Acaricidal Coumarins from the Medicinal Plant Acokanthera schimperi

Two coumarins were isolated from the plant Acokanthera schimperi (Apocynaceae), and the in vitro larvicidal activities of these compounds against East Coast Fever vector Rhipicephalus appendiculatus was investigated. The mortalities of the larvae were determined after 48 h post treatment. The finding demonstrated that Compound 1 and 2 as amixture registered LC50/LC90 values of 2.96/6.09 mg/ ml. These findings could be useful as lead compounds for the development of acaricides. Additionally, these findings underscore the fact that this plant is used ethnomedicinally as an acaricide. The discovery of plant compounds that may control ticks could be of great value to the agricultural sector.