Abstract: Two biflavonoids were isolated from ethanol extract from the roots of Stellera chamaejasme L.,and their chemical structures were identified as isoneochamaejasmin A and neochamaejasmin B by nuclear magnetic resonance spectral data.The nematicidal activities of the two compounds were tested by bioassay methods with second-stage juveniles (J2s) of Bursaphelenchus xylophilus and Bursaphelenchus mucronatus. The results showed these two biflavonoids exhibited significantly nematicidal activities against both B.xylophilus and B.mucronatus. Neochamaejasmin B displayed better nematicidal activity than isoneochamaejasmin A against two species nematodes under the same conditions.

Key words: Stellera chamaejasme L., Biflavonoids, Bursaphelenchus xylophilus, Bursaphelenchus mucronatus, Nematicidal activity