Superoxide anions radical was considered as a precursor of
hydroxyl radicals. In this study, the superoxide anion radical was
generated by auto oxidation of pyrogallol in an alkalescent condition [13]. As shown in Fig. 5b, the superoxide anion radical
scavenging activities of JQPs and Vc was correlated well with
increased concentrations. At the concentration of 5 mg/mL, the
scavenging of JQPs was 30.21%. The IC50 values of JQPs cannot
determined within the test dosage range. Compared with Vc, the
superoxide anion radical scavenging activities of JQPs was much
lower.