Nematicidal coumarins from Heracleum candicans Wall.

Abstract

The root extract of Heracleum candicans Wall. exhibited antagonistic activities against nematodes Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle and Panagrellus redivivus (Linn.) Goodey. Through bioassay-guided fractionations, three coumarins were obtained from the extract of H. candicans and determined to be 8-geranyloxypsoralen (1), imperatorin (2), and heraclenin (3) based on spectra data. All three compounds possessed nematicidal activities against the two tested nematodes. The median lethal concentrations (LC₅₀) of compounds 1–3 at 72 h were 188.3, 161.7, and 114.7 mg L⁻¹ respectively against B. xylophilus and were 117.5, 179.0, and 148.7 mg L⁻¹ respectively against P. redivivus. This is the first report about species in the Umbelliferae family that possesses nematicidal activity.

Keywords:

• Heracleum candicans Wall.
• Nematode
• Coumarin
• Nematicidal activity

Acknowledgements

This work was partially supported by the Science and Technology Department of Yunnan Province (2005NG05 and 2005NG03), the Natural Science Foundation of Yunnan Province (2004C0003Q), the Ministry of Science and Technology of P. R. China (2006BHD08A19115), and Key Applied Foundation Program of Yunnan Province (1999C0001Z).

Notes

¶The two authors contributed equally to this work.