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Antifeedant Activities of the Erythrinaline Alkaloids from Erythrina latissima against Spodoptera littoralis (Lepidoptera noctuidae)

Wanjala W. Cornelius, Teresa Akeng’a, George O Obiero and Kweyu P. Lutta

Department of Chemistry, Kigali Institute of Science and Technology, P.O Box 3900, Kigali, RWANDA

School of Chemical and Minerals Engineering, North West University, P.O Box 558, Potchefstroom 2520, South Africa

Institute of Tropical Medicine and Infectious Diseases, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200 , Nairobi , KENYA .

Abstract: The antifeedant activities of the Erythrina alkaloids from the seeds, seed pods and flowers of Erythrina latissima were investigated in laboratory dual- choice bioassays using third-instar Spodoptera littoralis (Boisduval) larvae. The new compound (+)-11β-methoxy-10-oxoerysotramidine (1) from the flowers, showed potent dose dependant activity at concentration >=500 pm while (+)-10,11-dioxoerysotramidine (2) also new from the flowers showed potent dose dependant activity at concentration >= 100 ppm. Three known compounds (+)-erysotrine, (+)-erysotramidine, (+)-erythraline, (+)-11β-hydroxyerysotramidine showed potent dose dependant antifeedant activity at concentrations >= 100 ppm while (+)-10,11-dioxoerysotrine and (+)-11 b-hydroxyerysotramidine also a known compounds showed potent dose dependant antifeedant activity at concentrations >= 100 ppm. Three known compounds (+)-11β-methoxyerysotramidine, (+)-8-oxoerythraline and (+)-15(16) b -D-glucoerysodine showed no appreciable change in antifeedant activity with concentration change.

Keywords: P Erythrina alkaloids; Erythrina latissima; antifeedant activity; Spodoptera littoralis.