Structure and diagenesis of fossil polyphenols

在原始时代，次生天然产物的存在只是初步的了解。第一个完整的结构阐明化石多酚类色素（borolithochromes）的基础上微克数量使用微型冷冻探针核磁共振光谱（NMR）的示范性显示了现代化学分析的潜力，对原始天然产物的研究。通过这种方法，可以将1.5亿多年前的化合物与现在的天然产物进行结构比较，最终确定化石生物分子的起源甚至生物合成。在后续项目中，将澄清以下问题：在地质时代，化石生物中的多酚类天然产物在结构上发生了什么？发生了哪些降解反应？关于天然产物的化石保存可以得出什么结论？为了回答这些问题，几组多酚类天然产物的化石生物体已知的特殊原位保存这些化合物将使用microcryoprobe核磁共振进行详细的结构分析。特别令人感兴趣的是化石生物和自然产物，它们经历了相当少的变化，可以直接与现在的后代及其代谢物进行比较，例如更新世和中新世海胆中的萘醌和上新世和中新世树叶中的黄酮苷。此外，更古老的多环酚从侏罗纪海百合将结构分析，暴露于稍微升高的温度。

The occurrence of secondary natural products in primeval times is only rudimentarily known. The first complete structural elucidation of fossil polyphenolic pigments (borolithochromes) based on microgram quantities using microcryoprobe nuclear magnetic resonance spectroscopy (NMR) has exemplarily shown the potential of modern chemical analysis for the research on primeval natural products. By this method, the more than 150-million-years-old compounds could be structurally compared with present-day natural products, finally allowing for the determination of origin and even biosynthesis of the fossil biomolecules.In the follow-up project, the following shall be clarified: what happens structurally with polyphenolic natural products in fossil organisms during geological times? Which degradation reactions take place? What conclusions on the fossil preservation of natural products can be drawn? To answer these questions, several groups of polyphenolic natural products from fossil organisms known for exceptional in situ preservation of such compounds will be structurally analyzed in detail using microcryoprobe NMR. Of special interest are fossil organisms and natural products that have experienced rather little changes and can be directly compared with present-day descendants and their metabolites, such as naphthoquinones from Pleistocene and Miocene sea urchins and flavonoid glycosides from Pliocene and Miocene leaves. Furthermore, much older polycyclic phenols from Jurassic sea lilies will be structurally analyzed, that were exposed to slightly elevated temperatures.