Chemical Constituents from Clerodendrum bungei and Their Cytotoxic Activities

A new phenylethanoid glycoside, two new cyclohexylethanoids, one new phenolic glycoside, and a new farnesane‐type sesquiterpenoid, namely 2‐phenylethyl 3‐O‐(6‐deoxy‐α‐L‐mannopyranosyl)‐β‐D‐glucopyranoside (1), 6″‐O‐[(E)‐caffeoyl] rengyoside B (2), clerodenone A (3), 2‐({6‐O‐[(4‐hydroxy‐3‐methoxyphenyl)carbonyl]‐β‐D‐glucopyranosyl}oxy)‐2‐methylbutanoic acid (4), 2‐{(2S,5R)‐5‐[(1E)‐4‐hydroxy‐4‐methylhexa‐1,5‐dien‐1‐yl]‐5‐methyltetrahydrofuran‐2‐yl}propan‐2‐yl β‐D‐glucopyranoside (5), together with 16 known compounds, were isolated from the roots of Clerodendrum bungei. All structures were elucidated by spectroscopic methods. The new compounds showed modest in vitro inhibition of the proliferation of the HeLa human cervical carcinoma cell line (CCL‐2), with IC50 values in the range of 3.5–8.7 μM, adriamycin being used as positive control, with an IC50 value of 0.026±0.001 μM.