The new base korselidine with mp 272-274°C (methanol), [α]D-75°, C27H43NO2 (I), (ethanol), composition C27H43NO2, has been isolated from the total alkaloids of the epigeal part of Korolkowia sewerzowii Regel. As a result of the study of the chemical properties of the alkaloid itself and of its products of its transformation, the structure and partial configuration of korselamine have been established as (1α,3β,-dihydroxy-Δ8,14)-cevanene. © 1989 Plenum Publishing Corporation.