Cuticular Lipid and Defense Chemistry of Collembola

弹尾目（跳虫）是昆虫的一个姊妹类，它们的成分显示出不同寻常的化学成分，通常与昆虫的成分不同。特别令人感兴趣的是构成皮肤最外层脂质层（角质层）的不寻常物质。这种脂质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至关重要，但它也可以通过其组成传递信息，作为化学信号。虽然昆虫的角质层在化学上主要由相对简单的碳氢化合物组成，但在弹尾纲中发现了一种更为复杂的化学物质，其中含有许多独特和新颖的化合物。这些化合物可以包括长链萜烯、聚甲基支化酯和其他先前未知的化合物。该项目旨在阐明这些化合物的结构，由于弹尾虫的体积小，这些化合物通常只能少量获得，使用质谱和红外光谱技术以及提取物的微衍生化。为了验证结构归属，将合成选定的关键化合物，如芳香族或支链萜烯或高度支链酯，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虫物种将获得更广泛的上表皮成分。这将使我们能够得出有关节肢动物角质层化学演变的结论，并将结果与我们独立研究的昆虫和蛛形纲动物的结果进行比较。为了能够进一步研究弹尾目，已经与生物学家建立了一个网络，他们将为我们提供更多的物种进行计划的分析。防御化合物被各种弹尾虫用作除了跳跃叉之外的额外防御机制。这些化合物通常也只在跳虫中发现。除表皮提取物外，现有或新获得的生物材料可用于获得含有更多极性次级代谢产物的提取物。在调查范围内，也将对这些问题进行分析。一些生物碱已经被发现，并将通过合成确定其结构。通过研究更多的物种，将有可能确定弹尾目中化学防御策略的广泛程度以及它们使用的生物合成途径。这对于理解这些小而重要的节肢动物的生态学具有根本的重要性。由于跳虫的表皮是非常防水的，合成的化合物将测试其疏水性能。还将评估防御物质的抗微生物效果。

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.