ABSTRACT
Ginsenoside-Rg5, which is derived from high temperature-processed ginseng, exhibits beneficial health effects. In the present study, ginsenoside-Rg5 was directly and rapidly prepared through the extraction of ginseng fibrous root powder (GFRP) at atmospheric pressure. The results showed that the highest extraction yield (3.79%) was obtained under optimal conditions (extraction temperature of 85 °C, acid concentration of 0.06 mol/L, sample to solvent ratio of 1:55 g/mL and ethanol concentration of 95% after 4 h). The current method integrates the extraction of original saponins and the modification of the saponins to rare ginsenosides Rg5, which was more simpler operation, more milder preparation condition and more efficient.
ABSTRACT
Ginseng saponin, the most important secondary metabolite in ginseng, has various pharmacological activities. Many studies have been directed towards converting major ginsenosides to the more active minor ginsenoside, Rg3. Due to the difficulty in preparing ginsenoside Rg3 enzymatically, the compound has been mainly produced by either acid treatment or heating. A microbial strain GS514 was isolated from soil around ginseng roots in a field and used for enzymatic preparation of the ginsenoside Rg3. Blast results of the 16S rRNA gene sequence of the strain GS514 established that the strain GS514 belonged to the genus Microbacterium. Its 16S rRNA gene sequence showed 98.7%, 98.4% and 96.1% identity with those of M. esteraromaticum, M. arabinogalactanolyticum and M. lacticum. Strain GS514 showed a strong ability to convert ginsenoside Rb1 or Rd into Rg3. Enzymatic production of Rg3 occurred by consecutive hydrolyses of the terminal and inner glucopyranosyl moieties at the C-20 carbon of ginsenoside Rb1 showing the biotransformation pathway: Rb1-->Rd-->Rg3.
Subject(s)
Actinomycetales/metabolism , Ginsenosides/biosynthesis , Ginsenosides/metabolism , Actinomycetales/classification , Actinomycetales/genetics , Actinomycetales/isolation & purification , Biotransformation , Culture Media/chemistry , Ginsenosides/chemistry , Isomerism , Magnetic Resonance Spectroscopy , Panax/chemistry , Panax/metabolism , Plant Roots/chemistry , Plant Roots/metabolism , RNA, Ribosomal, 16S/genetics , Soil Microbiology , beta-Glucosidase/metabolismABSTRACT
A new strain, GS603, having beta-glucosidase activity was isolated from soil of a ginseng field, and its ability to convert major ginsenoside Rb(1) to minor ginsenoside or gypenoside was studied. Strain GS603 was identified as an Intrasporangium species by phylogenetic analysis and showed high ginsenoside-converting activity in LB and TSA broth but not in nutrient broth. The culture broth of the strain GS603 could convert ginsenoside Rb(1 )into two metabolites, which were analyzed by TLC and HPLC and shown to be the minor ginsenoside F(2) and gypenoside XVII by NMR.
Subject(s)
Actinobacteria/metabolism , Ginsenosides/metabolism , Soil Microbiology , Actinobacteria/genetics , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Ginsenosides/chemistry , Gynostemma/chemistry , Gynostemma/metabolism , Nuclear Magnetic Resonance, Biomolecular , Phylogeny , Plant Extracts/chemistry , Plant Extracts/metabolism , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/geneticsABSTRACT
The ability of fresh lemon (Citrus limon) to convert protopanaxadiol-type saponins into ginsenoside Rg3 was investigated, and the structures of 20(S)-ginsenoside Rg3 (1) and 20(R)-ginsenoside Rg3 (2) were identified by 1H NMR and 13C NMR spectroscopy. The experiment showed that lemon possesses the strong ability to hydrolyze ginsenosides. When protopanaxadiol-type saponins (16 mg/mL) were hydrolyzed by fresh lemon juice at 80 degrees C for 3 hrs, the conversion ratios of ginsenoside Rb1, Rb2, Rc and Rd were 92.9%, 90.0%, 96.90/0 and 55.5%, respectively, and the yields of 20(S)-ginsenoside Rg3 and 20(R)-ginsenoside Rg3 were, respectively, 31.2% and 28.3%.
Subject(s)
Citrus , Ginsenosides/chemistry , Sapogenins/chemistry , Hydrolysis , Magnetic Resonance SpectroscopyABSTRACT
Ginsenoside Rb1 is the most predominant ginsenoside in Panax species (ginseng) and the hydrolysis of this ginsenoside produces pharmaceutically active compounds. Caulobacter leidyia GP45, one of the isolates having strong beta-glucosidase-producing activity, converted ginsenoside Rb(1) to the active metabolites by 91%. The structures of the resultant metabolites were identified by NMR. Ginsenoside Rb1 had been consecutively converted to ginsenoside Rd (1), F2(2) and compound K (3) via the hydrolyses of 20-C beta-(1-->6)-glucoside, 3-C beta-(1-->2)-glucoside, and 3-C beta-glucose of ginsenoside Rb1.