Isolation of bioactive 5α,8α-epidioxy sterols from the marine sponge <i>Luffariella cf. variabilis</i>
Bibliographic record
Abstract
The lipid extract of the marine sponge Luffariella cf. variabilis from Mayotte (Indian Ocean) has proven to be an extraordinarily rich source of a wide variety of unusual steroids belonging to the 5α,8α-epidioxy sterol family. Ten epidioxy sterols have been identified: 5α,8α-epidioxycholesta-6,22-dien-3β-ol, 5α,8α-epidioxycholest-6-en-3β-ol, 5α,8α-epidioxy-24(ξ)-methylcholesta-6,22-dien-3β-ol, 5α,8α-epidioxy-24(S)-methylcholest-6-en-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholesta-6,22-dien-3β-ol and its epimer (24R), 5α,8α-epidioxy-24(S)-ethylcholest-6-en-3β-ol and its epimer (24R), along with 5α,8α-epidioxy-24(ξ)-methylcholesta-6,9(11),22-trien-3β-ol. Their structures were determined by nuclear magnetic resonance (1H, 13C) and electron impact mass spectrometry. The mixture of the 10 steroids showed inhibitive activity against the human T-cell leukemia/lymphotropic virus type I (HTLV-I) and also displayed cytotoxic activity against the human breast cancer cell line (MCF7WT).Key words: Luffariella cf. variabilis, marine sponge, 5α,8α-epidioxy sterols, antitumor and antiviral activities.
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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 | 0.000 |
| 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".