Collaborative Research: Mixture synergy in Piper imides, iridoid glycosides, and furanocoumarins

植物次生代谢物以协同方式作为昆虫威慑的例子并不常见，许多研究都集中在天然产物的药物应用上，其中活性是偶然的，而不是进化的反应。这个项目将测试植物产品之间在威慑昆虫方面的协同作用，它们表面上是为了这种活动而进化的。由单一植物物种产生的混合物中化合物之间的协同作用（类内协同作用）将在三个系统中进行测试：胡椒种（胡椒科，胡椒科）的亚酰亚胺，车前草（车前草科，Lamiales）的环烯醚萜苷和pasinaca sativa（蜂科，蜂科）的呋喃香豆素。imperiale和melanocladum的亚酰亚胺在结构上与Piper cenocladum和P. tuberculatum的亚酰亚胺和酰胺非常相似，这两种亚酰亚胺和酰胺最近被证明对多种昆虫具有协同作用。这一提议的工作测试的一般类内协同作用的亚胺和酰胺属胡椒。为了测试类内协同作用是否适用于其他类别的天然产物，我们将对环烯醚萜苷（单萜苷）和呋喃香豆素进行研究，因为它们在结构上与Piper酰胺/亚胺无关，而且彼此之间也不相关，而且这两类化合物在植物与昆虫的相互作用中都有很好的记录。在这一关联合作奖的支持下，有机和大分子化学项目正在支持两位化学家和一位生态学家的合作工作，他们是梅萨州立学院物理与环境科学系的Craig D. Dodson教授和Joseph L. Richards教授，以及杜兰大学生态与进化生物学系的Lee A. Dyer教授。本提案中概述的方法将为化学生态学，生物测定和统计分析提供新的方法。它将为类内化合物如何协同作用以阻止昆虫的重要假设提供严格的测试。这项工作将有助于确定抗草食动物协同作用是否在植物次生代谢物中广泛存在的长期目标。如果在测试与生态相关的食草昆虫的活性时发现协同作用是普遍和广泛的，那么它就与植物进化出多种化合物作为防御食草动物和病原体的增效剂的一般假设是一致的。这些结果也直接关系到控制作物害虫的方式。这项提议的工作将延续两位化学家和一位生态学家长达十年的成功合作。该合作涉及一所本科院校和一所研究型大学，并成功培养了大量研究生和本科生。目前的提案包括为一名研究生和12名本科生提供资金。学生将在生物学和化学方面接受广泛的培训，合作者将继续参与杜兰大学为这些学生提供的重要培训项目，如本科生研究经验（REU）、美国生态学会的少数民族种子项目、路易斯安那州少数民族参与联盟，以及富布赖特的LASPAU项目，该项目旨在培训来自其他国家的教师。

Examples of plant secondary metabolites acting in a synergistic fashion as insect deterrents are not common, and many studies focus on the pharmaceutical applications of natural products where activity is serendipitous and not an evolved response. This project will test for synergy between plant products in the deterrence of insects, the activity for which they have ostensibly evolved. Synergy between compounds in a mixture produced by a single plant species (intraclass synergy) will be tested in three systems: the imides of Piper species (Piperaceae, Piperales), the iridoid glycosides of Plantago lanceolata (Plantaginaceae, Lamiales), and the furanocoumarins of Pastinaca sativa (Apiaceae, Apiales). The imides of P. imperiale and P. melanocladum are structurally very similar to imides and amides from Piper cenocladum and P. tuberculatum which have recently been shown to act synergistically against a broad array of insects. This proposed work tests the generality of intraclass synergy for imides and amides of the genus Piper. To test if intraclass synergy is general to other classes of natural products, the iridoid glycosides (monoterpene glycosides) and furanocoumarins will be examined, since they are structurally unrelated to the Piper amides/imides and to each other, and both classes of compounds have a well documented central role in plant insect interactions.With the support of this linked collaborative award, the Organic and Macromolecular Chemistry Program is supporting the collaborative work of two chemists and an ecologist, Professors Craig D. Dodson and Joseph L. Richards, of the Department of Physical and Environmental Sciences at Mesa State College, and Professor Lee A. Dyer, of the Department of Ecology and Evolutionary Biology at Tulane University. The approach outlined in this proposal will provide novel methods for chemical ecology, bioassays, and statistical analyses. It will provide rigorous tests of important hypotheses on how intraclass compounds act synergistically to deter insects. The work will contribute to a long term goal to determine if antiherbivore synergy is widespread among plant secondary metabolites. If synergy is found to be general and widespread when testing for activity against ecologically relevant insect herbivores, then it is consistent with a general hypothesis that plants evolved multiple compounds as synergists for defense against herbivores and pathogens. These results are also directly relevant to the way insects are controlled on crops. The proposed work will continue a decade-long, successful collaboration between two chemists and an ecologist. The collaboration involves an undergraduate institution and a research university and has successfully trained a large number of graduate and undergraduate students. The current proposal includes funding for one graduate student and 12 undergraduates. Students will be broadly trained in both biology and chemistry, and the collaborators will continue to be involved with important training programs for these students at Tulane, such as Research Experience for Undergraduates (REU), the Ecological Society of America's SEEDS program for minorities, the Louisiana Alliance for Minority Participation, and Fulbright's LASPAU program for training faculty from other countries.