Development of structural mass-spectrometric methods for the comprehensive comparison of natural organic matter on an individual molecular composition level

开发结构质谱方法，在单个分子组成水平上综合比较天然有机物

• 批准号: 445025664
• 负责人: Dr. Oliver Lechtenfeld
• 金额: --
• 依托单位: Skolkovo Institute of Science and Technology (Skoltech)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/445025664?language=en
• 关键词: Development; structural; mass; spectrometric; methods

The primary aim of the proposed project is to develop a new approach for examination of individual components of natural organic matter (NOM) on a structural level. NOM plays a major role in the global carbon cycle but its molecular complexity hampers thorough investigation of its environmental role and connection between molecular composition and origin. State-of-the art biogeochemical studies of NOM by ultra-high resolution mass spectrometry, e.g. FTICR MS, are limited by their view of NOM as collection of molecular formulas only and often conclusions on reactivity are based on rather nonspecific elemental ratios. Also, there is contradicting evidence on the degree of structural diversity within NOM and whether NOM from different environments will always converge to the same common structural motifs.This fundamental discussion is at the core of biogeochemical research but in order to obtain a deeper understanding of the formation, reactivity and fate of NOM in the environment, molecular level analysis of NOM needs to advance from individual molecular formulas to chemical structures.For this project we will use a powerful combination of functional group and carbon skeleton specific isotope tagging, ultra-high resolution mass spectrometry with structure-indicative fragmentation and application of chemoinformatics approaches to propose NOM structural assignments on an individual molecular level.To this end carboxylic, carbonyl and phenolic groups in the individual NOM components will be enumerated by combination of FTICR MS and deuteromethylation, reduction and acetylation, respectively. Additional tagging of carbon skeleton will be also proposed on the basis of two-dimensional NMR analysis. At the same time, fragmentation trees and neutral loss matrix of in-cell fragmentation of pre-selected ions will be determined followed by sample clustering to assess the degree of structural similarity between DOM from different environments. Data processing pipelines will be adapted to both isotope tagging and tandem FTICR MS experiments. Application of chemoinformatics approaches and FTICR MS data-mining in chemical databases will enable to create a tool for the generation of structures which are close to particular compounds in NOM samples under investigation.We will further test the hypothesis that structures of NOM molecular components are driven by its sources and biogeochemical boundary conditions. As a consequence, NOM molecular structures differ between environments and could be used to reconstruct the biogeochemical history and to predict its future reactivity.The proposed project and workflows will overcome current limitations in NOM biogeochemistry paving the way for quantitative structure-activity relationships of individual NOM molecular components. The developed workflows in this project are expected to become a new standard in biogeochemical research of NOM and future carbon cycle studies.

拟议项目的主要目的是开发一种新的方法，用于在结构水平上检查天然有机物（NOM）的单个组分。NOM在全球碳循环中起着重要作用，但其分子的复杂性阻碍了对其环境作用以及分子组成与起源之间联系的深入研究。通过超高分辨率质谱法（例如FTICR MS）对NOM进行的最先进的生物地球化学研究受到NOM仅作为分子式集合的观点的限制，并且通常关于反应性的结论是基于相当非特异性的元素比率。此外，关于NOM内部结构多样性的程度以及来自不同环境的NOM是否总是收敛于相同的共同结构基序，存在相互矛盾的证据。这一基本讨论是地球化学研究的核心，但为了更深入地了解NOM在环境中的形成、反应性和归宿，NOM的分子水平分析需要从单个分子式推进到化学结构，对于本项目，我们将使用官能团和碳骨架特异性同位素标记的强大组合，超高分辨率质谱与结构指示碎片和化学信息学方法的应用，以提出在单个分子水平上的NOM结构归属。为此，将通过FTICR MS和氘代甲基化的组合来枚举单个NOM组分中的羧基、羰基和酚基，还原和乙酰化。在二维核磁共振分析的基础上，还将提出碳骨架的附加标记。同时，将确定预先选择的离子的细胞内碎片化的碎片化树和中性损失矩阵，然后通过样品聚类来评估来自不同环境的DOM之间的结构相似性程度。数据处理管道将适用于同位素标记和串联FTICR MS实验。化学信息学方法和FTICR MS数据挖掘在化学数据库中的应用将使我们能够创建一个工具来生成与所研究的NOM样品中特定化合物结构接近的结构。我们将进一步验证NOM分子组分的结构由其来源和地球化学边界条件驱动的假设。因此，NOM分子结构在不同环境中存在差异，可用于重建生物地球化学历史并预测其未来的反应性。拟议的项目和工作流程将克服目前NOM生物地球化学的局限性，为单个NOM分子组分的定量结构-活性关系铺平道路。本项目开发的工作流程有望成为NOM地球化学研究和未来碳循环研究的新标准。