Isolation and Characterization of Biologically Active Secondary Metabolites Produced by Foliar Endophytes of Red and Black Spruce from the Acadian Forest
Bibliographic record
Abstract
The spruce budworm is the most economically important destructive insect pest affecting North American forests.Some endophytes, isolated from the Acadian forest, produce secondary metabolites, toxic to the spruce budworm in planta.The aim of this study was to investigate the biologically active extracts of endophytes of red (Picea rubens) and black spruce (P.mariana).This was hypothesized to result in the isolation of antifungal and antiinsectan metabolites with structural similarities to related pathogenic toxins.From this investigation, 13 secondary metabolites were isolated.Three macrocyclic lactones (1-3) were characterized from Nectria dacryocarpa.Five aromatic polyketides (4-8) were isolated from two unique species of Penicillium cf.glaucoalbidum belonging to the Thysanophora sect.One small amino acid derived molecule, tyrosol (9) was isolated from the endophyitc P. cf. glaucoalbidum.Four lachnellulone related compounds (10-13) were isolated from Lachnellula cf.calyciformis including two new compounds (12, 13).Most purified secondary metabolites inhibited the growth of test microorganisms in vitro, including Saccharomyces cerevisiae, Bacillus subtilis, Escherichia coli, and Microbotryum violaceum.
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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".