title: Toxicity, degradation and metabolic fate of ibuprofen on freshwater diatom Navicula sp.
abstract: Ibuprofen (IBU) is one of the most widely used and frequently detected human pharmaceuticals in aquatic environment. However, the toxicity of IBU on diatom and its fate remain still unkown. In the present study, the toxicity of IBU on the diatom was evaluated by the algal growth rate, the chlorophyll-a and carotenoids contents. The degradation of IBU including in particular the potential for the formation of incomplete degradation products was also explored. Biochemical characteristics of Navicula sp. were significantly inhibited at IBU concentrations up to 50mgL-1after 10days of exposure. The degradation of IBU was retarded by Navicula sp. at low concentration (1mgL-1), with t1/2being extended from 9.6±1.8 d to 12.0±1.5 d, indicating that Navicula sp. could prolong the exposure time of IBU. A total of 8 metabolites were identified by LC-MS/MS and the degradation pathway of IBU in Navicula sp. was proposed. Hydroxylation, acylation, demethylation, and glucuronidation contributed to IBU transformative reactions in diatom cells. These findings indicate that the presence of diatom Navicula sp. could hinder degradation of IBU, and IBU and/or its metabolites may pose high risks on aquatic ecosystem in natural waters.
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors.forename: Tengda
authors.initials: T
authors.lastname: Ding
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
authors.forename: Mengting
authors.initials: M
authors.lastname: Yang
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
authors.forename: Junmin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors.forename: Kunde
authors.initials: K
authors.lastname: Lin
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China. Electronic address: jyli@szu.edu.cn.
authors.forename: Juying
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Environmental Sciences, University of California, Riverside, CA 92521, United States.
authors.forename: Jay
authors.initials: J
authors.lastname: Gan
mesh_terms: D001673:Biodegradation, Environmental; D017377:Diatoms / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D007052:Ibuprofen / Q000378:metabolism* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D007052:Ibuprofen
keywords: Degradation; Ibuprofen; Metabolites; Navicula sp.; Toxicity