Discovery of Novel Inhibitors of Streptococcus pneumoniae - Recent Advances in Microbiology - page 94

compounds (Figure 4), each inhibiting the VicK' activity by more than 50% (52.8%,
54.8%, 51.6%, 61.9%, 71.1%, and 68.8%, respectively) (Figure 5), could obviously
inhibit the growth of S. pneumoniae , with MIC values below 200 μM. Moreover, their
MIC values were positively correlated with the corresponding IC50 (the concentration
of inhibiting 50% VicK' protein autophosphorylation) values (r = 0.93), which indi-
cates that the bactericidal effects of these chemicals were realized by disrupting the
VicK/R TCS system in S. pneumoniae . Chemical structures of these six compounds
are shown in Figure 4, which belong to three different classes of chemicals: one im-
idazole analogue, four furan derivatives and one derivative of thiophene (Figure 4).
Figure 4. Chemical structures of the compounds with inhibitive effects on the growth of S. pneumoniae .
These six inhibitors belong to three different classes of chemical structures: one imidazole analogue
(compound 6), four furan derivatives (compound 2, 3, 4, and 5) and one derivative of thiophene
(compound 1).