苦瓜叶提取物对美洲斑潜蝇取食和产卵行为的抑制作用

美洲斑潜蝇是危害蔬菜、观赏植物的重大害虫之一.苦瓜叶乙醇提取物(浓度为2000～4000 μg·ml^-1)对美洲斑潜蝇成虫的取食和产卵都具有较强的抑制作用.用环己烷、乙酸乙酯、正丁醇和水依次对乙醇提取物进行萃取，并测试了4种萃取物对美洲斑潜蝇成虫取食和产卵的抑制作用.结果表明: 环己烷、乙酸乙酯、正丁醇和水萃取物在浓度为1000 μg·ml^-1时，处理后2 d对美洲斑潜蝇成虫的拒食率分别是11.08%、34.89%、22.99%和 0，产卵抑制率分别是0、30.91%、6.45%和 0.其中，乙酸乙酯萃取物的活性最强，当其浓度为4000 μg·ml^-1时，处理后2 d对美洲斑潜蝇成虫的拒食率和产卵忌避率分别为70.95％ 和69.49％.乙酸乙酯萃取物经硅胶柱层析分离得到(19S,23E)-5β,19-环氧-19-甲氧葫芦素-6,23-二烯-3β,25-二醇 (化合物1)、(19R,23E)-5β,19-环氧-19-甲氧葫芦素-6,23-二烯-3β,25-二醇(化合物2) 和3β,7β,25-三羟基葫芦素-5,23-二烯-19-醛缩-3-O-β-D-吡喃葡糖苷（化合物3），3种化合物在供试的浓度（100～400 μg·ml^-1）条件下对美洲斑潜蝇的取食和产卵行为都有明显的抑制作用.在400μg·ml^-1浓度时，化合物1、化合物2和化合物3对美洲斑潜蝇成虫的拒食率分别是66.89%、53.53%和78.02%，产卵抑制率分别是76.32%、58.36%和78.36%.

Antifeedant and antioviposition activities of Momordica charantia leaf ethanol extract against Liriomyza sativae.

Liriomyza sativae Blanchard (Diptera: Agromyzidae) is one of the important pests harming a wide variety of vegetables and ornamental plants throughout the world. The leaf ethanol extract of Momordica charantia at the concentration of 2000〖KG-*2〗-〖KG-*7〗4000 μg·ml-1 displayed significant antifeedant and antioviposition activities against L. sativae adults. For further purifying the extract, four solvents, i.e., cyclohexane, ethyl acetate, n-butanol and water, were used to extract the ethanol extract, and the antifeedant and antioviposition activities of the extracts against L. sativae adults were te sted. The results showed that after treated with the extracts at the concentration of 1000 μg·ml-1 for 2 days, the antifeedant index (AFI) of cyclohexane-, ethyl acetate-, n-butanol- and water extracts against L. sativae adults was 1108%, 3489%, 2299% and 0, and the antioviposition index (AOI ) was 0, 3091%, 645% and 0, respectively. Ethyl acetate extract had the highest bioactivity. At the concentration of 4000 μg·ml-1, the AFI and AOI of ethyl acetate extract were 7095% and 6949%, respectively. The ethyl acetate extract was then isolated by silica gel column chromatography, a nd three compounds, i.e., (19S, 23E)-5β,19-epoxy-19-methoxy-cucurbita-6,23-dien-3β and 25-diol (compound 1), (19R, 23E)-5β,19-epoxy-19-methoxy-cucurbita-6,23-dien-3β and 25-diol (compound 2), and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al-3-O-β-D-glucopyranoside (compound 3), were obtained. These three compounds at concentration of 100〖KG-*2〗-〖KG-*7〗400 μg·ml-1 all had inhibitory effects on the feeding and oviposition of L. sativae. At the concentration of 400 μg·ml-1, the AFI and AOI were 6689%, 5353% and 7802%, and 7632%, 5836% and 7836% for compound 1, 2 and 3, respectively.