1-hydroxypyrene glucuronide as the major aqueous pyrene metabolite in tissue and gut fluid from the marine deposit-feeding polychaete Nereis diversicolor

Both 1‐hydroxypyrene and 1‐hydroxypyrene glucuronide are identified as the primary phase I and phase II metabolites of the four‐ringed polycyclic aromatic hydrocarbon (PAH) pyrene in the marine deposit‐feeding polychaete Nereis diversicolor. Identification of pyrene and primary metabolites was performed using high‐pressure liquid chromatography (HPLC) with diode‐array detection and fluorescence detection (HPLC/DAD/F) and an ion‐trap mass spectrometer for positive identification of 1‐hydroxypyrene glucuronide. Besides 1‐hydroxypyrene and 1‐hydroxypyrene glucuronide, the HPLC/F trace of tissue samples from pyrene‐exposed worms showed three additional low‐intensity peaks that may be related to pyrene metabolism based on similar excitation/emission wavelengths. The peaks were all too low in intensity to be positively identified. Of the total PAH in tissue, 1‐hydroxypyrene glucuronide, 1‐hydroxypyrene, and pyrene constituted 73%, 2%, and 25% respectively. Gut elimination of metabolic products is supported by the identification of 1‐hydroxypyrene and 1‐hydroxypyrene glucuronide in both gut fluid and defecation water. Being the only phase I metabolite of pyrene, 1‐hydroxypyrene becomes a useful marker for PAH exposure, and it may serve as a valuable model compound for assessing species‐specific PAH metabolic capabilities.