Please use this identifier to cite or link to this item:
Title: Removal of dexamethasone by oxidative processes : structural characterization of degradation products and estimation of the toxicity.
Authors: Quaresma, Amanda de Vasconcelos
Rúbio, Karina Taciana Santos
Taylor, Jason Guy
Sousa, Bianca Aline de
Silva, Silvana de Queiroz
Werle, Alceni Augusta
Afonso, Robson José de Cássia Franco
Keywords: Glucocorticoid
Mass spectrometry
Molecular docking
Issue Date: 2021
Citation: QUARESMA, A. de V. et al. Removal of dexamethasone by oxidative processes: structural characterization of degradation products and estimation of the toxicity. Journal of Environmental Chemical Engineering, v. 9, 2021. Disponível em: <>. Acesso em: 11 out. 2022.
Abstract: Dexamethasone (DEX) belongs to a class of steroid hormones that can potentially be harmful due to their endocrine disrupting properties. The efficient elimination of DEX during the treatment of drinking water is needed to ensure that the health of both human and aquatic species are protected. Thus different oxidative processes were investigated in order to assess the effect of these procedures and conditions on DEX. Aqueous solutions of DEX were treated by conventional chlorination ([NaClO]=10 mg L− 1 ) and advanced oxidative processes (ozonation – [O3]=8 mg L− 1 ; photocatalysis – [TiO2]=120 mg L− 1 and UV-C; photolysis – UV-C). The most and least efficient processes for DEX removal were ozonation (95%) and chlorination (54%), respectively. In total, 16 degradation products were identified and characterized by high-resolution mass spectrometry and only two have been proposed in previous reports. Chemical structures of the degradation products were proposed and alcohol oxidation, ozonolysis and decarboxylation were the main chemical transformations observed. The toxicities of DEX and its derivatives were evaluated by following methods: MTT assay (HepG2 cell), ECOSAR (acute and chronic toxicity) and molecular docking (AutoDock). MTT assay results demonstrated that only a mixture DEX and the chlorinated derivative were toxic at high concentrations. ECOSAR analysis showed that products formed from dehydration and fluoride elimination were more toxic than intact DEX, mainly for fish and Daphnid and to a lesser extent for green algae. The docking study revealed that these degradation products were not capable of making hydrogen bonds with residual amino acids GLN570, GLN642 and CYS736, but were stable at the glucocorticoid receptor indicating the possibility of being toxic to humans.
ISSN: 2213-3437
Appears in Collections:DEFAR - Artigos publicados em periódicos

Files in This Item:
File Description SizeFormat 
  Restricted Access
2,88 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.