Structure and diagenesis of fossil polyphenols

点击翻译按钮获取中文摘要

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.