title: Rapid identification and preparative isolation of antioxidant components in licorice.
abstract: This study employed the online HPLC-2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate radical cation (ABTS(+*)) bioassay to rapidly determine antioxidant compounds occurring in the licorice extract of Glycyrrhiza uralensis. The negative peaks of the ABTS(+*) radical scavenging detection system, which indicated the presence of antioxidant activity, were monitored by measuring the decrease in absorbance at 734 nm. The ABTS(+)-based antioxidant activity profile showed that three peaks exhibited antioxidant activity, and then the high-speed counter-current chromatography technique of preparative scale was successfully applied to separate the three peaks I-III in one step from the licorice extract. The high-speed counter-current chromatography was performed using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (6.5:5.5:6:4, v/v). Yields of the three peaks, dehydroglyasperin C (I, 95.1% purity), dehydroglyasperin D (II, 96.2% purity), and isoangustone A (III, 99.5% purity), obtained were 10.33, 10.43, and 6.7% respectively. Chemical structures of the purified dehydroglyasperin C (I), dehydroglyasperin D (II), and isoangustone A (III) were identified by ESI-MS and (1)H- and (13)C-NMR analysis.
authors.affiliation: Center for Efficacy Assessment and Development of Functional Foods and Drugs, Hallym University, Chuncheon, Republic of Korea.
authors.forename: Yeon Sil
authors.initials: YS
authors.lastname: Lee
authors.forename: Seon Ha
authors.initials: SH
authors.lastname: Kim
authors.forename: Jin Kyu
authors.initials: JK
authors.lastname: Kim
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Shin
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Kang
authors.forename: Jung Han Yoon
authors.initials: JH
authors.lastname: Park
authors.forename: Soon Sung
authors.initials: SS
authors.lastname: Lim
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D001578:Benzopyrans / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D006035:Glycyrrhiza / Q000737:chemistry*; D007529:Isoflavones / Q000032:analysis* / Q000737:chemistry; D015394:Molecular Structure; D013997:Time Factors
chemical_list: D000975:Antioxidants; D001578:Benzopyrans; D005419:Flavonoids; D007529:Isoflavones; C551631:isoangustone A; C548688:dehydroglyasperin C; C551630:dehydroglyasperin D