Antimicrobial Evaluation of Two Polycyclic Polyprenylated Acylphloroglucinol Compounds: PPAP23 and PPAP53
Bibliographic record
Abstract
Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. Chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here we studied two synthetic PPAP-derivatives, PPAP 23 and PPAP 53, as to their antimicrobial activity. While PPAP 23 is insoluble in water, PPAP 53, the sodium salt, is water-soluble. In vitro, both compounds exhibited good and comparable activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae, even at high concentrations. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar neutralizing effect was also seen with serum albumin. In a septic arthritis model triggered by S. aureus PPAP23 decreased the formation of abscesses and bacterial load in kidneys, and in a mouse skin abscess model topical treatment with PPAP 53 resulted in an approximately two-fold reduction in S. aureus counts. PPAP 23 and PPAP 53 also showed high growth inhibiting activity against anaerobic Gram-positive pathogenic gut bacteria such as Clostridium perfringens and Clostridium difficile. Based on these results, we envision potential application of PPAP 23 and PPAP 53 in the topical treatment of wound infections with Gram+ pathogens, and their oral use in intestinal infections with C. difficile.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.000 |
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 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".