Antioxidant Activity-Guided Isolation of Phenolic Compounds from Leaves of Vitex pinnata (Lamiaceae)

Abstract

The aim of this study is to isolate phenolic compounds from the ethyl acetate fraction of the leaves of V. pinnata Linn, which have antioxidant properties, guided by a TLC-Bioautography (Thin-layer chromatography) with a reagent of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The TLC-antioxidant bioautography technique has several advantages. It does not require a long time in testing, the sample used is small, and it can potentially obtain promising antioxidant-positive compounds.The isolation process led to obtaining two phenolic compounds. The UV-Vis, FTIR, and NMR spectrum analysis showed that the compounds were (1) p-hydroxybenzoate and (2) luteolin. Further antioxidant evaluation by DPPH assay showed a potential radical scavenging DPPH of luteolin (2) with an IC50 of 1.56±0.18 µg/mL.