Table 2.
Antibacterial activity against S. epidermidis LMG 10474 and S. aureus LMG 8224 at 24 h, of neat and drug-loaded electrospun CA- and PCL-based nanofibers and SAR study of pure compounds comprising the A/S mixture
| Zone of inhibition (mm) | ||||
|---|---|---|---|---|
| Sample |
S. epidermidis LMG 10474 |
S. aureus LMG 8224 |
||
| CA-n | – | – | ||
| CA-AS005 | – | – | ||
| CA-AS01 | – | – | ||
| CA-AS1 | 10.10 ± 0.25 | 9.39 ± 0.16 | ||
| CA-AS5 | 13.21 ± 0.09 | 10.15 ± 1.43 | ||
| PCL-n | – | – | ||
| PCL-AS1 | 8.71 ± 0.21 | 8.39 ± 0.16 | ||
| PCL-AS5 | 10.34 ± 0.24 | 8.82 ± 0.74 | ||
| Compound (30 μg/disc) | MW a | Log P b | ||
| Deoxy-shikonin | 272.3 | 1.08c | 13.20 ± 0.22 | 12.39 ± 0.23 |
| Shikonin | 288.3 | −0.27 c | 14.82 ± 2.12 | 12.34 ± 0.64 |
| Alkannin | 288.3 | −0.27 c | 15.16 ± 0.66 | 12.66 ± 0.58 |
| Acetyl-shikonin | 330.3 | 0.66 c | 14.06 ± 1.25 | 11.87 ± 1.43 |
| Isovaleryl-shikonin | 372.4 | 1.77 c | 11.10 ± 0.94 | 9.13 ± 0.51 |
| β,β-Dimethyl-acryl-shikonin | 370.4 | 1.38 c | 10.59 ± 0.57 | 8.98 ± 0.17 |
| Dimeric A/S | 558 | 0.18 d | 9.57 ± 0.38 | 8.87 ± 0.30 |
| A/S mixture | 358.4 e | 1.35e | 10.62 ± 0.75 | 10.31 ± 0.26 |
(−) indicates that no zone of inhibition was observed
a MW molecular weight
b Log P, partition coefficient in a n-octanol/water (1:1, v/v) system
c Ordoudi et al. [24]
d ChemDraw 20.0 Professional free trial (PerkinElmer Informatics Inc., 1985–2020) software
e Calculated according to the respective values of the pure compounds and the composition of A/S mixture