Abstract
Antibiotics are commonly used to treat microbial infections. Due to misuse or large-scale
use of antibiotics, many pathogens have gained resistance which makes antibiotic treatments
ineffective. The discovery that many bacteria use quorum sensing (QS) to regulate
their virulence factor and pathogenicity production makes the QS system an attractive
target for antimicrobial therapy. A series of 1,3-benzoxazol-2(3H)-one derivatives were designed and synthesized as QS inhibitors (QSIs) and tested
for their QS inhibitory activities. In vitro quorum sensing inhibitor screen (QSIS)
assay indicated that the 1,3-benzoxazol-2(3H)-one (compound 1), 5-chloro-1,3-benzoxazol-2(3H)-one (compound 6), 6-methyl-1,3-benzoxazol-2(3H)-one (compound 11), and 5-methyl-1,3-benzoxazol-2(3H)-one (compound 16), inhibit QS system in quorum sensing selector (QSIS)1 strain.
These 4 QSIs also significantly reduced elastase production, biofilm formation and
swarming motility of Pseudomonas aeruginosa PA01 strain. These results suggest that compound 1, 6, 11 and 16 may provide a starting
point for the design and development of new anti-pathogenic drugs that restrict virulence
of P. aeruginosa and possibly other clinically important human pathogens. In addition, these QSI molecules
could potentially be used in combination with conventional antibiotics to increase
the efficiency of disease control and to extend the life span of established antimicrobials.
Supporting information available online at http://www.thieme-connect.de/ejournals/toc/amf
Key words
acyl homoserine lactone - quorum sensing inhibitors - 1,3-benzoxazol-2(3
H)-one