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Record W6982345965

Identification and characterization of melatonin in medicinal plants : Feverfew, Huang-qin and St. John's Wort

2000· dissertation· en· W6982345965 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueThe Atrium (University of Guelph) · 2000
Typedissertation
Languageen
FieldSocial Sciences
TopicEuropean Linguistics and Anthropology
Canadian institutionsnot available
Fundersnot available
KeywordsOrganogenesisMedicinal plantsMelatoninPetiole (insect anatomy)AuxinCallusTrichomeExplant culture
DOInot available

Abstract

fetched live from OpenAlex

Medicinal plants are valued for their unique complement of bioactive molecules. However in most medicinal plant species, the bioactive compounds have not been completely characterized and the use of these plants as phytopharmaceuticals is based largely on anecdotal evidence. The principle finding of this study was the discovery of melatonin, a neural hormone secreted by the pineal gland in mammals, in three medicinal plants viz. feverfew, Huang-qin and St. John's wort. 'In vitro' regeneration protocols were developed to minimize the potential for the contamination of the plants with indoleamines produced by fungi or bacteria. Plantlets formed via 'de novo' shoot organogenesis induced on intact seedlings, petiole or etiolated hypocotyl explants in response to thidiazuron supplementation of the culture medium. Histological examination of the cultures revealed that the regenerants were primarily 'de novo' developed shoots in all three species. The most prolific regeneration was observed in cultures of St. John's wort and this species was selected for further analyses. For biochemical characterizations, 2-month-old sterile plantlets were excised from the cultures and exposed to 14C-tryptophan in liquid medium. Radiolabel from 14C-tryptophan was recovered as 14C-indoleacetic acid, 14C-hydroxytryptophan, 14C-serotonin and 14C-melatonin. These data suggested several new possibilities for investigation of the metabolism and function of serotonin and melatonin in plant tissues. These possibilities were investigated with inhibitors of auxin and indoleamine metabolism, viz. 2,3,5-triiodobenzoic acid (TIBA), p-chlorophenoxyisobutyric acid (PCIB), p-chlorophenylalanine (p-CPA), d-amphetamine, fluoxetine (Prozac) and methylphenidate (Ritalin). ' In vitro' morphogenesis was found to be significantly affected by relative ratio of serotonin to melatonin thereby poviding the first indication of a role for indoleamine hormones in the regulation of plant morphogenesis.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.915
Threshold uncertainty score0.423

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.013
GPT teacher head0.258
Teacher spread0.245 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it