Table 2.
Oligomers
| (a) Precursor oligomer characterization by GPCa
| |||||||
|---|---|---|---|---|---|---|---|
| sample | Mn Target g mol−1 | GPC Mn g mol−1 | nGPC | GPC Mw/Mn | MALDI Mn g mol−1 | MALDI Mw/Mn | nMALDI |
| monomer (3c, hydrolyzed) | 370 | 1080 | 2.9 | 1.04 | – | – | – |
| Oligo 1 | 740 | 3300 | 8.9 | 1.08 | 1529 | 1.11 | 3.7 |
| Oligo 2 | 1110 | 4300 | 11.6 | 1.09 | 2151 | 1.09 | 5.3 |
| Oligo 3 | 1480 | 5800 | 15.7 | 1.07 | 2642 | 1.07 | 6.7 |
| Oligo 4 | 1850 | 5900 | 16.0 | 1.09 | 2873 | 1.11 | 7.0 |
| Oligo 5 | 2220 | 6900 | 18.6 | 1.10 | 3260 | 1.08 | 8.2 |
| Oligo 6 | 2590 | 7400 | 20 | 1.08 | 3935 | 1.09 | 9.7 |
| (b) Characterization of the antimicrobial oligomers by biological assaysb
| |||||
| sample | MIC90
μg mL−1
|
HC50 μg mL−1 | selectivty
|
||
| E. coli | S. aureus | E. coli | S. aureus | ||
|
| |||||
| monomer (3c, hydrolyzed) | >200 | >200 | n.d. | n.d. | n.d. |
| Oligo 1 | 200 | <3.75 | 1050 | 5.25 | 280 |
| Oligo 2 | 100 | 6.25 | 800 | 8.0 | 128 |
| Oligo 3 | 200 | 25 | 1250 | 6.3 | 50 |
| Oligo 4 | >200 | 50 | >2000 | >10 | >40 |
| Oligo 5 | 100 | 50 | 1000 | 10 | 20 |
| Oligo 6 | 50 | 25 | 150 | 3.0 | 6.0 |
| Propyl_3k | 6.25 | 15 | 50 | 8.3 | 3.3 |
| Propyl_10k | 3.75 | 200 | <50 | <13 | <0.25 |
a
DMF, 0.01 mol L−1 LiCl, PS standards.
b
Inhibitory activity towards bacterial growth of E. coli and S. aureus bacteria (MIC90 = minimal inhibitory concentration preventing 90% bacterial growth) and hemolytic activity towards red blood cells (HC50 = concentration lysing 50% of blood cells).