Mosquito-larvicidal Activity and Activity Constituents of Acorus calamus L. Essential Oil

Abstract

Fractions of Acarus calamus oil obtained by vacuum liquid chromatography showed increased mosquito-larvicidal activity against III instar larvae of Culex quinquefasciatus from LCso' 39ppm in unfractionated oil to LCso,27ppm. The unidentified constituent of oil (GLC retention time, 37.65 min) which had the highest negative correlation (r = -0.954) between the LCso values for the VLC fractions, can be suggested as the major active principle responsible for mosquito-larvicidal activity. It is possible to increase the mosquito-larvicidal activity of calamus oil by removing its major constituent, f3-asarone (84%) which is known to be neurotoxic.