title: Emodin isolated from Cassia obtusifolia (Leguminosae) seed shows larvicidal activity against three mosquito species.
abstract: Mosquito larvicidal activity of Cassia obtusifolia (Leguminosae) seed-derived materials against the fourth-instar larvae of Aedes aegypti, Aedes togoi, and Culex pipiens pallens was examined. The chloroform fraction of C. obtusifolia extract showed a strong larvicidal activity of 100% mortality at 25 mg/L. The biologically active component of C. obtusifolia seeds was characterized as emodin by spectroscopic analyses. The LC(50) values of emodin were 1.4, 1.9, and 2.2 mg/L against C. pipiens pallens, A. aegypti, and A. togoi, respectively. Pirimiphos-methyl acts as a positive control directly compared to emodin. Pirimiphos-methyl was a much more potent mosquito larvicide than emodin. Nonetheless, emodin may be useful as a lead compound and new agent for a naturally occurring mosquito larvicidal agent. In tests with hydroxyanthraquinones, no activity was observed with alizarin, danthron, and quinizarin, but purpurin has an apparent LC(50) value of approximately 19.6 mg/L against A. aegypti.
authors.affiliation: Faculty of Biotechnology and Institute of Agricultural Science and Technology, College of Agriculture, and Department of Advanced Organic Materials Engineering, Chonbuk National University, Chonju 561-756, South Korea.
authors.forename: Young-Cheol
authors.initials: YC
authors.lastname: Yang
authors.forename: Mi-Youn
authors.initials: MY
authors.lastname: Lim
authors.forename: Hoi-Seon
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000330:Aedes; D000818:Animals; D002366:Cassia / Q000737:chemistry*; D003465:Culex; D009033:Culicidae; D004642:Emodin / Q000302:isolation & purification*; D007306:Insecticides / Q000302:isolation & purification*; D007814:Larva; D012639:Seeds / Q000737:chemistry*
chemical_list: D007306:Insecticides; D004642:Emodin