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Evidencing generation of persistent ozonation products of antibiotics roxithromycin and trimethoprim

J Radjenović1, M Godehardt, M Petrović

  • 1Department of Environmental Chemistry, IDAEA-CSIC, c/Jordi irona 18-26, 08034 Barcelona, Spain.

Environmental Science & Technology
|September 22, 2009
PubMed

Insights

Ozonation of roxithromycin and trimethoprim involves hydroxyl radical reactions, forming nine products. Some roxithromycin products resist ozonation, potentially retaining antimicrobial activity.

Area of Science:

  • Environmental Chemistry
  • Organic Chemistry
  • Pharmaceutical Chemistry

Background:

  • Roxithromycin and trimethoprim are widely used antimicrobial agents.
  • Understanding their transformation products during water treatment is crucial for environmental safety and efficacy.

Purpose of the Study:

  • To elucidate the reaction mechanisms and identify products formed during the ozonation of roxithromycin and trimethoprim.
  • To investigate the influence of water matrix (distilled water vs. wastewater effluent) on ozonation pathways.

Main Methods:

  • Laboratory-scale ozonation experiments were conducted.
  • Product identification and structural elucidation were performed using quadrupole-time-of-flight (QqToF) mass spectrometry.

Main Results:

  • Nine ozonation products were identified for both roxithromycin and trimethoprim.
  • Ozonation pathways were significantly influenced by hydroxyl radical (*OH) chain reactions, despite the compounds' high ozone affinity.
  • Two roxithromycin ozonation products showed high refractoriness to further degradation, particularly in distilled water.

Conclusions:

  • The ozonation of roxithromycin and trimethoprim proceeds via complex pathways involving *OH radicals.
  • The persistence of certain roxithromycin products suggests potential preservation of antimicrobial activity.
  • Further research is needed to assess the environmental fate and biological activity of these transformation products.

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