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2019 | Buch

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Enzymatic Polymerization towards Green Polymer Chemistry

herausgegeben von: Prof. Shiro Kobayashi, Prof. Hiroshi Uyama, Prof. Jun-ichi Kadokawa

Verlag: Springer Singapore

Buchreihe : Green Chemistry and Sustainable Technology

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

This book comprehensively covers researches on enzymatic polymerization and related enzymatic approaches to produce well-defined polymers, which is valuable and promising for conducting green polymer chemistry. It consists of twelve chapters, including the following topics: The three classes of enzymes, oxidoreductases, transferases and hydrolases, have been employed as catalysts for enzymatic polymerization and modification; Well-defined polysaccharides are produced by enzymatic polymerization catalyzed by hydrolases and transferases; Hydrolase-catalyzed polycondensation and ring-opening polymerization are disclosed to produce a variety of polyesters;Polyesters are synthesized by in-vivo acyltransferase catalysis produced by microorganisms; Enzymatic polymerization catalyzed by appropriate enzymes also produces polypeptides and other polymers;Poly(aromatic)s are obtained by enzymatic polymerization catalyzed by oxidoreductases and their model complexes;Such enzymes also induce oxidative polymerization of vinyl monomers; Enzymatic modification of polymers is achieved to produce functionalized polymeric materials; The enzymatic polymerization is a green process with non-toxic catalysts, high catalyst efficiency, green solvents and renewable starting materials, and minimal by-products; Moreover, renewable resources like biomass are potentially employed as a starting substrate, producing useful polymeric materials. This book is not only educative to young polymer chemists like graduate students but also suggestive to industrial researchers, showing the importance of the future direction of polymer synthesis for maintaining a sustainable society.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract

This chapter provides introductory aspects to the readers so that they may understand readily and clearly the significance of the book edition. It is important for polymer chemists to know the present status of “enzymatic polymerization” and “green polymer chemistry.” The former involves its historical background and characteristics including enzymatic reaction mechanism. The latter is related with several important “green” aspects, toward which the former is expected to contribute. Brief abstracts of all the chapters are also given for the easier understanding of the whole book.

Shiro Kobayashi, Hiroshi Uyama, Jun-ichi Kadokawa

Chapter 2. Synthesis of Polysaccharides I: Hydrolase as Catalyst

Abstract

The glycoside hydrolase-catalyzed polycondensation of activated glycosyl monomers such as glycosyl fluorides and polyaddition of sugar-oxazoline monomers have been reviewed. Various kinds of oligo- and polysaccharides including natural cellulose, xylan, chitin, hyaluronic acid, and specifically modified functional polysaccharides have successfully been prepared by this methodology. Based on the formation of metastable cellulose I by the enzymatic polymerization of β-cellobiosyl fluoride monomer catalyzed by cellulase, a new concept of “choroselective polymerization” for the control in high-order molecular assembly during polymerization was proposed.

The use of sugar oxazolines as a glycosyl monomer with a distorted conformation allowed the polymerization to proceed only in the direction of the product polysaccharides while suppressing hydrolysis. Sugar oxazolines which possess higher potential energy compared with the conventional glycosyl donors enabled us to produce various N-acetylglucosamine-containing polysaccharides such as chitin, hyaluronic acid, and chondroitin. A new concept of “transition state analogue substrate” (TSAS) has been introduced to polymerization chemistry.

Shin-ichiro Shoda, Masato Noguchi, Gefei Li, Shunsaku Kimura

Chapter 3. Synthesis of Polysaccharides II: Phosphorylase as Catalyst

Abstract

Oligo- and polysaccharides are important macromolecules in living systems, showing their multifunctional characteristics in the construction of cell walls, energy storage, cell recognition, and their immune response. The chemical synthesis of oligo- and polysaccharides is feasible though it can be laborious since multiple protection, deprotection, and purification steps are required. In contrast to this, phosphorylases are useful synthetic tools for the preparation of natural oligo- and polysaccharides, glycoconjugates, and their analogs. Since phosphorylases are rather tolerant with respect to utilizing modified donors and acceptor substrates, they can be used to prepare oligo- and polysaccharide analogs and for diversification of natural products. Their strict primer-dependence allows synthesis of interesting hybrid materials. Furthermore, enzymatic reaction, such as that using phosphorylase, is one of the most promising environmentally benign technologies with a simple operation under mild conditions, eliminating undesirable side reactions.

Katja Loos, Jun-ichi Kadokawa

Chapter 4. Synthesis of Polysaccharides III: Sucrase as Catalyst

Abstract

Sucrase-type glycosyltransferases that classified into non-Leloir glycosyltransferases, named glucansucrase and fructansucrase, catalyze in transfer of either a glucose or a fructose from sucrose to produce glucans or fructans. The reactions need only a renewable carbon resource, such as sucrose, and proceed very efficiently, with high yields, with regio- and stereoselectivity, and in one-pot water-based system. This chapter provides an overview of the glucansucrase and fructansucrase enzymes, their reaction, and product specificity. Finally, we discuss the potential applications of α-glucans produced by glucansucrase in new bio-based materials.

Satoshi Kimura, Tadahisa Iwata

Chapter 5. Synthesis of Polyesters I: Hydrolase as Catalyst for Polycondensation (Condensation Polymerization)

Abstract

Synthesis of polyesters via enzymatic polymerization is described comprehensively in up-to-dated review manner, in which the polymerization is of polycondensation type using hydrolases mainly lipase as catalyst. First, characteristics of lipase catalysis are discussed: catalyst nature for green polymer chemistry including the catalysis mechanism, immobilization of lipases, role of surfactants for lipase catalysis, and so forth. Then, the lipase-catalyzed polycondensation synthesis of polyesters is argued according to the types of polymerization reactions: via dehydration of α- and ω-oxyacids and of dicarboxylic acids, via transesterification using carboxylic acid esters, and via ring-opening addition-condensation polymerization using cyclic anhydrides or cyclic esters as a monomer component. Other polymers like polyamides, polyamines, polycarbonates, and sulfur-containing polymers were synthesized by lipase catalyst. These reaction results indicate that lipase catalysts induce various polycondensation reactions to produce a variety of new polyesters. Further, protease which catalyzes primarily the peptide bond cleavage and bond formation catalyzed also the polyester production via polycondensation.

Shiro Kobayashi, Hiroshi Uyama

Chapter 6. Synthesis of Polyesters II: Hydrolase as Catalyst for Ring-Opening Polymerization

Abstract

This chapter reviews enzymatic lipase-catalyzed ring-opening polymerizations (ROPs) to polyesters. A variety of cyclic esters are subjected to lipase- catalyzed ROP. Lipase catalysis shows unique polymerization behaviors of lactones with different ring sizes. ROP mechanism of lactones by lipase catalyst is mentioned, which applies to preparation of terminal functional polyesters. Lipase catalysis induces enantio-, regio-, and chemoselective ROPs, which can hardly be achieved by conventional chemical catalysts. ROP of cyclic esters in a variety of media is mentioned for green synthesis of polyesters. ROP of lactones is combined with living radical polymerizations, yielding designed block copolymers. ROP of other cyclic monomers, mainly cyclic carbonate, is also mentioned in this chapter.

Hiroshi Uyama, Shiro Kobayashi

Chapter 7. Synthesis of Polyesters III: Acyltransferase as Catalyst

Abstract

The natural polyester polyhydroxyalkanoate (PHA) is synthesized as an energy storage via thioester exchange reaction in microbial cells. The thermal and mechanical properties of PHA can be varied by modifying the monomeric composition, molecular weight, and chemical modification. To date, many efforts have been made to understand the polymerization mechanism and industrialization of PHA. PHA synthase (Acyltransferase; EC2.3) is the key player for making stereochemically regulated polyesters. PHA synthase should be one of the most important targets for the synthetic biology of PHA. In 2017, a major breakthrough occurred in the PHA research field, whereby the tertiary structures of two PHA synthases from the class I enzyme have been solved. Based on the crystal structures of the PHA synthases, the detailed reaction mechanism of PHA synthase is discussed in this chapter. Common and unique structural elements are extracted through structure- function relationships between both enzymes. Additionally, function-based studies of PHA synthases are introduced as another milestone. The discovery of a lactate-polymerizing enzyme (LPE) evolved from a PHA synthase is a typical case. The effectiveness of the evolutionary engineering of PHA synthases is demonstrated through case studies including the creation of new polyesters as well as tailor-made PHA production.

Ayaka Hiroe, Min Fey Chek, Toshio Hakoshima, Kumar Sudesh, Seiichi Taguchi

Chapter 8. Synthesis of Polypeptides

Abstract

Proteases (EC 3.4), enzymes originally used to cleave the amide bonds of proteins by hydrolysis, have been utilized for the enzymatic synthesis of peptide compounds. This enzymatic synthesis of polypeptides is a biomass-based, environmentally benign, atom-economical, and stereo-/regioselective method that can replace petroleum-derived chemical polypeptide syntheses. Enzymatic polymerization of amino acid derivatives using proteases proceeds via the reverse reaction of hydrolysis, which is aminolysis, in an equilibrium. Thermodynamic and kinetic controls in the aminolysis reaction rationally optimize enzymatic polymerization efficiency. Polymerization is regulated by the substrate specificity of proteases, namely, a combination of amino acid monomers and proteases. A great number of polypeptides, including homopolymers, random/block copolymers, and specific polymer architectures, such as star-shaped polymers, are synthesized by a protease-catalyzed polymerization technique. In this chapter, versatile designs and syntheses of polypeptide materials using various types of proteases are entirely reviewed in detail.

Kousuke Tsuchiya, Yu Miyagi, Takaaki Miyamoto, Prashant G. Gudeangadi, Keiji Numata

Chapter 9. Synthesis of Poly(aromatic)s I: Oxidoreductase as Catalyst

Abstract

This chapter reviews enzymatic oxidative polymerization to aromatic polymers. Phenols, anilines, and thiophenes are subjected to the enzymatic oxidative polymerization. Peroxidases with the use of hydrogen peroxide as oxidant efficiently induce the oxidative coupling of phenols to phenolic polymers, most of which are hardly obtained by conventional chemical catalysts. The enzymatic oxidative polymerizations have merits of using nontoxic catalysts and mild reaction conditions, and the specific enzyme catalysis provides regio- and chemoselective polymerizations to produce functional materials. Laccase and peroxidase are useful for production of cross-linked polymers such as artificial urushi and biopolymer hydrogel.

Hiroshi Uyama

Chapter 10. Synthesis of Poly(aromatic)s II: Enzyme-Model Complexes as Catalyst

Abstract

This chapter deals with oxidative polymerization of aromatic monomers catalyzed by enzyme-model complexes to produce poly(aromatic)s. The enzyme-model complexes include Fe/porphyrin complexes and Fe/N,N′-bis(salicylidene)ethylenediamine complexes as Fe-containing peroxidase-models, Cu complexes having three nitrogen coordination atoms as Cu-containing monooxygenase models, and multinuclear Cu complexes as Cu-containing oxidase models. By using the enzyme-model complex catalysts, the aromatic monomers such as phenols, anilines, and pyrroles can be polymerized with H₂O₂ or O₂ as oxidants at ordinary temperatures in environmentally benign manners. The obtained poly(aromatic)s like polyphenols, poly(phenylene oxide)s, polyanilines, and polypyrroles possess excellent characteristics in mechanical strength, heat-resistance, and electric property. Enzyme-model catalysts have the following advantages in comparison with enzyme catalysts: (1) lower cost that is important in practical use, (2) applicability in various reaction conditions and monomers, and (3) possibility to express unique functions that have not seen even in enzymes. Hence, oxidative polymerization of aromatic monomers by enzyme-model complex catalysts would be expected as one of the new synthetic methods for advanced materials in green polymer chemistry.

Hideyuki Higashimura

Chapter 11. Synthesis of Vinyl Polymers via Enzymatic Oxidative Polymerisation

Abstract

Enzymatic methods for the polymerisation of vinyl monomers are presented and critically discussed. Vinyl monomers can be polymerised initiated by enzyme-catalysed radical formation. The most widely used initiators for this purpose are β-diketo compounds, which can be transformed into the corresponding radicals via peroxidase- or laccase-catalysed oxidation. For this, peroxidases use hydrogen peroxide as oxidant, while laccases rely on molecular oxygen. Both enzyme classes comprise specific advantages and disadvantages that are discussed in this chapter. Also, parameters to control the polymer properties are introduced and discussed.

W. Zhang, F. Hollmann

Chapter 12. Enzymatic Modification of Polymers

Abstract

In polymer applications and development, it is often necessary to modify an existing polymer structure in order to impart special end-use properties. Whereas chemical modification methods are most commonly practiced, sometimes enzyme-catalyzed modifications may be desirable because of the specificity of the reactions, reduction in the by-products produced, milder reaction conditions, and more benign environmental impact. A number of enzyme-catalyzed reactions are reviewed in this paper, covering primarily biobased materials like polysaccharides, proteins, triglycerides, and lignin. The enzymes used include mostly hydrolases, oxidoreductases, and transferases, with occasional involvement of lyases and isomerases. The types of reactions are diverse and include polymer hydrolysis and degradation, polymerization, oxidation, glycosylation, cross-linking, and transformation of functional groups. Because biopolymers are agro-based and occur abundantly in nature, they are often available in large quantities and amenable to enzymatic reactions. As such, the combination of biopolymers and enzymes represents a good product development opportunity and a useful tool for postharvest agricultural technology and green polymer chemistry.

H. N. Cheng

Backmatter

Titel: Enzymatic Polymerization towards Green Polymer Chemistry
herausgegeben von: Prof. Shiro Kobayashi
Prof. Hiroshi Uyama
Prof. Jun-ichi Kadokawa
Verlag: Springer Singapore
Electronic ISBN: 978-981-13-3813-7
Print ISBN: 978-981-13-3812-0
DOI: https://doi.org/10.1007/978-981-13-3813-7

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