Discovery of steroidal alkaloid glycosides from the bulbs of Fritillaria unibracteata with anti-inflammatory activities using an in vivo zebrafish model.

Nine undescribed steroidal alkaloid glycosides, unibrasolanosides A-F, unibraverazosides A-B, and unibratomatoside A, were isolated from the bulbs of Fritillaria unibracteata P. K. Hsiao & K. C. Hsia (Liliaceae). Their structures were elucidated by HRESIMS and 1D and 2D NMR data analyses as well as chemical methods and single-crystal X-ray diffraction analyses. Further investigation revealed that eight steroidal alkaloid glycosides displayed moderate anti-inflammatory activity in vivo in a CuSO4-induced transgenic zebrafish model.

Steroidal alkaloids and their glycosides from the bulbs of Fritillaria unibracteata.

Seven undescribed steroidal alkaloids, including two jervine-type steroidal alkaloids, fritiunibras A-B (1-2), and five cevanine-type steroidal alkaloid glycosides, fritiunibras C-G (3-7), along with six known cevanine-type steroidal alkaloids and their glycosides (8-13) were isolated from the bulbs of Fritillaria unibracteata Hsiao et K. C. Hsia. Their structures were determined by interpretation of comprehensive spectroscopic and single-crystal X-ray diffraction analysis. The absolute configurations of sugar moieties were determined by HPLC analysis and compared with standards after hydrolysis and derivatization. Furthermore, their inhibitory effects on NO production and cytotoxic activities were evaluated.