The origin of maleimides in recent sediments - Sources, formation processes and palaeoenvironmental implications

近期沉积物中马来酰亚胺的起源 - 来源、形成过程和古环境影响

• 批准号: 253132634
• 负责人: Dr. Sebastian Näher, Ph.D.
• 金额: --
• 依托单位: Centre for Applied Organic Geochemistry
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/253132634?language=en
• 关键词: origin; maleimides; recent; sediments; Sources

Chlorophylls and bacteriochlorophylls are the most abundant and most important pigments on Earth. These compounds and their transformation products (chlorins, porphyrins, metalloporphyrins and maleimides) can be preserved in recent limnic and marine sediments, sedimentary rocks and crude oils and serve as valuable palaeoenvironmental proxies. Among these, maleimides (1H-pyrrole-2,5-diones), the assumed oxidation products of tetrapyrroles (i.e. chlorophylls, bacteriochlorophylls, related derivatives, hemes, phycobilins) have so far hardly been studied in recent sediments, most studies being focused on ancient deposits. Their formation processes are still incompletely understood and precursors of many maleimides are not known. In this project, the characterisation of maleimides in aquatic systems with different biogeochemical history will expand the very limited knowledge of maleimide sources and formation pathways in recent aquatic environments, which represents an important step to accurately apply them as biomarkers. These markers might be used for instance to describe changes in productivity and carbon cycling, microbial community structure, water column properties (e.g. photic zone anoxia/euxinia (persistent versus periodic), chemocline depth) and depositional conditions during sedimentation and diagenesis. This project aims at identifying maleimide sources by analysis of their distributions and comparing these with tetrapyrroles obtained in the same samples. Existing analytical procedures to determine maleimides with apolar functional groups will be modified to include polar maleimides. It is, hence, the first attempt to analyse polar maleimides in recent sediments. Furthermore, stable carbon and nitrogen isotope signatures of maleimides will be measured in environmental samples. This approach will enhance the understanding of the metabolism and cycling of organic carbon and nitrogen and to reconstruct changes in productivity, nutrient cycling and food web relationships.

叶绿素和细菌氯叶树是地球上最丰富，最重要的色素。这些化合物及其转化产物（氯蛋白，卟啉，金属核苷和马来酰亚胺）可以保存在最近的limni邦和海洋沉积物，沉积岩石和原油中，并用作有价值的古环境代理。其中，甲酰亚胺（1H-吡咯-2,5-二酮），四吡咯（即叶绿素，细菌叶绿素，相关衍生物，Hemes，phycobilins）的假定氧化产物迄今为止在最近的沉积物中几乎没有研究过，大多数研究都集中在古代沉积物上。它们的形成过程仍未完全理解，许多马来酰亚胺的前体尚不清楚。在这个项目中，在具有不同生物地球化学史的水生系统中对马来酰亚胺的表征将扩大最近水生环境中对马来酰亚胺源和形成途径的非常有限的知识，这代表了准确地将它们应用于生物标志物的重要步骤。例如，这些标记可用于描述生产力和碳循环的变化，微生物群落结构，水柱特性（例如，在沉积和成岩作用期间，持久性和周期性的光学区缺氧/Euxinia（持久性与周期性），化学固定深度）和沉积条件。该项目旨在通过分析其分布来识别马来酰亚胺的源，并将其与在相同样品中获得的四吡咯。现有的分析程序以确定用极光官能组确定马来酰亚胺，以包括极性马来酰亚胺。因此，这是在最近的沉积物中首次尝试分析极性马来酰亚胺的尝试。此外，将在环境样品中测量马来酰亚胺的稳定碳和氮同位素特征。这种方法将增强对有机碳和氮的代谢和循环的理解，并重建生产力，营养循环和食物网络关系的变化。