Abstract:

From the roots of Stemona japonica(Miq), five new alkaloids, namely tuberostemonine B(1), tuberostemonine C(2), bisdehydrotuberostemonine B(3), bisdehydrotuberostemonine C(4) and isomaistemonine(5) have been isolated. Their structures were elucidated by 2D NMR, IR andMS, in comparison with the spectral data of their analogues. Compound 1 was a C-10 isomer oftuberostemonine and compound 2 was a C-9 isomer of 1. Compounds 3 and 4 were identified as thedidehydrogenated products of tuberostemonine B and tuberostemonine C respectively due to theoxidation transformation. Compound 5 was the unsaturated lactone spiral isomer of maistemonine.

Key words: Stemona japonica Miq, Stemona japonica Miq, Tuberostemonine B, Tuberostemonine B, Tuberostemonine C, Tuberostemonine C, Bisdehydrotuberostemonine B, Bisdehydrotuberostemonine B, Bisdehydrotuberostemonine C, Isomaistemonine, Bisdehydrotuberostemonine C, Isomaistemonine