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

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

1.08^c

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

1.35^e

10.62 ± 0.75

10.31 ± 0.26