Water-soluble manganese porphyrins as good catalysts for cipro- and levofloxacin degradation: Solvent effect, degradation products and DFT insights

• Published in: Chemosphere (Oxford) 2021-04, Vol.268, p.129334, Article 129334
• Main Authors: Lage, Ana Luísa Almeida, Marciano, Aline Capelão, Venâncio, Mateus Fernandes, da Silva, Mirra Angelina Neres, Martins, Dayse Carvalho da Silva
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents; Bacterial resistance; Biomimetics systems; Catalysis; Catalysts; Ciprofloxacin; Drugs; Hydrogen Peroxide; Levofloxacin; Manganese; Porphyrins; Solvents; Water; Water Pollutants, Chemical
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.129334

Synthetic manganese porphyrins (MnPs), in the presence of oxidants, were employed for the degradation of fluoroquinolone antibiotics. Ciprofloxacin (CIP) and levofloxacin (LEV) degradation by iodosylbenzene, iodobenzene diacetate, H2O2 and meta-chloroperbenzoic acid using water-soluble MnP catalysts yielded thirteen and nine products, respectively, seven of which have been proposed for the first time. The MnP catalysts have demonstrated the ability to degrade these antibiotics to a high degree (up to 100% degradation). The structures of the degradation products were proposed based on mass spectrometry analysis, and density functional theory calculations could confirm how the substituent moieties attached to the basic chemical structure of the fluoroquinolones influence the degradation reactions. CIP has been shown to be a more reactive substrate towards the porphyrinic catalysts tested because of its three-membered ring. However, the catalysts could almost completely degrade LEV, highlighting the ability of these porphyrins to act as catalysts to degrade environmental pollutants. [Display omitted] •The CIP/LEV degradation were evaluated in the presence of four oxidants.•CIP degradation was better in aqueous solution and LEV was better in acetonitrile.•In both systems, the iodosylarenes showed the best degradation results (up to 100%).•It was proposed seven new products from CIP and LEV degradation.•Theoretical analysis had proven the trend of products formation in this study.