Fungal biotransformation of the benzotriazole ultraviolet stabilizer UV-P into glucosylated and O-methylated metabolites by Phanerochaetesordida.

Benzotriazole ultraviolet stabilizers (BUVSs) are widely used as additives in a variety of materials to protect against UV-induced degradation. Their widespread distribution in environmental and biological samples has raised concerns regarding their potential ecological and health risks. 2-(2'-Hydroxyphenyl)benzotriazole (UV-P), a structurally simple BUVS, was selected as a model compound to evaluate its metabolism by the white-rot fungus Phanerochaete sordida in potato dextrose broth cultures. UV-P gradually decreased, with approximately 10% and 40% removed in 2 and 4 weeks, respectively. Two metabolites were identified as glucosylated and O-methylated derivatives of UV-P. These metabolites retained, and in some assays slightly increased, cytotoxicity relative to the parent compound. This finding demonstrates that fungal transformation of BUVSs can generate biologically active glycosylated or O-methylated products, emphasizing the need to identify transformation products rather than evaluating only parent-compound disappearance.