Abstract: A white crystalline powder substance (m.p. 290–292℃; [a]23D=-48.3˚) was iso- lated from the roots of Paeonia lactiflora. It was identified by chemical and spectral analysis as β-sitosterol-D-glucoside, i.e. daucosterol. It amounts to 4×10-5 of the dry material Bioassays showed that daucosterol increased the fresh weight of cucumber cotyledons, promoted the elongation of wheat coleoptiles, and delayed the destruction of chlorophyll. Daucosterol also induced the initiation of root and leaf of isolated cucumber cotyledons. These phenomena showed that daucosterol was an active phytosetroid and exhibited both auxin-like and kinetin-like activities.

Key words: Paeonia lactiflora, Daucosterol, Active phytosteroid