Alkaline-degradation products of ginsenosides from leaves and stems of Panax quinquefolium

AimTo study the alkaline-degradation products of ginsenosides from leaves and stems of Panax quinquefolium L. MethodsIsolation and purification were carried out on silica gel and HPLC; the structures of chemical constituents were elucidated by spectral analysis. ResultsFrom the alkaline-degradation products, nine compounds were identified as: 20 (S)-protopanaxadiol (I), 20(S)-dammar-25(26)-ene-3β,12β,20-triol (II), 24(R)-ocotillol (III), 20(S)-protopanaxatriol (IV), 20(S)-dammar-25(26)-ene-3β,6α,12β,20-tetrol (V), dammar-20(21),24-diene-3β,12β-diol (VI), dammar-20(21),24-diene-3β,6α,12β-triol (VII), 20(S),24(S)-dammar-25(26)-ene-3β,6α,12β,20,24-pentanol (VIII), 20(S)-dammar-23-ene-25-hydroperoxyl-3β,6α,12β,20-tetrol (IX). Conclusion The configuration of C₂₀ position of ginsenosides was not changed by alkaline-degradation. The complete assignments of ¹H and ¹³C NMR chemical shifts of four new compounds V, VII, VIII, IX, were acquired by means of 2D NMR spectra. Compound I showed antitumor effect on human colon carcinoma cells in vivtro.