1,721,008 research outputs found
Toxicity and Risk of Transformation Products of Emerging Contaminants for Aquatic Organisms: Pharmaceutical Case Studies
No full textDiscussion about the environmental consequences of the presence of pharmaceuticals has taken place in the general absence of a systematic analysis of the potential risk. The lack of such an analysis means that, to date, decisions concerning environmental risk assessment criteria and/or regulatory thresholds have been somewhat arbitrary or based upon inappropriate groups of industrial chemicals. This chapter attempts to address this deficiency and collates examples of data relating to the ecotoxicity of existing pharmaceutical transformation photoproducts (TPs). The intention is to provide a perspective that will prove useful during the further development of assessment criteria. The database may also prove useful in the context of risk assessment of individual substances. There are mainly two different and independent approaches to assessing the risk associated with transformation product formation. We analyze these two approaches for transformation products coming from irradiation of pharmaceuticals under environment-like conditions
Comment on the paper: “Spectroscopic and computational study of the major oxidation products formed during the reaction of two quercetin conformers with a free radical
No full textthe title paper reports a study on the structural elucidation by spectroscopic and computational methods of the products obtained from the reaction of two conformers of quercetin with the 2,2-diphenyl-1- picrylhydrazyl radical (DPPH•). Many points of criticism, concerning both theoretical principles and experimental data, are highlighted in the present communication. © 2013 Elsevier B.V. All rights reserved
Olive oil mill wastewater: Isolation of polyphenols and their phytotoxicity in vitro
No full textOlive oil mill wastewater (OMW) was tested for phytotoxicity on seed germination and seedling growth of radish and wheat. The most potent inhibition was observed with the reverse osmosis fraction, from this, 17 polyphenols with molecular weight less than 300 Daltons were isolated by chromatographic processes and identified on the basis of their spectroscopic features. In seed bioassays, the inhibitory activity of each polyphenol was much lower than that observed for the original fraction and the mixture of the pure 17 polyphenols present in reverse osmosis fraction had less effect on seed germination. Thus, OMW phytotoxicity could be due to a synergic action of polyphenols with other unidentified substances present in the wastewater
New dimeric phenanthrenoids from the rhizomes of Juncus acutus. Structure determination and antialgal activity
No full textIn a study of the allelochemical interactions between the wetland plant Juncus acutus and microalgae some dimeric dihydrophenanthrenoids have been isolated. The structures have been determined on the basis of their spectroscopic properties and their phytotoxicity was evaluated on Selenastrum capricornutum. © 2003 Elsevier Science Ltd. All rights reserved
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