<p>The search for antibacterial agents for the combat
of nosocomial infections is a timely problem, as antibiotic-resistant bacteria continue
to thrive. The effect of indoline substituents on the antibacterial properties
of aminoalkylphenols was studied, leading to the development of a library of
compounds with minimum inhibitory concentrations (MICs) as low as 1.18 µM. Two novel aminoalkylphenols were identified as particularly promising,
after MIC and minimum bactericidal concentrations (MBC) determination against a
panel of reference strain Gram-positive bacteria, and further confirmed against
40 clinical isolates (<i>Staphylococcus
aureus</i>, <i>S. epidermidis</i>, <i>Enterococcus</i> <i>faecalis</i>,<i> E. faecium</i>, and<i> Listeria monocytogenes</i>). The same two
aminoalkylphenols displayed low toxicity against two <i>in vivo</i> models (<i>Artemia salina</i> brine shrimp and <i>Saccharomyces cerevisiae</i>)<i>.
</i>The <i>in vitro</i> cytotoxicity evaluation
(on human keratinocytes and human embryonic lung fibroblast cell lines)
of the same compounds was also carried out. They demonstrated a particularly
toxic effect on the fibroblast cell lines, with IC<sub>50</sub> in the 1.7-5.1 mM range, thus narrowing their
clinical use. The desired increase in the antibacterial properties of the
alkylaminophenols, particularly indoline-derived phenolic Mannich bases, was
reached by introducing an additional nitro group in the indolinyl substituent
or by the replacement of a methyl by a bioisosteric trifluoromethyl substituent.
Notably, the introduction of an additional nitro moiety did not confer added
toxicity to the alkylaminophenols.</p>
Establishment and characterization of equine fibroblast cell lines transformed in vivo and in vitro by BPV-1: Model systems for equine sarcoids
