Nematicidal activity of the alkaloids from Macleaya cordata against certain nematodes

Macleaya cordata R. Br. is a source of bioactive compounds which are used in phytopreparations with anti-inflammatory and antimicrobial activities. In this study, four isoquinoline alkaloids were isolated from the crude alkaloid extract of the aerial parts of M. cordata , and were identified as sanguinarine, chelerythrine, protopine and allocryptopine. These alkaloids were screened for their nematicidal activity against the nematodes Bursaphelenchus xylophilus , Caenorhabditis elegans and Meloidogyne incognita . Three alkaloids, sanguinarine, chelerytherine and allocryptopine, showed nematicidal activity with the median lethal concentration (LC 50 ) values as 28.52, 34.50 and 37.45 µg/ml, respectively, against B. xylophilus ; 22.78, 40.25 and 38.90 µg/ml, respectively, against C. elegans ; and 67.52, 61.00 and 76.56 µg/ml, respectively, against M. incognita at 24 h. This is the first report on the nematicidal activity of the alkaloids from M. cordata against the nematodes, B. xylophilus , C. elegans and M. incognita .