Inactivation quercetin mutagenicity

Table 7 shows that (a) copper, ferrous and ferric sulfates have the ability to inactivate quercetin mutagenicity at pH 7, even in a... 

FACTORS WHICH FACILITATE INACTIVATION OF QUERCETIN MUTAGENICITY... 

Several factors expected to modify quercetin mutagenicity were, therefore, studied to establish optimal conditions for inactivating or suppressing the mutagenic potential of quercetin. 

Exposure of quercetin to buffers in an oxygen atmosphere had no observable effect on quercetin mutagenicity in the pH range 2 to 5. The transition point for the pH-oxygen inactivation appears to be near pH 6.5, since the number of revertants at this pH was about 440 compared to about 1000 at the lower pH values. Complete inactivation, where the number of revertants equals that observed with buffer controls, took place at pH values above 8. 

Reversibility of copper sulfate and ferrous sulface catalyzed inactivation of quercetin mutagenicity . 

Two series of experiments were carried out to evaluate the influence of temperature on quercetin inactivation. In the first, quercetin solutions were kept for three hours at pH 7.5 in the temperature range 0 to 75 c in the presence of oxygen. Table 4 shows that temperature had only a minor influence on the mutagenic activity of quercetin at pH 7.5. 

Figure 2- suggest that these expectations were indeed observed. Both absorption maxima decreased with increasing pH on exposure of an oxygen-saturated solution of quercetin to tyrosinase. The extent of the decrease in the absorption maximum near 370 nm correlated with decreased mutagenicity. Spectroscopy may therefore be useful for monitoring the mutagenic inactivation of quercetin and possibly other flavonoids. 

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