Larvicidal activity of lignans identified in Phryma leptostachya Var. asiatica roots against three mosquito species.
The insecticidal activity of phytochemicals isolated from the roots of Phryma leptostachya var. asiatica against third instar larvae of Culex pipiens pallens, Aedes aegypti, and Ocheratatos togoi was examined. The two constituents of P. leptostachya var. asiatica roots were identified as the leptostachyol acetate (I) and 8'-acetoxy-2,2',6-trimethoxy-3,4,4',5'-dimethylenedioxyphenyl-7,7'-dioxabicyclo[3.3.0]octane (II) by spectroscopic analysis. Compound I was lethal to C. pipiens pallens, A. aegypti, and O. togoi at 10 ppm. Compound II showed weak or no insecticidal activity against three mosquito species at 10 ppm. The LC(50) values of I against C. pipiens pallens, A. aegypti, and O. togoi were 0.41, 2.1, and 2.3 ppm, respectively. Naturally occurring P. leptostachya var. asiatica root-derived compounds merit further study as potential mosquito larval control agents or lead compounds.
Park
Il-Kwon
IK
Division of Forest Diseases, Korea Forest Research Institute, Seoul 130-712, Republic of Korea. parkik1@foa.go.kr
Shin
Sang-Chul
SC
Kim
Chul-Su
CS
Lee
Hak-Ju
HJ
Choi
Won-Sil
WS
Ahn
Young-Joon
YJ
D000330:Aedes; D000818:Animals; D003465:Culex; D009033:Culicidae; D007306:Insecticides; D007814:Larva; D017705:Lignans / Q000032:analysis*; D019684:Magnoliopsida / Q000737:chemistry*; D044969:Ochlerotatus; D018517:Plant Roots / Q000737:chemistry*
D007306:Insecticides; D017705:Lignans