Uptake, subcellular accumulation and metabolism of ¹⁴C-bisphenol S in flowering cabbage

Due to the growing environmental and health concerns surrounding bisphenol S (BPS) as a common bisphenol A (BPA) substitute, this study investigated the metabolic pathways and tissue-specific accumulation of BPS in flowering cabbage under hydroponic conditions, revealing key insights into plant detoxification processes and potential human health risks. Over a 32-day exposure of 5 mg L^{-1 14}C-BPS, 60.2 ± 3.0 % of ¹⁴C in the nutrient solution was taken up, with the ¹⁴C-radioactivity accounting for 40.2 ± 2.6 %, 5.3 ± 0.3 %, and 14.5 ± 0.6 % in roots, stems, and leaves, respectively. Older leaves retained higher levels of BPS and/or its metabolites. Using HPLC-LSC, LC-MS/MS, and subcellular fractionation, we identified four metabolites, characterized by glycosylation, malonylation, sulfation, and amino acid conjugation pathways. BPS and its metabolites were primarily located in the cell wall, plastid, and soluble component. The segregation of BPS and metabolites into the cell wall and plastid resulted in the formation of large amounts of non-extractable residues in roots. Results highlight that BPS metabolites, particularly glycosylated forms like M526, may accumulate in edible plant parts. These findings advance understanding of BPS metabolism in plants, underlining the potential food safety risks posed by its uptake and metabolism in agricultural systems.