Imperialine (IP)

Imperialin is an alkaloid found in the bulbs of species of the genus Fritillaria, where it occurs to the extent of 0.1 - 2.0%. In humans it may cause spasms, vomiting, hypotension and cardiac arrest.

The structures of the four alkaloids - imperialine, imperialine-β-N-oxide, isoverticine, and isoverticine-β-N-oxide isolated from BFW were confirmed. The four alkaloids significantly inhibited cough frequency and increased latent period of cough in mice induced by ammonia. Imperialine and isoverticine showed obviously antitussive activities in a dose-dependent manner. Besides, the four alkaloids markedly enhanced mice's tracheal phenol red output in expectorant assessment and significantly inhibited the development of ear edema in anti-inflammatory evaluation assay. Moreover, significant differences were found between the structure-activity relationships of the four alkaloids.