GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSIS OF GINKGOLIDES PRODUCED BY GINKGO-BILOBA CELL-CULTURE

An analytical method was developed to confirm the production of ginkgolides by Ginkgo biloba cells cultured in vitro. Biomass samples were extracted for 16 h with acetone. This extract was loaded onto a silica gel column and purified by differential elution using a cyclohexane-ethyl acetate solvent system. The recoveries of ginkgolide A and ginkgolide B were x ei90% and x ei35%, respectively. Subsequently, this purified extract was trimethylsilylated for gas chromatographic separation of ginkgolide A and ginkgolide B. Flame-ionization detection was not selective enough for identification of ginkgolides A and B in the extracts. The ginkgolides were detected by coupling the gas chromatograph to a high-resolution mass spectrometer operated in the selected-ion monitoring mode. The concentration of ginkgolides A and B in culture extracts was determined by gas chromatography-mass spectrometry using deuterotrimethylsilylated ginkgolides as internal standards. This technique permitted detection of ginkgolides A and B at concentrations as low as 10(-1) pmol/mu-1 of injected purified extract.