Herbal Yield, Secondary Metabolites and Antioxidant Activities of Piper sarmentosum Roxb. affected by Different Harvest Maturity

The aim of this study was to assess the yields, total flavonoid content, total phenolic content, and antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 2,2'–azion–bis-3–ethylbenzothiazo line–6-sulphonic acid (ABTS) radical scavenging activity of Piper sarmentosum Roxb. tested after different harvesting maturity (30, 60, 90, and 120 days after planting). A completely randomised design was determined for the field experiments at the Department of Medicinal Plant Science, Faculty of Agricultural Production, Maejo University, Thailand. Results showed that the highest weight for fresh and dried leaves and total flavonoid content were observed at harvesting maturity of 90 days after planting with values of 18.03 ± 0.04 g fresh weight (FW)/plant, 4.08 ± 0.03 g dried weight (DW)/plant, and 4.52 ± 0.16 mg quercetin equivalent (mgQE)/g dried sample, respectively. Furthermore, the harvesting maturity at 120 days also gave the highest total phenolic content (14.53 ± 0.18 mg gallic acid equivalent (mgGAE)/g dried sample) and antioxidant activities in Piper sarmentosum Roxb.