Investigation of the Hydrolysis of Ginsenosides by High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry

Abstract

The hydrolysis of ginsenoside standards and the crude extracts of ginseng has been investigated at different pH values (2.4 - 11.2) using high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS). The experimental results indicated that the pH value of aqueous solutions is an important factor in changing the composition of ginsenosides. For (20S)-protopanaxadiol ginsenosides, ginsenosides with a large mass hydrolyzed to form hydrolysates (20S)-Rg₃ and (20R)-Rg₃ at pH 4.3. There were more hydrolyzed products observed at pH 3.3: (20S)-F₂, C-25,26 hydrated ginsenoside ”C-Y₁” and ”C-Y₂” (MW = 802 Da) accompanied with (20S)-Rg₃, (20R)-Rg₃. At pH 2.4, only (20R)-Rg₃, (20S)-F₂, a small quantity of (20S)-Rg₃ and three C-25,26 hydrated ginsenosides were obtained. For (20S)-protopanaxatriol Re, no hydrolysates were observed at pH 4.3; it was hydrolyzed at pH 3.3 to form hydrolysates (20S)-Rg₂, (20R)-Rg₂ and hydrated C-25,26 (MW = 802 Da) and at pH 2.4 only C-25,26 hydrated ginsenosides ”C-Y₁” and ”C-Y₂” (MW = 802 Da) were left in the solution. Similar hydrolysis reactions could be also observed for the crude extracts of ginseng. It showed that HPLC/ESI-MS is a fast and convenient method to study the hydrolysis of ginseng.

Key words

Hydrolysis - ginseng - Panax ginseng - Panax quinquefolius - Araliaceae - ginsenoside - HPLC-ESI-MS

References

• 1 Metori K, Furutsu M, Takahashi S. The preventive effect of ginseng with du-zhong leaf on protein metabolism in aging.  Biol Pharm Bull. 1997;  20 237-42.
• 2 Attele A S, Wu J A, Yuan C S. Ginseng pharmacology: multiple constituents and multiple actions.  Biochem Pharmacol. 1999;  58 1685-93.
• 3 Yun T K, Choi S Y. Nonorgan specific cancer prevention of ginseng: a prospective study in Korea.  Int J Epidemiol. 1998;  27 359-64.
• 4 Pietta P, Mauri P Rava A. Hydrolysis of ginsenosides in artificial gastric fluid monitored by high-performance liquid chromatography.  J Chromatogr. 1986;  362 291-7.
• 5 Feng Z Y, Zhang Y. Degradation of ginsenosides under mild acidic conditions monitored by high performance liquid chromatography.  J Chin Pharm. 1997;  32 772-4.
• 6 Feng Z Y, Zhang Y, Pei J. Degradation of ginsenosides under mild acidic conditions monitored by high performance liquid chromatography.  J Dalian Univ. 1997;  7 84-7.
• 7 Miyamoto E, Odashima S, Kitagawa I. Stability kinetics of ginsenosides in aqueous solution.  J Pharm Sci. 1984;  73 409-10.
• 8 Nagai M, Ando S, Tanaka N, Tanaka O, Shibata S. Chemical studies on the oriental plant drugs. XXVIII. Saponins and sapogenins of ginseng: stereochemistry of the sapogenin of ginsenoside Rb₁, Rb₂ and Rc.  Chem Pharm Bull. 1972;  20 1212-6.
• 9 Han B H, Park M H, Han Y N, Woo L K. Degradation of ginseng saponins under mild acidic conditions.  Planta. Med1982;  44 146-9.
• 10 Bae E A, Han M J, Kim E J, Kim D H. Transformation of ginseng saponins to ginsenoside Rh₂ by acids and human intestinal bacteria and biological activities of their transformants.  J Arch Pharm Res. 2004;  27 61-7.
• 11 Liu S Y, Cui M, Liu Z Q, Song F R, Mo W J. Structural analysis of saponins from medicinal herb using electrospray ionization tandem mass spectrometry.  J Am Soc Mass Spectrom. 2004;  15 133-41.
• 12 Liu J HC, Staba E J. The ginsenosides of various ginseng plants and selected products.  J Nat Prod. 1980;  43 340-6.
• 13 Corthout J, Naessens T, Apers S, Vlietinck A J. Quantitative determination of ginsenosides from Panax ginseng roots and ginseng preparations by thin layer chromatography - densitometry.  J Pharm Biomed Anal. 1999;  21 187-92.
• 14 Cui J F. Identification and quantification of ginsenosides in various commercial ginseng preparations.  Eur J Pharm Sci. 1995;  3 77-85.
• 15 Ren G X, Chen F. Simultaneous quantification of ginsenosides in american ginseng (Panax quinquefolium) root powder by visible/near-infrared reflectance spectroscopy.  J Agric Food Chem. 1999;  47 2771-5.
• 16 Chen Y, Sorensen L K. Determination of marker constituents in radix glycyrrhizae and radix notoginseng by near infrared spectroscopy.  J Anal Chem. 2000;  367 491-6.
• 17 Chuang W C, Sheu S J. Determination of ginsenosides in ginseng crude extracts by high-performance liquid chromatography.  J Chromatorgr A. 1994;  685 243-51.
• 18 Samukawa K, Yamashita H, Matsuda H, Kubo M. Simultaneous analysis of saponins in ginseng Radix by high performance liquid chromatography.  Chem Pharm Bull. 1995;  43 137-41.
• 19 Chuang W C, Wu H K, Sheu S J. A comparative study on commercial samples of ginseng radix.  Planta Med. 1995;  61 459-65.
• 20 Cui M, Song F R, Liu Z Q, Liu S Y. Rapid identification of saponins in plant extracts by electrospray ionization multi-stage tandem mass spectrometry and liquid chromatography/tandem mass spectrometry.  Rapid Commun Mass Spectrom. 2000;  14 1280-6.
• 21 Fuzzati N, Gabetta B, Jayakar K, Pace R, Reter-longo F. Liquid chromatography-electrospray mass spectrometric identification of ginsenosides in Panax ginseng roots.  J Chromatogr A. 1999;  854 69-79.
• 22 Cai Z W, Qian T X, Wong R NS, Jiang Z H. Liquid chromatography-electrospray ionization mass spectrometry for metabolism and pharmacokinetic studies of ginsenoside Rg3.  Anal Chim Acta. 2003;  492 283-93.