Lignin: Biosynthesis, Functions and Economic Significance

✍ Scribed by Fachuang Lu, Fengxia Yue

• Publisher: Nova Science Publishers
• Year: 2019
• Tongue: English
• Leaves: 320
• Series: Biochemistry Research Trends
• Edition: 1
• Category: Library

✦ Synopsis

Lignin is the main natural resource of aromatic structures on Earth. With the depletion of fossil oil and increased environmental concerns, renewable resources for energy and chemical production have attracted tremendous attention from scientists and engineers. As a renewable aromatic polymer, lignin has been, for a long time, studied in terms of its biosynthesis, structures, reactivities and applications although few portions of lignins available from the industry, mainly pulping mills, have been utilised for various applications. The key for complete and efficient utilisation of lignins is that all aspects, including lignin biosynthesis, structures, functionalities, and properties, about lignins should be understood. Another important attribute related to lignin utilisation comes from analytical methods essential for our understanding of lignins and mechanisms involved in various processes. This book provides critical reviews and the latest research results relating to selected fields of lignin biosynthesis, functional characterisation and applications.

✦ Table of Contents

Contents
Preface
Acronyms
Chapter 1
Lignin Biosynthesis and Control of Lignin Composition
Abstract
Introduction
Lignin Composition and Monolignol Biosynthesis
Un-Conventional Lignin Monomers
C-Lignin from Natural Plants
Potential Pathway Leading to C-Lignin Biosynthesis
C-Lignin as a Novel Natural Polymer
Conclusion and Perspectives
Acknowledgments
References
Chapter 2
Monolignol Acylation in Lignin Biosynthesis
Abstract
Introduction
Occurence and Characterization of Naturally Acylated Lignin Units
Studies on Detection/Determination of Acylated Lignin Units
Identification of Biosynthetic Pathway to Acylated Lignin Units
Redesigning Lignin in Plants
Bioengineering of Zip-Lignin Hybrid Poplar
Zip-Lignin Strategy Facilitates Utilization of Plant Cell Walls
Recent Advances in Understanding of Monolignol Acylation
Conclusion
Acknowledgments
References
Chapter 3
Tricin in Grass Lignin: Biosynthesis, Characterization, and Quantitation
Abstract
Introduction
Tricin as a Secondary Metabolite
Biosynthesis of Tricin
Tricin and Its Derivatives
Biological Functions and Potential Applications
Preparation of Tricin
Occurrence of Tricin in the Lignin Polymer
Characterization of Tricin
Quantitation of Tricin
Bioengineering of Tricin
Implications of Tricin’s Presence in Lignin
Conclusion
Acknowledgments
References
Chapter 4
Solution-State Multidimensional NMR of Lignins: Approaches and Applications
Abstract
Introduction
2D HSQC (Heteronuclear Single-Quantum Coherence)
Peak Assignments
Comparative Peak Quantification
Typical HSQC Profiles of Natural Lignins
Non-Canonical Lignin Substructures in Transgenic/Mutant Plants
HSQC Variants for Enhanced Quantitative Capability
2D HMBC (Heteronuclear Multiple-Bond Correlation)
2D HSQC-TOCSY (Heteronuclear Single-Quantum Coherence-Total Correlation Spectroscopy)
3D NMR Experiments
Sample Preparation Strategies for 2D and 3D NMR of Lignins
Direct Dissolution/Swelling of Whole Cell Walls
Derivatization of Whole Cell Walls for Complete Solubilization
Lignin-Enrichment via Cellulase Treatments
Isolation of Soluble Lignins
LCC Fractions
Conclusion
Acknowledgments
References
Chapter 5
Lignin Condensation and Lignin Depolymerization
Abstract
1. Introduction
2. Lignin Polymerization
3. Lignin Condensation
4. Lignin Depolymerization
4.1. Pyrolysis and Gasification
4.2. Catalytic Depolymerization
4.2.1. Reductive Depolymerization
4.2.2. Oxidative Depolymerization
4.3. Biological Degradation
Conclusion
References
Chapter 6
Challenges and Opportunities of Lignin Reductive Catalytic Depolymerization in the Bioethanol Refinary
Abstract
Introduction
Catalytic Reductive Depolymerization of Lignin
Depolymerization of Lignin Model Compounds
Depolymerization of Technical Lignins
Future Outlook
Activating C-C Bonds
Separating Monomeric Products
Catalysts Stability in Hot-Aqueous Environments
Conclusion
References
Chapter 7
The Potential Role of Enzymatic Catalysis and Metabolic Engineering in Lignin Valorization
Abstract
Introduction
The Bio-Degradation of Lignin-Derived Aromatic
The Enzymatic Degradation of β-Ethers
The Metabolic Pathways of Lignin Derivatives from G-/S-/H-Units
The Transportation of Lignin Derivatives from G-/S-/H-Units and Their Metabolic Regulation
Biotransformation for the Production of Chemicals from Depolymerized Lignin and Lignin Model Compounds
Enzymatic Conversion in Vitro
Metabolic Conversion in Vivo
Combining Enzymatic Catalysis and Metabolic Engineering with a Multi- Disciplinary Approach for Lignin Valorization
Conclusion
Acknowledgments
References
Chapter 8
Structural Elucidation of Lignin Macromolecules from p-Coumarate 3-Hydroxylase (C3H) Down-Regulated Transgenic Poplars (84 K)
Abstract
Introduction
Material and Methods
Plant Materials
Preparation of CELs
Structural Elucidation of CELs
Result and Discussion
The Fate of Lignin before and after C3H Down-Regulation
2D-HSQC NMR Analysis
13C NMR Spectra Analysis
31P-NMR Analysis
Molecular Weight Analysis
Conclusion
Acknowledgments
References
Chapter 9
Molecular Design and Controllable Self-Assembly of Lignin Hollow Nanospheres
Abstract
1. Introduction
2. Molecular Designs of Lignin Chain Structures
2.1. Click Reaction between Alkyne and Azide
2.2. Synthesis of Lignin Polymers via Click Reaction of Lignin-Alkyne with Lignin-Azide
2.3. Synthesis of Lignin Polymers via Click Reaction of Lignin-Alkyne with PEG-Azide
2.4. Synthesis of Lignin Polymers via Click Reaction of Lignin-PCL-Alkyne with Lignin-Azide
2.5. Synthesis of Lignin Polymers via the Click Reaction of Lignin- (PCL- co- PLA)-Alkyne with Lignin-Azide
2.6. DSC Analysis of Lignin Polymers Prepared by the Thermal Click Reactions
3. Fabrication of Size-Controlled Lignin Nanospheres
3.1. Size-Controlled Lignin Nanospheres
3.2. Morphology, Size and Yield of Lignin Nanospheres
3.3. The Chemical Characteristics of Lignin Nanospheres
3.4. The Composition Characteristics of Lignin Nanospheres
3.5. Size Influences of Lignin Nanospheres
3.6. The Formation Mechanism of Lignin Nanospheres
4. Fabrication of Hollow Nanospheres with a Single Hole
4.1. The Preparation of Lignin Hollow Nanospheres
4.2. Morphology and Size of Lignin Hollow Nanospheres
4.3. Surface Area, Pore Size and Distribution of Lignin Hollow Nanospheres
4.4. The Chemical Characteristics of Lignin Hollow Nanospheres
4.5. Effects of Stirring Rate, Dropping Speed of Water and pH on the Characteristics of Lignin Hollow Nanospheres
4.6. The Formation Mechanism of Lignin Hollow Nanospheres
Conclusion
Acknowledgment
References
Chapter 10
Thermal Characterization of Klason Lignins from Softwood and Hardwood Species
Abstract
Introduction
Theoretical Background
Kissinger Method
Flynn-Wall-Ozawa Method
Criado Method
Materials and Methods
Materials
Thermogravimetric Analysis (TGA)
Fourier Transform Infrared Spectroscopy (FTIR)
Results and Discussions
TGA Analysis
FTIR Analysis
Conclusion
Acknowledgments
References
Chapter 11
Lignin and Its Derivatives as Antioxidant, Antiviral and Antimicrobial Agents: Applicability in Human Health Promotion
Abstract
1. Introduction
2. Structure and Sources of Lignin
3. Methods of Isolation of Lignin and Lignin Fractions
3.1. Acid Precipitation
3.2. Membrane Filtration
3.3. Solvents
4. Biological Properties of Lignin
4.1. Antioxidant Properties
4.2. Antiviral Effects of Lignin
5. Antimicrobial Films Applications
Conclusion
References
Chapter 12
Preparation of Dehydrogenation Polymer from Isoeugenol and Biological Activity Characterization
Abstract
Introduction
Experimental
Materials
Methods
Synthesis of DHP
Fractionation of the DHP
Molecular Weight Determination
Determination of Total Phenol Content
Analysis of the Structure of the DHP
Evaluation of Antimicrobial Activity
Evaluation of Anticancer Activity
Results and Discussion
Molecular Weight of the DHP
FTIR Analysis of the DHP
Analysis of the DHP by 13C-NMR Spectroscopy
Investigation of Antibacterial Activity
Investigation of Anticancer Activity of the DHP Fractions
Conclusion
Acknowledgments
References
About the Editors
Index
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