Novel MS-based analytical approaches for shotgun lignomics and quantification of lignin
Final Report Abstract
The goal of this project was the development of novel mass spectrometric techniques for lignomics research. The lignome in this context is the full complement of lignin-related compounds in a given sample; that is, all lignin monomers, oligomers and polymers. Lignin is a major component of woody plants and second most abundant natural polymer. It is difficult to degrade by chemical or biochemical methods. Depolymerization, however, is extremely important for recovery of value chemicals and biofuels from lignin wastes. During the first funding phase, we have developed novel electrochemical methods for lignin cleavage by means of ionic liquids and efficient catalytically-active electrodes. Mass spectrometric (MS) analysis showed that electrochemical degradation yielded a very large number of breakdown products, typically >5000 compounds, which could be readily characterized and assigned to chemical classes by means of ultra-high resolution MS. We developed powerful twodimensional visualization tools that provided detailed information on the transformation and exact degradation mechanisms as well as on the identity of the cleavage products. In the second project phase, the focus was on the development of computational tools for reaching deeper into the lignome than presently possible, based on the discovery of repeating units in the complex lignin mass spectral raw data. For this purpose, we developed a web-based platform (“Constellation”), which is available to users worldwide without restrictions. The algorithms of the Constellation software permit detection and visualization of known and unknown structural motifs, thus allowing targeted and untargeted analysis. The performance of the cheminformatics approach was successfully demonstrated by analyzing multiple lignin samples. We were able to show that by using the novel data mining strategies for the acquired complex mass spectral raw data, the amount and quality of the obtained results clearly exceeded conventional mass spectrometric analysis, while avoiding some of the problems of existing wet chemistry degradation procedures.
Publications
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Enhanced Mass Defect Filtering To Simplify and Classify Complex Mixtures of Lignin Degradation Products. Analytical Chemistry, 88(2), 1328-1335.
Dier, Tobias K. F.; Egele, Kerstin; Fossog, Verlaine; Hempelmann, Rolf & Volmer, Dietrich A.
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Shedding light on the structures of lignin compounds: photo-oxidation under artificial UV light and characterization by high resolution mass spectrometry. Analytical and Bioanalytical Chemistry, 408(28), 8203-8210.
Qi, Yulin; Hempelmann, Rolf & Volmer, Dietrich A.
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Two-dimensional mass defect matrix plots for mapping genealogical links in mixtures of lignin depolymerisation products. Analytical and Bioanalytical Chemistry, 408(18), 4835-4843.
Qi, Yulin; Hempelmann, Rolf & Volmer, Dietrich A.
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Novel Mixed‐Mode Stationary Phases for Chromatographic Separation of Complex Mixtures of Decomposed Lignin. ChemistrySelect, 2(2), 779-786.
Dier, Tobias K. F.; Rauber, Daniel; Jauch, Johann; Hempelmann, Rolf & Volmer, Dietrich A.
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Sustainable Electrochemical Depolymerization of Lignin in Reusable Ionic Liquids. Scientific Reports, 7(1).
Dier, Tobias K. F.; Rauber, Daniel; Durneata, Dan; Hempelmann, Rolf & Volmer, Dietrich A.
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Chemical diversity of lignin degradation products revealed by matrix-optimized MALDI mass spectrometry. Analytical and Bioanalytical Chemistry, 411(23), 6031-6037.
Qi, Yulin & Volmer, Dietrich A.
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Assessment of molecular diversity of lignin products by various ionization techniques and high-resolution mass spectrometry. Science of The Total Environment, 713, 136573.
Qi, Yulin; Fu, Pingqing; Li, Siliang; Ma, Chao; Liu, Congqiang & Volmer, Dietrich A.
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Constellation: An Open-Source Web Application for Unsupervised Systematic Trend Detection in High-Resolution Mass Spectrometry Data. Journal of the American Society for Mass Spectrometry, 33(2), 382-389.
Letourneau, Dane R. & Volmer, Dietrich A.
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Characterizing lignins from various sources and treatment processes after optimized sample preparation techniques and analysis via ESI-HRMS and custom mass defect software tools. Analytical and Bioanalytical Chemistry, 415(27), 6663-6675.
Letourneau, Dane R.; Marzullo, Bryan P.; Alexandridou, Anastasia; Barrow, Mark P.; O.’Connor, Peter B. & Volmer, Dietrich A.
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New algorithms demonstrate untargeted detection of chemically meaningful changing units and formula assignment for HRMS data of polymeric mixtures in the open-source constellation web application. Journal of Cheminformatics, 15(1).
Letourneau, Dane R.; August, Dennis D. & Volmer, Dietrich A.
