Arundinosides I – IX and graminifolosides A – B: 2R-benzylmalate and 2R-isobutylmalates derivatives from Arundina graminifolia
Bibliographic record
Abstract
Glucosyloxybenzyl 2R-benzylmalate and glucosyloxybenzyl 2R-isobutylmalate derivatives are structurally unique group of plant metabolites that occurs primarily in the family Orchidaceae. There are very limited studies reporting this class of compounds due to their rare occurrence in nature. Arundina graminifolia D.Don Ochr. popularly known as bamboo orchid is widely distributed in subtropical Asia, particularly in Southeast Asian countries [ 1 ]. The roots/rhizomes and leaves are used for treating food poisoning, blood stasis, bacterial infections and rheumatism [ 1 ], [ 2 ]. A. graminifolia is a rich source of bibenzyls phenanthrenes, phenolics and glucosyloxybenzyl 2R-benzylmalate derivatives [ 1 ], [ 3 ], [ 4 ], [ 5 ]. As a furtherance to the studies on the bioactive constituents from A. graminifolia led to the isolation of eleven new compounds. Dried undergrounds parts of A. graminifolia were extracted with ethanol and the concentrated extract was partitioned into CH 2 Cl 2 and EtOAc and H 2 O fractions. The EtOAc fraction was subjected to centrifugal partition chromatography, sephadex LH-20 and semi preparative RP-HPLC to afford nine new glucosyloxybenzyl 2R-benzylmalate, arundinosides I – IX (1 – 9) and two new glucosyloxybenzyl 2R-isobutylmalates, graminifolosides A – B (10 – 11) ([ Fig. 1 ]). The structures were deduced using spectroscopic techniques including NMR and HRMS as well as comparing with previous literatures. Compounds 3 – 8 showed potent antioxidant activities in the ABTS radical scavenging, DPPH radical scavenging and FRAP activities. Furthermore, the compounds exerted minimal cytotoxic effects against RAW 264.7 cells and cytoprotective effects against hydrogen peroxide induced cell toxicity. Fig. 1 Publication History Article published online: 12 December 2022 © 2022. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".