A method of high performance liquid chromatography coupled with diode array detection and
electrospray ionization mass spectrometry (HPLC-DAD/MS) in negative ion mode was developed for the
analysis of ginsenosides in Sheng-Mai-Yin decoction (Panax gingeng C. A. Mey, Ophiopogon japonicus
(Thunb.) Ker-Gawl, Shisandra chinensis (Turcz.) Baill.). The analyses were preformed on a
reversed-phase C18 column (4.6 mm i.d.×150 mm, 5 μm) using a binary eluent (10 mmol/L ammonium
acetate (A) and acetonitrile (B), 1 mL/min) under gradient conditions (60%A-40%A at 0-30 min,
40%A-30%A at 30-40 min). Seventeen ginsenosides (20 (R)-Rh1, Rh2, Rg3, Rg2; 20(S)-Rh1, Rh2, Rg3,
Rg2; Rf, Rg6, Rg5, F4, Rk1, Rk3, Rh4; 20 (S)- and 20 (R)-protopanaxatriol) were well separated and
detected at 203 nm by a DAD detector. The effluent from the DAD detector was introduced into the
electrospray ionization (ESI) source in a post-column splitting flow rate at 0.3 mL/min. In the mass
spectrum two major ions ［M-H］- and ［M+AcO］- were observed for ginsenoside standards (20 (R)-Rh1,
Rg3, Rh2; 20 (S)-Rh1, Rg3, Rh2; 20 (S)- and 20 (R)-protopanaxatriol) and ginsenosides in
Sheng-Mai-Yin decoction. Some other ions ［M-Glc-H］-, ［M-2Glc-H］-, ［M-Rha-H］-and ［M-Rha-Glc-H］
- were also found in the mass spectrum of ginsenosides of Sheng-Mai-Yin decoction. In the decoction
process ginsenosides changed into constituents of moderate and low polarity by hydrolysis,
isomerization and dehydration at the site of C-20 and hydrolysis reaction also occurred at the site
of C-3 or C-6. The work above presents a quick and accurate assay method which can could be used for
the qualitative analysis of ginsenosides in Sheng-Mai-Yin decoction and the quality control of
Sheng-Mai-Yin preparation.
