| Reference | [1]. EFSA J. 2020 Sep 10;18(9):e06189. doi: 10.2903/j.efsa.2020.6189. eCollection 2020 Sep.<br />
Updated peer review of the pesticide risk assessment for the active substance dithianon in light of confirmatory data submitted.<br />
European Food Safety Authority (EFSA), Anastassiadou M, Arena M, Auteri D, Brancato A, Bura L, Carrasco Cabrera L, Chaideftou E, Chiusolo A, Crivellente F, De Lentdecker C, Egsmose M, Fait G, Greco L, Ippolito A, Istace F, Jarrah S, Kardassi D, Leuschner R, Lostia A, Lythgo C, Magrans O, Mangas I, Miron I, Molnar T, Padovani L, Parra Morte JM, Pedersen R, Reich H, Santos M, Sharp R, Stanek A, Sturma J, Szentes C, Terron A, Tiramani M, Vagenende B, Villamar-Bouza L.<br />
The conclusions of the EFSA following the peer review of the initial risk assessment carried out by the competent authority of the rapporteur Member State, Greece, for the pesticide active substance dithianon are reported. The context of the peer review was that requested by the European Commission following the submission and evaluation of confirmatory mammalian toxicology and residues data. The conclusions were reached on the basis of the evaluation of the representative uses of dithianon as a fungicide on table and wine grapes and on pome fruit. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Concerns are identified.<br />
DOI: 10.2903/j.efsa.2020.6189 PMCID: PMC7507480 PMID: 32994823<br />
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[2]. Chemosphere. 2020 Sep;254:126807. doi: 10.1016/j.chemosphere.2020.126807. Epub 2020 Apr 17.<br />
Enhanced photodegradation of applied dithianon fungicides on plant leaves by dissolved substances in atmosphere under simulated sunlight.<br />
Jiao X(1), Li Z(2), He J(3), Wang C(4).<br />
Author information: (1)College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, China. (2)College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, China. (3)Department of Chemical and Environmental Engineering, University of Nottingham-Ningbo China, Ningbo, 315100, China. (4)College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, China. Electronic address: [email protected].<br />
Photolysis of pesticides has been widely investigated for evaluating their environmental behavior and agricultural effectiveness after crop spraying. However, little information about the effects of the water-soluble substances in atmosphere on photodegradation of pesticides is available. In current study, we found that photolysis of applied dithianon fungicides on real plant leaves was much faster than that in sealed stock aqueous suspensions under simulated sunlight. To simulate the natural conditions, for the first time, photodegradation of dithianon in air-saturated solutions containing typical dissolved atmospheric substances (DAS) including CO2 (HCO3-/CO32-), NO2 (NO3-), Fe3+ (Fe3+-complexes), and humic-like substances (HULIS) exposed to simulated solar irradiations were carried out in lab-scale. Fulvic acid (FA) was used as a surrogate for atmospheric HULIS in this study. The dithianon photodegradation was significantly enhanced in the presence of DAS and the photo-generated reactive species such as ·OH, 1O2, CO3·- and 3FA∗ play important roles according to the results of reactive species quenching, electron spin resonance spectroscopy, and laser flash photolysis experiments. Moreover, the photodegraded intermediates and final products of dithianon on plant leaves have been identified by HPLC-MS analysis, and its possible photodegradation pathways were proposed. This work indicated that, except for direct photolysis, indirect photosensitive degradation induced by the dissolved photo-active substances in atmosphere should be considered for evaluating the degradation of the applied pesticides on crops.<br />
DOI: 10.1016/j.chemosphere.2020.126807 PMID: 32334257 [Indexed for MEDLINE]<br />
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[3]. Pestic Biochem Physiol. 2018 Jul;149:137-142. doi: 10.1016/j.pestbp.2018.06.006. Epub 2018 Jun 30.<br />
Necrotic cell death induced by dithianon on Saccharomyces cerevisiae.<br />
Scariot FJ(1), Jahn L(1), Delamare APL(1), Echeverrigaray S(2).<br />
Author information: (1)Institute of Biotechnology, University of Caxias do Sul, Rio Grande do Sul, Brazil. (2)Institute of Biotechnology, University of Caxias do Sul, Rio Grande do Sul, Brazil; Cytogene Diagnósticos Moleculares Ltda., Lajeado, Rio Grande do Sul, Brazil. Electronic address: [email protected].<br />
Dithianon is a broad-spectrum anthraquinone fungicide used to control several diseases of grapes, apples, and other fruits and vegetables. Its mode of action is described as multi-site and associated to thiol-reactivity. As other fungicides can affect non-phytopathogenic organisms as yeasts and bacteria, with impact on microbial population, diversity, and fermentation processes. In this context, we study the effect of dithianon on the model organism and fermentative yeast Saccharomyces cerevisiae in order to elucidate the mechanisms involved in yeast cell death., and explain its interference on wine fermentation kinetics. Thus for, we analyzed cellular protein and non-protein thiols, membrane and cell wall integrity, reactive oxygen species accumulation, mitochondrial membrane potential, and phosphatidylserine externalization. The results showed that when exponentially aerobic growing cells of S. cerevisiae are submitted to acute dithianon treatment they loss cell wall and membrane integrity, dying by necrosis, and this behavior is associated to a depletion of reduced proteic and non-proteic thiol groups. We also detected an important increase of cellular reactive oxygen species (ROS) associated to mitochondrial membrane potential modifications on dithianon treated cells. ROS accumulation was not associated to apoptotic cell death, but can be responsible for intracellular damages. Moreover, necrotic cell death induced by dithianon explains its effect on the kinetics of wine fermentations.<br />
DOI: 10.1016/j.pestbp.2018.06.006 PMID: 30033009 [Indexed for MEDLINE]<br />
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[4]. Eur J Mass Spectrom (Chichester). 2016;22(5):261-267. doi: 10.1255/ejms.1447.<br />
Automated online solid-phase extraction-liquid chromatography mass spectrometric analysis of dithianon in water.<br />
Passoni A(1), Vighi M(2), Davoli E(3), Fanelli R(3), Bagnati R(3).<br />
Author information: (1)Department of Environmental Health Sciences, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy. [email protected]. (2)IMDEA Water Institute, Alcalá de Henares (Madrid), Spain. (3)Department of Environmental Health Sciences, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.<br />
An automated online solid-phase extraction-liquid chromatography mass spectrometry (SPE-LC/MS) method was developed for the quantification of dithianon in surface water samples, using warfarin as internal standard. The method was developed on a liquid chromatography (LC) system with Flexible Cube interfaced to a quadrupole time-of-flight (Q-TOF) mass spectrometer. A small volume of acidified water (1 mL) was spiked with internal standard, pre-concentrated online on polymeric cartridges and analyzed by full-scan MS in high-resolution conditions. The quantitative data were obtained by [M]-• of dithianon and [M – H]- of warfarin, used as internal standard. The chromatographic separation was performed on a C18 column with a gradient mobile phase consisting of acetonitrile and water containing 0.05% acetic acid. The method was validated to measure concentrations of dithianon in the range of 0.010-4 µg L-1 in surface water samples. Twenty real water samples, collected from Torrente Novella, Val di Non (TN, Northern Italy), during fungicide treatments of large apple orchards, were analyzed. All samples were kept in glass bottles and stored in the lab at -20°C until analysis. It was found that in all samples dithianon was undetectable: if it is present, its concentration was lower than the limit of detection (LOD) (0.008 µg L-1.To investigate the stability of dithianon, a series of water samples were spiked at different concentrations and analyzed after different storage conditions. Results suggested that dithianon is not stable in water stored at -20°C at neutral or basic pH, but the addition of acetic acid to pH = 3.5 increases its stability to at least two weeks.<br />
DOI: 10.1255/ejms.1447 PMID: 27882892 [Indexed for MEDLINE]<br />
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[5]. J Environ Sci Health B. 2015;50(3):175-83. doi: 10.1080/03601234.2015.982414.<br />
Toxicity of copper hydroxide, dithianon, fluazinam, tebuconazole and pyraclostrobin to Didymella applanata isolates from Serbia.<br />
Mirković B(1), Tanović B, Hrustić J, Mihajlović M, Stević M, Delibašić G, Vukša P.<br />
Author information: (1)a Grant-holder of Ministry of Education, Science and Technological Development of the Republic of Serbia , Belgrade , Serbia.<br />
A study of the in vitro sensitivity of 10 isolates of Didymella applanata to copper hydroxide, dithianon, fluazinam, tebuconazole and pyraclostrobin, was conducted. The isolates were derived from diseased raspberry canes sampled during 2013 at five localities in western part of Serbia, known as the main raspberry growing region of the country. Prior to sensitivity testing experimental conditions for radial growth assay were optimized. The results showed that the temperature of 22 °C, oatmeal agar medium and 12/12 hrs light/ darkness light regimen provided the best conditions for sensitivity tests. Most of D. applanata isolates were sensitive to the tested fungicides. The narrowest range of EC50 values was recorded for tebuconazole (1.42-2.66 mg L(-1)). The widest range of EC50 values was obtained for pyraclostrobin, ranging from 0.17 mg L(-1) to 55.33 mg L(-1). The EC50 values for the studied isolates were 39.48-51.19 mg L(-1) for copper hydroxide, 12.12-18.73 mg L(-1) for dithianon and 5.72-42.56 mg L(-1) for fluazinam. According to resistance factor values, all D. applanata isolates were sensitive to copper hydroxide, dithianon and tebuconazole. Among tested isolates, six were highly resistant to pyraclostrobin (RFs in the range of 207.1-325.5) and two moderately resistant to fluazinam (RFs were 3 and 7.4), respectively.<br />
DOI: 10.1080/03601234.2015.982414 PMID: 25602150 [Indexed for MEDLINE]
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