Laser flash photolysis and quantum chemical studies of UV degradation of pharmaceutical drug chloramphenicol: Short-lived intermediates, quantum yields and mechanism of photolysis

Laser flash photolysis and quantum chemical studies of UV degradation of pharmaceutical drug chloramphenicol: Short-lived intermediates, quantum yields and mechanism of photolysis Full article

Journal

Chemosphere
ISSN: 0045-6535 , E-ISSN: 1879-1298

Output data

Year: 2024, Volume: 351, Article number : 141211, Pages count : 7 DOI: 10.1016/j.chemosphere.2024.141211

Tags

UV degradation, chloramphenicol, photolysis

Authors

Belikov Yury A. ^1,2 , Snytnikova Olga A. ^2,3 , Sheven Dmitriy G. ⁴ , Fedunov Roman G. ^1,2 , Grivin Vyacheslav P. ¹ , Pozdnyakov Ivan P. ^1,2

Affiliations

1	Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3 Institutskaya Str., 630090, Novosibirsk, Russian Federation
2	Novosibirsk State University, 2 Pirogova Str., 630090, Novosibirsk, Russian Federation
3	International Tomography Center SB RAS, 3a Institutskaya Str., 630090, Novosibirsk, Russian Federation
4	Nikolaev Institute of Inorganic Chemistry SB RAS, Acad. Lavrentieva Ave. 3, Novosibirsk, 630090, Russian Federation

Using methods of time-resolved and stationary photolysis, HPLC-MS and quantum-chemical calculations by the DFT method, the mechanism of direct UV photolysis of the antibiotic chloramphenicol (CAP) was established. For the first time, short-lived intermediates formed during photolysis were detected. The primary photoprocess is the cleavage of the β-C-C bond relative to the aromatic system with the formation of 4-nitrobenzylalcohol radical and residual aliphatic radical. The first radical in deoxygenated solutions predominantly transforms into para-nitrobenzaldehyde and its secondary photolysis products. In the presence of oxygen, the aromatic radical and para-nitrobenzaldehyde are transformed into para-nitrosobenzoic and para-nitrobenzoic acids as a result of reaction with reactive oxygen species (ROS). Formation of ROS is provoked by reactions of aliphatic radical with dissolved oxygen, so this radical is very important for CAP degradation. The quantum yield of direct photolysis of CAP is ∼3% and does not depend on the presence of dissolved oxygen and on the change of the excitation wavelength in the range of 254–308 nm. Obtained data are important for further understanding of the transformation pathways of CAP and similar PPCP in natural and wastewaters under the action of sunlight and artificial UV radiation.

Belikov Y.A. , Snytnikova O.A. , Sheven D.G. , Fedunov R.G. , Grivin V.P. , Pozdnyakov I.P.
Laser flash photolysis and quantum chemical studies of UV degradation of pharmaceutical drug chloramphenicol: Short-lived intermediates, quantum yields and mechanism of photolysis
Chemosphere. 2024. V.351. 141211 :1-7. DOI: 10.1016/j.chemosphere.2024.141211 Scopus РИНЦ OpenAlex

Published print:

Mar 1, 2024

Scopus:	2-s2.0-85182745598
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OpenAlex:	W4390811556

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