Isoduprezianane-Type Sesquiterpene and Rare Isocedrenes from Ainsliaea pertyoides Franch. 

An isoduprezianane-type sesquiterpene (1), with an unprecedented skeleton, along with rare isocedrenes (2-5) and known sesquiterpenes (6-11) were identified from the aerial parts of Ainsliaea pertyoides 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 8-11 suppressed HIF-2α expression without apparent cytotoxicity and further inhibited HIF-2α-regulated endothelial cell tube formation at 5 μM.