Table 2.
Values for the partition constants ( ± SD) of metalloantibiotics in different membrane mimetic systems of prokaryotic and eukaryotic cells, obtained by fluorescence and UV-vis spectroscopies and molecular dynamics (MD) simulations, from [38,71,75,77,87]. Speciation under physiological conditions (pH 7.4; concentrations in the same range of those used in the partition studies).
| Metalloantibiotic and its Speciation |
Membrane Mimetic System |
Log 𝑲𝒑 | Technique |
|---|---|---|---|
| Cucpxphen 97% di-cationic; 3% mono-cationic |
DMPC | 4.15 ± 0.11 [75] | Fluorescence ST |
| POPC | 3.2 ± 0.2 [38] | Fluorescence ST | |
| POPG | 3.38 ± 0.09 [38] | Fluorescence ST | |
| POPG | 3.69 ± 0.05 [38] | UV-vis | |
| POPC | −0.25–1.18 [38] | MD simulations | |
| POPG | 1.99–2.47 [38] | MD simulations | |
| POPE:POPG (75:25) | 4.94 ± 0.02 [75] | Fluorescence ST | |
| POPE:POPG (75:25) | 4.45 ± 0.02 [75] | Fluorescence TR | |
| POPE:POPG:CL (67:23:10) | 4.50 ± 0.03 [75] | Fluorescence ST | |
| POPE:POPG:CL (67:23:10) | 4.15 ± 0.01 [75] | Fluorescence TR | |
| E. coli total lipid extract | 5.32 ± 0.09 [75] | Fluorescence ST | |
| E. coli total lipid extract | 4.65 ± 0.03 [75] | Fluorescence TR | |
| Cuerxphen 42.7% di-cationic; 50.1% mono-cationic |
DMPC | 3.40 ± 0.03 a | Fluorescence ST |
| POPE:POPG (75:25) | 4.49 ± 0.02 [87] | Fluorescence ST | |
| POPE:POPG:CL (67:23:10) | 4.67 ± 0.01 [87] | Fluorescence ST | |
| E. coli polar lipid extract | 5.18 ± 0.01 [87] | Fluorescence ST | |
| E. coli total lipid extract | 4.85 ± 0.02 [87] | Fluorescence ST | |
| Culvxphen 38.5% di-cationic; 57% mono-cationic |
DMPC | 4.36 ± 0.03 a | Fluorescence ST |
| POPE:POPG:CL (67:23:10) | 4.33 ± 0.10 a | Fluorescence ST | |
| E. coli total lipid extract | 4.26 ± 0.04 a | Fluorescence ST | |
| Cumxfxphen 82.7% di-cationic; 16.1% mono-cationic |
DMPC | N.d. [77] | Fluorescence ST |
| POPE:POPG (75:25) | 4.22 ± 0.10 [77] | Fluorescence ST | |
| POPE:POPG:CL (67:23:10) | 4.38 ± 0.01 [77] | Fluorescence ST | |
| E. coli polar lipid extract | 4.39 ± 0.02 [77] | Fluorescence ST | |
| E. coli total lipid extract | 4.75 ± 0.01 [77] | Fluorescence ST | |
| Cuspxphen 52.6% di-cationic; 38.1% mono-cationic |
POPE:POPG (75:25) | 5.05 ± 0.08 [71] | Fluorescence ST |
| POPE:POPG (75:25) | 5.04 ± 0.04 [71] | Fluorescence TR | |
| E. coli total lipid extract | 4.87 ± 0.08 [71] | Fluorescence ST | |
| E. coli total lipid extract | 5.24 ± 0.01 [71] | Fluorescence TR |
values calculated taking into account the water molar concentration (55.3 mol dm−3, at 37 ˚C [78]). a Data determined by Gameiro’s research group in liposomes prepared in HEPES buffer (10 mmol dm−3, pH 7.4, NaCl 0.1 mol dm−3). Data not published. N.d.-not possible to determine with the experimental data obtained; ST means Steady-State; TR means Time-Resolved.