Limonoid derivatives and its pesticidal activities

Diverse pesticidal activities of anthothecol derived from Khaya anthotheca (Meliaceae) and three limonoids (gedunin, limonin and obacunone) were determined using six phytopathogenic fungi and four insect pests. Anthothecol showed fungicidal activity to Puccinia recondita with control rates of 90, 76 and 53% at concentrations 0.5, 0.25 and 0.1mg/mL, respectively, while the other limonoids exhibited little inhibitory effect on the fungal survival. The currently used fungicide mancozeb possessed potent fungicidal activity on P.recondite, with 92.3% controlling effect at a concentration of 0.005mg/mL. Anthothecol exhibited larvicidal activity to Plutella xylostella with 80, 50 and 30% mortality at concentrations of 1.0, 0.5 and 0.25mg/mL, respectively. Anthothecol showed selective pesticidal activity on P.recondita and P.xylostella. Structural re-examination of anthothecol was conducted and is reported.