IDENTIFICATION OF SOYASAPONINS BY LIQUID-CHROMATOGRAPHY THERMOSPRAY MASS-SPECTROMETRY

Saponins are important bioactive molecules widespread in the plant kin gdom. Soyasaponins, isolated from Glicine max (Leguminosae), have been shown to exhibit various biological activities, e.g., an inhibitory e ffect on lipid-oxidation and liver-lesion generation and an improving effect on hyper-cholesteremia. Mass spectral investigation of these me tabolites requires soft ionization techniques such as desorption chemi cal ionization, fast atom bombardment and thermospray mass spectrometr y. A high-performance liquid chromatographic method was developed for thermospray mass spectrometric analysis of saponins contained in soybe an flour extracts. The analyses were performed using a ternary eluent (water-acetonitrile-methanol) in gradient conditions with post-column addition of aqueous ammonium acetate. Six saponin components could be separated and identified. The mass spectra obtained provided informati on concerning both molecular masses and aglycone composition. (C) 1997 Elsevier Science B.V.