Antioxidant Activity of Vitex rotundifolia Seeds and Phytochemical Analysis Using HPLC-PDA

This study assessed in vitro antioxidant activity (ABTS+ and DPPH) of Vitex rotundifolia seeds collected from two different regions in Korea (Jungjang City and Sindu City). Three extraction methods using ethanol, methanol, and water were prepared separately and subjected to quantification by reverse-phase highperformance liquid chromatography-photodiode array (HPLC-PDA) analysis as well as antioxidant testing.Among them, the water-based extract exhibited superior activity in the ABTS+ compared with the ethanol- and methanol-based extracts, while the DPPH assay analysis, revealed that the methanol-based extract had very low antioxidant activity. The concentrations of vanillic acid (1), luteolin (2), vitexicarpin (3), and artemetin (4) were quantified using HPLC-PDA analysis. Vanillic acid (1) was identified as the main antioxidant in V. rotundifolia seeds. Combining the antioxidant activity and quantitative analysis results, the water-based extract was considered to have the highest antioxidant activity. Furthermore, vanillic acid (1) was detected in the leaves and stems of V. rotundifolia plants from different regions, indicating that this species has the potential for use in future antioxidant-applications.

Analysis of the Total Polyphenol, Flavonoid, and Phenolic Acid Contents in Three Different Leaf Types of Lepidium sativum

Lepidium sativum (LS) is an annual plant that has been used for the treatment of many ailments. The ethanol extracts of pinnately-lobed (PL), pinnately-compound (PC), and pinnately-veined (PV) leaves of LS were examined for their total polyphenol and flavonoid contents, and their phenolic acid (namely caffeic acid (CA), p-coumaric acid (PA), and ferulic acid (FA)) contents were determined using reverse-phase high-performance liquid chromatography-photodiode array (HPLC/PDA) analysis. Among the three leaf types, the highest average total polyphenol content was found in PV (79.87 mg GAE/g extract), whereas PC showed the highest average total flavonoid content (53.35 mg QE/g extract). According to the HPLC/PDA results, PV exhibited a high amount of CA (78.60 µg/g extract) and FA (1,722.85 µg/g extract), whereas a high content of PA (258.72 µg/g extract) was detected in PC. Higher amounts of the phytochemical compounds PV and PC might be indicative of their superior biological activities compared to PL. To the best of our knowledge, this study is the first to quantify and compare the total polyphenol, flavonoid, and phenolic acid contents in three different leaf types of LS.