Relationship between molecular structure and nematicidal activity of quinolizidine alkaloids

Abstract

The nematicidal activity of aloperine, cytisine, N-methylcytisine and matrine was bioassayed by the agar medium method and the cotton ball method. [Aloperine and matrine have both been isolated from Sophora alopecuroides]. Aloperine had the strongest nematicidal activity [against Bursaphelenchus xylophilus] in both tests. Its log (1/ID50) (mol/cotton ball) value (8.67) was also the strongest in comparison with published data on the nematicidal activity of 7 other quinolizidine alkaloids bioassayed by the same method. A hypothesis that nematicidal activity of quinolizidine alkaloids is mainly determined by types of functional groups and group pairs in their molecular structures is proposed. Based on this hypothesis, the structure of alkaloids with strong nematicidal activity is predicted.