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

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