Nematicidal metabolites from roots of Stellera chamaejasme against Bursaphelenchus xylophilus and Bursaphelenchus mucronatus

BACKGROUND: Bursaphelenchus xylophilus, the causal agent of pine wilt disease, severely damages pine forests, and Bursaphelenchus mucronatus, a species related to B. xylophilus, is weakly pathogenic. Because the use of synthetic pesticides to control pine wilt disease has raised concerns for human and environmental health, a search for useful botanically based compounds is needed. RESULTS: The ethyl acetate layer from an ethanol extract of Stellera chamaejasme L. roots showed significant nematicidal activity against B. xylophilus and B. mucronatus, with LC50 values of 169.7 and 37.7 µg mL(-1), respectively, at 72 h. Further purification of the active layer yielded eight effective nematicidal compounds, which were identified by mass and nuclear magnetic resonance spectral data. Among the eight bioactive compounds, chamaejasmenin C induced the highest mortality against B. xylophilus, with an LC50 value of 2.7 µM at 72 h, and chamaechromone exhibited strong nematicidal activity against B. mucronatus, with an LC50 value of 0.003 µM at 72 h. CONCLUSION: The nematicidal metabolites from S. chamaejasme roots could be used as lead compounds for developing botanically based nematicides for the management of pine wilt disease.