Studies On The Insecticidal Components Of Tripterygium Hypogyium

An available pathway to develop new classes insecticides is to find new lead moleculesfrom plants. For this purpose, Insecticidal components of Tripterygium hypoglaucum were studiedin this paper. Four insecticideal constituents of Tripterygium hypoglaucum were isolated by means ofphytochemistry combined with bioassay method. The structures of the compounds weredetermined by HNMR, 1 13CNMR,1H-1HCOSY,HMBC, HMQC and mass spectral analysis aswilfortrine(sb01),wilforgine(sb02),wilfordine(sb03) and wilforine(sb04).bioassay showed sb01and sb02 had only stomachic toxicity against the 4th larvae of Mythimna separata , but sb03 andsb04 had strong topical toxicity against the 4th larvae of Mythimna separate.. Medium narcosisdose (ND50) of sb03 and sb04 were 0.0033 μg·larvae-1,0.0006μg·larvae-1. During the course of bioassay with four insecticidal constituents against the 4th larvae ofMythimna separata we found different toxic symptoms. When wilfordine and wilforine treated onthe notum of Mythimna separate,the larvaes were narcotic after 2 hours, revived completely after8 hours, then narcotic again after 24 hours, part larvaes were dead after 48 hours. The larvaes feedthe wheat leaves of sb01 and sb02 were narcotic after 8 hours, revived completely after 24 hours. The insecticidal scope of wilfordine and wilforine were studied. Results showed thatwilfordine and wilforine had topical toxicity against Mythimna separata, Mamestra brassicae,Plutella xyllostella, Myzus malisuctus and Trichop1usia ni.., and had stomachic toxicity againstAgrotls ypsilon, Pieris rapae and Plutella xyllostella .