污泥蓼茎中抑制甘薯天蛾幼虫生长发育的活性成分

Growth inhibition ingredients isolated from Poloygonum limicola stems against larvae of Herse convolvuli

为研究污泥蓼(Poloygonum limicola)对甘薯天蛾(Herse convolvuli)幼虫生长发育的抑制活性及其有效成分,通过叶碟法测定了该植物提取物对甘薯天蛾3龄幼虫的生长发育抑制活性,并在活性跟踪的基础上,通过萃取、柱层析、薄层制备、核磁共振和质谱等方法对其活性成分进行分离和结构鉴定.结果表明,500mg/L污泥蓼茎甲醇提取物处理甘薯天蛾3龄幼虫48h的生长发育抑制率为57.3%.从污泥蓼茎中分离得到karptioctoxicoral,medicarpin和5-甲氧基黄烷酮(5-methoxyflavone).当甘薯天蛾幼虫每头口服剂量为50,400μg时,karptioctoxicoral对该虫48h的抑制率分别为17.3%和81.6%;medicarpin和5-methoxyflavone没有表现出生物活性.Karptioctoxicoral为活性成分,其作用方式为胃毒作用.

Growth inhibition and active compounds of Poloygonum limicola were studied. The activities were determined by leaf disk method. The active ingredients were isolated from the stems by activity-directed fractionation with column chromatography and thin layer chromatography （TLC）, and identified predominantly on the basis of MS and NMR data. The results showed that only the methanol extracts from the stems exhibited growth inhibition activity against the third instar larvae of Herse convolvuli, the growth inhibition rate was 57.3% at 48 h after treatment at the concentration of 500 mg/L. Three known compounds, karptioctoxicoral, medicarpin and 5-methoxyflavone, were isolated and identified for the first time from the plant. At the dosage of 50 and 400 μg per insect, karptioctoxicoral inhibited the growth of the third instar larvae at 48 h after treatment with the corresponding inhibition rate of 17.3% and 81.6%, but medicarpin and 5-methoxyflavone didn＇t possess any activities against the tested insect. Karptioctoxicoral was the active ingredient, and its action mode was stomach poison. The growth inhibition of the plant and karptioctoxicoral were reported against the larvae of H. convolvuli for the first time.