Alkaloids of Importance in Plant-Insect Interactions

科罗拉多州立大学化学系的Frank R. Stermitz教授，因其对植物与昆虫相互作用中重要的生物碱的研究而受到有机合成计划的支持。主要研究方向为针叶树（松树、云杉和冷杉）生物碱的分离、结构、生物合成和昆虫加工。在针叶树中发现了一系列2,6-二取代胡椒碱生物碱的结构，目前正通过分离、质谱分析和光谱方法以及合成和/或半合成的方法来阐明。用碳-13标记的化合物作为生物合成前体的植物喂养实验将阐明这些生物碱合成的细节。还将探讨云杉种产生反式二取代哌替啶的能力，而松树种只产生顺式二取代化合物。对以针叶树为食的甲虫、蝴蝶和蛾子幼虫及其排泄产物的分析将决定昆虫如何处理胡椒碱生物碱。最后，对具有抗结核分枝杆菌活性的植物提取物进行分析，以确定潜在的抗结核药物。在有机合成计划的支持下，科罗拉多州立大学化学系的Frank R. Stermitz教授研究了针叶树（松树、云杉和冷杉）中显示生物活性的化合物的发生。在这些树木中发现的特殊的“生物碱”（自然产生的含氮化合物）在其他各种惊人的自然来源中也以相似或相同的形式被发现，包括墨西哥豆甲虫，它自己合成生物碱，还有有毒的青蛙，它从未知的食物来源中获取生物碱。对生物碱的植物来源和以生物碱为食的昆虫的研究有望揭示一些重要问题，包括昆虫如何绕过植物的防御策略，并可能利用摄入的化合物来阻止它们自己的捕食者。在相关研究过程中，分离出了对结核杆菌有活性的植物提取物。将对这些提取物进行分析，以确定具有潜在治疗应用的新型化合物，以治疗对当前药物治疗具有耐药性的结核病菌株。

Professor Frank R. Stermitz, of the Department of Chemistry of Colorado State University, is supported by the Organic Synthesis Program for his studies of alkaloids of importance in plant-insect interactions. His studies focus on the isolation, structure, biosynthesis, and insect processing of alkaloids in conifers (pine, spruce, and fir trees). The structures of an array of 2,6-disubstituted piperidine alkaloids is found in the conifers are being elucidated by a combination of isolation, mass spectral analysis, and spectroscopic methods, as well as by synthesis and/or semisynthesis. Plant feeding experiments with carbon-13 labeled compounds appearing to be plausible biosynthetic precursors will elucidate details of the synthesis of these alkaloids. The ability of spruce species to generate trans-disubstituted piperidines, whereas pine species generate only cis-disubstituted compounds, will also be explored. Analysis of conifer-feeding beetle, butterfly, and moth larvae and their excretion products will determine how insects process the piperidine alkaloids. Finally, extracts of plants displaying activity against Mycobacterium tuberculosis will be analyzed in order to identify potential anti-tuberculosis agents. With support from the Organic Synthesis Program, Professor Frank R. Stermitz, of the Department of Chemistry of Colorado State University, studies the occurrence in conifers (pine, spruce, and fir trees) of compounds displaying biological activity. The particular `alkaloids` (naturally occurring nitrogen-containing compounds) found in these trees are found in similar or identical forms in an astounding variety of other natural sources, including the Mexican bean beetle, which synthesizes the alkaloids itself, and poisonous frogs, which obtain the alkaloids from unknown food sources. Study of both the plant sources of the alkaloids and the insects which feed upon them is expected to shed light on a number of important issues, including the way in which insects circumvent the defensive strategies of plants and possibly use ingested compounds to deter their own predators. In the course of related studies, plant extracts were isolated which display activity against the bacillus which causes tuberculosis. These extracts will be analyzed in order to identify new classes of compounds with potential therapeutic applications against strains of tuberculosis resistant to current drug therapies.