Cuticular Lipid and Defense Chemistry of Collembola

弹尾目(弹尾目)是一类姊妹昆虫，它们的成分显示出不寻常的化学成分，这往往与昆虫的不同。特别令人感兴趣的是构成皮肤最外层脂层的不寻常物质--角质层。这种脂层在节肢动物中特别重要，因为它的疏水特性在调节水平衡方面是必不可少的，但它也可以通过其组成传递信息，作为化学信号。虽然昆虫角质层的化学成分主要是相对简单的碳氢化合物，但在弹尾目动物中发现了许多独特和新颖的化合物，其化学成分要复杂得多。这些化合物可以包括长链萜烯、聚甲基支化酯和其他以前未知的化合物。该项目旨在利用质谱学和红外光谱技术以及提取物的微量衍生化来阐明这些化合物的结构，由于弹尾目动物的体积很小，往往只能获得少量的结构。为了验证结构分配，将合成选定的关键化合物，如芳香或支化萜烯或高度支化的酯，这在某些情况下需要更长的复杂合成。虽然我们在这里提出了一些目标化合物的结构，但通过研究其他弹尾目动物物种，将获得更广泛的表皮层成分。这将使我们能够得出关于节肢动物角质层化学进化的结论，并将结果与我们独立研究的昆虫和蜘蛛类动物的结果进行比较。为了能够进一步研究弹尾目动物，已经与生物学家建立了一个网络，他们将为我们计划中的分析提供更多的物种。除了跳叉之外，各种弹尾目动物还使用防御化合物作为额外的防御机制。这些化合物通常也只有从跳虫中才能知道。除了角质层提取物，现有的或新获得的生物材料可以用来获得含有更多极性次生代谢物的提取物。在调查范围内，这些也将被分析。一些生物碱已经被发现，并将通过合成来确定其结构。通过对更多物种的研究，将有可能确定弹尾目的化学防御策略有多普遍，以及它们使用了哪些生物合成途径。这对于了解这些微小但重要的节肢动物的生态是至关重要的。由于跳虫的角质层具有极强的疏水性，合成的化合物将进行疏水性能测试。防御性物质的抗菌效果也将进行评估。

Collembola (springtails), a sister class of insects, show unusual chemistry in their constituents, which often differs from that of insects. Of particular interest are the unusual substances that make up the outermost lipid layer of the skin, the cuticle. This lipid layer is of particular importance in arthropods because its hydrophobic properties are essential in regulating the water balance, but it can also transmit information through its composition, serving as a chemical signal. While the insect cuticle is chemically dominated by relatively simple hydrocarbons, a much more complex chemistry with many unique and novel compounds is found in Collembola. These compounds can comprise long-chain terpenes, polymethyl-branched esters, and other previously unknown compounds. The project aims to elucidate the structure of these compounds, which can often only be obtained in small amounts due to the small size of Collembola, using mass spectrometric and infrared spectroscopic techniques as well as microderivatization of extracts. In order to verify the structure assignments, selected key compounds such as aromatic or branched terpenes or highly branched esters will be synthesized, which in some cases requires longer, complex syntheses. While the structures of some target compounds have been proposed by us here, a broader picture of epicuticle composition will be obtained by studying additional collembolan species. This will allow us to draw conclusions about the evolution of the chemistry of the cuticle of arthropods, comparing the results with those of insects and arachnids that we have studied independently. In order to be able to study further Collembola, a network has been established with biologists who will provide us with more species for the planned analyses. Defense compounds are used by a variety of Collembola as an additional defense mechanism besides the jumping fork. These compounds are also often only known from springtails. In addition to cuticular extracts, existing or newly obtained biological material can be used to obtain extracts containing more polar secondary metabolites. Within the scope of the investigations, these will also be analyzed. Some alkaloids have already been found and will be strucutrally defined by syntheses. By studying more species, it will be possible to determine how widespread chemical defense strategies are in Collembola and which biosynthetic pathways are used by them. This is of fundamental importance for understanding the ecology of these small but important arthropods. Since the cuticle of springtails is extremely water repellent, the synthesized compounds will be tested for their hydrophobic properties. The antimicrobial effect of the defense substances will also be evaluated.