Structure-Dependent <i>in Vitro</i> Metabolism of Alkyl-Substituted Analogues of Triphenyl Phosphate in East Greenland Polar Bears and Ringed Seals
Bibliographic record
Abstract
Organophosphate esters (OPEs), used as plasticizers and flame retardants, are major emerging environmental contaminants in the Arctic. OPEs of environmental interest include triphenyl phosphate (TPHP) and a growing array of alkyl-substituted TPHP analogues. Using a microsomal assay of the liver tissue of polar bears and their ringed seal prey, the comparative in vitro metabolism of TPHP was investigated relative to the analogues of isodecyl diphenyl phosphate (IDDPP), ( p-tert -butylphenyl) diphenyl phosphate (TBPDPP), tris( p-tert -butylphenyl) phosphate (TTBPP), and two tris(isopropylphenyl) phosphate isomers (T2IPPP and T4IPPP). Polar bear metabolism of the p-tert- butylphenyl-substituted OPEs, TBPDPP and TTBPP, had a substantially slower rate and percent metabolic depletion compared to those with TPHP. Isodecyl- and isopropyl-substituted OPEs, IDDPP, T2IPPP, and T4IPPP, were also more slowly depleted by polar bears than TPHP was. TPHP, IDDPP, T2IPPP, TBPDPP, TTBPP, and T4IPPP were all slowly metabolized by ringed seals. Overall, TPHP in vitro metabolism was clearly affected by o - and p -alkyl substitution that generally hindered the depletion rate. This information is important in understanding the accumulation, biotransformation, and magnification of TPHP and other OPEs in top predator polar bears and their ringed seal prey as well as transfer of OPEs between trophic levels, i.e., ringed seal to polar bears.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".