Isoduprezianane-Type Sesquiterpene and Rare Isocedrenes from <i>Ainsliaea pertyoides</i> Franch.

An isoduprezianane-type sesquiterpene (<b>1</b>), with an unprecedented skeleton, along with rare isocedrenes (<b>2-5</b>) and known sesquiterpenes (<b>6-11</b>) were identified from the aerial parts of <i>Ainsliaea pertyoides</i> Franch. The structures, including absolute configurations, were established with a combination of NMR spectroscopy, single crystal X-ray diffraction analyses, and modified Mosher's method. The effect of these compounds on HIF-2α expression was evaluated using a laboratory-developed 786-O/HRE reporter cell line, which was designed for screening of bioactive compounds targeting HIF-2α signaling in ccRCC. As a result, compounds <b>8</b>-<b>11</b> suppressed HIF-2α expression without apparent cytotoxicity and further inhibited HIF-2α-regulated endothelial cell tube formation at 5 μM.