Synthesis and Biological Evaluation of Harmol Derivatives as Potential Nematicidal Agents

A series of o-alkyl derivatives of harmol was synthesized along with 10- and 12- bromo derivatives and characterized by IR, UV, H-1-NMR and HREIMS. Six compounds are new while eleven are known.The H-1-NMR data of known compounds are reported for the first time. Fourteen ompounds were evaluated for their nematicidal activity against dagger nematode Xiphinema index. Most of the alkyl derivatives showed activity against this nematode while bromo derivatives were found to be inactive. Among alkyl derivatives 4-nitrobenzyl harmol was found to be most active and showed 100% mortality after 24h at 1% and 0.1% concentration while at 0.01% concentration it showed 90% mortality after 24h. Parent compound harmolwas found to be more active than carbofuran (positive control) at 0.01% concentration after 1 hour. This is the first report of nematicidal activity of harmol and these derivatives.