Methyl palmitate, an acaricidal compound occurring in green walnut husks.
Walnut, Juglans regia L., is known for its insecticidal activities to a range of herbivores and microbes. Isolation and identification of bioactive compounds from walnut is a potential approach for the development of new pesticides. Laboratory experiments were carried out to investigate the acaricidal activities of green husk extracts of walnut. Bioassay-guided fractionation of petroleum-ether extracts of walnut led to the identification of a common plant-borne fatty acid ester, methyl palmitate (MP), which produced strong acaricidal activity (62.8% mortality) at 1 mg/ml at 24 h. The structure of MP was characterized with infrared spectrum and NMR, and the identification of MP confirmed using an authentic standard on high-performance liquid chromatography. Based on a slide dip bioassay, 10 mg/ml MP provided 97.9% mortality against adults of Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae), whereas mortality against eggs was much lower (57.2%).
Wang
Y N
YN
Beijing University of Agriculture, Beijing 102206, People's Republic of China.
Wang
H X
HX
Shen
Z J
ZJ
Zhao
L L
LL
Clarke
S R
SR
Sun
J H
JH
Du
Y Y
YY
Shi
G L
GL
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D007306:Insecticides / Q000302:isolation & purification*; D031324:Juglans / Q000737:chemistry*; D010168:Palmitates / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D040102:Tetranychidae
D007306:Insecticides; D010168:Palmitates; D010936:Plant Extracts; C019012:methyl palmitate