Antioxidant activity optimization and GC-MS profile of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. leaves

The temperature and extraction time of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. (AEVP) leaves obtained by decoction were optimized for maximum recovery of DPPH radical scavenging activity, ABTS⁺ inhibition activity, total phenolic content (TPC) and total flavonoids content (TFC) using response surface methodology (RSM). A central composite design (CCD) of 13 experimental runs was applied and second order polynomial models were used to describe the responses of the assessed extraction parameters. The optimized conditions: 79.79 °C and 126.23 minutes were found using the composite desirability function. The scavenging activity of assessed extracts could be correlated mostly to the presence of malic acid, succinic acid, α-ketoglutaric acid, citric acid, m-hydroxybenzoic acid, caffeic acid, inositol, and β-amyrin detected by gas chromatography-mass spectrometry (GC-MS). These results have not been reported and support the potential application of AEVP as natural source of antioxidants.