摘要
Ginsenoside compound K(GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have developed a rapid and sensitive liquid chromatography–tandem mass spectrometric method for analysis of GCK in human plasma based on formation of a lithium adduct. The analyte and paclitaxel(internal standard) were extracted from 50 m L human plasma using methyl tertbutyl ether. Chromatographic separation was performed on a Phenomenex Gemini C18 column(50 mm 2.0 mm; 5 μm) using stepwise gradient elution with acetonitrile–water and 0.2 mmol/L lithium carbonate at a flow rate of 0.5 m L/min. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions at m/z 629-449 for the GCK-lithium adduct and m/z 860-292 for the adduct of paclitaxel. The assay was linear in the concentration range 1.00–1000 ng/m L(r^2>40.9988)with intra- and inter-day precision of ±8.4% and accuracy in the range of 4.8% to 6.5%. Recovery,stability and matrix effects were all satisfactory. The method was successfully applied to a pharmacokinetic study involving administration of a single GCK 50 mg tablet to healthy Chinese volunteers.
Ginsenoside compound K(GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have developed a rapid and sensitive liquid chromatography–tandem mass spectrometric method for analysis of GCK in human plasma based on formation of a lithium adduct. The analyte and paclitaxel(internal standard) were extracted from 50 m L human plasma using methyl tertbutyl ether. Chromatographic separation was performed on a Phenomenex Gemini C18 column(50 mm 2.0 mm; 5 μm) using stepwise gradient elution with acetonitrile–water and 0.2 mmol/L lithium carbonate at a flow rate of 0.5 m L/min. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions at m/z 629-449 for the GCK-lithium adduct and m/z 860-292 for the adduct of paclitaxel. The assay was linear in the concentration range 1.00–1000 ng/m L(r^2>40.9988)with intra- and inter-day precision of ±8.4% and accuracy in the range of 4.8% to 6.5%. Recovery,stability and matrix effects were all satisfactory. The method was successfully applied to a pharmacokinetic study involving administration of a single GCK 50 mg tablet to healthy Chinese volunteers.
