Fig. 5From: Exploration of isoxanthohumol bioconversion from spent hops into 8-prenylnaringenin using resting cells of Eubacterium limosumTheoretic calculations of undissociated fractions (HA) of substrate IX, product 8-PN and traces of bitter acids in spent hops at pH 5 (pH of stationary phase cultures in absence of pH control) versus pH 8 (maximal tolerable pH value for Eubacterium limosum), based on reported pKa values and the Henderson–Hasselbalch equation (Simpson and Smith 1992). Considering the relatively high (estimated) log P values of the most abundant antibacterial hop compounds, bioavailability via diffusion into the bacterial cells may be much altered based on the pH of the medium. %HA: undissociated fraction of the weak acids. The structures in the figure are the most commonly represented stereo form of the compoundsBack to article page