Allicin also specifically inhibits other bacterial enzymes
such as the acetyl-CoA-forming system, consisting
of acetate kinase and phosphotransacetyl-CoA synthetase
[26]. The inhibition is noncovalent and reversible.
(14C) acetate incorporation into fatty acids of isolated
plastids was inhibited by allicin with a 50% inhibitory
concentration (I50 value) lower than 10 mM. Furthermore,
allicin at bacteriostatic concentrations (0.2 to 0.5 mM) was
found to partially inhibit, in Salmonella typhimurium, the
DNA and protein synthesis, but the effect on RNA synthesis
was immediate, suggesting that this could be a primary
target of allicin action [27]. E. coli RNA polymerase, in its
alpha-subunit, contains a single sulfhydryl group which
was shown to react with the monomercuric derivative of
fluorescein, a specific reagent for thiol groups (fluorescein
monomercuracetate) [28]. This suggests that RNA polymerase
could also be a target for allicin.