posted on 2016-10-25, 00:00authored byAbhishek Bhattacherjee, Yuliya Hrynets, Mirko Betti
Fructosazine
is a polyhydroxyalkylpyrazine recently reported to
have antimicrobial activity against heat-resistant Escherichia
coli AW 1.7. This study investigated fructosazine’s
antimicrobial mechanism of action and compared it to that of riboflavin.
Fructosazine–acetic acid was effective in permeabilizing the
outer membrane based on an evaluation of bacterial membrane integrity
using 1-N-phenyl-1-naphthylamine and propidium iodide.
The uptake of fructosazine by E. coli was pH-dependent
with a greater uptake at pH 5 compared to pH 7 for all times throughout
16 h, except 2, 3, and 10 h. Fructosazine generates 1O2, which is partially why it damages E. coli. DNA fragmentation was confirmed by fluorescence microscopy, and
the fructosazine–acetic acid was the second most intense treatment
after riboflavin–acetic acid. Electron microscopy revealed
membrane structural damage by fructosazine at pH 5 and 7. This study
provides evidence that fructosazine exerts antimicrobial action by
permeabilizing the cell membrane, damaging membrane integrity, and
fragmenting DNA.