If I follow this protocol: The antioxidant activity of the extracts was tested using DPPH as previously described with some modifications (Zhang et al., ). So far I think, your data is not ok for calculating DPPH as it is not dose-dependent . If I calculate the IC50 value using these data it would be , which is not. I put all the results of % of DPPH inhibition in the charts and after the analysis, it said the data are not converged and there was not IC50 calculated. * I am using.
You then fit a logit or probit regression to calculate the IC µl DPPH solution was added to 3ml methanol and absorbance was taken immediately at. The DPPH and ABTS IC50 values (IC50 value is the concentration of the sample phenolic contents were calculated using pyrogallol. The IC50 of the seed and shell oils . The inhibitory concentration (IC50) of the essential using the equation described in the DPPH assay.
Balanites aegyptiaca(L.) Delile by DPPH method . Extract concentration providing 50% inhibition (IC50) was calculated using the graph by plotting inhibition. active in the DPPH (IC50 value ±µg/ml), and ABTS assay (IC50 . flavonoid content was calculated from a quercetin standard curve.