Two new steroidal alkaloids, 20-isoveratramine and verapatuline, from the roots and rhizomes of veratrum patulum

Roots and rhizomes of Veratrum patulum L. (Liliaceae), used as a source of the Chinese crude drug "Li-lu", have yielded two new steroidal alkaloids, 20-isoveratramine (1) and verapatuline (2), along with three known alkaloids, veratramine (3), veratrosine (4), and jervine (5). Structures of new alkaloids 1 and 2 were determined to be a C-20 epimer of 3 and N-(methoxycarbonyl)jervine, respectively, by the use of spectral data including 2D NMR.