几种长白山有毒植物提取的生物碱杀虫活性

不同生物碱处理，对菜青虫的生长发育构成显著影响。延胡索、北乌头生物碱处理可使菜青虫提前化蛹，蛹态畸形；延胡索、北乌头、天南星生物碱处理，48h后菜青虫拒食率在90％以上，延胡索处理拒食率最高为99．87％：对蚜虫杀虫活性较高的处理为北乌头、藜芦生物碱处理，北乌头生物碱处理48h后的校正死亡率高达92．41％。     

八宝景天乙醇提取物对菜青虫的生物活性

[目的]室内测定了八宝景天乙醇提取物对菜青虫3龄幼虫的拒食和触杀作用。[方法]采用小叶碟法和浸渍法分别测定乙醇提取物对菜青虫的拒食和触杀作用。[结果]浸渍法处理对菜青虫3龄幼虫48、72 h的致死中浓度(LC50)分别为7.768、0.183 g/L,且校正死亡率均达100%,24、48 h的拒食率最高分别为99.15%、91.94%,拒食中浓度(AFC50)分别为4.819、15.442 g/L。[结论]八宝景天乙醇提取物对菜青虫3龄幼虫具有较高的拒食和触杀活性,为生物源农药提供了一种新的植物来源。     

坡柳种子提取物对菜青虫取食和生长发育的影响

研究了坡柳种子乙醇提取物对菜青虫4龄幼虫的拒食作用和生长发育的影响。结果表明,坡柳种子乙醇提取物对菜青虫4龄幼虫有显著的拒食活性,24、48h的非选择性拒食性AFC50值分别为742.14、1099.93mg/L;选择性拒食AFC50值分别为1081.15、1553.2mg/L;乙醇提取物对菜青虫4龄幼虫的生长发育抑制作用明显,随施药剂量的增加,生长抑制率增大,化蛹率降低,处理剂量为5000mg/L时,生长抑制率大于100%,化蛹率仅为13.33%。     

麻疯树种子提取物对几种害虫的杀虫活性

在室内测定并比较了3种麻疯树种子提取物对同翅目、鳞翅目和鞘翅目害虫桃蚜、菜青虫和米象的杀虫活性。结果显示种子油、种子乙醇提取物和石油醚提取物对3种害虫都具有一定杀虫活性，对桃蚜的触杀活性LC50分别为5．1154、2．0796、13．9882g／L；对米象的杀虫活性LC50分别为8．0243、3．0701、24．3458g／L；种子油和乙醇提取物对菜青虫的胃毒活性LC加分别为18．1043、3．0796g／L，此外这2种提取物对菜青虫也显示出较强的拒食活性；而种子石油醚提取物对菜青虫无明显胃毒活性，拒食活性也很弱。麻疯树种子提取物对3种害虫的相对毒力顺序为乙醇提取物〉种子油〉石油醚提取物。     

银杏酚对菜青虫拒食活性的研究

从银杏外种皮中提取含94.8%银杏酚的提取物,用氯仿溶解提取物,并加适量乳化剂烷基酚聚氧乙烯醚,配制含12.6%银杏酚的液剂,称为银杏酚液剂。用水稀释银杏酚液剂50、100、150和200倍,用稀释液浸泡苏州青青菜的菜叶,喂饲菜青虫三龄、四龄幼虫。用叶碟法测定银杏酚对菜青虫的拒食活性。结果表明,银杏酚对菜青虫三龄、四龄幼虫具有明显的拒食活性,拒食率达30.14%～85.3%。稀释浓度在150倍以下,对三龄幼虫拒食效果较好,处理后3天拒食作用最强,对三龄幼虫的拒食作用优于四龄幼虫。同时讨论了银杏酚对菜青虫拒食活性的机理。银杏酚对菜青虫拒食活性,是由于银杏酚抑制了酪氨酸酶等酶的合成,影响了菜青虫的蜕皮和生长发育,使其表现为拒食和发育为超龄幼虫,多数不能形成蛹而致死。     

松香含氮衍生物对小地老虎四龄幼虫的拒食活性及构效关系

采用叶碟浸叶法,研究了4种不同类型的松香含氮衍生物对小地老虎4龄幼虫的拒食活性。结果显示：脱氢枞胺对氯水杨醛Schiff碱（2i）和二氢枞酸异丙醇酰基硫脲（4b）较大地抑制了小地老虎4龄幼虫的取食,质量浓度1 g/L时2i和4b 24 h后的拒食率分别为86.12%和85.13%;脱氢枞胺对甲氧基苯甲醛Schiff碱（2b）、二氢枞酸2-羟甲基-1,3-丙二醇酰基硫脲（4c）和二氢枞酸呋喃酰基硫脲（4g）对小地老虎4龄幼虫具有较强的拒食活性,拒食率分别为52.04%、66.70%和50.48%。2i具有极低的拒食中质量浓度（AFC₅₀）,为0.04 g/L,2b、4b、4c和4g的AFC₅₀分别为0.66、0.25、1.47和0.69 g/L。脱氢枞胺（取代）苯甲醛Schiff碱和二氢枞酸酰基硫脲2类衍生物对小地老虎具有较强的拒食活性,甲氧基、氯原子和羟基对脱氢枞胺（取代）苯甲醛Schiff碱的拒食活性有明显的增强作用,二氢枞酸酰基硫脲衍生物中羟基的位置和个数对小地老虎4龄幼虫的拒食活性有明显的影响。脱氢枞酸酰胺和脱氢枞酸酰基硫脲衍生物对小地老虎4龄幼虫的拒食活性较弱,且其结构变化对小地老虎4龄幼虫的拒食活性影响较小。     

木荷树皮杀虫活性成分追踪的初步试验

采用活性追踪和化学分离相结合的方法对木荷树皮甲醇提取物中的活性成分进行分离,用石油醚、氯仿和正丁醇连续萃取,经生物活性测定,正丁醇萃取物的活性最大.木荷树皮正丁醇萃取物在2g/L质量浓度下,对小菜蛾3龄幼虫24、48 h的拒食率分别为91.30%和92.44%,拒食中浓度(AFC50)分别为0.4570、0.4346 g/L;对菜青虫4龄幼虫,在1 g/L质量浓度下,24、48 h的拒食率分别为99.08%和96.44%,拒食中浓度(AFC50)分别为0.041 9、0.0557 g/L.     

木荷提取物对小菜蛾和菜青虫的拒食活性

室内测定了木荷甲醇提取物对小菜蛾、菜青虫3龄幼虫的拒食活性。结果表明，木荷树皮甲醇提取物对小菜蛾、菜青虫3龄幼虫的拒食活性最高。木荷树皮甲醇提取物在10g／L的质量浓度下，对小菜蛾3龄幼虫24h和48h的拒食率分别为94．27％和94．78％，拒食中浓度（AFC50）分别为2．7445g／L和1．5519g／L；对菜青虫3龄幼虫，在2g/L的质量浓度下，24h和148h的拒食率均达到100％，拒食中浓度（AFC50）分别为0．1053g／L和0．1488g／L。     

银杏酚对菜青虫的拒食活性研究

用叶碟法测定银杏酚对菜青虫的拒食活性,拒食率为30.1%至81.5%,银杏酚影响菜青虫的生长发育,使其发育为超龄幼虫,多数超龄幼虫不能形成蛹而致死。银杏酚对菜青虫防治作用机理是：银杏酚抑制了前胸腺一些重要酶的合成活性,影响了正常蜕皮和生长发育,使其拒食和死亡。例如,银杏酚抑制酪氨酸酶的合成。酪氨酸酶的作用是,催化酪氨酸,经过一系列反应,生成蜕皮后新表皮所需的硬化物质。由于银杏酚抑制了酪氨酸的合成,影响了害虫的正常蜕皮和生长发育,使其发育为超龄幼虫,拒食而死亡。由于昆虫都有外骨骼,在生长发育过程中都要多次蜕皮,所以银杏酚对蚜虫防治作用机理,与银杏酚对菜青虫防治作用机理相同。都是由于银杏酚抑制了前胸腺一些重要酶合成,影响了正常蜕皮和生长发育,致其死亡。     

醚桥联二聚体合成的关键中间产物-9，10-脱水青蒿素

以二氢青蒿素为反应原料在制备不对称醚桥联二聚体时得到了关键的中间产物9,10-脱水青蒿素。9,10-脱水青蒿素保留了母体化合物青蒿素中的过氧基团并且含有一个C=C双键,其抗疟活性与蒿乙醚的抗疟活性相似。9,10-脱水青蒿素在合成蒿醚类衍生物时,是关键的中间产物。培养9,10-脱水青蒿素的单晶,通过X射线表征其结构。运用Puckering分析方法对9,10-脱水青蒿素结构中环的构象进行了半定量描述。其中几个六元环分别呈现椅式、扭船式、信封式构象。     

脱氢枞基酰胺及亚胺衍生物对粘虫的拒食活性

采用叶碟浸液法,研究松香基三环二萜类脱氢枞基酰胺及亚胺衍生物对粘虫(Mythimna separata)的拒食活性.结果显示,含有脱氢枞基结构的酰胺衍生物脱氢枞基酰胺(A-1)、脱氢枞基酰苄胺(A-3)、脱氢枞基酰邻氟苯胺(A-4)、脱氢枞基酰三氟甲基苯胺(A-8)、脱氢枞基吗啉(A-10)及含有亚胺结构的衍生物脱氢枞胺对三氟甲基苯甲醛(I-6)对粘虫的拒食活性较高,24 h的拒食率均达到90%以上.A-1、 A-4、A-8、A-10 及I-6 在48、72 h的拒食率也达到80%以上.大部分酰胺化合物表现出拒食活性,部分亚胺衍生物施药时间长的情况下表现出一定的诱食活性.部分化合物在拒食活性测试过程中发现幼虫死亡现象,可以作为杀虫剂继续开发.     

松香多元酸对小地老虎的拒食活性研究

以松香为原料经Diels-Alder加成反应合成了松香多元酸如丙烯海松酸（APA）、富马海松酸（FPA）及马来海松酸（MPA）。采用浸叶法,研究了松香多元酸以及脱氢枞酸对小地老虎（Agrotis ypsilon）的拒食活性。结果显示：质量浓度为1g/L时,脱氢枞酸、丙烯海松酸、马来海松酸和富马海松酸对4龄小地老虎幼虫的24h拒食率分别为0.68%、78.41%、13.41%和79.94%,其中丙烯海松酸及富马海松酸对小地老虎的拒食活性较高,而马来海松酸对小地老虎的拒食活性较弱,脱氢枞酸几乎没有拒食活性。丙烯海松酸及富马海松酸对小地老虎的拒食中质量浓度（AFC₅₀）分别为0.04和0.06g/L,可以进行田间试验,进一步明确其在生产中的实际防治效果。     

Dihydroartemisinin–Bile Acid Hybridization as an Effective Approach to Enhance Dihydroartemisinin Anticancer Activity

A series of hybrid compounds based on natural products—bile acids and dihydroartemisinin—were prepared by different synthetic methodologies and investigated for their in vitro biological activity against HL-60 leukemia and HepG2 hepatocellular carcinoma cell lines. Most of these hybrids presented significantly improved antiproliferative activities with respect to dihydroartemisinin and the parent bile acid. The two most potent hybrids of the series exhibited a 10.5- and 15.4-fold increase in cytotoxic activity respect to dihydroartemisinin alone in HL-60 and HepG2 cells, respectively. Strong evidence that an ursodeoxycholic acid hybrid induced apoptosis was obtained by flow cytometric analysis and western blot analysis.     

Antifeedant and Termiticidal Activities of 6-Alkoxycoumarins and Related Analogs Against <Emphasis Type="Italic">Coptotermes formosanus</Emphasis> Shiraki

We synthesized 23 6-alkoxycoumarin derivatives, 20 of which are novel compounds. The structures of all compounds were confirmed by NMR, MS, and elemental analysis, and their antifeedant and termiticidal activities against Coptotermes formosanus Shiraki were examined. In a no-choice test, 6-(2-pentynyloxy)coumarin (2v), 6-(2-butynyloxy)coumarin (2u), 6-(2-octynyloxy)coumarin (2w), and 6-methoxycoumarin (2a), demonstrated high termiticidal activity at a concentration of 10 μmol. At a concentration of 5 μmol, 6-(2-butynyloxy)coumarin (2u) produced the highest mortality among the compounds tested. On the other hand, all of the 6-alkoxycoumarins showed antifeedant activity at both concentrations, except 6-octadecyloxycoumarin (2j) that was inactive at 5 μmol. Among the 23 compounds and the control, 6-ethoxycoumarin (2b), 6-isopropoxycoumarin (2d), and 6-isobutoxycoumarin (2f) exhibited the highest antifeedant activity with no mass loss (0.00%) at a concentration of 10 μmol. Our findings indicate that the presence of alkenyloxy and alkynyloxy groups was important for the termiticidal activity, while the incorporation of alkoxy groups with longer alkyl chains tended to reduce both the termiticidal and antifeedant activities. Furthermore, short chain alkoxy and arylalkoxy-substituted analogs showed good antifeedant activity, but methoxy groups on the benzene ring had a negative effect.     

1.5%斑蝥素AS对粘虫的生物活性

通过研究发现1．5％斑蝥素AS对粘虫具有较强的触杀作用与拒食作用，处理24h后，除了400mg／L的处理外，其余各处理粘虫的死亡率和拒食率均随药剂质量浓度的降低而降低。其触杀毒力的LD50值为0．4570mg／kg，拒食作用的EC50值为2．5692mg／L，表明1．5％斑蝥素AS对粘虫具有很高的杀虫效果。     

Antifeedant and toxic effects of sesquiterpenes fromSenecio palmensis to colorado potato beetle

A bioassay-guided fractionation of the aerial parts ofSenecio palmensis resulted in the isolation of two sesquiterpenes, 2,10-bisaboladien-1-one and 11-acetoxy-5-angeloyloxy-silphinen-3-one. The bisabolene and the silphinene represented 0.012% and 0.024% of the plant dry weight, respectively. Both compounds showed antifeedant activity againstLeptinotarsa decemlineata larvae and adults in short-term choice and no-choice bioassays. Both compounds were also tested against different species of phytopathogenic fungi. The beetles were more sensitive to these compounds in choice than in no-choice assays, with a gradient of increasing sensitivity from second instars to adults. Bisabolene was 45 times less active as an antifeedant than juglone, which was tested as a positive control. The silphinen was more active than the bisabolene, with a range of activity similar to juglone. Furthermore, exposure of fourth instars to these compounds over a 24-hr period resulted in reduced feeding and growth rates. To distinguish between antifeedant and toxic effects, growth efficiencies were calculated as the slope of the regression of relative growth rate on relative consumption rate. The comparison of these results with those of antifeedant simulation and contact toxicity bioassays indicates that feeding inhibition is the primary mode of action of the bisabolene, while the silphinene shows both antifeedant and toxic effects.     

2种植物提取物对3种害虫的生物活性

主要对草乌、辣椒提取物对不同试虫的生物活性进行了初步研究。结果表明,草乌根提取物表现出较好的触杀活性,1g·mL-1草乌根提取物对麦二叉蚜和天幕毛虫的校正死亡率分别为78.51%和70.32%。辣椒果实提取物表现出较好的拒食活性,0.0625g·mL-1辣椒果实提取物对小菜蛾的拒食率为94.78%。     

Antifeedants against <Emphasis Type="Italic">Hylobius abietis</Emphasis> Pine Weevils: An Active Compound In Extract of Bark of <Emphasis Type="Italic">Tilia cordata</Emphasis> Linden

Linden (Tilia cordata) bark was shown to contain an antifeedant effective against the large pine weevil, Hylobius abietis. Soxhlet extraction of inner and outer bark resulted in an extract that showed antifeedant activity in a microfeeding assay. The extract was fractionated by chromatography on silica gel using gradient elution with solvents of increasing polarity. The content of the fractions obtained was monitored by thin layer- and gas chromatography. Fractions of similar chemical composition were merged. Two of the 17 fractions showed antifeedant activity in the microfeeding assay. Nonanoic acid was identified in both of these fractions. Subsequent testing in the microfeeding assay showed that nonanoic acid possessed strong antifeedant activity against H. abietis adults.