3-Epiabruslactone A, a New Triterpene Lactone Isolated from Austroplenckia populnea

A new lactonic triterpene isolated from the heartwood of Austroplenckia populnea (Celastraceae) was characterized as 3a-hydroxyolean-12-en-29,22a-olide (the g-lactone of the 3a,22a-dihydroxyolean-12-en-29a-oic acid), the 3-epimer of the abruslactone A, on the basis of its spectral data, chemical transformations, and single crystal X-ray analysis.