Nematicidal activity of quinolizidine alkaloids and the functional group pairs in their molecular structure

Nematicidal activity of aloperine, cytisine, N-methylcytisine, and matrine was bioassayed by the agar medium method and the cotton ball method. The corresponding results from the two methods showed that the nematicidal activity of aloperine was the strongest. Its activity, expressed as log (1/ID50) was also the strongest (8.67) in comparison with the previously reported nematicidal activity of seven other quinolizidine alkaloids bioassayed by the same method. We hypothesize that the nematicidal activity of quinolizidine alkaloids is determined primarily by the types of functional group pairs and types of functional group in their molecular structures. Based on this hypothesis, alkaloids with strong nematicidal activity can be predicted on the basis of their structure.