팽화 홍삼으로부터 20(S)-Ginsenoside Rg₃와 Rg₅의 분리 및 구조동정

Red ginseng tail roots (9.8 g water/100 g sample) were puffed at 7, 8, 9, and 10 kg_f/cm² using a rotational puffing gun. Puffed red ginseng was extracted with 70% ethanol, and the concentrated extract was successively partitioned with diethyl ether, n-butanol and H₂O. Two unknown ginsenosides from puffed red ginseng were found at 63 and 65 min of retention time in HPLC chromatogram suggesting that chemical structure of some ginsenosides might be altered during the puffing process. Identification of two unknown compounds was carried out using TLC, HPLC and NMR. Two major compounds were isolated from TLC. According to TLC result, compound I was expected to be the mixture of ginsenosides Rk1 and Rg5, and compound II was expected to be a 20(S)-ginsenoside Rg₃. Three compounds were isolated from n-butanol fraction through repeated silica gel and octadecyl silica gel column chromatographies. From the result of ¹H- and ¹³C-NMR data, the chemical structures of unknown compounds were determined as ginsenoside Rg₅ and 20(S)-ginsenoside Rg₃. Unfortunately, ginsenoside Rk₁ could not be separated from ginsenoside-Rg₅ in the compound I. It was carefully reexamined using HPLC and confirmed that the last unknown compound was ginsenoside-Rk₁.