The production of hypericins and hyperforin by<i>in vitro</i>cultures of St. John's wort (<i>Hypericum perforatum</i>)
Bibliographic record
Abstract
St. John's wort ( Hypericum perforatum L.) is a herbaceous perennial distributed throughout the World that has been widely used in traditional medicine. H. perforatum produces several types of biologically active compound, including the hypericins--a family of light-activated anthraquinones, localized within specialized glands found predominantly on flowers and leaves--and the hyperforins--a family of prenylated acylphloroglucinols localized in the reproductive structures of the plant. Hypericins are known to be toxic to mammals and display antiviral and anticancer activity, but the role of these compounds within the plant is unknown. Hyperforins display potent antimicrobial activity and are thought to be the primary bioactive ingredient for anti-depressive effects of the herb. The introduction of H. perforatum from Europe into the U.S.A. occurred in the 17th Century. Since the plant is considered a noxious weed, few efforts have been carried out to analyse populations in the context of secondary-metabolite concentrations. But in terms of secondary-metabolite studies, H. perforatum is an ideal model system to study the biosyntheses of aromatic polyketides and regulation of those pathways by environmental and genetic influences. This is due, in part, to the ease of conducting these studies in plant tissue culture. This review describes the progress of secondary-metabolite studies currently underway using H. perforatum. Specifically, this Review focuses on the production and regulation of the hypericins and the hyperforin in wild populations, field cultivation, greenhouse studies and plant tissue culture. Additionally, factors optimizing compound production--particularly in in vitro cultures--are presented and reviewed.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
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 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".