Characterization of Spirolides A, C, and 13-Desmethyl C, New Marine Toxins Isolated from Toxic Plankton and Contaminated Shellfish
Bibliographic record
Abstract
Three additional marine toxins, spirolides A (1), C (3), and 13-desmethyl-C (7), were isolated from contaminated scallops and phytoplankton collections obtained from a Nova Scotian aquaculture site, as well as from batch cultures of the dinoflagellate Alexandrium ostenfeldii obtained as a single-cell isolate from these phytoplankton assemblages. The structures of these new spirolide derivatives, characterized by mass spectrometry and NMR, indicate a close relationship with spirolides B (2) and D (4) isolated previously from contaminated shellfish in the same area. All of these compounds display "fast-acting" toxicity in the traditional bioassay used for monitoring shellfish, and this is related to the presence of a cyclic imine function in all these compounds. Those spirolides containing a vicinal dimethyl group in the seven-membered ring are resistant to oxalic acid hydrolysis, whereas those that do not are readily hydrolyzed. These observations suggest that the extra methyl group on the seven-membered imine ring of 3, 4, and 7 appears to block the process of imine hydrolysis perhaps by stereochemical interference.
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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) | 0.000 | 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".