Two new guaiane-type sesquiterpenoids from Valeriana hardwickii and their cytotoxicity

Two new guaiane-type sesquiterpenoids, named 4α,5α-epoxy-8β-hydroxy-1α-hydro-α-guaiene (1) and 4α,5α-epoxy-1-hydroxy-α-guaiene (2), were isolated from the whole plants of Valeriana hardwickii. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1 and 2 showed weak cytotoxicity against the lung adenocarcinoma (A549) and hepatoma (Bel7402) cell lines with IC₅₀ values of 9.2 and 8.5 μM, respectively.