title: Characterization of cylindrospermopsin chlorination.
abstract: In temperate countries, the occurrence of cyanobacterial blooms threatens drinking water resources. Consequently, cyanotoxins are increasingly considered in water treatment, and their reactions with chlorine used to disinfect drinking water are particularly investigated. This study presents new elements for further understanding of cylindrospermopsin chlorination, through reactants and by-products monitoring, UV spectrum examination, and cytotoxicity assessment on human intestinal Caco-2 cells. On the one hand, the evolution of mixture UV spectrum indicated that cylindrospermopsin was quickly transformed at least into one intermediate by-product. While mass spectrometry experiments confirmed that cylindrospermopsin was almost totally transformed within 5 min, chlorine was consumed up to 20 min after the beginning of the reaction with a rate of 5 mol per mol of toxin. Then, LC-MS analysis gave rise to the formation of a third cylindrospermopsin by-product in addition to 5-chloro-cylindrospermopsin and cylindrospermopsic acid previously identified. Thanks to the accurate mass measurement provided by the LTQ-Orbitrap mass spectrometer, this new and stable chlorination by-product was assigned the chemical formula C(13)H(18)N(4)O(7)S. On the other hand, both of the mitochondrial and lysosomal activities measured on Caco-2 cells revealed that cylindrospermopsin chlorination significantly decreases mixture cytotoxicity.
authors.affiliation: Environment and Health Research Laboratory (LERES), French School of Public Health (EHESP), Avenue du Professeur Léon-Bernard-CS 74312, 35043 Rennes Cedex, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Merel
authors.forename: Michel
authors.initials: M
authors.lastname: Clément
authors.forename: Annick
authors.initials: A
authors.lastname: Mourot
authors.forename: Valérie
authors.initials: V
authors.lastname: Fessard
authors.forename: Olivier
authors.initials: O
authors.lastname: Thomas
mesh_terms: D000470:Alkaloids; D001427:Bacterial Toxins; D018938:Caco-2 Cells; D002713:Chlorine / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D000087522:Cyanobacteria Toxins; D006801:Humans; D013058:Mass Spectrometry; D013056:Spectrophotometry, Ultraviolet; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000470:Alkaloids; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; C089595:cylindrospermopsin; D002713:Chlorine; D014498:Uracil