Halaweish Fathi T, Kronberg Scott, Hubert Mindy B, Rice James A
Department of Chemistry & Biochemistry, South Dakota State University, Brookings 57007, USA.
J Chem Ecol. 2002 Aug;28(8):1599-611. doi: 10.1023/a:1019976413040.
Leafy spurge (Euphorbia esula L.), a plant introduced into the Great Plains of North America from Europe, has become a serious economic and ecological threat to the productivity of agricultural and natural areas. Cattle, the predominant livestock species on the Great Plains, as well as common wild ruminant species in this region appear to consume little if any leafy spurge. This is likely because they experience a toxic response after consuming small amounts of this plant, and they consequently learn to avoid it. Domestic sheep and goats can consume considerable amounts of leafy spurge and are used to help control it, but even these species may suffer a toxic response at high levels of intake. Toxic diterpene ingenols have been isolated from leafyspurge tissues, but compounds in this plant have not been evaluated with respect to their capacity to induce food aversion learning in ruminants. We conducted bioassay-guided fractionations of leafy spurge in an attempt to isolate toxic and aversive compounds. These bioassay-guided fractionations led to identification of ingenol and one of its diesters as two toxic compounds in leafy spurge that are potentially aversive to cattle.
叶状大戟（Euphorbia esula L.）是一种从欧洲引入北美大平原的植物，已对农业和自然区域的生产力构成严重的经济和生态威胁。牛是大平原上的主要牲畜种类，该地区常见的野生反刍动物似乎很少食用叶状大戟，即便食用也量微。这可能是因为它们在食用少量这种植物后会产生毒性反应，从而学会避开它。家养绵羊和山羊可以食用大量叶状大戟，并被用于帮助控制其生长，但即使是这些物种在摄入量较高时也可能产生毒性反应。有毒的二萜类大戟醇已从叶状大戟组织中分离出来，但该植物中的化合物尚未就其在反刍动物中诱导食物厌恶学习的能力进行评估。我们对叶状大戟进行了生物测定引导的分级分离，试图分离出有毒和引起厌恶的化合物。这些生物测定引导的分级分离导致鉴定出大戟醇及其一种二酯是叶状大戟中的两种有毒化合物，它们可能会让牛产生厌恶。
