title: Structural characterization of phenolic antioxidants from purple perilla (Perilla frutescens var. acuta) leaves.
abstract: The antioxidant activities of various extracts from purple perilla (Perilla frutescens var. acuta) leaves based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, 2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulfonic acid) (ABTS) radical cation scavenging ability, and reducing power were investigated. Purple perilla leaves were initially extracted with 80% ethanol and then sequentially fractionated according to solvent polarity. Of all fractions, the ethyl acetate fraction had the highest antioxidant activity. This fraction was separated into four sub-fractions (sub-fractions 1-4) by Sephadex LH-20 chromatography. Of the four sub-fractions, sub-fraction 3 had the highest antioxidant activity. The EC50 values of sub-fraction 3 for DPPH radical scavenging activity and reducing power were 2.4 and 1.7 times lower than those of butylated hydroxytoluene (BHT), respectively. Based on HPLC analysis, the most abundant phenolic acid in sub-fraction 3 of purple perilla leaves was rosmarinic acid, at 314.3 mg/g. The structure of rosmarinic acid was confirmed by ESI-IT-TOF MS and NMR analysis.
authors.affiliation: Department of Food Science & Technology, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Hyun-Il
authors.initials: HI
authors.lastname: Jun
authors.forename: Beom-Tae
authors.initials: BT
authors.lastname: Kim
authors.forename: Geun-Seoup
authors.initials: GS
authors.lastname: Song
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Kim
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000737:chemistry*; D013058:Mass Spectrometry; D015394:Molecular Structure; D031344:Perilla frutescens / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D000975:Antioxidants; D062385:Hydroxybenzoates; D010936:Plant Extracts; C017616:phenolic acid
keywords: Antioxidant activity; Ethyl acetate sub-fraction; Phenolic compounds; Purple perilla leaves; Rosmarinic acid