Two Unusual Nitro-substituted Hasubanan-type Alkaloids from Stephania longa
Project supported by the National Natural Science Foundation of China (No. 30025044), Shanghai Municipal Scientific Foundation (No. 04XD14019), and the Foundation from the Ministry of Science and Technology (No. 2002CB512807) of China.
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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.
