Synthesis and herbicidal activity evaluation of novel β-carboline derivatives

Abstract

Based on the original structure of harmine, several novel 1,2,3,4-tetrahydro-β- carboline, β-carboline and 1-substituted-β- carboline derivatives bearing a substituted carbohydrazide group at C-3 were designed and synthesized to investigate the structureactivity relationship of their analogues. All of the compounds were characterized by infrared (IR), proton and carbon nuclear magnetic resonance ( 1H-NMR, 13C-NMR), and mass spectroscopy (MS). The bioassay tests showed that N'-benzylidene-1-phenyl-β- carboline-3-carbohydrazide (C 25H 18N 4O, m.w. 390.4) (c2) and N'-(4- trifluoromethylbenzylidene)- 1-phenyl-β-carboline-3-carbohydrazide (C26H17N4OF3, m.w. 458) (d2) exhibited good inhibitory activity against dicotyledonous and monocotyledonous weeds, with EC50 values of 4.83 μM and 14.25 μM, respectively. © 2012 by the authors.