Characteristic
Profiles of Benzonphenone‑3
and its Derivatives in Urine of Children and Adults from the United
States and China
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Abstract
Widespread
exposure of humans to benzophenone-3 (BP-3) is a concern
due to this compound’s potential to disrupt endocrine function.
BP-3 can be metabolized by phase I and phase II reactions of the human
cytochrome P450 system. Urinary measurements of BP-3 have been used
as a biomarker of exposure. Nevertheless, metabolic transformation
pathway and the transformation products of BP-3 in humans are still
less known. In this study, 166 urine samples collected from children
and adults in the U.S. and China were analyzed for free and total
forms (free plus conjugated) of BP-3 as well as four of its metabolic
derivatives, 4-OH–BP, 2,4-diOH–BP, 2,2′,4,4′-tetraOH–BP,
and 2,2′-diOH–4-MeO–BP, using high performance
liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). BP-3
was found in almost all urine samples from the U.S. and China. Concentrations
of BP-3 in urine from children (GM: 9.97 ng/mL) and adults (15.7 ng/mL)
in the U.S. were significantly higher than those in children (0.622
ng/mL) and adults (0.977) from China. A significant positive relationship
was found between the concentrations of urinary BP-3 and its derivatives.
The profiles of BP derivatives in urine suggested that demethylation
was a major route of BP-3 metabolism. The percentage of the free form
of BP-3 in urine was used in the determination of efficacy of phase
II metabolism among the different population groups studied. A significantly
lower percentage of the free form of BP-3 was found in urine from
the U.S. population than in the Chinese population