title: Enzymatic formation of compound-K from ginsenoside Rb1 by enzyme preparation from cultured mycelia of Armillaria mellea.
abstract: BACKGROUND
  Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms.
  
  
  METHODS
  Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at 25°C for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30-80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1.
  
  
  RESULTS
  Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was Rb1 → Rd → F2 → compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72-96 h, pH 4.0-4.5, and temperature 45-55°C.
  
  
  CONCLUSIONS
  AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.
authors.affiliation: Department of Food Science and Technology, Chonbuk National University, Iksan, Korea.
authors.forename: Jitendra
authors.initials: J
authors.lastname: Upadhyaya
authors.affiliation: Department of Food Science and Technology, Chonbuk National University, Iksan, Korea.
authors.forename: Min-Ji
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Food Science and Technology, Chonbuk National University, Iksan, Korea.
authors.forename: Young-Hoi
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Bureau of General Affairs, The Korean Society of Ginseng, Seoul, Korea.
authors.forename: Sung-Ryong
authors.initials: SR
authors.lastname: Ko
authors.affiliation: Korea Ginseng Corporation Research Institute, Korea Ginseng Corporation, Daejeon, Korea.
authors.forename: Hee-Won
authors.initials: HW
authors.lastname: Park
authors.affiliation: Department of Food Science and Technology, Chonbuk National University, Iksan, Korea.
authors.forename: Myung-Kon
authors.initials: MK
authors.lastname: Kim
keywords: Armillaria mellea; compound K; enzymatic hydrolysis; ginsenoside Rb1