Identification of the disinfection byproducts of bisphenol S and the disrupting effect on peroxisome proliferator-activated receptor gamma (PPARγ) induced by chlorination.

Bisphenol S (BPS), an alternative product to bisphenol A (BPA), has been the focus of increasing public concern due to its potential endocrine disrupting effect and its adverse effects related to metabolic disorders such as obesity. The detection of its residue in drinking water supply systems suggests that BPS can be chlorinated; however, whether its endocrine disrupting effect can be disrupted by this chlorination remains unclear. In the present study, we identified the byproducts of the reaction of BPS with chlorine and assessed the effect of the main byproducts on peroxisome proliferator-activated receptor gamma (PPARγ). BPS was chlorinated in a simulation experiment. The chlorination reaction in this study was chlorine and pH dependent, and the pseudo-first-order reaction rate constant was controlled by the chlorine concentration and pH. The reaction rate at pH 8.5 was 7 times faster than that at pH 6.5. Twenty-two byproducts were putatively identified by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-ESI-Q-ToF-MS), and five main byproducts were purified and characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The PPARγ effects of the byproducts were assayed, revealing a2-to4-fold enhancement in their activities in comparison with the parent compound.