Antifeedant activity of ethanolic extract from Flourensia oolepis and isolation of Pinocembrin as its active principle

GEORGINA N. DIAZ NAPAL; SARA M. PALACIOS; MARÍA C. CARPINELLA

BIORESOURCE TECHNOLOGY

Elsevier

Año: 2009 vol. 100 p. 3669 - 3673

0960-8524

The ethanolic extract from Flourensia oolepis aerial parts showed strong antifeedant activity against the pest larvae, Epilachna paenulata, with an antifeedant index (AI% ) of 99.1% at 100 mg/cm2. Through a bio-guide chromatographic fractionation of the extract, led by bioassays on E. paenulata, the flavanone pinocembrin (1) was isolated as the most active principle. In a choice assay, compound 1 showed strong antifeedant activity against E. paenulata, Xanthogaleruca luteola and Spodoptera frugiperda with an AI% of  90, 94 and 91% (p< 0.01) respectively, at 50 mg/cm2.  The dosages necessary for 50% feeding inhibition of the insects (ED50) were 7.98, 6.13 and 8.86 mg/cm2, respectively. The feeding inhibitory activity of  1 against E. paenulata  was compared with the activity of other structurally related flavanoids like naringenin, which was inactive up to 100 mg/cm2, catechin which was nearly 6 times less active than 1, and quercetin which was 30 times more active than 1.