Table 1.
Antibacterial activity of PABA derivatives 1.
| ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Code | R1 | R2 | MIC [µM] | |||||||||||||||
| SA | MRSA | SE | EF | EC | KP | KP-E | PA | |||||||||||
| 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | 24 h | 48 h | |||
| 1a | H | H | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1b | 5-F | H | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1c | 5-Cl | H | >500 | >500 | >500 | >500 | 62.5 | 62.5 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1d | 5-Br | H | >250 | >250 | >250 | >250 | 62.5 | 62.5 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 |
| 1e | 5-I | H | >250 | >250 | 250 | 250 | 62.5 | 62.5 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 | >250 |
| 1f | 5-NO2 | H | 500 | 500 | 500 | 500 | 250 | 250 | 500 | 500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1g | 5-CH3 | H | >500 | >500 | >500 | >500 | 250 | 250 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1h | 5-OCH3 | H | >500 | >500 | >500 | >500 | 500 | 500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1i | 5-OH | H | 500 | 500 | 250 | 250 | 250 | 250 | 500 | 500 | >500 | >500 | 500 | 500 | 500 | 500 | 500 | 500 |
| 1j | 5-tert-Bu | H | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1k | 6-Cl | H | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1l | 4-Cl | H | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1m | H | Cl | >500 | >500 | >500 | >500 | 500 | 500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1n | 5-Cl | Cl | 125 | 125 | 250 | 250 | 250 | 250 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1o | 5-Cl | Br | 15.62 | 15.62 | 31.25 | 31.25 | 15.62 | 31.25 | 62.5 | 62.5 | 500 | 500 | 500 | 500 | 500 | 500 | >500 | >500 |
| 1p | 5-Cl | I | 15.62 | 15.62 | 15.62 | 15.62 | 31.25 | 31.25 | 62.5 | 62.5 | 62.5 | 62.5 | 125 | 125 | 125 | 125 | >500 | >500 |
| 1q | 5-I | I | 62.5 | 62.5 | 62.5 | 62.5 | 62.5 | 62.5 | 500 | 500 | 500 | 500 | 500 | 500 | 500 | 500 | >500 | >500 |
| 1r | - | - | 62.5 | 62.5 | 62.5 | 62.5 | 125 | 125 | >500 | >500 | >500 | >500 | 500 | 500 | 500 | 500 | 500 | 500 |
| 1s | - | - | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1t | - | - | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| 1u | - | - | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| PABA 1 | - | - | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| BAC | - | - | 7.81 | 15.62 | 15.62 | 15.62 | 15.62 | 31.25 | 15.62 | 62.5 | >500 | >500 | >500 | >500 | >500 | >500 | >500 | >500 |
| NEO | - | - | ND | ND | ND | ND | ND | ND | ND | ND | 3.9 | 3.9 | 1.95 | 1.95 | 3.9 | 3.9 | 7.81 | 15.62 |
BAC = bacitracin; NEO = neomycin; PABA = 4-aminobenzoic acid. SA: Staphylococcus aureus CCM 4516/08; MRSA: methicillin-resistant Staphylococcus aureus H 5996/08; SE: Staphylococcus epidermidis H 6966/08; EF: Enterococcus faecalis J 14365/08. EC: Escherichia coli CCM 4517; KP: Klebsiella pneumoniae D 11750/08; KP-E: ESBL-positive Klebsiella pneumoniae J 14368/08; PA: Pseudomonas aeruginosa CCM 1961. ND = not determined. One or two of the best MIC value(s) for each strain are shown in bold.