Rapid identification and preparative isolation of antioxidant components in licorice

• Published in: Journal of separation science 2010-03, Vol.33 (4-5), p.664-671
• Main Authors: Sil Lee, Yeon, Ha Kim, Seon, Kyu Kim, Jin, Shin, Hyun-Kyung, Kang, Young-Hee, Yoon Park, Jung Han, Lim, Soon Sung
• Format: Article
• Language: English
• Subjects: Antioxidants; Antioxidants - analysis; Antioxidants - chemistry; Aroma and flavouring agent industries; Benzopyrans - analysis; Benzopyrans - chemistry; Biological and medical sciences; Chromatography; Chromatography, High Pressure Liquid; Flavonoids - analysis; Flavonoids - chemistry; Food industries; Fundamental and applied biological sciences. Psychology; General pharmacology; Glycyrrhiza - chemistry; Glycyrrhiza uralensis; High speed; High-speed counter-current chromatography; Isoflavones - analysis; Isoflavones - chemistry; Isoflavonoid; Medical sciences; Molecular Structure; On-line HPLC-ABTS+· bioassay; On-line systems; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Purity; Radicals; Scavenging; Solvents; Time Factors
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.200900620

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 ¹H- and ¹³C-NMR analysis.