Identification of methylated avenanthramides in human plasma
Bibliographic record
Abstract
Avenanthramides (AVs) are phytochemicals unique to oats consisting of an anthranilic acid and hydroxycinnamic acid linked by a pseudo‐peptide bond. We have demonstrated AV bioavailability to be low in hamsters and humans, suggesting they may be metabolized by phase II enzymes to facilitate their rapid excretion. Thus, we sought to identify the presence of phase II metabolites of 6 dominant AV isomers (A, B, C, O, P, and Q). AV‐A, ‐B, and ‐C differ in the moiety at position 3 (A: ‐H; B: ‐CH 3 O; and C: ‐OH) of the cinnamic acid ring, and AV‐O, ‐P, and ‐Q correspond to A, B, and C in terms of position 3 but differ in the length of the pseudo‐peptide linkage. We conducted a placebo‐controlled, crossover study in 10 healthy adults (60.4 y, BMI = 25.3). Blood was collected at 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, and 24 h after consumption of a muffin made with either 20 g AV‐enriched oat bran (containing 46.2 mg total AVs) or regular oat bran. After removal of lipids with hexane, AV phase II metabolites in the defatted plasma were extracted twice with ethyl acetate, dried under N 2 , and reconstituted in 55% methanol for analysis on an Agilent UPLC‐QToF‐MS equipped with an Agilent Zorbax Extend C‐18 RR HT column (2.1 × 50 mm, 1.8 μm). Utilizing the MassHunter Qualitative Analysis software, we identified with a confidence score ≥80 for aglycones AV‐O and ‐A, and ≥90 for methylated AV‐O. Their detection is consistent with plasma AV results obtained after the removal of the glucuronide and sulfate conjugates that AV‐O and ‐A were the most abundant isomers. AV‐A was detected at fewer time points than AV‐O probably due to its much lower circulating concentrations. AV‐A had a maximum concentration (C max ) of 2.2 ± 1.6 ng/mL with the time to reach C max (T max ) at 1.9 ± 0.8 h. The C max for AV‐O was 6.4 ± 3.9 ng/mL and the T max was 2.6 ± 0.8 h, as well as 14.0 ± 8.2 ng/mL AV‐O equivalents and 1.9 ± 0.7 h for methylated AV‐O. Though AVs are extensively transformed to phase II metabolites, our analyses reveal the presence of AV‐O and ‐A aglycones in the circulation. Ours is the first report of a methylated AV metabolite following acute AV consumption. Future studies are warranted to explore the potential bioactivity of methylated AVs. Support or Funding Information Supported by USDA and PepsiCo
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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".