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Metz F, Olsen AM, Lu F, Myers KS, Allemann MN, Michener JK, Noguera DR, Donohue TJ. Catabolism of β-5 linked aromatics by Novosphingobium aromaticivorans. mBio 2024; 15:e0171824. [PMID: 39012147 PMCID: PMC11323797 DOI: 10.1128/mbio.01718-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Accepted: 06/17/2024] [Indexed: 07/17/2024] Open
Abstract
Aromatic compounds are an important source of commodity chemicals traditionally produced from fossil fuels. Aromatics derived from plant lignin can potentially be converted into commodity chemicals through depolymerization followed by microbial funneling of monomers and low molecular weight oligomers. This study investigates the catabolism of the β-5 linked aromatic dimer dehydrodiconiferyl alcohol (DC-A) by the bacterium Novosphingobium aromaticivorans. We used genome-wide screens to identify candidate genes involved in DC-A catabolism. Subsequent in vivo and in vitro analyses of these candidate genes elucidated a catabolic pathway composed of four required gene products and several partially redundant dehydrogenases that convert DC-A to aromatic monomers that can be funneled into the central aromatic metabolic pathway of N. aromaticivorans. Specifically, a newly identified γ-formaldehyde lyase, PcfL, opens the phenylcoumaran ring to form a stilbene and formaldehyde. A lignostilbene dioxygenase, LsdD, then cleaves the stilbene to generate the aromatic monomers vanillin and 5-formylferulate (5-FF). We also showed that the aldehyde dehydrogenase FerD oxidizes 5-FF before it is decarboxylated by LigW, yielding ferulic acid. We found that some enzymes involved in the β-5 catabolism pathway can act on multiple substrates and that some steps in the pathway can be mediated by multiple enzymes, providing new insights into the robust flexibility of aromatic catabolism in N. aromaticivorans. A comparative genomic analysis predicted that the newly discovered β-5 aromatic catabolic pathway is common within the order Sphingomonadales. IMPORTANCE In the transition to a circular bioeconomy, the plant polymer lignin holds promise as a renewable source of industrially important aromatic chemicals. However, since lignin contains aromatic subunits joined by various chemical linkages, producing single chemical products from this polymer can be challenging. One strategy to overcome this challenge is using microbes to funnel a mixture of lignin-derived aromatics into target chemical products. This approach requires strategies to cleave the major inter-unit linkages of lignin to release monomers for funneling into valuable products. In this study, we report newly discovered aspects of a pathway by which the Novosphingobium aromaticivorans DSM12444 catabolizes aromatics joined by the second most common inter-unit linkage in lignin, the β-5 linkage. This work advances our knowledge of aromatic catabolic pathways, laying the groundwork for future metabolic engineering of this and other microbes for optimized conversion of lignin into products.
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Affiliation(s)
- Fletcher Metz
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin, Madison, Wisconsin, USA
| | - Abigail M. Olsen
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
| | - Fachuang Lu
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
| | - Kevin S. Myers
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
| | - Marco N. Allemann
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Joshua K. Michener
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Daniel R. Noguera
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
- Department of Civil and Environmental Engineering, University of Wisconsin, Madison, Wisconsin, USA
| | - Timothy J. Donohue
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
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2
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Peracchi LM, Panahabadi R, Barros-Rios J, Bartley LE, Sanguinet KA. Grass lignin: biosynthesis, biological roles, and industrial applications. FRONTIERS IN PLANT SCIENCE 2024; 15:1343097. [PMID: 38463570 PMCID: PMC10921064 DOI: 10.3389/fpls.2024.1343097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/06/2024] [Indexed: 03/12/2024]
Abstract
Lignin is a phenolic heteropolymer found in most terrestrial plants that contributes an essential role in plant growth, abiotic stress tolerance, and biotic stress resistance. Recent research in grass lignin biosynthesis has found differences compared to dicots such as Arabidopsis thaliana. For example, the prolific incorporation of hydroxycinnamic acids into grass secondary cell walls improve the structural integrity of vascular and structural elements via covalent crosslinking. Conversely, fundamental monolignol chemistry conserves the mechanisms of monolignol translocation and polymerization across the plant phylum. Emerging evidence suggests grass lignin compositions contribute to abiotic stress tolerance, and periods of biotic stress often alter cereal lignin compositions to hinder pathogenesis. This same recalcitrance also inhibits industrial valorization of plant biomass, making lignin alterations and reductions a prolific field of research. This review presents an update of grass lignin biosynthesis, translocation, and polymerization, highlights how lignified grass cell walls contribute to plant development and stress responses, and briefly addresses genetic engineering strategies that may benefit industrial applications.
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Affiliation(s)
- Luigi M. Peracchi
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, United States
| | - Rahele Panahabadi
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States
| | - Jaime Barros-Rios
- Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
| | - Laura E. Bartley
- Institute of Biological Chemistry, Washington State University, Pullman, WA, United States
| | - Karen A. Sanguinet
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, United States
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3
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Pecio Ł, Pecio S, Mroczek T, Oleszek W. Spiro-Flavonoids in Nature: A Critical Review of Structural Diversity and Bioactivity. Molecules 2023; 28:5420. [PMID: 37513292 PMCID: PMC10385819 DOI: 10.3390/molecules28145420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Based on the literature data from 1973 to 2022, this work summarizes reports on spiro-flavonoids with a spiro-carbon at the center of their structure and how this affects their isolation methods, stereochemistry, and biological activity. The review collects 65 unique structures, including spiro-biflavonoids, spiro-triflavonoids, spiro-tetraflavonoids, spiro-flavostilbenoids, and scillascillin-type homoisoflavonoids. Scillascillin-type homoisoflavonoids comprise spiro[bicyclo[4.2.0]octane-7,3'-chromane]-1(6),2,4-trien-4'-one, while the other spiro-flavonoids contain either 2H,2'H-3,3'-spirobi[benzofuran]-2-one or 2'H,3H-2,3'-spirobi[benzofuran]-3-one in the core of their structures. Spiro-flavonoids have been described in more than 40 species of eight families, including Asparagaceae, Cistaceae, Cupressaceae, Fabaceae, Pentaphylacaceae, Pinaceae, Thymelaeaceae, and Vitaceae. The possible biosynthetic pathways for each group of spiro-flavonoids are summarized in detail. Anti-inflammatory and anticancer activities are the most important biological activities of spiro-flavonoids, both in vitro and in vivo. Our work identifies the most promising natural sources, the existing challenges in assigning the stereochemistry of these compounds, and future research perspectives.
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Affiliation(s)
- Łukasz Pecio
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, 8 Czartoryskich Street, 24-100 Puławy, Poland
- Department of Chemistry of Natural Products, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland
| | - Solomiia Pecio
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, 8 Czartoryskich Street, 24-100 Puławy, Poland
| | - Tomasz Mroczek
- Department of Chemistry of Natural Products, Medical University of Lublin, 1 Chodźki Street, 20-093 Lublin, Poland
| | - Wiesław Oleszek
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation-State Research Institute, 8 Czartoryskich Street, 24-100 Puławy, Poland
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4
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Kim H, Rencoret J, Elder TJ, del Río JC, Ralph J. Biomimetic oxidative copolymerization of hydroxystilbenes and monolignols. SCIENCE ADVANCES 2023; 9:eade5519. [PMID: 36888720 PMCID: PMC9995074 DOI: 10.1126/sciadv.ade5519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Hydroxystilbenes are a class of polyphenolic compounds that behave as lignin monomers participating in radical coupling reactions during the lignification. Here, we report the synthesis and characterization of various artificial copolymers of monolignols and hydroxystilbenes, as well as low-molecular-mass compounds, to obtain the mechanistic insights into their incorporation into the lignin polymer. Integrating the hydroxystilbenes, resveratrol and piceatannol, into monolignol polymerization in vitro, using horseradish peroxidase to generate phenolic radicals, produced synthetic lignins [dehydrogenation polymers (DHPs)]. Copolymerization of hydroxystilbenes with monolignols, especially sinapyl alcohol, by in vitro peroxidases notably improved the reactivity of monolignols and resulted in substantial yields of synthetic lignin polymers. The resulting DHPs were analyzed using two-dimensional NMR and 19 synthesized model compounds to confirm the presence of hydroxystilbene structures in the lignin polymer. The cross-coupled DHPs confirmed both resveratrol and piceatannol as authentic monomers participating in the oxidative radical coupling reactions during polymerization.
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Affiliation(s)
- Hoon Kim
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Jorge Rencoret
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Avenida de la Reina Mercedes, 10, 41012, Seville, Spain
| | - Thomas J. Elder
- USDA-Forest Service, Southern Research Station 521 Devall Dr. Auburn, AL 36849, USA
| | - José C. del Río
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Avenida de la Reina Mercedes, 10, 41012, Seville, Spain
| | - John Ralph
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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5
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Li W, Zhang X, Han J. Formation of Larger Molecular Weight Disinfection Byproducts from Acetaminophen in Chlorine Disinfection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16929-16939. [PMID: 36409822 DOI: 10.1021/acs.est.2c06394] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Acetaminophen is widely used to treat mild to moderate pain and to reduce fever. Under the worldwide COVID-19 pandemic, this over-the-counter pain reliever and fever reducer has been drastically consumed, which makes it even more abundant than ever in municipal wastewater and drinking water sources. Chlorine is the most widely used oxidant in drinking water disinfection, and chlorination generally causes the degradation of organic compounds, including acetaminophen. In this study, a new reaction pathway in the chlorination of acetaminophen, i.e., oxidative coupling reactions via acetaminophen radicals, was investigated both experimentally and computationally. Using an ultraperformance liquid chromatograph coupled to an electrospray ionization-triple quadrupole mass spectrometer, we detected over 20 polymeric products in chlorinated acetaminophen samples, some of which have structures similar to the legacy pollutants "polychlorinated biphenyls". Both C-C and C-O bonding products were found, and the corresponding bonding processes and kinetics were revealed by quantum chemical calculations. Based on the product confirmation and intrinsic reaction coordinate computations, a pathway for the formation of the polymeric products in the chlorination of acetaminophen was proposed. This study suggests that chlorination may cause not only degradation but also upgradation of a phenolic compound or contaminant.
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Affiliation(s)
- Wanxin Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR00000, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR00000, China
| | - Jiarui Han
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR00000, China
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6
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Khachatryan L, Barekati-Goudarzi M, Asatryan R, Ozarowski A, Boldor D, Lomnicki SM, Cormier SA. Metal-Free Biomass-Derived Environmentally Persistent Free Radicals (Bio-EPFRs) from Lignin Pyrolysis. ACS OMEGA 2022; 7:30241-30249. [PMID: 36061701 PMCID: PMC9434622 DOI: 10.1021/acsomega.2c03381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
To assess contribution of the radicals formed from biomass burning, our recent findings toward the formation of resonantly stabilized persistent radicals from hydrolytic lignin pyrolysis in a metal-free environment are presented in detail. Such radicals have particularly been identified during fast pyrolysis of lignin dispersed into the gas phase in a flow reactor. The trapped radicals were analyzed by X-band electron paramagnetic resonance (EPR) and high-frequency (HF) EPR spectroscopy. To conceptualize available data, the metal-free biogenic bulky stable radicals with extended conjugated backbones are suggested to categorize as a new type of metal-free environmentally persistent free radicals (EPFRs) (bio-EPFRs). They can be originated not only from lignin/biomass pyrolysis but also during various thermal processes in combustion reactors and media, including tobacco smoke, anthropogenic sources and wildfires (forest/bushfires), and so on. The persistency of bio-EPFRs from lignin gas-phase pyrolysis was outlined with the evaluated lifetime of two groups of radicals being 33 and 143 h, respectively. The experimental results from pyrolysis of coniferyl alcohol as a model compound of lignin in the same fast flow reactor, along with our detailed potential energy surface analyses using high-level DFT and ab initio methods toward decomposition of a few other model compounds reported earlier, provide a mechanistic view on the formation of C- and O-centered radicals during lignin gas-phase pyrolysis. The preliminary measurements using HF-EPR spectroscopy also support the existence of O-centered radicals in the radical mixtures from pyrolysis of lignin possessing a high g value (2.0048).
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Affiliation(s)
- Lavrent Khachatryan
- Department
of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | | | - Rubik Asatryan
- Department
of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Florida, Tallahassee 32310, United States
| | - Dorin Boldor
- Department
of Biological and Agricultural Engineering, LSU AgCenter and LSU A&M College, Baton Rouge, Louisiana 70803, United States
| | - Slawomir M. Lomnicki
- Department
of Environmental Sciences, Louisiana State
University, Baton Rouge, Louisiana 70803, United States
| | - Stephania A. Cormier
- Department
of Biological Sciences, LSU Superfund Research
Program and Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, United States
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7
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Wang Y, Kalscheur J, Ebikade E, Li Q, Vlachos DG. LigninGraphs: lignin structure determination with multiscale graph modeling. J Cheminform 2022; 14:43. [PMID: 35794646 PMCID: PMC9261032 DOI: 10.1186/s13321-022-00627-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/12/2022] [Indexed: 11/10/2022] Open
Abstract
Lignin is an aromatic biopolymer found in ubiquitous sources of woody biomass. Designing and optimizing lignin valorization processes requires a fundamental understanding of lignin structures. Experimental characterization techniques, such as 2D-heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectra, could elucidate the global properties of the polymer molecules. Computer models could extend the resolution of experiments by representing structures at the molecular and atomistic scales. We introduce a graph-based multiscale modeling framework for lignin structure generation and visualization. The framework employs accelerated rejection-free polymerization and hierarchical Metropolis Monte Carlo optimization algorithms. We obtain structure libraries for various lignin feedstocks based on literature and new experimental NMR data for poplar wood, pinewood, and herbaceous lignin. The framework could guide researchers towards feasible lignin structures, efficient space exploration, and future kinetics modeling. Its software implementation in Python, LigninGraphs, is open-source and available on GitHub.
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Affiliation(s)
- Yifan Wang
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy St, Newark, DE, 19716, USA.,Catalysis Center for Energy Innovation, RAPID Manufacturing Institute, and Delaware Energy Institute (DEI), University of Delaware, 221 Academy St, Newark, DE, 19716, USA
| | - Jake Kalscheur
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy St, Newark, DE, 19716, USA.,Catalysis Center for Energy Innovation, RAPID Manufacturing Institute, and Delaware Energy Institute (DEI), University of Delaware, 221 Academy St, Newark, DE, 19716, USA
| | - Elvis Ebikade
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy St, Newark, DE, 19716, USA.,Catalysis Center for Energy Innovation, RAPID Manufacturing Institute, and Delaware Energy Institute (DEI), University of Delaware, 221 Academy St, Newark, DE, 19716, USA
| | - Qiang Li
- Catalysis Center for Energy Innovation, RAPID Manufacturing Institute, and Delaware Energy Institute (DEI), University of Delaware, 221 Academy St, Newark, DE, 19716, USA
| | - Dionisios G Vlachos
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy St, Newark, DE, 19716, USA. .,Catalysis Center for Energy Innovation, RAPID Manufacturing Institute, and Delaware Energy Institute (DEI), University of Delaware, 221 Academy St, Newark, DE, 19716, USA.
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8
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Elder T, Del Río JC, Ralph J, Rencoret J, Kim H. Density functional theory study on the coupling and reactions of diferuloylputrescine as a lignin monomer. PHYTOCHEMISTRY 2022; 197:113122. [PMID: 35131641 DOI: 10.1016/j.phytochem.2022.113122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/25/2022] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Diferuloylputrescine has been found in a variety of plant species, and recent work has provided evidence of its covalent bonding into lignin. Results from nuclear magnetic resonance spectroscopy revealed the presence of bonding patterns consistent with homo-coupling of diferuloylputrescine and the possibility of cross-coupling with lignin. In the present work, density functional theory calculations have been applied to assess the energetics associated with radical coupling, rearomatization, and dehydrogenation for possible homo-coupled dimers of diferuloylputrescine and cross-coupled dimers of diferuloylputrescine and coniferyl alcohol. The values obtained for these reaction energetics are consistent with those reported for monolignols and other novel lignin monomers. As such, this study shows that there would be no thermodynamic impediment to the incorporation of diferuloylputrescine into the lignin polymer and its addition to the growing list of non-canonical lignin monomers.
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Affiliation(s)
- Thomas Elder
- USDA-Forest Service, Southern Research Station, 521 Devall Drive, Auburn, AL, 36849, USA.
| | - José C Del Río
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes, 10, 41012, Seville, Spain
| | - John Ralph
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, 1552 University Ave, Madison, WI, 53726, USA; Department of Biochemistry, University of Wisconsin, 433 Babcock Drive, Madison, WI, 53706, USA
| | - Jorge Rencoret
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Av. Reina Mercedes, 10, 41012, Seville, Spain
| | - Hoon Kim
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, 1552 University Ave, Madison, WI, 53726, USA
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9
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Zhang H, Song R, Guo F, Chai L, Wang W, Zeng J, Yu H, Ji L. Using Physical Organic Chemistry Knowledge to Predict Unusual Metabolites of Synthetic Phenolic Antioxidants by Cytochrome P450. Chem Res Toxicol 2022; 35:840-848. [PMID: 35416036 DOI: 10.1021/acs.chemrestox.2c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biotransformation, especially by human CYP450 enzymes, plays a crucial role in regulating the toxicity of organic compounds in organisms, but is poorly understood for most emerging pollutants, as their numerous "unusual" biotransformation reactions cannot retrieve examples from the textbooks. Therefore, in order to predict the unknown metabolites with altering toxicological profiles, there is a realistic need to develop efficient methods to reveal the "unusual" metabolic mechanism of emerging pollutants. Combining experimental work with computational predictions has been widely accepted as an effective approach in studying complex metabolic reactions; however, the full quantum chemical computations may not be easily accessible for most environmentalists. Alternatively, this work practiced using the concepts from physical organic chemistry for studying the interrelationships between structure and reactivity of organic molecules, to reveal the "unusual" metabolic mechanism of synthetic phenolic antioxidants catalyzed by CYP450, for which the simple pencil-and-paper and property-computation methods based on physical organic chemistry were performed. The phenol-coupling product of butylated hydroxyanisole (BHA) (based on spin aromatic delocalization) and ipso-addition quinol metabolite of butylated hydroxytoluene (BHT) (based on hyperconjugative effect) were predicted as two "unusual" metabolites, which were further confirmed by our in vitro analysis. We hope this easily handled approach will promote environmentalists to attach importance to physical organic chemistry, with an eye to being able to use the knowledge gained to efficiently predict the fates of substantial unknown synthesized organic compounds in the future.
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Affiliation(s)
- Huanni Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Fangjie Guo
- School of Management Engineering and Electronic Commerce, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Lihong Chai
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 81377 Munich, Germany
| | - Wuwei Wang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Jingyi Zeng
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China
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10
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Chai L, Zhang H, Guo F, Song R, Yu H, Ji L. Computational Investigation of the Bisphenolic Drug Metabolism by Cytochrome P450: What Factors Favor Intramolecular Phenol Coupling. Chem Res Toxicol 2022; 35:440-449. [PMID: 35230092 DOI: 10.1021/acs.chemrestox.1c00350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intramolecular phenol coupling reactions of alkaloids can lead to active metabolites catalyzed by the mammalian cytochrome P450 enzyme (P450); however, the mechanistic knowledge of such an "unusual" process is lacking. This work performs density functional theory computations to reveal the P450-mediated metabolic pathway leading from R-reticuline to the morphine precursor salutaridine by exploring possible intramolecular phenol coupling mechanisms involving diradical coupling, radical addition, and electron transfer. The computed results show that the outer-sphere electron transfer with a high barrier (>20.0 kcal/mol) is unlikely to happen. However, for inter-sphere intramolecular phenol coupling, it reveals that intramolecular phenol coupling of R-reticuline proceeds via the diradical mechanism consecutively by compound I and protonated compound II of P450 rather than the radical addition mechanism. The existence of a much higher radical rebound barrier than that of H-abstraction in the quartet high-spin state can endow the R-reticuline phenoxy radical with a sufficient lifetime to enable intramolecular phenol coupling, while the H-abstraction/radical rebound mode with a negligible rebound barrier leading to phenol hydroxylation can only happen in the doublet low-spin state. Therefore, the ratio [coupling]/[hydroxylation] can be approximately reflected by the relative yield of the high-spin and low-spin H-abstraction by P450, which thus can provide a theoretical ratio of 16:1 for R-reticuline, which is in accordance with previous experimental results. Especially, the high rebound barrier of the phenoxy radical derived from the weak electron-donating ability of the phenoxy radical is revealed as an intrinsic nature. Therefore, the revealed intramolecular phenol coupling mechanism can be potentially extended to several other bisphenolic drugs to infer groups of unexpected metabolites in organisms.
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Affiliation(s)
- Lihong Chai
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China.,College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstrasse 4, Munich 81377, Germany
| | - Huanni Zhang
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Fangjie Guo
- School of Management Engineering and Electronic Commerce, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Runqian Song
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Li Ji
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Daxue Road 1, Xuzhou 221116, China.,College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.,Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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11
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Beck S, Choi P, Mushrif SH. Physico-chemical interactions within lignocellulosic biomass and their importance in developing solvent based deconstruction methods. REACT CHEM ENG 2022. [DOI: 10.1039/d2re00374k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Fundamental understanding of physico-chemical interactions among the biopolymers in lignocellulosic biomass is crucial to develop atom-efficient deconstruction methods.
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Affiliation(s)
- Seth Beck
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 St NW, Edmonton, AB, T6G 1H9, Canada
| | - Phillip Choi
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 St NW, Edmonton, AB, T6G 1H9, Canada
- Faculty of Engineering and Applied Science, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - Samir H. Mushrif
- Department of Chemical and Materials Engineering, University of Alberta, 9211-116 St NW, Edmonton, AB, T6G 1H9, Canada
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12
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Zhou S, Jin K, Buehler MJ. Understanding Plant Biomass via Computational Modeling. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2003206. [PMID: 32945027 DOI: 10.1002/adma.202003206] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Plant biomass, especially wood, has been used for structural materials since ancient times. It is also showing great potential for new structural materials and it is the major feedstock for the emerging biorefineries for building a sustainable society. The plant cell wall is a hierarchical matrix of mainly cellulose, hemicellulose, and lignin. Herein, the structure, properties, and reactions of cellulose, lignin, and wood cell walls, studied using density functional theory (DFT) and molecular dynamics (MD), which are the widely used computational modeling approaches, are reviewed. Computational modeling, which has played a crucial role in understanding the structure and properties of plant biomass and its nanomaterials, may serve a leading role on developing new hierarchical materials from biomass in the future.
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Affiliation(s)
- Shengfei Zhou
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Mass. Ave 1-290, Cambridge, MA, 02139, USA
| | - Kai Jin
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Mass. Ave 1-290, Cambridge, MA, 02139, USA
| | - Markus J Buehler
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Mass. Ave 1-290, Cambridge, MA, 02139, USA
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13
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Dörrstein J, Schwarz D, Scholz R, Walther F, Zollfrank C. Tuneable material properties of Organosolv lignin biocomposites in response to heat and shear forces. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Elder T, Rencoret J, del Río JC, Kim H, Ralph J. Radical Coupling Reactions of Hydroxystilbene Glucosides and Coniferyl Alcohol: A Density Functional Theory Study. FRONTIERS IN PLANT SCIENCE 2021; 12:642848. [PMID: 33737945 PMCID: PMC7960926 DOI: 10.3389/fpls.2021.642848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/10/2021] [Indexed: 06/12/2023]
Abstract
The monolignols, p-coumaryl, coniferyl, and sinapyl alcohol, arise from the general phenylpropanoid biosynthetic pathway. Increasingly, however, authentic lignin monomers derived from outside this process are being identified and found to be fully incorporated into the lignin polymer. Among them, hydroxystilbene glucosides, which are produced through a hybrid process that combines the phenylpropanoid and acetate/malonate pathways, have been experimentally detected in the bark lignin of Norway spruce (Picea abies). Several interunit linkages have been identified and proposed to occur through homo-coupling of the hydroxystilbene glucosides and their cross-coupling with coniferyl alcohol. In the current work, the thermodynamics of these coupling modes and subsequent rearomatization reactions have been evaluated by the application of density functional theory (DFT) calculations. The objective of this paper is to determine favorable coupling and cross-coupling modes to help explain the experimental observations and attempt to predict other favorable pathways that might be further elucidated via in vitro polymerization aided by synthetic models and detailed structural studies.
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Affiliation(s)
- Thomas Elder
- USDA-Forest Service, Southern Research Station, Auburn, AL, United States
| | - Jorge Rencoret
- Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Seville, Spain
| | - José C. del Río
- Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Seville, Spain
| | - Hoon Kim
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, WI, United States
| | - John Ralph
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, WI, United States
- Department of Biochemistry, University of Wisconsin, Madison, WI, United States
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15
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Jasiukaitytė-Grojzdek E, Huš M, Grilc M, Likozar B. Acid-Catalyzed α-O-4 Aryl-Ether Cleavage Mechanisms in (Aqueous) γ-Valerolactone: Catalytic Depolymerization Reactions of Lignin Model Compound During Organosolv Pretreatment. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2020; 8:17475-17486. [PMID: 33335815 PMCID: PMC7735783 DOI: 10.1021/acssuschemeng.0c06099] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/12/2020] [Indexed: 06/12/2023]
Abstract
In this study, acidolysis of benzyl phenyl ether (BPE), being a representative lignin model compound with the α-O-4 linkage, was examined in γ-valerolactone (GVL) and a GVL/water mixture, each time acidified with sulfuric acid. The product distribution was strongly affected by water used as a cosolvent, which was found to be advantageous by inhibiting the formation of larger structures and introducing reactive OH groups instead. The experimental results indicate the GVL/water ratio as an important parameter to attain an optimal hydrolytic α-ether bond cleavage. Differences between the organosolv lignins (molecular weight distribution, OH group content, and structural features with reaction time), isolated under moderate reaction conditions, supported the findings obtained using BPE. A beneficial effect of the added water is reflected in the higher aliphatic OH group content and less intact structure. Analysis of the reaction mechanism represents an initial step toward kinetics and structure-activity correlation of biorefining industrial resources.
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Affiliation(s)
- Edita Jasiukaitytė-Grojzdek
- Department
of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Matej Huš
- Department
of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Miha Grilc
- Department
of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Blaž Likozar
- Department
of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
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16
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Wackett LP, Robinson SL. The ever-expanding limits of enzyme catalysis and biodegradation: polyaromatic, polychlorinated, polyfluorinated, and polymeric compounds. Biochem J 2020; 477:2875-2891. [PMID: 32797216 PMCID: PMC7428800 DOI: 10.1042/bcj20190720] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/29/2020] [Accepted: 07/31/2020] [Indexed: 11/17/2022]
Abstract
Biodegradation is simply the metabolism of anthropogenic, or otherwise unwanted, chemicals in our environment, typically by microorganisms. The metabolism of compounds commonly found in living things is limited to several thousand metabolites whereas ∼100 million chemical substances have been devised by chemical synthesis, and ∼100 000 are used commercially. Since most of those compounds are not natively found in living things, and some are toxic or carcinogenic, the question arises as to whether there is some organism somewhere with the enzymes that can biodegrade them. Repeatedly, anthropogenic chemicals have been denoted 'non-biodegradable,' only to find they are reactive with one or more enzyme(s). Enzyme reactivity has been organized into categories of functional group transformations. The discovery of new functional group transformations has continually expanded our knowledge of enzymes and biodegradation. This expansion of new-chemical biodegradation is driven by the evolution and spread of newly evolved enzymes. This review describes the biodegradation of widespread commercial chemicals with a focus on four classes: polyaromatic, polychlorinated, polyfluorinated, and polymeric compounds. Polyaromatic hydrocarbons include some of the most carcinogenic compounds known. Polychlorinated compounds include polychlorinated biphenyls (PCBs) and many pesticides of the twentieth century. Polyfluorinated compounds are a major focus of bioremediation efforts today. Polymers are clogging landfills, killing aquatic species in the oceans and increasingly found in our bodies. All of these classes of compounds, each thought at one time to be non-biodegradable, have been shown to react with natural enzymes. The known limits of enzyme catalysis, and hence biodegradation, are continuing to expand.
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Affiliation(s)
- Lawrence P. Wackett
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Twin Cities, Minneapolis, MN 55108, U.S.A
- Biotechnology Institute, University of Minnesota, Twin Cities, Minneapolis, MN 55108, U.S.A
- Program in Microbiology, Immunology and Cancer Biology, University of Minnesota, Twin Cities, Minneapolis, MN 55108, U.S.A
| | - Serina L. Robinson
- Biotechnology Institute, University of Minnesota, Twin Cities, Minneapolis, MN 55108, U.S.A
- Program in Microbiology, Immunology and Cancer Biology, University of Minnesota, Twin Cities, Minneapolis, MN 55108, U.S.A
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17
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Hudzik JM, Barekati-Goudarzi M, Khachatryan L, Bozzelli JW, Ruckenstein E, Asatryan R. OH-Initiated Reactions of para-Coumaryl Alcohol Relevant to the Lignin Pyrolysis. Part II. Kinetic Analysis. J Phys Chem A 2020; 124:4875-4904. [DOI: 10.1021/acs.jpca.9b11894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jason M. Hudzik
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | | | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Joseph W. Bozzelli
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Eli Ruckenstein
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14226, United States
| | - Rubik Asatryan
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14226, United States
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18
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Bertella S, Luterbacher JS. Lignin Functionalization for the Production of Novel Materials. TRENDS IN CHEMISTRY 2020. [DOI: 10.1016/j.trechm.2020.03.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Slight Shading Stress at Seedling Stage Does not Reduce Lignin Biosynthesis or Affect Lodging Resistance of Soybean Stems. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10040544] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Shade is widespread in agricultural production and affects lignin biosynthesis and lodging resistance of crops. We explored the effects of shade intensity on lignin biosynthesis and lodging resistance at the physiological and molecular levels in two soybean cultivars (Nandou12 and E93) with different shade tolerance under four progressively severe shade treatments, S0–S3 (S0: no shade, S1: slight shade, S2: moderate shade, S3: heavy shade). Our results showed no significant difference in breaking strength of the two cultivars under S1 and S0 treatments, with no prominent decrease in the lodging resistance index. The activity of lignin biosynthesis rate-limiting enzymes phenylalanine ammonia-lyase (PAL), peroxidase and cinnamyl alcohol dehydrogenase (CAD), which were considerably related to the two lodging resistance indexes above, was not significantly decreased by slight shade, while 4-coumaric acid ligase (4CL) activity was increased. Most genes involved in lignin biosynthesis were not significantly down-regulated by slight shade (S1) compared to S0, while p-coumarate 3-hydroxylase (C3H), 4-coumaric acid ligase (4CL) and laccase (LAC) genes were upregulated. Under heavy shade (S3), enzyme activity and gene expression associated with lignin synthesis in both soybean cultivars were strongly inhibited; moreover, stem mechanical strength and lodging resistance were remarkably decreased compared with those under S0. These physiological and molecular changes suggested that applicable shade levels do not significantly affect the mechanical strength and lodging resistance of soybean stem. Exploiting the lodging resistance potential of existing soybean cultivars was an effective and efficient way to address yield reduction caused by lodging in intercropped soybeans.
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20
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Guo F, Chai L, Zhang S, Yu H, Liu W, Kepp KP, Ji L. Computational Biotransformation Profile of Emerging Phenolic Pollutants by Cytochromes P450: Phenol-Coupling Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2902-2912. [PMID: 31967796 DOI: 10.1021/acs.est.9b06897] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phenols are ubiquitous environmental pollutants, whose biotransformation involving phenol coupling catalyzed by cytochromes P450 may produce more lipophilic and toxic metabolites. Density functional theory (DFT) computations were performed to explore the debated phenol-coupling mechanisms, taking triclosan as a model substrate. We find that a diradical pathway facilitated by compound I and protonated compound II of P450 is favored vs alternative radical addition or electron-transfer mechanisms. The identified diradical coupling resembles a "two-state reactivity" from compound I characterized by significantly high rebound barriers of the phenoxy radicals, which can be formulated into three equations for calculating the ratio [coupling]/[hydroxylation]. A higher barrier for rebound than for H-abstraction in high-spin triclosan can facilitate the phenoxy radical dissociation and thus enable phenol coupling, while H-abstraction/radical rebound causing phenol hydroxylation via minor rebound barriers mostly occurs via the low-spin state. Therefore, oxidation of triclosan by P450 fits the first equation with a ratio [coupling]/[hydroxylation] of 1:4, consistent with experimental data indicating different extents of triclosan coupling (6-40%). The high rebound barrier of phenoxy radicals, as a key for the mechanistic identification of phenol coupling vs hydroxylation, originates from their weak electron donor ability due to spin aromatic delocalization. We envision that the revealed mechanism can be extended to the cross-coupling reactions between different phenolic pollutants, and the coupling reactions of several other aromatic pollutants, to infer unknown metabolites.
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Affiliation(s)
- Fangjie Guo
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Lihong Chai
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shubin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, P. R. China
| | - Weiping Liu
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, Building 206, Kgs. Lyngby DK-2800, Denmark
| | - Li Ji
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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21
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Ferreira da Silva T, Menezes F, Montagna LS, Lemes AP, Passador FR. Synergistic effect of adding lignin and carbon black in poly(lactic acid). POLIMEROS 2020. [DOI: 10.1590/0104-1428.06819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Elder T, Carlos Del Río J, Ralph J, Rencoret J, Kim H, Beckham GT. Radical coupling reactions of piceatannol and monolignols: A density functional theory study. PHYTOCHEMISTRY 2019; 164:12-23. [PMID: 31060026 DOI: 10.1016/j.phytochem.2019.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/14/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
Recent experimental work has revealed that the hydroxystilbene piceatannol can function as a monomeric unit in the lignification of palm fruit endocarp tissues. Results indicated that piceatannol homo-couples and cross-couples with monolignols through radical reactions and is integrally incorporated into the lignin polymer. The current work reports on the thermodynamics of the proposed reactions using density functional theory calculations. The results indicated that, in general, the energetics of both homo-coupling and cross-coupling are not dissimilar from those of the monolignol coupling, demonstrating the compatibility of piceatannol with the lignification process. Moreover, the DFT methods appear to predict the correct courses of post-coupling rearomatization reactions.
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Affiliation(s)
- Thomas Elder
- USDA-Forest Service, Southern Research Station, 521 Devall Drive, Auburn, AL, 36849, USA.
| | - José Carlos Del Río
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Avenida Reina Mercedes, 10, 41012, Seville, Spain
| | - John Ralph
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jorge Rencoret
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Avenida Reina Mercedes, 10, 41012, Seville, Spain
| | - Hoon Kim
- Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, 53726, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Gregg T Beckham
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
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23
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Sato H, Saito K, Yamazaki M. Acceleration of Mechanistic Investigation of Plant Secondary Metabolism Based on Computational Chemistry. FRONTIERS IN PLANT SCIENCE 2019; 10:802. [PMID: 31293608 PMCID: PMC6606707 DOI: 10.3389/fpls.2019.00802] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 06/04/2019] [Indexed: 05/04/2023]
Abstract
This review describes the application of computational chemistry to plant secondary metabolism, focusing on the biosynthetic mechanisms of terpene/terpenoid, alkaloid, flavonoid, and lignin as representative examples. Through these biosynthetic studies, we exhibit several computational methods, including density functional theory (DFT) calculations, theozyme calculation, docking simulation, molecular dynamics (MD) simulation, and quantum mechanics/molecular mechanics (QM/MM) calculation. This review demonstrates how modern computational chemistry can be employed as an effective tool for revealing biosynthetic mechanisms and the potential of computational chemistry-for example, elucidating how enzymes regulate regio- and stereoselectivity, finding the key catalytic residue of an enzyme, and assessing the viability of hypothetical pathways. Furthermore, insights for the next research objective involving application of computational chemistry to plant secondary metabolism are provided herein. This review will be helpful for plant scientists who are not well versed with computational chemistry.
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Affiliation(s)
- Hajime Sato
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
- Center for Sustainable Resource Science, Advanced Elements Chemistry Laboratory, Cluster for Pioneering Research (CPR), RIKEN, Saitama, Japan
| | - Kazuki Saito
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Mami Yamazaki
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
- *Correspondence: Mami Yamazaki,
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24
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Chen J, Dong J, Yang G, He M, Xu F, Fatehi P. A process for purifying xylosugars of pre-hydrolysis liquor from kraft-based dissolving pulp production process. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:337. [PMID: 30598699 PMCID: PMC6302441 DOI: 10.1186/s13068-018-1336-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/10/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND In the kraft-based dissolving pulp production process, pre-hydrolysis liquor (PHL) is produced, which contains hemicelluloses, lignin, furfural and acetic acid. PHL is currently burned in the recovery boiler of the kraft pulping process, but it can be utilized for the generation of high-valued products, such as xylitol and xylanase, via fermentation processes. However, some PHL constituents, e.g., furfural and lignin, are contaminants for fermentation processes and they must be eliminated for production of value-added products. RESULTS In this work, a process is introduced for removing contaminants of PHL. Ca(OH)2 treatment is the first step of this process, which removed 41.2% of lignin and negligible amount of sugars. In this step, a notable increase in the concentration of acetic acid was achieved (ranging from 6.2 to 11.7 g/L). In the second step, the implementation of adsorption using activated carbon (AC) at 1 wt% dosage led to additional 32% lignin and 5.9% xylosugar removals. In addition, laccase assisted activated carbon treatment led to further removal of lignin via accelerating lignin polymerization and adsorption on AC (i.e., removal from PHL). Overall, 90.7% of lignin, 100% of furfural, 5.7% of xylose, and 12% of xylan were removed from PHL, while the concentration of acetic acid became twofolds in the PHL. CONCLUSIONS This study reports an attractive process for purifying sugars and acetic acid of PHL. This process may be implemented for producing sugar-based value-added products from PHL. It also discusses the mechanism of Ca(OH)2 treatment, AC adsorption and laccase assisted activated carbon treatment for lignin removal.
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Affiliation(s)
- Jiachuan Chen
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
| | - Jiran Dong
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
| | - Guihua Yang
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
| | - Ming He
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
| | - Feng Xu
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
| | - Pedram Fatehi
- State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 Shandong China
- Green Processes Research Centre and Department of Chemical Engineering, Lakehead University, Thunder Bay, ON P7B 5E1 Canada
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25
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Lignin polymerization: how do plants manage the chemistry so well? Curr Opin Biotechnol 2018; 56:75-81. [PMID: 30359808 DOI: 10.1016/j.copbio.2018.10.001] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/05/2018] [Accepted: 10/03/2018] [Indexed: 11/22/2022]
Abstract
The final step of lignin biosynthesis is the polymerization of monolignols in apoplastic cell wall domains. In this process, monolignols secreted by lignifying cells, or occasionally neighboring non-lignifying and/or other lignifying cells, are activated by cell-wall-localized oxidation systems, such as laccase/O2 and/or peroxidase/H2O2, for combinatorial radical coupling to make the final lignin polymers. Plants can precisely control when, where, and which types of lignin polymers are assembled at tissue and cellular levels, but do not control the polymers' exact chemical structures per se. Recent studies have begun to identify specific laccase and peroxidase proteins responsible for lignin polymerization in specific cell types and during different developmental stages. The coordination of polymerization machinery localization and monolignol supply is likely critical for the spatio-temporal patterning of lignin polymerization. Further advancement in this research area will continue to increase our capacity to manipulate lignin content/structure in biomass to meet our own biotechnological purposes.
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26
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Kim JE, Lee JW. Enzyme adsorption properties on dilute acid pretreated biomass by low vacuum-scanning electron microscopy and structural analysis of lignin. BIORESOURCE TECHNOLOGY 2018; 262:107-113. [PMID: 29702419 DOI: 10.1016/j.biortech.2018.04.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 05/09/2023]
Abstract
In this study, enzyme adsorption properties were investigated as a function of the structural change of lignin in dilute acid pretreated biomass using oxalic and sulfuric acid catalysts under the same reaction conditions. Although the contents of glucan and lignin in the dilute acid pretreated biomass were similar regardless of the catalysts used, the enzymatic hydrolysis efficiency and degree of enzyme adsorption differed considerably. The highest efficiencies were 87.79% and 96.49% for the oxalic acid and sulfuric acid catalysts, respectively. The reasons for this observation were investigated by low vacuum-scanning electron microscopy and the structural analysis of lignin. In the oxalic acid pretreated biomass, the enzyme was irreversibly adsorbed onto the lignin. The oxalic acid pretreated biomass possessed a higher content of G-type lignin than did the sulfuric acid pretreated biomass. This type of lignin has a high affinity for the enzyme, inducing irreversible enzyme adsorption onto the biomass.
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Affiliation(s)
- Jo Eun Kim
- Department of Forest Products and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Jae-Won Lee
- Department of Forest Products and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea.
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27
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Asatryan R, Bennadji H, Bozzelli JW, Ruckenstein E, Khachatryan L. Molecular Products and Fundamentally Based Reaction Pathways in the Gas-Phase Pyrolysis of the Lignin Model Compound p-Coumaryl Alcohol. J Phys Chem A 2017; 121:3352-3371. [PMID: 28406634 DOI: 10.1021/acs.jpca.7b01656] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The fractional pyrolysis of lignin model compound para-coumaryl alcohol (p-CMA) containing a propanoid side chain and a phenolic OH group was studied using the System for Thermal Diagnostic Studies at temperatures from 200 to 900 °C, in order to gain mechanistic insight into the role of large substituents in high-lignin feedstocks pyrolysis. Phenol and its simple derivatives p-cresol, ethyl-, propenyl-, and propyl-phenols were found to be the major products predominantly formed at low pyrolysis temperatures (<500 °C). A cryogenic trapping technique was employed combined with EPR spectroscopy to identify the open-shell intermediates registered at pyrolysis temperatures above 500 °C. These were characterized as radical mixtures primarily consisting of oxygen-linked conjugated radicals. A comprehensive potential energy surface analysis of p-CMA and p-CMA + H atom systems was performed using various DFT protocols to examine the possible role of concerted molecular eliminations and free-radical mechanisms in the formation of major products. Other significant unimolecular concerted reactions along with formation and decomposition of primary radicals are also described and evaluated. The calculations suggest that a set of the chemically activated secondary radical channels is relevant to the low temperature product formation under fractional pyrolysis conditions.
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Affiliation(s)
- Rubik Asatryan
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York , Buffalo, New York 14226, United States
| | - Hayat Bennadji
- Department of Environmental Sciences, Louisiana State University , Baton Rouge, Louisiana 70808, United States
| | - Joseph W Bozzelli
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology , Newark, New Jersey 07102, United States
| | - Eli Ruckenstein
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York , Buffalo, New York 14226, United States
| | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
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28
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Mar BD, Kulik HJ. Depolymerization Pathways for Branching Lignin Spirodienone Units Revealed with ab Initio Steered Molecular Dynamics. J Phys Chem A 2017; 121:532-543. [PMID: 28005362 DOI: 10.1021/acs.jpca.6b11414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lignocellulosic biomass is an abundant, rich source of aromatic compounds, but direct utilization of raw lignin has been hampered by both the high heterogeneity and variability of linking bonds in this biopolymer. Ab initio steered molecular dynamics (AISMD) has emerged both as a fruitful direct computational screening approach to identify products that occur through mechanical depolymerization (i.e., in sonication or ball-milling) and as a sampling approach. By varying the direction of force and sampling over 750 AISMD trajectories, we identify numerous possible pathways through which lignin depolymerization may occur in pyrolysis or through catalytic depolymerization as well. Here, we present eight unique major depolymerization pathways discovered via AISMD for the recently characterized spirodienone lignin branching linkage that may comprise around 10% weight of all lignin in some softwoods. We extract representative trajectories from AISMD and carry out reaction pathway analysis to identify energetically favorable pathways for lignin depolymerization. Importantly, we identify dynamical effects that could not be observed through more traditional calculations of bond dissociation energies. Such effects include thermodynamically favorable recovery of aromaticity in the dienone ring that leads to near-barrierless subsequent ether cleavage and hydrogen-bonding effects that stabilize newly formed radicals. Some of the most stable spirodienone fragments that reside at most 1 eV above the reactant structure are formed with only 2 eV barriers for C-C bond cleavage, suggesting key targets for catalyst design to drive targeted depolymerization of lignin.
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Affiliation(s)
- Brendan D Mar
- Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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29
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Rais D, Zibek S. Biotechnological and Biochemical Utilization of Lignin. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 166:469-518. [PMID: 28540404 DOI: 10.1007/10_2017_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This chapter provides an overview of the biosynthesis and structure of lignin. Moreover, examples of the commercial use of lignin and its promising future implementation are briefly described. Many applications are still hampered by the properties of technical lignins. Thus, the major challenge is the conversion of lignins into suitable building blocks or aromatics in order to open up new avenues for the usage of this renewable raw material. This chapter focuses on details about natural lignin degradation by fungi and bacteria, which harbor potential tools for lignin degradation and modification, which might help to develop eco-efficient processes for lignin utilization.
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Affiliation(s)
| | - Susanne Zibek
- Fraunhofer Institute for Interfacial Engineering and Biotechnology, Stuttgart, Germany.
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30
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Harman-Ware AE, Happs RM, Davison BH, Davis MF. The effect of coumaryl alcohol incorporation on the structure and composition of lignin dehydrogenation polymers. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:281. [PMID: 29213321 PMCID: PMC5707875 DOI: 10.1186/s13068-017-0962-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/06/2017] [Indexed: 05/14/2023]
Abstract
BACKGROUND Lignin dehydrogenation polymers (DHPs) are polymers generated from phenolic precursors for the purpose of studying lignin structure and polymerization processes. METHODS Here, DHPs were synthesized using a Zutropfverfahren method with horseradish peroxidase and three lignin monomers, sinapyl (S), coumaryl (H), and coniferyl (G) alcohols, in the presence of hydrogen peroxide. The H monomer was reacted with G and a 1:1 molar mixture of S:G monomers at H molar compositions of 0, 5, 10, and 20 mol% to study how the presence of the H monomer affected the structure and composition of the recovered polymers. RESULTS At low H concentrations, solid-state NMR spectra suggest that the H and G monomers interact to form G:H polymers that have a lower average molecular weight than the solely G-based polymer or the G:H polymer produced at higher H concentrations. Solid-state NMR and pyrolysis-MBMS analyses suggest that at higher H concentrations, the H monomer primarily self-polymerizes to produce clusters of H-based polymer that are segregated from clusters of G- or S:G-based polymers. Thioacidolysis generally showed higher recoveries of thioethylated products from S:G or S:G:H polymers made with higher H content, indicating an increase in the linear ether linkages. CONCLUSIONS Overall, the experimental results support theoretical predictions for the reactivity and structural influences of the H monomer on the formation of lignin-like polymers.
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Affiliation(s)
- Anne E. Harman-Ware
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
- Bioenergy Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Renee M. Happs
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
- Bioenergy Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Brian H. Davison
- Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Mark F. Davis
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
- Bioenergy Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
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31
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Leblanc N, Sproules S, Powell AK. An alternative method to access diverse N,N′-diquaternised-3,3′-biquinoxalinium “biquinoxen” dications. NEW J CHEM 2017. [DOI: 10.1039/c7nj00531h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biquinoxens synthesis via oxidative radical homocoupling of N-alkylquinoxalinium – an alternative method.
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Affiliation(s)
- Nicolas Leblanc
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- D-76344 Eggenstein-Leopoldshafen
- Germany
| | | | - Annie K. Powell
- Institut für Nanotechnologie
- Karlsruher Institut für Technologie
- D-76344 Eggenstein-Leopoldshafen
- Germany
- Institut für Anorganische Chemie
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32
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Murillo JD, Biernacki JJ, Northrup S, Mohammad AS. BIOMASS PYROLYSIS KINETICS: A REVIEW OF MOLECULAR-SCALE MODELING CONTRIBUTIONS. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2017. [DOI: 10.1590/0104-6632.20170341s20160086] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- J. D. Murillo
- Tennessee Technological University, USA; Tennessee Technological University, USA
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33
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Khachatryan L, Xu MX, Wu AJ, Pechagin M, Asatryan R. Radicals and molecular products from the gas-phase pyrolysis of lignin model compounds. Cinnamyl alcohol. JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 2016; 121:75-83. [PMID: 28344372 PMCID: PMC5363761 DOI: 10.1016/j.jaap.2016.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The experimental results on detection and identification of intermediate radicals and molecular products from gas-phase pyrolysis of cinnamyl alcohol (CnA), the simplest non-phenolic lignin model compound, over the temperature range of 400-800 °C are reported. The low temperature matrix isolation - electron paramagnetic resonance (LTMI-EPR) experiments along with the theoretical calculations, provided evidences on the generation of the intermediate carbon and oxygen centered as well as oxygen-linked, conjugated radicals. A mechanistic analysis is performed based on density functional theory to explain formation of the major products from CnA pyrolysis; cinnamaldehyde, indene, styrene, benzaldehyde, 1-propynyl benzene, and 2-propenyl benzene. The evaluated bond dissociation patterns and unimolecular decomposition pathways involve dehydrogenation, dehydration, 1,3-sigmatropic H-migration, 1,2-hydrogen shift, C-O and C-C bond cleavage processes.
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Affiliation(s)
- Lavrent Khachatryan
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
- Corresponding author. (L. Khachatryan)
| | - Meng-xia Xu
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Ang-jian Wu
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
| | - Mikhail Pechagin
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Rubik Asatryan
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
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34
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Sangha AK, Petridis L, Cheng X, Smith JC. Relative Binding Affinities of Monolignols to Horseradish Peroxidase. J Phys Chem B 2016; 120:7635-40. [DOI: 10.1021/acs.jpcb.6b00789] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Amandeep K. Sangha
- UT/ORNL
Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Biochemistry and Cellular
and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Loukas Petridis
- UT/ORNL
Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Xiaolin Cheng
- UT/ORNL
Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Biochemistry and Cellular
and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jeremy C. Smith
- UT/ORNL
Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Biochemistry and Cellular
and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
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35
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Rinaldi R, Jastrzebski R, Clough MT, Ralph J, Kennema M, Bruijnincx PCA, Weckhuysen BM. Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis. Angew Chem Int Ed Engl 2016; 55:8164-215. [PMID: 27311348 PMCID: PMC6680216 DOI: 10.1002/anie.201510351] [Citation(s) in RCA: 794] [Impact Index Per Article: 99.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 01/28/2016] [Indexed: 12/23/2022]
Abstract
Lignin is an abundant biopolymer with a high carbon content and high aromaticity. Despite its potential as a raw material for the fuel and chemical industries, lignin remains the most poorly utilised of the lignocellulosic biopolymers. Effective valorisation of lignin requires careful fine-tuning of multiple "upstream" (i.e., lignin bioengineering, lignin isolation and "early-stage catalytic conversion of lignin") and "downstream" (i.e., lignin depolymerisation and upgrading) process stages, demanding input and understanding from a broad array of scientific disciplines. This review provides a "beginning-to-end" analysis of the recent advances reported in lignin valorisation. Particular emphasis is placed on the improved understanding of lignin's biosynthesis and structure, differences in structure and chemical bonding between native and technical lignins, emerging catalytic valorisation strategies, and the relationships between lignin structure and catalyst performance.
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Affiliation(s)
- Roberto Rinaldi
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
| | - Robin Jastrzebski
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Matthew T Clough
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - John Ralph
- Department of Energy's Great Lakes Bioenergy Research Center, the Wisconsin Energy Institute, and Department of Biochemistry, University of Wisconsin, Madison, WI, 53726, USA.
| | - Marco Kennema
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Pieter C A Bruijnincx
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands.
| | - Bert M Weckhuysen
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands.
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36
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Rinaldi R, Jastrzebski R, Clough MT, Ralph J, Kennema M, Bruijnincx PCA, Weckhuysen BM. Wege zur Verwertung von Lignin: Fortschritte in der Biotechnik, der Bioraffination und der Katalyse. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201510351] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Roberto Rinaldi
- Department of Chemical Engineering Imperial College London South Kensington Campus London SW7 2AZ Großbritannien
| | - Robin Jastrzebski
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science Utrecht University Universiteitsweg 99 3584 CG Utrecht Niederlande
| | - Matthew T. Clough
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
| | - John Ralph
- Department of Energy's Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, and Department of Biochemistry University of Wisconsin Madison WI 53726 USA
| | - Marco Kennema
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
| | - Pieter C. A. Bruijnincx
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science Utrecht University Universiteitsweg 99 3584 CG Utrecht Niederlande
| | - Bert M. Weckhuysen
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science Utrecht University Universiteitsweg 99 3584 CG Utrecht Niederlande
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37
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Elder T, Berstis L, Beckham GT, Crowley MF. Coupling and Reactions of 5-Hydroxyconiferyl Alcohol in Lignin Formation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:4742-4750. [PMID: 27236926 DOI: 10.1021/acs.jafc.6b02234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The catechol alcohols, caffeyl and 5-hydroxyconiferyl alcohol, may be incorporated into lignin either naturally or through genetic manipulation. Due to the presence of o-OH groups, these compounds form benzodioxanes, a departure from the interunit connections found in lignins derived from the cinnamyl alcohols. In nature, lignins composed of caffeyl and 5-hydroxyconiferyl alcohol are linear homopolymers and, as such, may have properties that make them amenable for use in value-added products, such as lignin-based carbon fibers. In the current work, results from density functional theory calculations for the reactions of 5-hydroxyconiferyl alcohol, taking stereochemistry into account, are reported. Dehydrogenation and quinone methide formation are found to be thermodynamically favored for 5-hydroxyconiferyl alcohol, over coniferyl alcohol. The comparative energetics of the rearomatization reactions suggest that the formation of the benzodioxane linkage is under kinetic control. Ring-opening reactions of the benzodioxane groups show that the bond dissociation enthalpy of the α-O cleavage reaction is lower than that of the β-O reaction. The catechol lignins represent a novel form of the polymer that may offer new opportunities for bioproducts and genetic targets.
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Affiliation(s)
- Thomas Elder
- Southern Research Station, USDA-Forest Service , 521 Devall Drive, Auburn, Alabama 36849, United States
| | - Laura Berstis
- National Bioenergy Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Gregg T Beckham
- National Bioenergy Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Michael F Crowley
- Biosciences Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
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38
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Petridis L, Smith JC. Conformations of Low-Molecular-Weight Lignin Polymers in Water. CHEMSUSCHEM 2016; 9:289-295. [PMID: 26763657 DOI: 10.1002/cssc.201501350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/04/2015] [Indexed: 06/05/2023]
Abstract
Low-molecular-weight lignin binds to cellulose during the thermochemical pretreatment of biomass for biofuel production, which prevents the efficient hydrolysis of the cellulose to sugars. The binding properties of lignin are influenced strongly by the conformations it adopts. Here, we use molecular dynamics simulations in aqueous solution to investigate the dependence of the shape of lignin polymers on chain length and temperature. Lignin is found to adopt collapsed conformations in water at 300 and 500 K. However, at 300 K, a discontinuous transition is found in the shape of the polymer as a function of the chain length. Below a critical degree of polymerization, Nc =15, the polymer adopts less spherical conformations than above Nc. The transition disappears at high temperatures (500 K) at which only spherical shapes are adopted. An implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures.
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Affiliation(s)
- Loukas Petridis
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Jeremy C Smith
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
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39
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Qi YB, Wang XL, Shi T, Liu S, Xu ZH, Li X, Shi X, Xu P, Zhao YL. Multicomponent kinetic analysis and theoretical studies on the phenolic intermediates in the oxidation of eugenol and isoeugenol catalyzed by laccase. Phys Chem Chem Phys 2015; 17:29597-607. [PMID: 26477512 DOI: 10.1039/c5cp03475b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Laccase catalyzes the oxidation of natural phenols and thereby is believed to initialize reactions in lignification and delignification. Numerous phenolic mediators have also been applied in laccase-mediator systems. However, reaction details after the primary O-H rupture of phenols remain obscure. In this work two types of isomeric phenols, EUG (eugenol) and ISO (trans-/cis-isoeugenol), were used as chemical probes to explore the enzymatic reaction pathways, with the combined methods of time-resolved UV-Vis absorption spectra, MCR-ALS, HPLC-MS, and quantum mechanical (QM) calculations. It has been found that the EUG-consuming rate is linear to its concentration, while the ISO not. Besides, an o-methoxy quinone methide intermediate, (E/Z)-4-allylidene-2-methoxycyclohexa-2,5-dienone, was evidenced in the case of EUG with the UV-Vis measurement, mass spectra and TD-DFT calculations; in contrast, an ISO-generating phenoxyl radical, a (E/Z)-2-methoxy-4-(prop-1-en-1-yl) phenoxyl radical, was identified in the case of ISO. Furthermore, QM calculations indicated that the EUG-generating phenoxyl radical (an O-centered radical) can easily transform into an allylic radical (a C-centered radical) by hydrogen atom transfer (HAT) with a calculated activation enthalpy of 5.3 kcal mol(-1) and then be fast oxidized to the observed eugenol quinone methide, rather than an O-radical alkene addition with barriers above 12.8 kcal mol(-1). In contrast, the ISO-generating phenoxyl radical directly undergoes a radical coupling (RC) process, with a barrier of 4.8 kcal mol(-1), while the HAT isomerization between O- and C-centered radicals has a higher reaction barrier of 8.0 kcal mol(-1). The electronic conjugation of the benzyl-type radical and the aromatic allylic radical leads to differentiation of the two pathways. These results imply that competitive reaction pathways exist for the nascent reactive intermediates generated in the laccase-catalyzed oxidation of natural phenols, which is important for understanding the lignin polymerization and may shed some light on the development of efficient laccase-mediator systems.
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Affiliation(s)
- Yan-Bing Qi
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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40
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Engineering Plant Biomass Lignin Content and Composition for Biofuels and Bioproducts. ENERGIES 2015. [DOI: 10.3390/en8087654] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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41
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Barsberg S. Identification of the best DFT functionals for a reliable prediction of lignin vibrational properties. Theor Chem Acc 2015. [DOI: 10.1007/s00214-015-1638-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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42
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Hong N, Qiu X, Deng W, He Z, Li Y. Effect of aggregation behavior and phenolic hydroxyl group content on the performance of lignosulfonate doped PEDOT as a hole extraction layer in polymer solar cells. RSC Adv 2015. [DOI: 10.1039/c5ra19676k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aggregation behaviour and –OH content of lignosulfonate play a key role for the promising performance when PEDOT:LS acts as the HEL in PSCs.
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Affiliation(s)
- Nanlong Hong
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- China
- State Key Laboratory of Pulp and Paper Engineering
| | - Xueqing Qiu
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- China
- State Key Laboratory of Pulp and Paper Engineering
| | - Wanyuan Deng
- Institute of Polymer Optoelectronic Materials and Devices
- State Key Laboratory of Luminescent Materials and Devices
- South China University of Technology
- Guangzhou
- China
| | - Zhicai He
- Institute of Polymer Optoelectronic Materials and Devices
- State Key Laboratory of Luminescent Materials and Devices
- South China University of Technology
- Guangzhou
- China
| | - Yuan Li
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- China
- State Key Laboratory of Pulp and Paper Engineering
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43
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Carmona C, Langan P, Smith JC, Petridis L. Why genetic modification of lignin leads to low-recalcitrance biomass. Phys Chem Chem Phys 2015; 17:358-64. [DOI: 10.1039/c4cp05004e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Molecular dynamics simulations show genetically modified lignin to associate less with hemicellulose than does wild type.
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Affiliation(s)
- Christopher Carmona
- University of California
- Los Angeles
- Los Angeles
- USA
- Center for Molecular Biophysics
| | - Paul Langan
- Biology and Soft Matter Division
- Oak Ridge
- USA
| | - Jeremy C. Smith
- Center for Molecular Biophysics
- Oak Ridge National Laboratory
- Oak Ridge
- USA
- Department of Biochemistry and Cellular and Molecular Biology
| | - Loukas Petridis
- Center for Molecular Biophysics
- Oak Ridge National Laboratory
- Oak Ridge
- USA
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44
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Hao Z, Mohnen D. A review of xylan and lignin biosynthesis: Foundation for studying Arabidopsisirregular xylemmutants with pleiotropic phenotypes. Crit Rev Biochem Mol Biol 2014; 49:212-41. [DOI: 10.3109/10409238.2014.889651] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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45
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Beste A. ReaxFF study of the oxidation of lignin model compounds for the most common linkages in softwood in view of carbon fiber production. J Phys Chem A 2014; 118:803-14. [PMID: 24428197 DOI: 10.1021/jp410454q] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lignin is an underused but major component of biomass. One possible area of utilization is the production of carbon fiber. A necessary processing step is the stabilization of lignin fiber (typically in an oxygen environment) before high temperature treatment. We investigate oxidative, thermal conversion of lignin using computational methods. Dilignol model compounds for the most common (seven) linkages in softwood are chosen to represent the diverse structure of lignin. We perform molecular dynamics simulation where the potential energy surface is described by a reactive force field (ReaxFF). We calculate overall activation energies for model conversion and reveal initial mechanisms of formaldehyde formation. We record fragmentation patterns and average carbon oxidation numbers at various temperatures. Most importantly, we identify mechanisms for stabilizing reactions that result in cyclic and rigid connections in softwood lignin fibers that are necessary for further processing into carbon fibers.
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Affiliation(s)
- Ariana Beste
- Joint Institute for Computational Sciences, The University of Tennessee , Oak Ridge, Tennessee 37831, United States
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46
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Hao Z, Avci U, Tan L, Zhu X, Glushka J, Pattathil S, Eberhard S, Sholes T, Rothstein GE, Lukowitz W, Orlando R, Hahn MG, Mohnen D. Loss of Arabidopsis GAUT12/IRX8 causes anther indehiscence and leads to reduced G lignin associated with altered matrix polysaccharide deposition. FRONTIERS IN PLANT SCIENCE 2014; 5:357. [PMID: 25120548 PMCID: PMC4112939 DOI: 10.3389/fpls.2014.00357] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/03/2014] [Indexed: 05/02/2023]
Abstract
GAlactUronosylTransferase12 (GAUT12)/IRregular Xylem8 (IRX8) is a putative glycosyltransferase involved in Arabidopsis secondary cell wall biosynthesis. Previous work showed that Arabidopsis irregular xylem8 (irx8) mutants have collapsed xylem due to a reduction in xylan and a lesser reduction in a subfraction of homogalacturonan (HG). We now show that male sterility in the irx8 mutant is due to indehiscent anthers caused by reduced deposition of xylan and lignin in the endothecium cell layer. The reduced lignin content was demonstrated by histochemical lignin staining and pyrolysis Molecular Beam Mass Spectrometry (pyMBMS) and is associated with reduced lignin biosynthesis in irx8 stems. Examination of sequential chemical extracts of stem walls using 2D (13)C-(1)H Heteronuclear Single-Quantum Correlation (HSQC) NMR spectroscopy and antibody-based glycome profiling revealed a reduction in G lignin in the 1 M KOH extract and a concomitant loss of xylan, arabinogalactan and pectin epitopes in the ammonium oxalate, sodium carbonate, and 1 M KOH extracts from the irx8 walls compared with wild-type walls. Immunolabeling of stem sections using the monoclonal antibody CCRC-M138 reactive against an unsubstituted xylopentaose epitope revealed a bi-lamellate pattern in wild-type fiber cells and a collapsed bi-layer in irx8 cells, suggesting that at least in fiber cells, GAUT12 participates in the synthesis of a specific layer or type of xylan or helps to provide an architecture framework required for the native xylan deposition pattern. The results support the hypothesis that GAUT12 functions in the synthesis of a structure required for xylan and lignin deposition during secondary cell wall formation.
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Affiliation(s)
- Zhangying Hao
- Department of Plant Biology, University of GeorgiaAthens, GA, USA
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Utku Avci
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Li Tan
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Xiang Zhu
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- Department of Chemistry, University of GeorgiaAthens, GA, USA
| | - John Glushka
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
| | - Sivakumar Pattathil
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Stefan Eberhard
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
| | - Tipton Sholes
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
| | - Grace E. Rothstein
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- Department of Biology, Lawrence UniversityAppleton, WI, USA
| | | | - Ron Orlando
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- Department of Chemistry, University of GeorgiaAthens, GA, USA
| | - Michael G. Hahn
- Department of Plant Biology, University of GeorgiaAthens, GA, USA
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
| | - Debra Mohnen
- Complex Carbohydrate Research Center, University of GeorgiaAthens, GA, USA
- BioEnergy Science Center (BESC), Oak Ridge National LaboratoryOak Ridge, TN, USA
- Department of Biochemistry and Molecular Biology, University of GeorgiaAthens, GA, USA
- *Correspondence: Debra Mohnen, Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd., Athens, GA 30602, USA e-mail:
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Janesko BG. Acid-catalyzed hydrolysis of lignin β-O-4 linkages in ionic liquid solvents: a computational mechanistic study. Phys Chem Chem Phys 2014; 16:5423-33. [DOI: 10.1039/c3cp53836b] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Sangha AK, Davison BH, Standaert RF, Davis MF, Smith JC, Parks JM. Chemical Factors that Control Lignin Polymerization. J Phys Chem B 2013; 118:164-70. [DOI: 10.1021/jp411998t] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Amandeep K. Sangha
- UT/ORNL Center
for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
| | | | - Robert F. Standaert
- Department
of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Mark F. Davis
- National
Bioenergy Center and Bioenergy Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Jeremy C. Smith
- UT/ORNL Center
for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
- Department
of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jerry M. Parks
- UT/ORNL Center
for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
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Wittman JM, Hayoun R, Kaminsky W, Coggins MK, Mayer JM. A C-C bonded phenoxyl radical dimer with a zero bond dissociation free energy. J Am Chem Soc 2013; 135:12956-9. [PMID: 23952108 DOI: 10.1021/ja406500h] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The 2,6-di-tert-butyl-4-methoxyphenoxyl radical is shown to dimerize in solution and in the solid state. The X-ray crystal structure of the dimer, the first for a para-coupled phenoxyl radical, revealed a bond length of 1.6055(23) Å for the C4-C4a bond. This is significantly longer than typical C-C bonds. Solution equilibrium studies using both optical and IR spectroscopies showed that the Keq for dissociation is 1.3 ± 0.2 M at 20 °C, indicating a C-C bond dissociation free energy of -0.15 ± 0.1 kcal mol(-1). Van't Hoff analysis gave an exceptionally small bond dissociation enthalpy (BDE) of 6.1 ± 0.5 kcal mol(-1). To our knowledge, this is the smallest BDE measured for a C-C bond. This very weak bond shows a large deviation from the correlation of C-C bond lengths and strengths, but the computed force constant follows Badger's rule.
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Affiliation(s)
- Jessica M Wittman
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
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50
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Oxidative Decomposition of Propylene Carbonate in Lithium Ion Batteries: A DFT Study. J Phys Chem A 2013; 117:7959-69. [DOI: 10.1021/jp403436u] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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