Structure and configuration of stenanzine

From the total alkaloids isolated by chloroform extraction of the epigeal part ofRhinopetalum stenantherum a new base has been isolated — stenanzine — with mp 203–205°C, [α]_D-44°, C₂₇H₄₃NO₃. On the basis of a study of the IR, NMR, and mass spectra of stenanzine and its conversion products the configuration and structure of 3β,23α-dihydroxy-5α-veratr-12-enin-6-one have been established for this alkaloid.