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Villaverde J.J.,University of Aveiro | Villaverde J.J.,DTEVPF Unit of Plant Protection Products | Oliveira L.,University of Aveiro | Oliveira L.,Regional Laboratory of Veterinary and Food Safety | And 6 more authors.
Industrial Crops and Products | Year: 2013

The lipophilic extractives of the unripe peel of ten banana cultivars belonging to the Musa acuminata and Musa balbisiana species (namely 'Giant Cavendish', 'Chinese Cavendish', 'Grand Nain', 'Gruesa', 'Williams', 'Ricasa', 'Eilon', 'Zelig', 'Dwarf Red' and 'Silver') were studied by gas chromatography-mass spectrometry. The extractives content were in the range of 2-3% with substantially higher values for 'Silver' and 'Dwarf Red' (5.7 and 10.7% respectively). Sterols and fatty acids were the major families of compounds identified, with respectively 55.1-87.5% and 10.6-43.2% of total of lipophilic components. Cycloeucalenone was the main component identified in 'Williams' and 'Dwarf Red', with abundances ranging from 806 to 9453mgKg -1 of dry unripe peels, respectively. The identification of high contents of valuable compounds, can open new strategies for the valorization of the studied banana residues and particularly of those from 'Dwarf Red' followed by 'Silver' and 'Ricasa', as potential sources of high-value phytochemicals. © 2012 Elsevier B.V.. Source


Sandin-Espana P.,DTEVPF Unit of Plant Protection Products | Sevilla-Moran B.,DTEVPF Unit of Plant Protection Products | Villarroya-Ferruz M.,DTEVPF Unit of Plant Protection Products | Alonso-Prados J.L.,DTEVPF Unit of Plant Protection Products
Weed Science | Year: 2015

When herbicides are sprayed in the field, a proportion of the herbicide falls onto leaves and soil surfaces, where it can be exposed to sunlight, generating photoproducts that can be more toxic and/or persistent than the parent substance and affect human health and the environment. The aim of this study was to identify the photoproducts of the herbicide alloxydim in leaf and soil model systems and to perform phytotoxicity studies. Alloxydim was rapidly photodegraded in systems simulating plant cuticles and soil surfaces, with half-lives ranging from 1 to 30 min. The main by-product, identified by LC-Qtof-MS as deallyoxylated alloxydim, was more stable than the active substance. The EC50 values on root lengths of different varieties of wheat plants and one grass weed ranged from 0.38 to 0.50 mg L-1 for alloxydim. In contrast, the EC50 values for deallyoxylated alloxydim ranged from 94 to 600 mg L-1 in the same species and in crops where the herbicide was applied. Special attention should be given to alloxydim degradation products because of the rapid degradation of this herbicide. Comparative bioassay studies between alloxydim and its photostable by-product showed that the by-product presents low phytotoxicity, whereas alloxydim can cause injury to neighboring and succeeding cereal crops. Nomenclature: Alloxydim. © Weed Science Society of America. Source


Sandin-Espana P.,DTEVPF Unit of Plant Protection Products | Sevilla-Moran B.,DTEVPF Unit of Plant Protection Products | Lopez-Goti C.,DTEVPF Unit of Plant Protection Products | Mateo-Miranda M.M.,DTEVPF Unit of Plant Protection Products | Alonso-Prados J.L.,DTEVPF Unit of Plant Protection Products
Arabian Journal of Chemistry | Year: 2015

Photolysis is an important degradation process to consider when evaluating the persistence of a pesticide in the field. In this work, photolytic behavior of clethodim and sethoxydim herbicides under simulated solar radiation was examined in organic solvents, on glass disk and silica gel plates as leaf and soil model surfaces. The photodegradation was characterized by determination of their half-lives (t 1/2), dissipation rate constant (k) and identification of degradation products by means of HPLC-Qtof-MS. Photolytic degradation of clethodim and sethoxydim was very rapid. The photodegradation rate was enhanced in leaf model than in water with half-lives that ranged from 6.3±0.5 to 10.1±0.4min for clethodim and from 8.0±0.3 to 20.5±0.5min for sethoxydim. The fastest rate of degradation was obtained on silica gel plates with half-lives of 1.8 and 5.0min for clethodim and sethoxydim respectively. Photoreduction of the oxime ether moiety was the main transformation processes giving rise to a photostable product, the corresponding dealkoxylated derivative. Isomerization of oxime ether bond and oxidation of sulfur atom to form Z-isomer and the corresponding sulfoxides were the others reactions involved. The different environments tested influenced the concentrations of photoproducts formed during the irradiation of both herbicides. This result suggests that photolysis will be an important pathway of dissipation of the two herbicides. On the basis of these findings, further studies could be desirable to estimate the effects of transformation products on the environment. © 2015 The Authors. Source


Sandin-Espana P.,DTEVPF Unit of Plant Protection Products | Sevilla-Moran B.,DTEVPF Unit of Plant Protection Products | Lopez-Goti C.,DTEVPF Unit of Plant Protection Products | Mateo-Miranda M.M.,DTEVPF Unit of Plant Protection Products | Alonso-Prados J.L.,DTEVPF Unit of Plant Protection Products
Microchemical Journal | Year: 2015

Photodegradation process is one of the most important abiotic factors affecting the fate of pesticides in aquatic ecosystems. As consequence of this transformation pathway, different photoproducts can be formed with unknown toxicity, mobility and persistence in aqueous media. The information obtained is even more valuable for new families of pesticides, like cyclohexanedione herbicides, because the scientific literature about their environmental behavior and persistence is quite limited. Although there are evidences that the persistence of sethoxydim, a cyclohexanedione herbicide, in aquatic media is largely affected by reactions initiated by solar radiation, there are no studies about the photoproducts formed in natural waters. Therefore, we studied for the first time the photoproducts formed during the irradiation of sethoxydim herbicide under natural and simulated sunlight in different sources of waters. Ten photoproducts of sethoxydim were separated and identified by means of the HPLC-ESI-Qtof-MS technique. Main phototransformation processes of sethoxydim involved isomerization of oxime ether bond, oxidation of sulfur atom and cleavage of oxime ether bond. Photoproducts dealkoxy ketone, dealkoxy sulfoxides and dealkoxy sethoxydim resulted to more photostable than sethoxydim hence probably more persistent in the environmental. Both radiation and water sources influenced the concentrations of photoproducts formed during the irradiation of sethoxydim.These findings highlight the need for further insight in the study of photoproducts to understand the environmental fate of sethoxydim herbicide. © 2014. Source

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