Since antioxidant activity has been considered a key characteristic
for the compounds detected, HELZJ was tested for this activity
in this study by the DPPH free radical scavenging and iron reducing
assays. We obtained an EC50 of 735.72 lg/mL for HELZJ and
40.82 lg/mL for ascorbic acid for the DPPH test, and an EC50 of
870 lg/mL for the FRAP test. In a comparative study, Silva et al.
(2011) identified an EC50 of 461.88 and 1743.05 lg/mL for leaves
and bark of Z. juazeiro, respectively, and an EC50 of 13.95 lg/mL
for ascorbic acid, where these values were in line with our finding
of lower DPPH scavenging activity in HELZJ when compared to
ascorbic acid.