Pterocarpadiols A–D, Rare 6a,11b-Dihydroxypterocarpans from Derris robusta
Bibliographic record
Abstract
The genus Derris (Leguminosae) contains about 800 species, widely distributed in tropical and subtropical parts of the world [ 1 ]. The bark and leaves of Derris species are commonly utilized as folk medicine to treat human diseases such as arthritis and eczema [ 2 ]. The extracts and reported chemical constituents exhibit antioxidant, antibacterial and pesticidal activities [ 2 ]. Previous studies show the genus is a rich source of flavonoids, isoflavonoids, pterocarpans and rotenoids [ 2 ]. As part of a BioBioPha [ http://www.chemlib.cn ] objective to assemble a large-scale natural product library very valuable in the discovery of new drug leads from nature [ 3 – 7 ], the phytochemical investigation on the twigs and leaves of Derris robusta led to the isolation of four new 6a,11b-dihydroxypterocarpans, namely pterocarpadiols A–D ( 1 – 4 ), together with 10 known pterocarpans: 1,11b-dihydro-11b-hydroxymaackiain ( 5 ) [ 8 ], 1,11b-dihydro-11b-hydroxymedicarpin ( 6 ) [ 8 ], pisatin ( 7 ) [ 9 ], variabilin ( 8 ) [ 10 ], 6a-hydroxymaackiain ( 9 ) [ 11 ], 6a-hydroxymedicarpin ( 10 ) [ 12 ], maackiain ( 11 ) [ 13 ], medicarpin ( 12 ) [ 14 ], 3-hydroxy-8,9-methylenedioxypterocarpene ( 13 ) [ 15 ], and anhydroglycinol ( 14 ) [ 16 ]. Among the known pterocarpans, compounds 5 – 10 and 14 were isolated from the genus for the first time. This paper reports the isolation and structure elucidation of pterocarpadiols A–D.
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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.002 | 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".