Papaverine 7‐<i>O</i>‐demethylase, a novel 2‐oxoglutarate/Fe<sup>2+</sup>‐dependent dioxygenase from opium poppy
Bibliographic record
Abstract
Opium poppy (Papaver somniferum) produces several pharmacologically important benzylisoquinoline alkaloids including the vasodilator papaverine. Pacodine and palaudine are tri-O-methylated analogs of papaverine, which contains four O-linked methyl groups. However, the biosynthetic origin of pacodine and palaudine has not been established. Three members of the 2-oxoglutarate/Fe(2+)-dependent dioxygenases (2ODDs) family in opium poppy display widespread O-dealkylation activity on several benzylisoquinoline alkaloids with diverse structural scaffolds, and two are responsible for the antepenultimate and ultimate steps in morphine biosynthesis. We report a novel 2ODD from opium poppy catalyzing the efficient substrate- and regio-specific 7-O-demethylation of papaverine yielding pacodine. The occurrence of papaverine 7-O-demethylase (P7ODM) expands the enzymatic scope of the 2ODD family in opium poppy and suggests an unexpected biosynthetic route to pacodine.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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 teacher head, 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".