Newly Identified AhR-Active Compounds in the Sediments of an Industrial Area Using Effect-Directed Analysis

Abstract

Effect-directed analysis was used to identify previously unidentified aryl hydrocarbon receptor (AhR) agonists in sediments collected from a highly industrialized area of Ulsan Bay, Korea. The specific objectives were to (i) investigate potent fractions of sediment extracts using the H4IIE-luc bioassay, (ii) determine the concentrations of known AhR agonists (polycyclic aromatic hydrocarbons (PAHs) and styrene oligomers (SOs)), (iii) identify previously unreported AhR agonists in fractions by use of GC-QTOFMS, and (iv) evaluate contributions of individual compounds to overall AhR-mediated potencies, found primarily in fractions containing aromatics with log K ow 5–8. Greater concentrations of PAHs and SOs were also found in those fractions. On the basis of GC-QTOFMS and GC-MSD analyses, 16 candidates for AhR agonists were identified in extracts of sediments. Of these, seven compounds, including 1-methylchrysene, benzo­[j]­fluoranthene, 3-methylchrysene, 5-methylbenz­[a]­anthracene, 11H-benzo­[b]­fluorene, benzo­[b]­naphtho­[2,3-d]­furan, and benzo­[b]­naphtho­[2,1-d]­thiophene, exhibited significant AhR activity. Relative potency values of newly identified AhR agonists were found to be greater than or comparable to that of benzo­[a]­pyrene (BaP). The potency balance analysis showed that newly identified AhR agonists explained 0.07–16% of bioassay-derived BaP-EQs. These chemicals were widely distributed in industrial sediments; thus, it is of immediate importance to conduct studies on sources and potential effects of those chemicals.

Substituted Two- to Five-Ring Polycyclic Aromatic Compounds Are Potent Agonists of Atlantic Cod (Gadus morhua) Aryl Hydrocarbon Receptors Ahr1a and Ahr2a

“…CHR and methylchrysenes originate from both pyrogenic and petrogenic sources, and methylchrysenes can also be formed from chrysene by bioalkylation. , CHR has previously been found in mollusks, crustaceans, and fish and appears to be diluted in the marine food webs. − CHR and its derivatives have been shown to activate rat and human AHR in vitro − and to induce Cyp1a activity in desert topminnow (Poeciliopsis lucida) hepatoma cells, and in vivo studies have indicated that CHR can activate both Ahr1 and Ahr2 in zebrafish . Unsubstituted CHR, in the current study, was found to act solely as an agonist of Ahr1a.…”

Distribution of Polychlorinated Naphthalenes in Sediment From Industrialized Coastal Waters of Korea With the Optimized Cleanup and GC-MS/MS Methods

“…Thus, the higher concentrations of PCDD/Fs and dioxin-like PCBs are expected in sediments from inner parts of bays, rivers, and streams. Kim et al (2019b) also reported the newly identified dioxin-like contaminants, such as new polycyclic aromatic hydrocarbons, in sediments from tributaries of Ulsan and Onsan Bays. Our findings indicate the cumulative risks of dioxinlike contaminants to inhabiting species in the sedimentary environments surveyed.…”

Multiple Bioassays and Targeted and Nontargeted Analyses to Characterize Potential Toxicological Effects Associated with Sediments of Masan Bay: Focusing on AhR-Mediated Potency

“…The RePs of AhR-active PAHs are summarized in Table S4. 33,34 VirtualToxLab In Silico Analysis. For compounds without reference compounds, tentative identification was completed using QSAR modeling.…”