Nematicidal prenylated flavanones from Phyllanthus niruri

Two prenylated flavanones have been isolated from the hexane extract of Phyllanthus niruri plant. The structure of these flavanones were established as 8-(3-Methyl-but-2-enyl)-2-phenyl chroman-4-one (1) and 2-(4-hydroxyphenyl)-8-(3-methyl-but-2-enyl)-chroman-4-one (2) on the basis of spectral analysis. These were evaluated for nematicidal activity against root-knot, Meloidogyne incognita, and reniform, Rotylenchulus reniformis, nematodes. Compound 2 exhibited nematicidal activity at par with the standard carbofuran (LC50 3.3 and 3.1 ppm, respectively) when tested against reniform nematode. The LC50 value against root-knot nematode was found to be 14.5 ppm. Compound 1 however, showed moderate activity against both the test nematodes. (c) 2007 Elsevier Ltd. All rights reserved.