Photodegradation of norfloxacin in ice: Role of the fluorine substituent

Li, Zhuojuan; Dong, Deming; Zhang, Liwen; Xia, Hua; Guo, Zhiyong

doi:10.1016/j.chemosphere.2021.133042

Cited by 17 publications

(2 citation statements)

References 52 publications

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“…Ammonium ion was found to accumulate gradually in the solution during GRNX photodegradation. Although the pathway of piperazinyl side-chain cleavage has been extensively reported for FQs, the oxidation of five-membered N-heterocycles is rather uncommon. , The ammonium ion detected in the photodegradation of GRNX could only result from the oxidation of the five-membered N-heterocycle, which occurs through several pathways under the attack of different ROSs. The formate ion detected in the photochemical system resulted from the decarboxylation of GRNX, probably through direct photolysis.…”

Section: Resultsmentioning

confidence: 96%

“…Although the pathway of piperazinyl side-chain cleavage has been extensively reported for FQs, the oxidation of five-membered N-heterocycles is rather uncommon. 50,51 The ammonium ion detected in the photodegradation of GRNX could only result from the oxidation of the five-membered N-heterocycle, which occurs through several pathways under the attack of different ROSs.…”

Section: Photodegradation Pathways Of Grnxmentioning

confidence: 99%

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Solar Photodegradation of a Novel des-F(6)-Fluoroquinolone, Garenoxacin, and Ecotoxicity of Its Phototransformation Products

Huang,

Zhang,

Lin

et al. 2024

Environ. Sci. Technol.

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Garenoxacin (GRNX) is a novel des-F(6)-fluoroquinolone on the horizon; thus, its fate and risk in the aquatic environment deserve attention. This study systematically investigated, for the first time, the phototransformation of GRNX under simulated and natural sunlight and assessed the ecotoxicity of its photodegradation products. Phototransformation of GRNX was observed to depend strongly on its ionization state, with direct photolysis and self-sensitized photolysis having comparable contributions for the cationic and zwitterionic species, while the latter dominated for the anionic species. Singlet oxygen generated via the self-sensitized photolysis of GRNX was the major reactive oxygen species in its photodegradation. Phototransformation of GRNX in different ionization states followed distinct pathways, with defluorination of the difluoromethyl group occurring only for the zwitterionic and anionic species. GRNX photodegradation in natural water could be described by a simple kinetic model based on the measured steady-state concentrations of 1 O 2 and •OH. Toxicity tests with Vibrio fischeri and Chlorella vulgaris consistently indicate that the generation of hydroxylation and decarboxylation products during photodegradation of GRNX increased the acute toxicity. These findings not only provide insights into the fate of GRNX in sunlit surface water but also reveal the potentially significant risk of its photodegradation products to the aquatic ecosystem.

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Section: Resultsmentioning

confidence: 96%

Section: Photodegradation Pathways Of Grnxmentioning

confidence: 99%