Abstract: Two sesquiterpenoids were obtained from the extract of 70% aqueous ethanol of Saussurea involucrata kar.et kin.by means of silica gel column chromatography.Their chemical structures are elucidated on the basis of spectral analysis (IR, UV, ¹H NMR, ¹³C NMR, MS-EI, MS-FAB, HRMS), chemical transformations and comparison with authentic samples.Crystal I: m.p.244-245℃, C₂₁H₃₀O₉, 3a-OH, 11β, 13-dihydrodehydrocostuslactone-β-D-glucoside.Crystal Ⅱ m.p.> 300℃.C₂₀H₂₇NO₄; Mayer reagent test: positive, Dragendorff reagent test: positive.It is a novel sesquiterpene lactone alkaloid named as Involucratine.

Key words: Saussurea involucrata kar.et.kin, Sesquiterpene lactone, Involucratine