#$%^&*AU2014100813A420140828.pdf#####2'-Epi-uscharin from the Latex of Calotropis gigantea with HIF-1 Inhibitory Activity ABSTRACT Uscharin (compound 1) and its stereoisomer, 2'-epi-uscharin (compound 2), were isolated from the latex of Calotropis gigantea (Asclepiadaceae). The structure of compound 1 was elucidated based on its spectroscopic data and its absolute configuration was confirmed by X-ray crystallographic method. The stereochemistry of new compound 2 was determined by comparison of its spectroscopic data with those of compound 1 and its 2'-hydroxy group was proposed to be in the a-configuration based on chemical transformation. The inhibitory effects of compounds 1 and 2 on hypoxia-inducible factor1 (HIF-1) transcriptional activity were evaluated by using a T47D cell-based HREluciferase reporter assay. The present invention demonstrates that compounds 1 and 2 possess potent HIF-1 transcriptional inhibitory activity with different magnitudes. <；DocRef#00128140-CP >； M006.036.DRF 18 Spec final version1/6 O O 0 0 OOH OH OH H CH C ~ OH33 1 2 Figure 1
