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Four new prenylated phloroglucinol derivatives (+)-erectumol I (1a), (-)-erectumol I (1b), (-)-erectumol II (2a), and (+)-erectumol II (2b) were isolated from the methanol extracts of the whole plants of Hypericum erectum. These new compounds were isolated as a pair of enantiomers, respectively. The planar chemical structures and relative configurations of the new compounds were suggested by Cu-Kα X-ray diffraction analysis and been confirmed by high-resolution mass and 1D and 2D NMR spectroscopic data. The absolute configuration of the four new compounds were established by comparing the experimental and predicted electronic circular dichroism data. Isolated compounds 1b and 2b induced death of Adriamycin-treated HeLa cells. Their enantiomers 1a and 2a did not. In addition, the apparent mechanism of cell death of 1b was the inhibited expression of heat shock protein 105.

Two new pyrrole alkaloids methyl-E-mangolamide (1) and methyl-Z-mangolamide (2), four new megastigmane glycosides nandinamegastigmanes I–IV (3–6), and eight known compounds (7–14) were isolated from the methanol extract of the fruits of Nandina domestica. The structures of the new compounds were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of nandinamegastigmane I (3) was established upon comparing the experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, 1 and 2 showed cell death-inducing activity on the Adriamycin-treated HeLa cells. In addition, one of the mechanisms for cell death-inducing activity of 1 and 2 was suggested as inhibition of P-glycoprotein.

Five new cadinene-type sesquiterpenes, hibiscusterpenes I-V (1-5), and six known compounds (6-11) have been isolated from the methanol extract of the stems and the twigs of Hibiscus tiliaceus. The structures of the new compounds were elucidated based on chemical and spectroscopic evidence. The absolute stereochemistry of hibiscusterpene I (1) was determined using X-ray crystallography. For hibiscusterpene III (3), the absolute configuration was established upon comparison of the experimental and predicted electronic circular dichroism (ECD) data. Among the isolated compounds, hibiscone C (7) and syriacusin A (11) showed cytotoxic activity in HeLa cells. In addition, their cell death-inducing activity was observed using time-lapse cell imaging.