Changes

Another antimicrobial mechanism resulting from oxidative stress has been attributed to both iso-α-acids and humulinic acids<ref name="Schurr et al, 2015"> [http://www.sciencedirect.com/science/article/pii/S0740002014002470 Schurr et al., (2015)] </ref>. Humulinic acids are either not bitter tasting or much less bitter than iso-α-acids but are similar in structure to and are formed from the degradation of iso-α-acids. This oxidative stress-driven antimicrobial activity is due to potential for oxidation-reduction (redox) reactions between Mn2+ ions and specific hop acids within the cell. Iso-α-acids or humulinic acids pass into the cell, where environmental which is due to different conditions promote redox reactions between inside (higher pH, higher Mn2+ ) and outside (lower pH, lower Mn2+) of the acidsbacterial cell<ref name="Schurr et alBehr and Vogel, 20152010"> [http://wwwaem.sciencedirectasm.comorg/sciencecontent/article76/pii1/S0740002014002470 Schurr et al142.short Behr and Vogel, (20152010)] </ref><ref name="Schurr et al, 2015"/>. These redox reactions result in Iso-α-acids or humulinic acids passing into the cell, form complexes with Mn2+ and transfer of electrons out of the cell (-----look up <ref name="Behr and Vogel, 2010)"/>. By targeted molecular modifications [http://www.sciencedirect.com/science/article/pii/S0740002014002470 Schurr et al. (2015)] determined that the Mn oxidative stress-driven antimicrobial effect of iso-α-acids was more important than antimicrobial effect of the ionophore proton transfer discussed above in the overall anitmicrobial antimicrobial activity of hops on microbes<ref name="Schurr et al, 2015"> [http://www.sciencedirect.com/science/article/pii/S0740002014002470 Schurr et al., (2015)] </ref>.