Wabu Fritillaria Alkaloids

Eight steroidal alkaloids have been isolated from the Bulbus Fritillaria Wabuensis S.Y. Tang et S.C.Yueh. Isoverticine-β-N-oxide was first obtained from the Bulbus Fritillaria Wabuensis. Three of other steroidal alkaloids are known compounds:imperialine, isoverticine and imperialine-β-N-oxide. Their structure were elucidated on the base of spectral methods (¹H-NMR,¹³C-NMR and MS ,et al. ). And the other four alkaloids (WB1,WB2,WB4,WB6) couldn' t be identified because they were not enough for structure identification.Isoverticine-β-N-oxide is a rarely N-oxide-type steroidal alkaloid and was first obtained from nature.Structural modifications were carried out to synthesize several derivatives of imperialine(such as acylation and alkylation on 3-OH ) .The changements of their M-cholinoblocking activity were examined.