TWO NEW STEROIDAL ALKALOIDS FROM THE BULBS OF FRITILLARIA THUNBERGII

Abstract

In the quest for biologically active compounds from natural medicinal sources in Korea, the bulbs of Fritillaria thunbergii were investigated. Phytochemical analysis of the Me0H extracts resulted in the isolation and identification of ten steroidal alkaloids (1-10) including two new compounds, named frithunbol A and B (1 and 2). The structures of these new compounds were elucidated based on 1D, 2D NMR analyses and HR-FAB-MS. All the isolated compounds (1-10) were evaluated for their effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells and the neuroprotective effect was determined via induction of nerve growth factor (NGF) in C6 glioma cells. Compounds 2, 3, and 10 significantly inhibited NO levels with ICso values of 16.35 mu M, 11.45 mu M and 18.02 mu M, respectively. Also, compound 9 was a potent stimulant of NGF release, and enhanced the levels of NGF by 134.81 +/- 3.66%.