<i>ent</i>-Labdane Diterpenes from the Stems of <i>Mallotus japonicus</i>

Eight new <i>ent</i>-labdane diterpenoids, mallonicusins A–H (<b>1</b>–<b>8</b>), were isolated from the stems of <i>Mallotus japonicus</i>. Their structures, including the absolute configurations, were determined by extensive analyses of spectroscopic data and the ECD spectra of the Pr­(FOD)₃ complex of substrates in CCl₄. The absolute configuration of compound <b>1</b> was confirmed by single-crystal X-ray crystallography using Cu Kα radiation