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 nematodesBursaphelenchus xylophilus, Caenorhabditis elegans and Meloidogyne incognita. Three alkaloids, sanguinarine, chelerytherine and allocryptopine, showed nematicidal activity with the median lethal concentration (LC50) 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.   Key words: Nematicidal activity, alkaloids, Macleaya cordata, Bursaphelenchus xylophilus, Caenorhabditis elegans, Meloidogyne incognita.