Three Types of Cytotoxic Natural Caged-Scaffolds: Pure Enantiomers or Partial Racemates
Bibliographic record
Abstract
Two rare new natural products, the neocaged-xanthone pruniflorone T (1) and the rearranged caged-xanthone pruniflorone U (3), and the known caged-xanthone cochinchinone C (2) were isolated from the roots of Cratoxylum formosum ssp. pruniflorum. The unique structures of 1-3 were determined by analysis of NMR and X-ray diffraction data. The X-ray data of 1-3 revealed that they all exist with both enantiomers in their crystal packing. Separation of 1-3 by chiral HPLC led to the isolation of three pairs of enantiomers, (-)-1/(+)-1, (-)-2/(+)-2, and (-)-3/(+)-3, and their absolute configurations were determined by analysis of single-crystal X-ray diffraction and ECD spectroscopic data. A 1:1 mixture of 1 and 3 showed potent in vitro cytotoxicity against an MCF-7 human breast cancer cell line with an IC50 value of 0.11 μg/mL.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 teacher head, 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".