Chlorogenic acid as a natural scavenger for hypochlorous acid.

The effect of chlorogenic acid (CGA) on the killing of Escherichia coli by hypochlorous acid (HOCI) was examined. CGA prevented E. coli from bactericidal action of HOCI in a concentration-dependent manner. HOCI reacted rapidly with CGA. By comparison with the one- and two-electron oxidation products produced by peroxidase and phenolase reactions, respectively, the main product was identified as o-quinone of CGA via the formation of o-semiquinone of CGA as an intermediate The quinone form of CGA reacted further with HOCI to yield unstable product(s).