Soluble Diamagnetic Model for Malaria Pigment: Coordination Chemistry of Gallium(III)protoporphyrin-IX
Bibliographic record
Abstract
The facile axial ligand exchange properties of gallium(III) protoporphyrin IX in methanol solution were utilized to explore self-association interactions by NMR techniques. Structural changes were observed, as well as competitive behavior with the ligands acetate and fluoride, which differed from that seen with the synthetic analogue gallium(III) octaethylporphyrin which lacks acid groups in its side-chains and has less solution heterogeneity as indicated by absorption and MCD spectroscopies. The propionic acid side chains of protoporphyrin IX are implicated in all such interactions of PPIX, and both dynamic metal-propionic interactions and the formation of propionate-bridged dimers are observed. Fluoride coordination provides an unusual example of slow ligand exchange, and this allows for the identification of a fluoride bridged dimer in solution. An improved synthesis of the chloride and hydroxide complexes of gallium(III) protoporphyrin IX is reported. An insoluble gallium analogue of hematin anhydride is described. In general, the interactions between solvent and the metal are found to confer very high solubility, making [Ga(PPIX)](+) a useful model for ferric heme species.
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) | 0.000 | 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".