Vol. 4, Issue 4 (2015)
Comparison of cycloartenone from four insecticidal Kotschya species (Fabaceae) harvested during dry and wet seasons
Author(s): Ester Innocent, Joseph Sempombe, Pax J Masimba, Innocent Daniel, Matthias Heydenreich
Abstract: Kotschya plant species have been shown to be potential larvicides against Culex quinquefasciatus and Anopheles gambiae species. Isolation of compounds from larvicidal crude extracts of selected four Kotschya plant species namely K. uguenensis, K. strigosa, K. speciosa and K thymodora yielded cycloartenone (1) as the major compound. The presence of this compound in the four species was confirmed by detailed spectroscopic methods and the already published data. Quantitative analysis of cycloartenone (1) in the four species collected during wet and dry seasons was compared. Findings indicated higher yields during wet seasons ranging from 68 x 10-2 to 120 x 10-2 mg/ml than dry seasons which revealed amounts ranging from 0 to 150 x 10-2 mg/ml. However, the highest amount of cycloartenone (1) was present in the stem barks of K. uguenensis for the dry season whereas the 120 x 10-2 mg/ml was observed in the aerial parts of K. strigosa collected during wet season. Cycloartenone (1) is being isolated for the first time in the genus Kotschya while also revealing mild larvicidal activity against Anopheles gambiae with mortality up to 40% below the concentration of 50 ppm.