title: Effects of chlorophenoxy herbicides and their main transformation products on DNA damage and acetylcholinesterase activity.
abstract: Persistent pesticide transformation products (TPs) are increasingly being detected among different environmental compartments, including groundwater and surface water. However, there is no sufficient experimental data on their toxicological potential to assess the risk associated with TPs, even if their occurrence is known. In this study, the interaction of chlorophenoxy herbicides (MCPA, mecoprop, 2,4-D and dichlorprop) and their main transformation products with calf thymus DNA by UV-visible absorption spectroscopy has been assessed. Additionally, the toxicity of the chlorophenoxy herbicides and TPs was also assessed evaluating the inhibition of acetylcholinesterase activity. On the basis of the results found, it seems that AChE is not the main target of chlorophenoxy herbicides and their TPs. However, the results found showed that the transformation products displayed a higher inhibitory activity when compared with the parent herbicides. The results obtained in the DNA interaction studies showed, in general, a slight effect on the stability of the double helix. However, the data found for 4-chloro-2-methyl-6-nitrophenol suggest that this transformation product can interact with DNA through a noncovalent mode.
authors.affiliation: Departamento de Engenharia Química, Instituto Superior de Engenharia do Porto (ISEP), Instituto Politécnico Porto, 4200-072 Porto, Portugal ; CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Benfeito
authors.affiliation: CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Silva
authors.affiliation: Departamento de Engenharia Química, Instituto Superior de Engenharia do Porto (ISEP), Instituto Politécnico Porto, 4200-072 Porto, Portugal ; CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Garrido
authors.affiliation: REQUIMTE/Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, 4050-313 Porto, Portugal.
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
authors.affiliation: CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Sottomayor
authors.affiliation: CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Borges
authors.affiliation: Departamento de Engenharia Química, Instituto Superior de Engenharia do Porto (ISEP), Instituto Politécnico Porto, 4200-072 Porto, Portugal ; CIQ/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: E Manuela
authors.initials: EM
authors.lastname: Garrido
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000031:analogs & derivatives* / Q000633:toxicity; D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000031:analogs & derivatives* / Q000633:toxicity; D000110:Acetylcholinesterase / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D006540:Herbicides / Q000633:toxicity*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid; C008340:mecoprop; D004247:DNA; C427203:calf thymus DNA; D008456:2-Methyl-4-chlorophenoxyacetic Acid; D000110:Acetylcholinesterase; C010571:dichlorprop