Table 2.
Comparative enhanced activity of pyridinone polymers
| Activity characteristic | Polymer 16–4 (Zhou et al. 2015a, b) | DIBI (Gumbau-Brisa et al. 2020) |
|---|---|---|
| Log Keq (β3) Fe(III) monomer (pFe3+) | 33.61 (29.7) | 38.22 |
| Log Keq (β3) Fe(III) polymer (pFe3+) | n/a (29.8) | 41.05 |
| PAI-iron binding (P/M) | ~ 1 | 676 |
| MIC S. aureus monomer µM | 41 | 176 |
| MIC S. aureus polymer µM | 41 | 0.04 |
| PAI-MIC (M/P) | 1 | 4400 |
PAI-Fe binding is defined as the ratio between the polymer log Keq or pFe3+ and the monomer Keq or pFe3+. PAI-MIC is defined as the ratio between the MIC of the monomer and the MIC of the polymer: For both PAIs if < 1, polymer is less active than monomer, if PAI ~ 1, polymer and monomer have similar activity and if PAI > 1, polymer has enhanced activity over the free monomer. pFe3+ is the negative logarithm of the free ferric iron in solution at pH 7.4 for a defined concentration of ligand (10–5 M) and iron (10–6 M) (Harris et al. 1979)