Journal of Food and Nutrition Research, 2017, Vol. 5, No. 3, 176-179 Available online at http://pubs.sciepub.com/jfnr/5/3/6 ©Science and Education Publishing DOI:10.12691/jfnr-5-3-6 Optimal Conditions for Extracting the Ginsenosides Rg3, Rg5, and Rk1 from Black Ginseng Myo Jin Kwon 1,# , Kui-Jin Kim 2,# , Byung Wook Yang 3 , Boo-Yong Lee 2 , Hyoung Chun Kim 4,* , Sung Kwon Ko 1,3,* 1 Department of Oriental Medical Food & Nutrition, Semyung University, Jecheon, Republic of Korea 2 Department of Food Science and Biotechnology, CHA University, Seongnam, Republic of Korea 3 Ginseng Research Center, Koyeon, Jecheon, Republic of Korea 4 College of Pharmacy, Kangwon National University, Chunchon, Republic of Korea # These authors contributed equally to this work. *Corresponding author: kimhc@kangwon.ac.kr; skko@semyung.ac.kr Abstract Ginseng is known to contain numerous ginsenosides, which exhibit beneficial health effects. In particular, ginsenoside Rg3, Rg5, and Rk1, derived from high temperature-processed ginseng, have higher bioactivities compared to other types of ginsenosides. In this study, we determined the optimal conditions for extraction of the valuable ginsenosides Rg3, Rg5, and Rk1 from black ginseng. Our results revealed that black ginseng extracted with 100°C distilled water for 0.5 hours and 6 hours yields large amounts of Rg3, Rg5, and Rk1 compared with other extraction times. We also found that protopanaxadiol (PPD) and protopanaxatriol (PPT) were also efficiently extracted from black ginseng with 100 °C distilled water at 0.5 hours and 6 hours and then rapidly degraded in a time-dependent manner. Therefore, we posit that short extraction times such as 0.5 hours and 6 hours might be optimal for isolation of the ginsenosides Rg3, Rg5, and Rk1 from black ginseng as opposed to longer extraction periods. Keywords: black ginseng, ginsenoside, prosapogenin, protopanaxadiol, protopanaxatriol, Rg3, Rg5, Rk1 Cite This Article: Myo Jin Kwon, Kui-Jin Kim, Byung Wook Yang, Boo-Yong Lee, Hyoung Chun Kim, and Sung Kwon Ko, “Optimal Conditions for Extracting the Ginsenosides Rg3, Rg5, and Rk1 from Black Ginseng.” Journal of Food and Nutrition Research, vol. 5, no. 3 (2017): 176-179. doi: 10.12691/jfnr-5-3-6. 1. Introduction Ginseng radix (Panax ginseng Meyer) is used worldwide in the treatment of certain diseases [1,2,3,4,5]. Shin-Nong-Bon-Cho-Kyung, the oldest oriental medicine reference book, first noted that ginseng can be used as a herbal medicine to strengthen activities of the five internal organs and increase stamina [6]. Ginseng is known to contain a number of ginsenosides that exhibit anti-inflammatory, anti-oxidant, anti-obesity, and anti-cancer effects [7,8,9,10,11]. The majority of commercial ginseng is separated into three different types, fresh ginseng, white ginseng, and red ginseng, depending on the food processing method used, such as clean, dry, or steam with high pressure [12,13]. Moreover, fresh ginseng, white ginseng, and red ginseng contain two classes of ginsenosides, including protopanaxadiol (PPD: Rb1, Rb2, Rb3, Rc, Rd, Rg3, and Rh2) and protopanaxatriol (PPT: Rg1, Rg2, Rh1, Re, and Rf) [14,15,16]. Both PPD and PPT are converted during food processing. In particular, high pressure steaming produces enhanced activity of bio-transformed ginsenosides, such as Rg3 and Rh2, resulting in increased pharmacological effects of red ginseng [12,17]. Recently, several reports have suggested that black ginseng, which refers to high pressure steaming and drying of fresh ginseng, contains not only more of the ginsenosides PPD and PPT than red ginseng does (at least nine times) but also has a high quantity of unique types of ginsenosides, i.e., Rg5 and Rk1 [18,19]. The ginsenosides Rg3, Rg5, and Rk1 in black ginseng appear to be promising bioactive compounds for the prevention of certain types of diseases, including obesity, cancer, and inflammation [20,21,22]. However, no studies have attempted to optimize their isolation from black ginseng. In the this study, we determined the effect of different extraction times under chemical hydrolyzing conditions on the recovery of the ginsenosides Rg3, Rg5, and Rk1 from black ginseng. 2. Materials and Methods 2.1. Materials Black ginseng (Panax ginseng) was purchased from Ganghwa Cheonto Heuksam (Incheon, South Korea) in September, 2014. Ginsenoside standards were purchased from Chromadex (St. Santa Ana, CA, U.S.A.) and the Ambo Institute (Seoul, Korea). Diethyl ether and n- butanol were purchased from Sigma (St. Louis, MO, USA). Acetonitrile (HPLC grade, >99.9% purity) and distilled water (HPLC grade, >99.9% purity) were purchased from JT Baker Inc. (Phillipsburg, NJ, USA).