Evaluation of Hydroxyl Radical Reduction Activity of Red Ginseng Extract Using ESR Spectroscopy

다국어 초록 (Multilingual Abstract)

This study was conducted in order to investigate the reduction activity of red ginseng extract (RGE; Panax ginseng, C. A. Meyer) on hydroxyl radical (·OH) using an electron spin resonance (ESR) spectrometer and spin-trapping techniques. ·OH generated by a Fenton Reaction System was trapped by 5, 5-dimethyl-l-pyrroline-N oxide (DMPO). The decay rate showed approximately pseudo-firs order kinetics over the period of measurement (by 10 min), and the half lifetime of the DMPO/·OH signal was estimated as approximately 8.15 min. However, the half lifetime of RGE/·OH was estimated as approximately 7.5 min, and the half lifetime of RGE was higher than that of DMPO/·OH adduct only. The order of reduction activities was ascorbic acid > N, Nʹ-dimethylthiourea (DMTU) > RGE > trolox > mannitol in the Fenton Reaction System. Thus, these observations indicate that RGE reaction with ·OH has relative reduction activity. The second-order rate constant of RGE/·OH may be 3.5~4.5 × 109 M-¹ ∙ S-¹.