ABSTRACT

A very recent study published in Science reported that N-1,3-dimethylbutyl-N’-phenyl-p-phenylenediamine quinone (6PPD-quinone) is the conversion product of a tire rubber antioxidant 6PPD in natural environment, and it was also identified as the causative agent of acute mortality in Pacific Northwest coho salmon (Oncorhynchus kisutch) at an extremely low level of 95 ng/L (less than its environmental concentrations). In addition, 6PPD-quinone has been found to be present in different environmental matrices (air particles, roadside soils, dust and runoff waters), including shown to be toxic to other aquatic organisms such as rainbow trout, brook trout and zebrafish larvae, which are closely related to mankind’s activities. However, the impact of this emerging contaminant on human health remains elusive. Given this, isotope-labeled 6PPD-quinone was synthesized in our laboratory and was applied with mass spectrometry approach for investigation of the adsorption, distribution, metabolism and excretion of 6PPD-quinone in mice. It is found that 6PPD-quinone can be fast adsorption and distribute in different organs in mice. In addition, a series of novel metabolites were identified in vivo. Our research fulfilled the gap in understanding the toxicity of 6PPD-quinone and evaluating its potential health risks to mammals and humans.