASEL, SWITZERLAND) 2015; 15:2232-43. [PMID: 25621602 PMCID: PMC4367303 DOI: 10.3390/s150202232] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/31/2014] [Accepted: 01/13/2015] [Indexed: 11/16/2022]
Abstract
This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3), a repeatability of 9.4% (n = 3) and a detection limit of 0.29 ± 0.01 µM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case) and a dynamic range from 0.6 to 30 µM. This study was performed by means of a Lineweaver-Burk plot, showing a mixed kinetic inhibition.
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Affiliation(s)
- Ana Lorena Alvarado-Gámez
- School of Chemistry & CELEQ, University of Costa Rica, San Pedro de Montes de Oca, 11500-2060 San José, Costa Rica.
| | | | - Olga Domínguez-Renedo
- Department of Chemistry, Faculty of Sciences, University of Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
| | - María Julia Arcos-Martínez
- Department of Chemistry, Faculty of Sciences, University of Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
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12
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Lee K, Lee BI, Byeon SH. The selective antenna effect of tungstate anions for Tb-doped layered yttrium hydroxynitrate. Chem Commun (Camb) 2013; 49:7165-7. [DOI: 10.1039/c3cc43155j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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El-Shahawi MS, Al Khateeb LA. Spectrofluorometric determination and chemical speciation of trace concentrations of tungsten species in water using the ion pairing reagent procaine hydrochloride. Talanta 2011; 88:587-92. [PMID: 22265545 DOI: 10.1016/j.talanta.2011.11.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 11/13/2011] [Accepted: 11/14/2011] [Indexed: 11/19/2022]
Abstract
A highly selective and low cost extractive spectrofluorimetric method was developed for determination of trace concentrations of tungsten (VI) in water. The method was based upon solvent extraction of the developed ion associate [(PQH(+))(2)·WO(4)(2-)] of the fluorescent ion-pairing reagent [2-(diethylamino)ethyl 4 aminobenzoate] hydrochloride namely procaine hydrochloride, PQH(+)·Cl(-) and tungstate (WO(4)(2-)) in aqueous solution of pH 6-7 followed by measuring the resulting fluorescence enhancement in n-hexane at λ(ex/em)=270/320nm. The fluorescence intensity of PQH(+)·Cl(-) increased linearly on increasing tungstate concentration in the range 25-250μgL(-1). The limits of detection (LOD) and quantification (LOQ) of tungsten (VI) were found 7.51 and 24.75μgL(-1), respectively. Chemical composition of the developed ion associate and the molar absorptivity at 270nm were found to be [(PQH(+))(2)·WO(4)(2-)] and 2.7×10(4)Lmol(-1)cm(-1), respectively. Other oxidation states (III, IV, V) of tungsten species could also be determined after oxidation with H(2)O(2) in aqueous solution to tungsten (VI). The method was applied for analysis of tungsten in certified reference material (IAEA Soil-7) and wastewater samples. The results were compared successfully (>95%) with the data of inductively coupled plasma-mass spectrometry (ICP-MS).
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Affiliation(s)
- M S El-Shahawi
- Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
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14
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Strigul N. Does speciation matter for tungsten ecotoxicology? ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2010; 73:S0147-6513(10)00092-8. [PMID: 20965092 DOI: 10.1016/j.ecoenv.2010.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 03/16/2010] [Accepted: 05/01/2010] [Indexed: 05/27/2023]
Abstract
Tungsten is a widely used transition metal that has not been thoroughly investigated with regards to its ecotoxicological effects. Tungsten anions polymerize in environmental systems as well as under physiological conditions in living organisms. These polymerization/condensation reactions result in the development of several types of stable polyoxoanions. Certain chemical properties (in particular redox and acidic properties) differentiate these polyanions from monotungstates. However, our current state of knowledge on tungsten toxicology, biological and environmental effects is based entirely on experiments where monotungstates were used and assumed by the authors to be the form of tungsten that was present and that produced the observed effect. Recent discoveries indicate that tungsten speciation may be important to ecotoxicology. New results obtained by different research groups demonstrate that polytungstates develop and persist in environmental systems, and that polyoxotungstates are much more toxic than monotungstates. This paper reviews the available toxicological information from the standpoint of tungsten speciation and identifies knowledge gaps and pertinent future research directions.
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15
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Ultrasensitive determination of tungsten(VI) on pikomolar level in voltammetric catalytic adsorptive catechol-chlorate(V) system. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Strigul N, Koutsospyros A, Christodoulatos C. Tungsten speciation and toxicity: acute toxicity of mono- and poly-tungstates to fish. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2010; 73:164-71. [PMID: 19836837 DOI: 10.1016/j.ecoenv.2009.08.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 05/03/2009] [Accepted: 08/29/2009] [Indexed: 05/23/2023]
Abstract
Tungsten is a widely used transition metal for which very limited information on environmental and toxicological effects is available. Of particular interest is the lack of information linking tungsten speciation and environmental effects. Tungsten anions may polymerize (depending upon concentration, pH, and aquatic geochemistry) in aquatic and soil systems. However, to this date, of all soluble tungstate species only monotungstates have been scrutinized to a fair extent in toxicological studies. The objective of this work is a comparative assessment of the acute toxicity of monotungstates (sodium tungstate, Na(2)WO(4)) and polytungstates (sodium metatungstate, 3Na(2)WO(4).9WO(3)) to Poecilia reticulate. The experiments have been performed according to the OEDC protocols 203 and 204. LD50 values for 1-14 days show that sodium metatungstate is significantly more toxic to fish than sodium tungstate. Based on LD50 (0.86-3.88gL(-1) or 4.67-21.1x10(-3)molNa(2)WO(4)L(-1)), sodium tungstate may be classified as a chemical of low toxicity to fish. Sodium metatungstate caused similar fish mortality to sodium tungstate when it was introduced in 55-80 times lower concentrations (in terms of molL(-1)) than sodium tungstate. LD50 values for sodium metatungstate range from 0.13 to 0.85gWL(-1) or 5.69 to 38.71x10(-5)mol 3Na(2)WO(4).9WO(3)L(-1). Based on these values sodium metatungstate can be classified as a moderate toxic agent to fish.
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Affiliation(s)
- Nikolay Strigul
- Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA.
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17
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Adamakis IDS, Panteris E, Eleftheriou EP. Tungsten affects the cortical microtubules of Pisum sativum root cells: experiments on tungsten-molybdenum antagonism. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:114-24. [PMID: 20653894 DOI: 10.1111/j.1438-8677.2009.00197.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Tungsten (W) is increasingly shown to be toxic to various organisms, including plants. Apart from inactivation of molybdo-enzymes, other potential targets of W toxicity in plants, especially at the cellular level, have not yet been revealed. In the present study, the effect of W on the cortical microtubule array of interphase root tip cells was investigated, in combination with the possible antagonism of W for the pathway of molybdenum (Mo). Pisum sativum seedlings were treated with W, Mo or a combination of the two, and cortical microtubules were examined using tubulin immunofluorescnce and TEM. Treatments with anti-microtubule (oryzalin, colchicine and taxol) or anti-actomyosin (cytochalasin D, BDM or ML-7) drugs and W were also performed. W-affected cortical microtubules were low in number, short, not uniformly arranged and were resistant to anti-microtubule drugs. Cells pre-treated with oryzalin or colchicine and then treated with W displayed W-affected microtubules, while cortical microtubules pre-stabilized with taxol were resistant to W. Treatment with Mo and anti-actomyosin drugs prevented W from affecting cortical microtubules. Cortical microtubule recovery after W treatment was faster in Mo solution than in water. The results indicate that cortical microtubules of plant cells are indirectly affected by W, most probably through a mechanism depending on the in vivo antagonism of W for the Mo-binding site of Cnx1 protein.
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Affiliation(s)
- I-D S Adamakis
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
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18
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Thomas VG, Roberts MJ, Harrison PTC. Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2009; 72:1031-7. [PMID: 19232723 DOI: 10.1016/j.ecoenv.2009.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 11/03/2008] [Accepted: 01/10/2009] [Indexed: 05/08/2023]
Abstract
The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5-13.5mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1-4.4mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation.
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Affiliation(s)
- Vernon G Thomas
- Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
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19
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Tajima Y, Takagi R, Nakajima T, Yasuda T, Kominato Y. 11-Tungstophosphate with Iron(II) and Hydrogen Peroxide Efficiently Detached Bacterial Biofilm. Biol Pharm Bull 2009; 32:1783-9. [DOI: 10.1248/bpb.32.1783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yutaka Tajima
- Legal Medicine and Molecular Genetics, Postgraduate School of Medicine, Gunma University
| | - Rie Takagi
- Legal Medicine and Molecular Genetics, Postgraduate School of Medicine, Gunma University
| | - Tamiko Nakajima
- Legal Medicine and Molecular Genetics, Postgraduate School of Medicine, Gunma University
| | - Toshiro Yasuda
- Division of Medical Genetics and Biochemistry, Faculty of Medical Sciences, Fukui University
| | - Yoshihiko Kominato
- Legal Medicine and Molecular Genetics, Postgraduate School of Medicine, Gunma University
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Ogundipe A, Braida W, Koutsospyros A, Christodoulatos C, O'Connor G, Larson S. Re: "release of copper from sintered tungsten-bronze shot under different pH conditions and its potential toxicity to aquatic organisms". THE SCIENCE OF THE TOTAL ENVIRONMENT 2007; 383:241-2; author reply 243-5. [PMID: 17574653 DOI: 10.1016/j.scitotenv.2007.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Accepted: 05/16/2007] [Indexed: 05/15/2023]
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Koutsospyros A, Braida W, Christodoulatos C, Dermatas D, Strigul N. A review of tungsten: from environmental obscurity to scrutiny. JOURNAL OF HAZARDOUS MATERIALS 2006; 136:1-19. [PMID: 16343746 DOI: 10.1016/j.jhazmat.2005.11.007] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Since its discovery, tungsten, a transition element of Group VIb of the Periodic Table of Elements, and its compounds have been considered environmentally benign. Its presence in biological and drinking water samples in Fallon, Nevada, an acute lymphocytic leukemia cluster struck community has alarmed public health, environmental and regulatory agencies. Tungsten, a metal of extraordinary properties that make it hardly substitutable, is considered an essential commodity with a wide variety of uses stretching from household necessities to highly specialized applications. This work is undertaken in order to explore aspects of environmental behavior of tungsten and its compounds. Occurrence data in terrestrial, atmospheric, aquatic and biotic systems are presented. Various aspects of environmental chemistry, fate transport across environmental interfaces and toxicology are discussed with the objective of identifying knowledge gaps and outlining directions for future research.
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Affiliation(s)
- A Koutsospyros
- Department of Mechanical, Civil, and Environmental Engineering, University of New Haven, West Haven, CT 06516, USA.
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Strigul N, Koutsospyros A, Arienti P, Christodoulatos C, Dermatas D, Braida W. Effects of tungsten on environmental systems. CHEMOSPHERE 2005; 61:248-58. [PMID: 16168748 DOI: 10.1016/j.chemosphere.2005.01.083] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 01/14/2005] [Accepted: 01/19/2005] [Indexed: 05/04/2023]
Abstract
Tungsten is a metal with many industrial and military applications, including manufacturing of commercial and military ammunition. Despite its widespread use, the potential environmental effects of tungsten are essentially unknown. This study addresses environmental effects of particulate and soluble forms of tungsten, and to a minor extent certain tungsten alloy components, present in some munitions formulations. Dissolution of tungsten powder significantly acidifies soils. Tungsten powder mixed with soils at rates higher than 1% on a mass basis, trigger changes in soil microbial communities resulting in the death of a substantial portion of the bacterial component and an increase of the fungal biomass. It also induces the death of red worms and plants. These effects appear to be related with the soil acidification occurring during tungsten dissolution. Dissolved tungsten species significantly decrease microbial yields by as much as 38% for a tungsten media concentration of 89 mg l(-1). Soluble tungsten concentrations as low as 10(-5) mg l(-1), cause a decrease in biomass production by 8% which is possibly related to production of stress proteins. Plants and worms take up tungsten ions from soil in significant amounts while an enrichment of tungsten in the plant rhizosphere is observed. These results provide an indication that tungsten compounds may be introduced into the food chain and suggest the possibility of development of phytoremediation-based technologies for the cleanup of tungsten contaminated sites.
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Affiliation(s)
- Nikolay Strigul
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08540, USA
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Inoue M, Segawa K, Matsunaga S, Matsumoto N, Oda M, Yamase T. Antibacterial activity of highly negative charged polyoxotungstates, K27[KAs4W40O140] and K18[KSb9W21O86], and Keggin-structural polyoxotungstates against Helicobacter pylori. J Inorg Biochem 2005; 99:1023-31. [PMID: 15833325 DOI: 10.1016/j.jinorgbio.2005.01.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 01/04/2005] [Accepted: 01/18/2005] [Indexed: 01/09/2023]
Abstract
The antibacterial activity of polyoxometalates (PMs) against Helicobacter pylori was investigated based on determinations of minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIC), time-killing of the bacteria, bacterial morphology and PM-uptake into the bacteria cell. The result of MIC values revealed that, of 13 PMs used in this study, highly negative-charged polyoxotungstates, such as K27[KAs4W40O140] and K18[KSb9W21O86], and Keggin-structural polyoxotungstates exhibited a potent antibacterial activity with the MIC values of less than 256 microg/ml. The former was the most active, and superior to metronidazole (MTZ) against MTZ-susceptible and resistant strains and also to clarithromycin (CLR) against CLR-resistant strains. In contrast, most of polyoxomolybdates showed little antibacterial activity with the MIC values of more than 256 microg/ml. The result of FIC index values indicated that the antibacterial polyoxotungstates had partially synergistic effect in combination with MTZ and CLR but indifferent effect in combination with amoxicillin (AMX). From the results of the time-killing and scanning electron microscope images, K27[KAs4W40O140] and K18[KSb9W21O86] proved the concentration-dependent bactericidal activity with the morphological change from bacillary form to coccoid form, while Keggin-structural K5[SiV(V)W11O40] showed the bacteriostatic activity with small change of morphology to coccoid form. The fluorescent X-ray analysis demonstrated that these polyoxotungstates were taken into the bacteria cell. It is pointed out that the Keggin-structure and/or high negativity polyoxotungstates are an important factor for the antibacterial activity against H. pylori.
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Affiliation(s)
- Miyao Inoue
- Chemical Resource Laboratory, Tokyo Institute of Technology, R1-21, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
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