New Alkaloids, Sessilifoliamides K and L from the Roots of Stemona sessilifolia
Plants belonging to the genus Stemona (family Stemonaceae) are noted for producing a series of alkaloids with unique structures, most of which are characterized by incorporating a pyrrolo[ 1,2-a]azepine core. Of the genus Stemona plants, Stemona japonica (Blume) Miq., S. tuberosa Lour., and S. sessilifolia Franch. & Sav. have been used in China and Japan as an insecticide and also as a remedy for cough, and their biological activities are considered to be related to their alkaloid components. In our studies on the chemical constituents of S. sessilifolia, we isolated eleven new alkaloids, sessilifoliamides A – J and sessilifoliamine A, with novel alkaloid skeletons. In this meeting, the isolation and structure determination of further new Stemona alkaloids, sessiliamides K and L are represented.