Two Unusual Nitro‐substituted Hasubanan‐type Alkaloids from Stephania longa

Abstract Two unusual nitro‐substituted hasubanan‐type alkaloids, stephalonines J ( 1 ) and K ( 2 ), together with ten known alkaloids, protostephanine, dehydrostephanine, (−)‐stephanine, (−)‐isolaureline, R ‐roemeroline, (+)‐pronuciferine, (+)‐stepharine, (+)‐ N ‐acetylstepharine, (+)‐lirioferine, and (+)‐norlirioferine, were isolated from the whole plant of Stephania longa . Their structures were characterized mainly by spectroscopic methods including IR, MS, and NMR experiments, and the structures of 1 and 2 were further confirmed through chemical correlations with the known alkaloids stephalonines A ( 1a ) and B ( 2a ), respectively.