Two new alkaloids have been isolated from the combined alkaloids of the epigeal part of Korolkowia sewerzowii Regel.: a base with mp 272-274°C (methanol) and the alkaloid korselidine. As a result of a study of the chemical and physical properties of the alkaloid itself and of the products of its transformation, the structure and partial configuration of 3β, 6β, 20β-trihydroxy-27α-methylcevanine has been established for korselidine. © 1989 Plenum Publishing Corporation.