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Introduction: Laccases are blue-multicopper containing enzymes that are known to play a role in the bioconversion of recalcitrant compounds. Their role in free radical polymerization of aromatic compounds for their valorization remains underexplored. In this study, we used a pBAD plasmid containing a previously characterized CotA laccase gene (abbreviated as Bli -Lacc) from Bacillus licheniformis strain ATCC 9945a to express this enzyme and explore its biotransformation/polymerization potential on β-naphthol. Methods: The protein was expressed from TOP10 cells of Escherichia coli after successful transformation of the plasmid. Immobilized metal affinity chromatography (IMAC) was used to generate pure protein. The biocatalytic polymerization reaction was optimized based on temperature, pH and starting enzyme concentration. 1H and 13C solution nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and solid-state NMR (ssNMR) were used to characterize the formed polymer. A one-gram conversion reaction was done to explore applicability of the reaction in a pilot-scale. Results: The polymerization reaction generated a brown precipitate, and its chemical structure was confirmed using 1H and 13C NMR and FTIR. SsNMR revealed the presence of two different orientational hydroxyl functional groups in the polymer in addition to the presence of a very small amount of ether linkages (< 2%). This analysis elucidated that polymerization occurred mainly on the carbons of the aromatic rings, rather than on the carbons attached to the hydroxyl groups, resulting in a condensed ring or polynuclear aromatic structure. The reaction was optimized, and the highest yield was attained under conditions of 37°C, pH 10 and a starting enzyme concentration of 440 nM in 50 mM phosphate buffer. A one-gram conversion yielded 216 mg of polymer as dry mass. The crystal structure of the enzyme was solved at 2.7 Å resolution using X-ray crystallography and presented with a hexagonal space group. The final structure was deposited in the Protein Databank (PDB) with an ID−9BD5. Discussion: This article provides a green/enzymatic pathway for the remediation of phenolics and their valorization into potential useful polymeric materials. The comprehensive analysis of the formed polymer provides insight into its structure and functional moieties present. Based on the yield of the one-gram conversion, this synthetic method proves useful for a pilot-scale production level and opens opportunities to invest in using this polymer for industrial/environmental applications. [ABSTRACT FROM AUTHOR]

Introduction: Laccases are blue-multicopper containing enzymes that are known to play a role in the bioconversion of recalcitrant compounds. Their role in free radical polymerization of aromatic compounds for their valorization remains underexplored. In this study, we used a pBAD plasmid containing a previously characterized CotA laccase gene (abbreviated as Bli -Lacc) from Bacillus licheniformis strain ATCC 9945a to express this enzyme and explore its biotransformation/polymerization potential on β-naphthol. Methods: The protein was expressed from TOP10 cells of Escherichia coli after successful transformation of the plasmid. Immobilized metal affinity chromatography (IMAC) was used to generate pure protein. The biocatalytic polymerization reaction was optimized based on temperature, pH and starting enzyme concentration. 1H and 13C solution nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and solid-state NMR (ssNMR) were used to characterize the formed polymer. A one-gram conversion reaction was done to explore applicability of the reaction in a pilot-scale. Results: The polymerization reaction generated a brown precipitate, and its chemical structure was confirmed using 1H and 13C NMR and FTIR. SsNMR revealed the presence of two different orientational hydroxyl functional groups in the polymer in addition to the presence of a very small amount of ether linkages (< 2%). This analysis elucidated that polymerization occurred mainly on the carbons of the aromatic rings, rather than on the carbons attached to the hydroxyl groups, resulting in a condensed ring or polynuclear aromatic structure. The reaction was optimized, and the highest yield was attained under conditions of 37°C, pH 10 and a starting enzyme concentration of 440 nM in 50 mM phosphate buffer. A one-gram conversion yielded 216 mg of polymer as dry mass. The crystal structure of the enzyme was solved at 2.7 Å resolution using X-ray crystallography and presented with a hexagonal space group. The final structure was deposited in the Protein Databank (PDB) with an ID−9BD5. Discussion: This article provides a green/enzymatic pathway for the remediation of phenolics and their valorization into potential useful polymeric materials. The comprehensive analysis of the formed polymer provides insight into its structure and functional moieties present. Based on the yield of the one-gram conversion, this synthetic method proves useful for a pilot-scale production level and opens opportunities to invest in using this polymer for industrial/environmental applications. [ABSTRACT FROM AUTHOR]

In this study, gallic acid-g-chitosan colored complex were produced using the HRP-catalyzed method. Then, these were used to successfully dye silk fabrics. The dyed silk fabrics were characterized through K/S, color fastness, and antibacterial tests. We studied the polymerization mechanism in detail using FT-IR and ESI-MS technologies, then the dyeing process and optimum reaction conditions were further investigated using the K/S values. Chitosan and gallic acid were polymerized to form a dark yellow polymer, which was successfully colored on silk fabrics. In addition, significant color differences were observed between fabrics dyed without chitosan and fabrics dyed in the presence of chitosan. In particular, the fabric treated with the pre-polymerization dyeing process showed high antibacterial properties, color fastness, and color depth compared to other dyeing processes. We found that the optimum reaction conditions for dyeing silk fabrics are as follows: 3-hour incubation period, 50 ℃ temperature, 3 mM gallic acid; 3 g/L chitosan. While the GA and CS pre-treatment or co-treatment process resulted in lower color fastness, the pre-polymerization approach offered enhanced fastness and overall performance. Based on the findings, the pre-polymerization process is recommended as the most effective method for dyeing silk fabrics with chitosan and natural dyes, optimizing both aesthetic and functional properties. [ABSTRACT FROM AUTHOR]

Here, we report the effects of peroxidase-mimicking activity of flower shaped hybrid nanobiocatalyst obtained from Viburnum-Opulus L. (Gilaburu) extract and Cu2+ ions on the polymerization of phenol and its derivatives (guaiacol and salicylic acid). The obtained nanoflowers exhibited quite high catalytic activity upon the polymerization of phenol and guaiacol. The yields and the number average molecular weights of the obtained polymers were significantly high. Due to solubility issue of salicylic acid in aqueous media, polymerization of salicylic acid resulted in very low yields. Free-horseradish peroxidase (HRP) enzyme is known to be losing its catalytic activity at 60 °C and above temperatures. However, the synthesized nanoflowers exhibited quite high catalytic activity even at 60 °C and above reaction temperatures. This provides notable benefits for reactions needed at high temperatures, and it is very important to use these kinds of nanobiocatalysts for both scientific studies and industrial applications. [ABSTRACT FROM AUTHOR]

Enzyme catalyzed reactions are known to be environmental friendly and easy method for many applications. However, utilization of enzymes in a variety of reactions is strictly limited due to their high cost, instability in aqueous solutions, denaturation in organic solvents and high temperatures. For this reason, it is important to discover new generation catalyst systems indicating enzyme‐like catalytic activity. Here, we report hybrid organic–inorganic flower‐shaped green tea‐Cu2+ nanobiocatalyst synthesized from green tea extract as an organic component and copper (II) ions (Cu2+) as inorganic component. The effect of the peroxidase‐mimicking activity of green tea‐Cu2+ nanobiocatalyst was investigated on the polymerization of phenol and derivatives (guaiacol and salicylic acid) through Fenton‐like reaction mechanism. Obtained successful outcomes showed that the synthesized nanobiocatalyst showed very high catalytic activity upon polymerization of phenol and guaiacol. The slight solubility of salicylic acid in water limited to achieve its polymerization under‐performed reaction conditions. The yields and molecular weights of the obtained polymers were found to be quite high. While free peroxidase enzymes like horseradish peroxidase (HRP) enzyme loses its catalytic activity at 60°C and above temperatures, green tea‐Cu2+ nanobiocatalyst exhibited very high catalytic activity upon polymerization reactions even at 60°C reaction temperature. This outcome provides significant advantages in some reactions requiring high temperatures. In order to understand the origin of the catalytic activity of the green tea‐Cu2+ nanoflowers, similar biocatalysts were also synthesized from caffeine and catechin alkaloids which are the active components of green tea. Caffeine‐Cu2+ and catechine‐Cu2+ nanobiocatalysts also exhibited quite high catalytic activity toward polymerization of phenol and derivatives. We suggest that green tea‐Cu2+ and similar types of nanobiocatalysts may expand their utilization in polymer chemistry as promising catalytic agents for radicalic polymerizations. [ABSTRACT FROM AUTHOR]

Hydrogels were prepared by Steglich esterification and by crosslinking pre-synthesized poly(sorbitol adipate)-graft-poly(ethylene glycol) mono methyl ether (PSA-g-mPEG) using different-chain-length-based disuccinyl PEG. PSA and PSA-g-mPEG were investigated for polymer degradation as a function of time at different temperatures. PSA-g-mPEG hydrogels were then evaluated for their most crucial properties of swelling that rendered them suitable for many pharmaceutical and biomedical applications. Hydrogels were also examined for their Sol-Gel content in order to investigate the degree of cross-linking. Physical structural parameters of the hydrogels were theoretically estimated using the modified Flory–Rehner theory to obtain approximate values of polymer volume fraction, the molecular weight between two crosslinks, and the mesh size of the hydrogels. X-ray diffraction was conducted to detect the presence or absence of crystalline regions in the hydrogels. PSA-g-mPEG hydrogels were then extensively examined for higher and lower molecular weight solute release through analysis by fluorescence spectroscopy. Finally, the cytotoxicity of the hydrogels was also investigated using a resazurin reduction assay. Experimental results show that PSA-g-mPEG provides an option as a biocompatible polymer to be used for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Polymers that can be extracted or manufactured from renewable resources such as sugars, natural acids, or terpenes are increasingly relevant. In this context, biobased lactones are a group of monomers that can be synthesized from renewable feedstocks and combine versatility with the ability to yield high-performing materials including both thermoplastics and thermosets. In this chapter, an overview of different kinds of catalytic ring-opening polymerization (ROP) mechanisms including coordination, organocatalyzed, and enzymatic reactions is discussed. ROP of renewable lactones to yield polyesters are classified by their origin. In particular, we report on recent advances in ROP of terpene-based precursors such as limonene and pinene that lead to a variety of caprolactone derivatives which are available for polymerization. Moreover, lactones that can be converted from sugars and natural acids (e.g., fatty acids, amino acids) will be discussed. [ABSTRACT FROM AUTHOR]

Polysaccharide-based amphiphilic copolymers self-assemble in water to form micelle-like structures. They are expected to be used as nanocarriers in the biomedical field owing to their biocompatibility, biodegradability, and low toxicity. α-1,3-Glucan is a water-insoluble glucose homopolymer that can be generated through environmentally friendly enzymatic polymerization and easily purified without using organic solvents. Thus, it has attracted attention as a new bio-based material. In this study, we developed new nanomicelles based on α-1,3-glucan. Glycosyltransferase I from Streptococcus mutans was used to synthesize α-1,3-glucan, and a series of amphiphilic α-1,3-glucan-based graft copolymers (α-1,3-glucan-g-PLA) were synthesized with different L-Lactide supply ratios in the ionic liquid BmimCl. The results of FT-IR, 1H NMR, 13C NMR, XRD, and TGA verified that the reaction proceeded successfully. These amphiphilic α-1,3-glucan derivatives with low critical micelle concentrations can self-assemble to form core–shell structural micelles of various sizes (approximately 57–125 nm) in water. Furthermore, the self-assembled micelles were investigated as drug carriers using prednisone acetate (PA) as a model drug, and their sustained drug release behavior for 9 days was confirmed. These results revealed that the synthesized self-assembled micelles have promising potential as new carriers for the efficient delivery of hydrophobic drugs. [ABSTRACT FROM AUTHOR]

This review article presents the biomimetic helical inclusion of amylose toward hydrophobic polyesters as guests through a vine-twining polymerization process, which has been performed in the glucan phosphorylase (GP)-catalyzed enzymatic polymerization field to fabricate supramolecules and other nanostructured materials. Amylose, which is a representative abundant glucose polymer (polysaccharide) with left-handed helical conformation, is well known to include a number of hydrophobic guest molecules with suitable geometry and size in its cavity to construct helical inclusion complexes. Pure amylose is prepared through enzymatic polymerization of α-d-glucose 1-phosphate as a monomer using a maltooligosaccharide as a primer, catalyzed by GP. It is reported that the elongated amylosic chain at the nonreducing end in enzymatic polymerization twines around guest polymers with suitable structures and moderate hydrophobicity, which is dispersed in aqueous polymerization media, to form amylosic nanostructured inclusion complexes. As the image of this system is similar to how vines of a plant grow around a support rod, this polymerization has been named 'vine-twining polymerization'. In particular, the helical inclusion behavior of the enzymatically produced amylose toward hydrophobic polyesters depending on their structures, e.g., chain lengths and substituents, has been systematically investigated in the vine-twining polymerization field. Furthermore, amylosic supramolecular network materials, such as hydrogels, are fabricated through vine-twining polymerization by using copolymers, where hydrophobic polyester guests or maltooligosaccharide primers are covalently modified on hydrophilic main-chain polymers. The vine-twining polymerization using such copolymers in the appropriate systems induces the formation of amylosic nanostructured inclusion complexes among them, which act as cross-linking points, giving rise to supramolecular networks at the nanoscale. The resulting materials form supramolecular hydrogels, films, and microparticles. [ABSTRACT FROM AUTHOR]

The mechanisms of the enzymatic polymerization of flavonoids, including quercetin, rutin and catechins, have been fairly well researched, but the properties of polymeric forms of flavonoids still require in-depth analysis. The products of enzymatic polymerization are oligomeric flavonoids. The antioxidant and antimicrobial properties of many oligomeric flavonoids have been described in the literature. However, data on the thermal properties of oligomeric flavonoids are lacking and the supplementing of these deficiencies is a scientific novelty of this work. The aim of this study is to determine the effect of enzymatic polymerization on thermal stability of oligomeric flavonoids. As part of the work, oligomeric quercetin, rutin and catechin were prepared by the enzymatic polymerization reaction with laccase and horseradish peroxidase enzymes. The oligomeric structure of the flavonoids was confirmed by spectroscopic (Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy (UV–Vis)) as well as chromatographic (ultra-performance liquid chromatography (UPLC) and gel permeation chromatography (GPC)) methods. Thermal properties of oligomeric flavonoids were investigated using differential scanning calorimetry (DSC) and thermogravimetry (TG). Moreover, the antioxidant and antimicrobial properties of oligomeric forms of selected polyphenols were investigated. Based on DSC analysis, it was found that the common feature of all oligomeric flavonoids was a higher final oxidation temperature and a higher oxidation enthalpy than the reference flavonoids. Thermogravimetric analysis showed that oligomeric poly(flavonoids)-laccase had better thermal stability, which correlated with higher molar mass. [ABSTRACT FROM AUTHOR]

Semi-conductive polymers have been used in a few area applications such as coatings, accumulators, solar cells, rechargeable batteries, ion sensors, photoreceptors, light-emitting diodes and electrochromic instruments. Poly(4-(trifluoromethyl)benzene-1,2-diamine)s of Poly(TFMBDA)-O and Poly(TFMBDA)-E were synthesized via chemical oxidative and enzymatic polymerization methods, respectively, using 4-(trifluoromethyl)benzene-1,2-diamine (TFMBDA) as monomer. FT-IR, UV-vis and 1H-NMR and 13C-NMR instruments were utilized in order to confirm the structures of all compounds. The Mw values of the polymers and their PDI values were found to be between 5000-7000 Da and 1.045-1.115, respectively, from GPC measurements. The glass temperature of phenazine-type structure of Poly(TFMBDA)-O was higher compared to that of Poly(TFMBDA)-E, which was composed of phenyl units linked with -NH bridges. As soon as Poly(TFMBDA)-O and Poly(TFMBDA)-E were excited by UV light, they had a quantum efficiency of 6.3% and 13.7%, respectively, in DMF for violet photoluminescence (PL) emission depending on photoluminescence measurement. SEM images revealed that Poly(TFMBDA)-O consisted of approximately 1-2 µm of uniform micro-spheres and a granular surface with different pore diameters. The enzymatic oxidation with HRP afforded Poly(TFMBDA)-E micro-rods of about 5-10 µm-long shape in their SEM images. [ABSTRACT FROM AUTHOR]

In this study, gallic acid-g-chitosan colored complexes were produced using the HRP-catalyzed method and successfully used to dye silk fabrics. The reaction mechanism was studied using FT-IR, 1H-NMR, and ESI-MS technologies; the dyed silk fabrics were characterized through K/S, color fastness, and antibacterial tests. In addition, an in situ staining process based on enzyme catalysis was explored to simplify the pretreatment process of chitosan. Chitosan and gallic acid were polymerized through O–Ph, Ph–Ph and amino-phenyl bonds to form a dark-yellow polymer that was successfully used to dye silk fabrics. In addition, significant color differences were observed between fabrics dyed without chitosan and dyed in the presence of chitosan. As a result, gallic acid-g-chitosan dyes polymerized via HRP catalysis improved the antimicrobial properties of the colored fabrics without significantly affecting the color fastness of the silk fabrics. [ABSTRACT FROM AUTHOR]

This study investigates inclusion behavior of amylose towards, poly(β-propiolactone) (PPL), that is a hydrophobic polyester, via the vine-twining process in glucan phosphorylase (GP, isolated from thermophilic bacteria, Aquifex aeolicus VF5)-catalyzed enzymatic polymerization. As a result of poor dispersibility of PPL in sodium acetate buffer, the enzymatically produced amylose by GP catalysis incompletely included PPL in the buffer media under the general vine-twining polymerization conditions. Alternatively, we employed an ethyl acetate–sodium acetate buffer emulsion system with dispersing PPL as the media for vine-twining polymerization. Accordingly, the GP (from thermophilic bacteria)-catalyzed enzymatic polymerization of an α-d-glucose 1-phosphate monomer from a maltoheptaose primer was performed at 50 °C for 48 h in the prepared emulsion to efficiently form the inclusion complex. The powder X-ray diffraction profile of the precipitated product suggested that the amylose-PPL inclusion complex was mostly produced in the above system. The 1H NMR spectrum of the product also supported the inclusion complex structure, where a calculation based on an integrated ratio of signals indicated an almost perfect inclusion of PPL in the amylosic cavity. The prevention of crystallization of PPL in the product was suggested by IR analysis, because it was surrounded by the amylosic chains due to the inclusion complex structure. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

After 2 h of reaction, the PGA/PEG and PGA/PM complexes exhibited polymerization rates two times faster than PGA and the PGA/PF68 complex showed a three times faster polymerization rate than PGA. Anti-UV activity of the treated silk fabrics HT

The use of natural plants for dyeing is a new green approach in the textile industry using eco-friendly, renewable, and non-toxic reductants for dyeing fabric. Recently, various templates have been reported to enhance the polymerization of natural phenols. In this paper, ferulic acid (FA) was synthesized using a new approach and arranged on poly(ethylene glycol) (PEG) templates using horseradish peroxide (HRP)-catalyzed oxidative polymerization. The polymerization mechanism was studied in detail using high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis. In addition, the template effect of PEG on 13 natural phenols was also investigated. Upon analyzing the color depth, the K/S value of the silk fabric dyed using PEG as a template was significantly higher than that in the absence of PEG. The higher color depth of the poly(ferulic acid)/PEG-treated silk fabrics further validated the important role of PEG as a template. This study presents an environmentally friendly method for dyeing silk fabric under mild conditions and the polymerization mechanism. Compared to chemical polymerization reactions, this enzyme (HRP)-based synthesis is more environmentally friendly due to its milder reaction conditions. [ABSTRACT FROM AUTHOR]

Cellular metabolism in multiple organelles utilizes compartmentalized multienzyme efficient catalysis to realize substance metabolism, energy conversion and immune defenses. The convenient and biomimetic design of artificial multienzymes has become an emerging research topic. Herein, we employ a facile enzyme-initiated radical polymerization to self-anchor multienzyme in cell-like hydrogels with mesoscale compartments. The dynamic assembly of glucose oxidase/cytochrome c (GOx/Cyt c) with methacrylate-modified hyaluronic acid can form nanoaggregates, where only the bound enzyme pairs with the adjacent position can catalyze the polymerization to compartmentalize multienzymes within hydrogel. Consequently, the cascade enzymes within hydrogel display 33.9 times higher activity compared to free enzymes, as well as excellent thermostability and multiple recyclability. The mechanism study indicates that the compartmental effect of the hydrogel and the anchoring effect of Cyt c synergistically enhance GOx/Cyt c activity. According to the density functional theory (DFT) calculation, Cyt c activity increment originates from its ligand changes of Fe(III) porphyrin, which has a smaller energy barrier of the catalytic reaction. This study provides a promising strategy for autonomous colocalization of multienzyme in biocompatible hydrogels which can be potentially applied in cascade enzyme induced catalysis applications. [ABSTRACT FROM AUTHOR]

In this study, 4‐amino‐3‐hydroxy‐1‐naphthalene sulfonic acid (Monomer) was converted to its enzyme‐catalyzed oxidative polymerization (Poly‐enz) in dioxane solvent by horseradish peroxidase enzyme (HRP) in the presence of hydrogen peroxide as oxidant. For the analysis of the monomer and its synthesized Poly‐enz, 1H‐NMR, 13C‐NMR, FT‐IR, TGA, and SEM measurements were determined. In addition, the optical ion sensor properties of Poly‐enz against metals such as Ag+, Cd2+, Co2+, Hg2+, Ni2+, Pb2+, Zn2+, Cu2+ were examined with UV‐Vis spectrophotometer. It was observed that Cu metal showed sensory properties. DNA cleavage and DNA binding activities of monomer and Poly‐enz were done using by agarose gel electrophoresis and UV‐Vis methods, respectively. It was seen that the Poly‐enz interacted with DNA electrostatically. This enzymatic polymer was found to cleave pBR322 plasmid DNA both hydrolytically and oxidatively as well. The antioxidant activities of the compounds were examined by three different methods (DPPH, ABTS, FRAP) and it was found that the Poly‐enz showed high antioxidant activity compared to its monomer. Antimicrobial activities were studied against various bacterial and yeast cultures by the minimum inhibition concentration (MIC) method. It was observed that the antimicrobial activities of the enzymatic polymer in different microorganisms increased depending on the concentration. [ABSTRACT FROM AUTHOR]

This study investigates vine-twining polymerization using poly(γ-butyrolactone) (PBL) as a new guest polyester to evaluate inclusion behavior of amylose toward PBL. The polymerization system was conducted by glucan phosphorylase (GP)-catalyzed enzymatic polymerization to produce amylose in the presence of PBL dispersed in aqueous acetate buffer at 50 °C for 48 h. The product was characterized by X-ray diffraction, 1H NMR, and IR measurements to support the structure of the amylose-PBL inclusion complex. Our previous study showed that the structural isomer of PBL, that is, poly[(R)-3-hydroxybutyrate] (PRHB) with a methyl substituent, was not included by amylose by the same operation and its oligomer with Mn = ~ 500 could form the inclusion complex with amylose only under specific conditions in the GP-catalyzed enzymatic polymerization. Accordingly, the present and previous results suggest that amylose includes PBL in its cavity more facilely than PRHB and its oligomer. [ABSTRACT FROM AUTHOR]

Naringenin is one of the flavonoids originating from citrus fruit. This polyphenol is mainly found in grapefruit, orange and lemon. The antioxidant and antimicrobial properties of flavonoids depend on their structure, including the polymeric form. The aim of this research was to achieve enzymatic polymerization of naringenin and to study the properties of poly(naringenin). The polymerization was performed by methods using two different enzymes, i.e., laccase and horseradish peroxidase (HRP). According to the literature data, naringenin had not been polymerized previously using the enzymatic polymerization method. Therefore, obtaining polymeric naringenin by reaction with enzymes is a scientific novelty. The research methodology included analysis of the structure of poly(naringenin) by NMR, GPC, FTIR and UV-Vis and its morphology by SEM, as well as analysis of its properties, i.e., thermal stability (DSC and TGA), antioxidant activity (ABTS, DPPH, FRAP and CUPRAC) and antimicrobial properties. Naringenin oligomers were obtained as a result of polymerization with two types of enzymes. The polymeric forms of naringenin were more resistant to thermo-oxidation; the final oxidation temperature To of naringenin catalyzed by laccase (poly(naringenin)-laccase) was 28.2 °C higher, and poly(naringenin)-HRP 23.6 °C higher than that of the basic flavonoid. Additionally, due to the higher molar mass and associated increase in OH groups in the structure, naringenin catalyzed by laccase (poly(naringenin)-laccase) showed better activity for scavenging ABTS+• radicals than naringenin catalyzed by HRP (poly(naringenin)-HRP) and naringenin. In addition, poly(naringenin)-laccase at a concentration of 5 mg/mL exhibited better microbial activity against E. coli than monomeric naringenin. [ABSTRACT FROM AUTHOR]

Conductive polyester non-woven fabric was prepared using horseradish peroxidase (HRP) catalytic agent, 3,4-ethylenedioxythiophene monomer and poly(p-styrenesulfonic acid) dopant. The electrical resistance of the prepared conductive polyester non-woven fabric was reduced to 1.3×104 Ω from 1014 Ω of the raw polyester non-woven fabric because of the addition of poly(3,4-ethylenedioxythiophene) the conductivity of conductive polyester non-woven fabric decreased by about 60 % after 300 bending cycles. Notably, the temperature of the conductive polyester non-woven fabric increased by 73.1 °C after 150 s of light irradiation from a lamp source, while that of the raw polyester non-woven fabric increased by only 19.4 °C under the same conditions. [ABSTRACT FROM AUTHOR]

In this paper, we report that polysaccharide substrates bearing 2‐deoxygenated amylose chains are hydrophobic. A pure partially 2‐deoxygenated amylose was synthesized by the thermostable glucan phosphorylase‐catalyzed enzymatic copolymerization of d‐glucal, a non‐native monomer, with α‐d‐glucose 1‐phosphate, a native monomer from maltotriose, as a primer. A water contact angle on a cast film of the resulting polysaccharide confirms that it is hydrophobic. Enzymatic copolymerization using glycogen as a polymeric primer was used to investigate the possibility of engendering hydrophilic substrates with hydrophobicity by incorporating such polysaccharide chains; the resulting glycogen‐derived films with elongated partially 2‐deoxygenated amylose chains are strongly hydrophobic. [ABSTRACT FROM AUTHOR]

Surface‐independent smart antibacterial coatings with on‐demand antibiotics release profiles have attracted increasing attention in medical instruments, antibiotics delivery platforms, and implanted devices. Although several approaches have been well documented, the facile preparation of antibacterial coatings onto universal substrates with high antibiotics loading efficiencies, tunable drug release profiles, and excellent antibacterial performances is still met with many challenges, especially related to the redundant coating material synthesis and selective substrate fabrication process. To resolve this issue, the authors report a facile and robust fabrication method towards smart antibacterial coating surfaces on various substrates via a one‐pot integration of two types of naturally occurring building blocks, aminoglycosides and protocatechualdehyde in the presence of plant enzyme horseradish peroxidase. The simultaneous dynamic imine bonds formation and enzymatic polymerization within the system during the one‐pot reaction enable the facile fabrication of diverse surface‐independent smart antibacterial coatings, which can demonstrate several promising features including high drug loading and dynamic (i.e., pH‐responsive) properties, tunable and on‐demand antibiotics release behaviors, and efficient antibacterial activities both in vitro and in vivo. This work may offer new opportunities towards the robust and universal antibacterial coating materials by the bioinspired integration of all natural building blocks. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are an alternative to traditional organic solvents for enzymatic reactions between compounds with poor solubility. Biocatalytic polymerization of the flavonoid (+)-catechin (CC) was carried out with laccase from the fungus Trametes hirsuta in a DES–buffer mixture (betaine/glycerol 60 vol %–buffer 40 vol %). The conditions for the synthesis of catechin oligomers (oligoCCs) soluble in organic solvents have been selected. According to the data from high-performance liquid chromatography, the oligoCCs had average molecular weights of 10 620 and 2540 g/mol with polydispersity indices of 1.1 and 1.09, respectively. The physicochemical properties of the obtained oligomers were studied via UV-visible, FTIR, 1H and 13C NMR spectroscopy. The resulting oligoCCs inhibited the α-glucosidase activity (IC50 ~ 8 μg/mL). [ABSTRACT FROM AUTHOR]

Properties of polymers were obtained by enzyme catalyzed oxidative polymerization varies according to oxidative polymerization products and thus polymeric materials with different properties are obtained. In this study, polymerization of 4-amino-2,6-dichlorophenol (ADCP), an aminophenol compound containing dihalogen, was carried out by two different methods and the two methods were compared with each other. One of the methods was oxidative polymerization in the presence of hydrogen peroxide with heating, and the other was enzyme-catalyzed oxidative polymerization that took place at room temperature in the presence of Horse Radish Peroxidase (HRP) enzyme and hydrogen peroxide. The structural characterization of the products obtained as a result of oxidative polymerization (PADCP-O) and as a result of enzyme catalyzed oxidative polymerization (PADCP-E) was performed by 1H-NMR, 13C-NMR, FT-IR, UV–Vis spectroscopy methods. The molecular masses of PADCP-O and PADCP-E were analyzed by GPC and the average molecular mass of PADCP-E was found to be higher than that of PADCP-O. Thermal properties were examined by TGA and it was determined that the thermal stability of the obtained polymers was higher than that of the monomer. Electrochemical and optical properties were determined by CV and UV–Vis spectroscopy methods, respectively. Electrochemical and optical band gap values were calculated as 1.61 and 1.33 eV, and 1.88 and 1.83 eV for PADCP-O and PADCP-E, respectively. In addition, it was observed that PADCP-O emitted green in UV light, while PADCP-E emitted red in DMSO. Surface properties and morphology of polymers were analyzed by SEM and it was observed that PADCP-O obtained by oxidative polymerization had a spongy structure, but the enzymatic polymerization product PADCP-E had a uniformly dispersed nanoparticle structure. [ABSTRACT FROM AUTHOR]

The in situ gelation of injectable precursors is desirable in the field of tissue regeneration, especially in the context of irregular defect filling. The current driving forces for fast gelation include the phase‐transition of thermally sensitive copolymers, click chemical reactions with tissue components, and metal coordination effect. However, the rapid formation of tough hydrogels remains a challenge. Inspired by aerobic metabolism, we herein propose a tissue‐fluid‐triggered cascade enzymatic polymerization process catalyzed by glucose oxidase and ferrous glycinate for the ultrafast gelation of acryloylated chondroitin sulfates and acrylamides. The highly efficient production of carbon radicals and macromolecules contribute to rapid polymerization for soft tissue augmentation in bone defects. The copolymer hydrogel demonstrated the regeneration‐promoting capacity of cartilage. As the first example of using artificial enzyme complexes for in situ polymerization, this work offers a biomimetic approach to the design of strength‐adjustable hydrogels for bio‐implanting and bio‐printing applications. [ABSTRACT FROM AUTHOR]

The in situ gelation of injectable precursors is desirable in the field of tissue regeneration, especially in the context of irregular defect filling. The current driving forces for fast gelation include the phase‐transition of thermally sensitive copolymers, click chemical reactions with tissue components, and metal coordination effect. However, the rapid formation of tough hydrogels remains a challenge. Inspired by aerobic metabolism, we herein propose a tissue‐fluid‐triggered cascade enzymatic polymerization process catalyzed by glucose oxidase and ferrous glycinate for the ultrafast gelation of acryloylated chondroitin sulfates and acrylamides. The highly efficient production of carbon radicals and macromolecules contribute to rapid polymerization for soft tissue augmentation in bone defects. The copolymer hydrogel demonstrated the regeneration‐promoting capacity of cartilage. As the first example of using artificial enzyme complexes for in situ polymerization, this work offers a biomimetic approach to the design of strength‐adjustable hydrogels for bio‐implanting and bio‐printing applications. [ABSTRACT FROM AUTHOR]

Due to the increasing importance of environmentally friendly processes, the development of monomer synthesis and its polymerization using enzymes has been investigated throughout the world. In this paper, the polymerization mechanism between silk fabrics and gallic acid (GA) in the presence of horseradish peroxidase (HRP) has been studied. The polymerization mechanism was studied in detail using UV-Vis and Fourier transform infrared spectroscopy (FT-IR), and high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis. In addition, the dyeing properties and optimum reaction conditions were further investigated using the K/S values. The color fastness of the resulting silk fabrics has also been discussed. The results show that the dyeing mechanism for GA and silk fabric involved linking via the -NH2 and -OH groups in silk fiber and the -OH groups in GA. This was probably formed via the formation of phenyl-phenyl, oxygen-phenyl, or amino-phenyl linkages. HRP significantly improved the dyeing properties of GA dyes toward silk fabrics. The optimum reaction conditions for dyeing silk fabrics have been proposed (Incubation period, 5 h; temperature, 50 °C; GA dosage, 10 mM; HRP, 6 U/ml, and H2O2, 5 mM). The color fastness of the resulting silk fabrics displayed high colorfastness in all the colorfastness tests performed. [ABSTRACT FROM AUTHOR]

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Due to the damage of scalp because of chemical dyes, increasing attention had been paid to the ecological dyeing of human hair. To address the need for ecological restoration and dyeing of human hair, herein, a novel approach has been proposed via laccase-mediated in situ oxidation of dihydroxy phenylalanine (dopamine). As laccase can catalyze dopamine oxidation and then polymerization to produce strongly colored polymers, different biological coloration processes of human hair based on this process were investigated: (i) Human hair was treated with laccase alone; (ii) The absorption of human hair with dopamine, followed by further catalysis of air; (iii) The absorption of human hair with dopamine, followed by further catalysis of laccase; (iv) Simultaneous laccase-mediated polymerization and dyeing of human hair; and (v) Polymerization of Dopamine with laccase and then dyeing human hair. The surface properties of dyed hair were evaluated in terms of ultraviolet (UV)-protection, color fastness, Fourier transforming infrared spectrum (FT-IR), optical microscope, and scanning electron microscopy (SEM). The results show that best hair dyeing effect was achieved via simultaneous laccase-mediated polymerization and dyeing. The dyed hair obtained K/S values of 28, light fastness of level 5, and UPF of 100+. The optical microscope and SEM observations show that the surface of colored hair fibers was covered with thin burrs, which can be attributed to polydopamine attached with physical adhesive force and covalent reaction. FT-IR analysis shows that functional groups were present on the surface of the dyed hair which can be considered as introduction of hydroxyl radical groups. This biological stain technique may be widely used in dyeing of hair with black color. [ABSTRACT FROM AUTHOR]

This article overviews the synthesis of amylosic supramolecular materials through inclusion complexation in glucan phosphorylase (GP)-catalyzed enzymatic polymerization. Amylose is a polysaccharide that is known to form inclusion complexes with a number of hydrophobic small guest molecules. A pure amylose can be synthesized by the enzymatic polymerization of α- d -glucose 1-phosphate monomer with a maltooligosaccharide primer catalyzed by GP. The author has reported that the propagating amylosic chain in the enzymatic polymerization twines around hydrophobic polymers present in aqueous reaction media to form supramolecular inclusion complexes. As it is similar to the way that vines of a plant grow around a rod, this polymerization is termed 'vine-twining polymerization'. Amylosic supramolecular network materials have been obtained through the vine-twining polymerization by using copolymers, where hydrophobic guest polymers are covalently grafted on hydrophilic main-chain polymers. The enzymatically produced amylosic chains form complexes with the guest polymers among graft copolymers, which act as cross-linking points to form supramolecular networks, resulting in the formation of soft materials, such as gels and films. Vine-twining polymerization using appropriately designed guest polymers has also been performed, which leads to supramolecular products that exhibit new functionality. 1 Introduction 2 Vine-Twining Polymerization to Form Supramolecular Inclusion Complexes 3 Selective Complexation of Amylose toward Guest Polymers in Vine-Twining Polymerization 4 Hierarchical Architecture of Amylosic Supramolecular Network Materials by Vine-Twining Polymerization Approach 5 Hierarchical Fabrication of Amylosic Supramolecular Materials by Vine-Twining Polymerization Using Designed Guest Polymers 6 Conclusions [ABSTRACT FROM AUTHOR]

Enzymatic polymerization of 2,6-diaminopyridine (DAP) compound in the presence of HRP (Horse radish peroxidase) and H2O2 (hydrogen peroxide) with Poly(DAP-en) with the structures of two different types of polymers obtained by the oxidative polymerization of Poly(DAP-ox) using H2O2 in an aqueous basic environment was illuminated by 1H-NMR, 13C-NMR, FT-IR, UV-Vis spectral methods. GPC (gel permeation chromatography), TGA (thermal gravimetric analysis), DSC (differential scanning calorimetry), CV (cyclic voltammetry), fluorescence analysis and conductivity measurements to characterize the compounds and their electronic structure were examined. SEM analyzes were performed for the morphological properties of the compounds. As a result of the analysis, it was observed that the polymer obtained by enzymatic polymerization was better than the polymer obtained by oxidative method. It was observed that the results of the fluorescence measurements were better than Poly(DAP-en) in Poly(DAP-ox) emitting blue and green light. According to TGA analysis, the first decay temperatures for Poly (DAP-en) and Poly (DAP-ox) were calculated as 342 °C and 181 °C, respectively. The higher value of glass transition temperature for poly (DAP-en) confirms that the average molar mass is higher than 8650 Da for Poly (DAP-en) according to GPC analysis. [ABSTRACT FROM AUTHOR]

Bio-based star-shaped poly(e-caprolactone)s (S-PCL) derived from sugar-based D-sorbitol as an initiator were obtained via solvent-free enzymatic ring-opening polymerization (eROP). The star S-PCL were converted into UV-curable maleates by employing maleic anhydride for subsequent crosslinking with tri(ethylene glycol) divinyl ether (DVE-3) in the presence of Darocur 1173 as a radical photoinitiator. The kinetics of the UV-induced radical copolymerization was monitored by real-time Fourier-Transform InfraRed (FTIR) spectroscopy, which revealed that the star S-PCL maleate/divinyl ether system was not scavenged by molecular oxygen (donor/acceptor polymerization). The UV-crosslinking reaction was fast (~10 s) to reach near quantitative conversions. The S-PCL maleate / divinyl ether liquid formulation cast on glass substrates successfully gave films upon UV-crosslinking. The thermal properties of the polymer films and their precursor polymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Finally, the crosslinked polymer film demonstrated promising adhesive properties on steel, aluminum and glass substrates. [ABSTRACT FROM AUTHOR]

Template polymerization of aniline was performed using a laccase-mediator system. The high redox-potential laccase from the basidiomycete fungus Trametes hirsuta was a catalyst for polymerization. The aniline dimer served as the redox mediator; atmospheric oxygen served as the oxidant. Sodium dodecylbenzenesulfonate micelles were used as a "soft" template. The biocatalytic polymerization of aniline resulted in conducting polyaniline/sodium dodecylbenzene sulfonate complex that was tested as a protective coating. The efficiency of the inhibition of copper corrosion by the complex was 86–87%, and the dissipation rate of positive and negative charges from cotton fabrics increased by 56 and 27 times, respectively. [ABSTRACT FROM AUTHOR]

A series of novel aliphatic poly(β‐thioether ester)s with various methylene group contents were prepared by direct lipase‐catalyzed polycondensation of the monomer with an acid‐labile β‐thiopropionate group. The polycondensation reaction using immobilized lipase B from Candida antarctica was carried out in diphenyl ether at 90 °C. Poly(β‐thioether ester)s with high molecular weights of 20 500–57 000 Da and narrow polydispersities in the range 1.40–1.48 were obtained. Thermogravimetric analysis, differential scanning calorimetry and wide‐angle X‐ray diffraction were used to investigate the thermal properties and crystal structures of these polyesters. All the poly(β‐thioether ester)s were semicrystalline polymers and thermally stable up to at least 200 °C. In vitro degradation studies showed that they can rapidly degrade under acidic conditions by the hydrolysis of the β‐thiopropionate groups, suggesting their potential as acid‐degradable polymeric materials. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

We propose a new fluorometric method for alkaline phosphatase (ALP) determination. This method is based on the regulation of enzymatically generated poly(thymine) for the preparation of copper nanoparticles (CuNPs). 2′-Deoxythymidine 5′-triphosphate (dTTP) serves as the source for polymerization mediated by terminal deoxynucleotidyl transferase (TdT). This process generates poly(thymine), which acts as the template for synthesis of fluorescent CuNPs. However, if ALP catalyzes the hydrolysis of dTTP, the TdT-mediated polymerization will be disabled. This prevents the formation of CuNPs and causes a drop in fluorescence. The findings were used to design a sensitive and selective fluorometric method for ALP determination. A linear response in the activity range from 0.1 to 20 U L-1 and a limit of quantification of 0.3 U L-1 were obtained. The results indicate that the proposed method can be successfully applied to ALP assay in spiked diluted serum. This demonstrates the method's reliability and practicability. [ABSTRACT FROM AUTHOR]

Novel amphiphilic triblock copolymers poly(β-thioether ester)-b-poly(ethylene glycol)-b-poly(β-thioether ester) (PTE-b-PEG-b-PTE) were designed for the first time and used as carriers for the sustained release of the hydrophobic drug curcumin (Cur). These BAB-type triblock copolymers were synthesized via one-step enzymatic polycondensation with catalysis by immobilized lipase B from Candida antarctica (CALB). The copolymers could self-assemble to form flower-like nanosized micelles in aqueous solution. The pH-triggered disassembly behaviors of the micelles were evaluated from the changes of the micellar size and molecular weight due to the acid-degradable β-thiopropionate groups in the hydrophobic PTE core. Cur was encapsulated into the micelles and showed faster release at pH 5.0 than pH 7.4. In vitro experiments indicated that the copolymers were non-cytotoxic, while the Cur-loaded micelles effectively inhibited the proliferation of HeLa cells. All these findings demonstrated the potential of PTE-b-PEG-b-PTE triblock copolymers as a promising pH-responsive nanocarrier for controlled drug delivery. [ABSTRACT FROM AUTHOR]

Polyaniline/carboxylated multiwalled carbon-nanotube composites were synthesized with the use of laccase from the fungus Trametes hirsuta as a catalyst of aniline oxidative polymerization. Atmospheric oxygen was an oxidant. Aniline dimer adsorbed on the carbon material surface served as an enhancer of the enzymatic polymerization of aniline. The composites were synthesized in deionized water without any acidic dopant. The structure, morphology, and electrochemical characteristics of the obtained nanocomposite were examined. It has been shown that the carboxylic groups on the surface of multiwalled carbon nanotubes result in the electrochemical activity of polyaniline in solutions with a neutral pH. [ABSTRACT FROM AUTHOR]

In recent years, there has been extensive interest in the research of smart fabrics and functional textiles. The present work has successfully developed the enzymatic approach for dyed wool fabrics in possession of special pH-responsive color-changing and conductive properties, via in-situ polymerization of 2,5-diaminobenzenesulfonic acid (DABSA) by laccase from Trametes versicolor. The enzymatically synthesized product, poly(2,5-diaminobenzenesulfonic acid) (PDABSA), was characterized by Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The redox property and thermal stability of the polymer products were studied by cyclic voltammetry and thermogravimetric analysis, respectively. The results proved that the resulting polymer reached 2 KDa and showed strong pH-dependence of UV-Vis absorption, electrochemical activity and high thermal stability. Utilizing the doping/dedoping process of PDABSA, the dyed wool fabrics were endowed with a pH-dependent redox potential. Furthermore, the dyed wool fabrics exhibited reversible color change from dark purple at pH 1.8 to yellowish-brown at pH 10.0, indicating that the PDABSA showed unusual pH-dependent color-changing properties on dyed wool fabrics. [ABSTRACT FROM AUTHOR]

Chrysoidine (CHRY) is a type of azo‐dye extensively used in industry. This study delineates 2 routes as enzymatically and oxidatively polycondensation of chrysoidine for the syntheses of poly (chry‐enz) and poly (chry‐ox), respectively. The molecular structures of enzymatically and oxidatively polymerized chrysoidine were described by the FT‐IR, UV‐Vis, 1H‐NMR, and 13C‐NMR techniques. The molecular structures were obtained to be different as in the cyclization process of the enzymatic polymerization. Solvatochromic behavior in selected polar solvents on the optical properties of poly (chry‐ox) were studied. Further characterization was implemented by fluorescence (PL), electrochemical, thermogravimetric (TG‐DTA), cyclic voltammetry (CV), and differential scanning calorimetry (DSC) measurements. The number of average molecular weight of poly(chry‐ox) was found to be higher than that of poly(chry‐enz). Photoluminescence (PL) measurements enlightened the response of poly (chry‐ox) with intense light emissions upon a bicolor irradiation by Ultra‐Violet and visible light. CV technique was utilized to make a comment about HOMO‐LUMO energy levels and electrochemical ( E g ') band gaps of the polymers. Optical and electrochemical band gaps of poly (chry‐enz) were lower than those of poly (chry‐ox), proving the successful synthesis of π‐conjugated structure of poly (chry‐enz). To further make comments about the features of the polymers, scanning electron microscopy (SEM) images were exemplified to study the surface forms of the polymers. Surface morphology of poly (chry‐enz) was seen as agglomerates of grains toward the out‐of‐plane direction. As the polymerization method was changed, the morphology was transformed into a flat‐smooth surface present with visible holes for poly (chry‐ox). [ABSTRACT FROM AUTHOR]

Multicopper oxidases such as bilirubin oxidase (BOD) from Myrothecium verrucaria and laccase (LC) from the basidial fungus Trametes hirsuta have been used as catalysts in dihydroquercetin (DHQ) oxidative polymerization. The conditions selected enabled good yields of DHQ oligomers, which were then analyzed using UV-vis, FTIR, 1Н and 13С NMR spectroscopy. DHQ oligomers synthesized using both enzymes showed higher thermostability as compared with the monomer. Depending on the oxidase, the products of DHQ polymerization differed in physicochemical properties, and as shown by NMR studies, had different structures. [ABSTRACT FROM AUTHOR]

Abstract: The renaissance of the bio‐based chemical industry over the last 20 years has seen an ever growing interest in the synthesis of new bio‐based polymers. The building blocks of these new polymers, so called platform molecules, contain significantly more chemical functionality than their petrochemical counterparts (such as ethene, propene and para‐xylene). As a result bio‐based polymers often contain greater residual chemical functionality in their chains, with groups such as alkenes and hydroxyls commonly observed. These functional groups can act as sites for post‐polymerization modification (PPM), thus further extending the range of applications for bio‐based polymers by tailoring the polymers' final properties. This mini‐review highlights some of the most recent and compelling examples of how to make use of bio‐based polymers with residual functional groups for PPM. It also looks at how the emerging interdisciplinary field of enzymatic polymer synthesis allows for increased functionality in polymers by avoiding side‐reactions as a result of milder reaction conditions, and additionally offers an alternative means of polymer surface modification. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Aliphatic polyesters are the most used biodegradable polymers in biomedical applications. These polymers can be synthesized by two main routes: polycondensation and ring-opening polymerization. In this work, polyester nanoparticles were synthesized by an environmentally friendly process, enzymatic ring-opening polymerization (ε-ROP) of different 16-membered macrolactones (globalide (unsaturated) and ω-pentadecalactone (saturated)), catalyzed by a biocatalyst (free Candida antarctica B lipase) in aqueous miniemulsion. Reactions were conducted varying parameters as surfactant concentration, polymerization temperature (45 and 60 °C), and co-stabilizer type (hexadecane and crodamol, a medium chain saturated triglyceride). Saturated and unsaturated poly(macrolactones) were successfully synthesized via ε-ROP in miniemulsion, and weight average molecular weights of up to 23,200 g/mol were reached. Nanoparticles showed a “lemon-shaped” morphology, and their average diameter was affected by surfactant concentration, varying from 75 to 283 nm and from 218 to 436 nm for poly(globalide) and poly(ω-pentadecalactone), respectively. Melting points of 47-49 °C (unsaturated poly(macrolactones)) and 91-92 °C (saturated poly(macrolactones)) were obtained. [ABSTRACT FROM AUTHOR]

A hindered polyphenol, oligo(4‐methoxyphenol), has been first successfully synthesized via a mild biocatalytic pathway using horseradish peroxidase as catalyst in water without any additive. Then the efficiency of oligo(4‐methoxyphenol) in stabilization of polypropylene (PP) was evaluated in terms of thermal analysis and accelerated aging test. It was observed that the apparent activation energy for thermal decomposition of PP/oligo(4‐methoxyphenol) calculated by Friedman's method is higher than that of virgin PP. Oligo(4‐methoxyphenol)‐stabilized PP maintains its tensile strength even after aging at 120°C for 800 hours. Oxidation induction time and onset oxidation temperature of PP/oligo(4‐methoxyphenol) are higher than both virgin PP and PP/4‐methoxyphenol, as well as PP stabilized with commercially available 6‐di‐tert‐buty‐4‐methylphenol or 1076. These results indicate that oligo(4‐methoxyphenol) can effectively improve the thermo‐oxidative resistance of PP. Noting that oligo(4‐methoxyphenol) is synthesized via enzymatic polymerization in water under mild condition with a facile procedure, oligo(4‐methoxyphenol) is thus proposed as a new efficiency and readily available antioxidant for PP. [ABSTRACT FROM AUTHOR]

ε-caprolactone (CL) has been enzymatically polymerized using α-amino acids based on sulfur (methionine and cysteine) as (co-)initiators and immobilized lipase B of Candida antarctica (CALB) as biocatalyst. In-depth characterizations allowed determining the corresponding involved mechanisms and the polymers thermal properties. Two synthetic strategies were tested, a first one with direct polymerization of CL with the native amino acids and a second one involving the use of an amino acid with protected functional groups. The first route showed that mainly polycaprolactone (PCL) homopolymer could be obtained and highlighted the lack of reactivity of the unmodified amino acids due to poor solubility and affinity with the lipase active site. The second strategy based on protected cysteine showed higher monomer conversion, with the amino acids acting as (co-)initiators, but their insertion along the PCL chains remained limited to chain endcapping. These results thus showed the possibility to synthesize enzymatically polycaprolactone-based chains bearing amino acids units. Such cysteine endcapped PCL materials could then find application in the biomedical field. Indeed, subsequent functionalization of these polyesters with drugs or bioactive molecules can be obtained, by derivatization of the amino acids, after removal of the protecting group. [ABSTRACT FROM AUTHOR]

ABSTRACT Cyclic oligo(butylene 2,5-furandicarboxylate) and ɛ-caprolactone were copolymerized in bulk at 130-150 °C by enzymatic ring opening polymerization using CALB as catalyst. Copolyesters within a wide range of compositions were thus synthesized with weight-average molecular weights between 20,000 and 50,000, the highest values being obtained for equimolar or nearly equimolar contents in the two components. The copolyesters consisted of a blocky distribution of the ɛ-oxycaproate (CL) and butylene furanoate (BF) units that could be further randomized by heating treatment. The thermal stability of these copolyesters was comparable to those of the parent homopolyesters (PBF and PCL), and they all showed crystallinity in more or less degree depending on composition. Their melting and glass-transition temperatures were ranging between those of PBF and PCL with values increasing almost linearly with the content in BF units. The ability of these copolyesters for crystallizing from the melt was evaluated by comparative isothermal crystallization and found to be favored by the presence of flexible ɛ-oxycaproate blocks. These copolyesters are essentially insensitive to hydrolysis in neutral aqueous medium but they became noticeably degraded by lipases in an extend that increased with the content in CL units. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 290-299 [ABSTRACT FROM AUTHOR]

Candida antarctica: lipase B (CALB) is the most widely studied enzyme, due to its high selectivity and catalytic activity in organic and polymer synthesis. To avoid organometallic catalysts in the synthesis of biodegradable polyesters, the enzymatic ring-opening polymerization of cyclic esters can be carried out with CALB as a biocatalyst. This paper reviews selected examples of the application of lipases in polymer chemistry covering the synthesis of cyclic ester monomers, linear and star oligomers, as well as well-defined high molar mass polymers with improved mechanical properties. It is shown that by the selection of appropriate conditions of temperature and solvent assortment, CALB effectively catalyzes the polymerization of large size lactones obtaining polyesters with Mn up to 80 kg mol−1. The chemical structure and main applications of described materials are also discussed. As the polymer recycling is an important topic from environmental point of view, we also described the potential applications of CALB in degradation process of aliphatic polyesters. [ABSTRACT FROM AUTHOR]

This review presents our researches on the preparation and material application of inclusion complexes that comprises an amylose host and polymeric guests through phosphorylase-catalyzed enzymatic polymerization. Amylose is a well-known polysaccharide and forms inclusion complexes with various hydrophobic small molecules. Pure amylose is produced by enzymatic polymerization by using α-D-glucose 1-phosphate as a monomer and maltooligosaccharide as a primer catalyzed by phosphorylase. We determined that a propagating chain of amylose during enzymatic polymerization wraps around hydrophobic polymers present in the reaction system to form inclusion complexes. We termed this polymerization "vine-twining polymerization" because it is similar to the way vines of a plant grow around a rod. Hierarchical structured amylosic materials, such as hydrogels and films, were fabricated by inclusion complexation through vine-twining polymerization by using copolymers covalently grafted with hydrophobic guest polymers. The enzymatically produced amyloses induced complexation with the guest polymers in the intermolecular graft copolymers, which acted as cross-linking points to form supramolecular hydrogels. By including a film-formable main-chain in the graft copolymer, a supramolecular film was obtained through hydrogelation. Supramolecular polymeric materials were successfully fabricated through vine-twining polymerization by using primer-guest conjugates. The products of vine-twining polymerization form polymeric continuums of inclusion complexes, where the enzymatically produced amylose chains elongate from the conjugates included in the guest segments of the other conjugates. [ABSTRACT FROM AUTHOR]

Yarrowia lipolytica (YL) is a "non-conventional" yeast that is capable of producing important metabolites. One of the most important products that is secreted by this microorganism is lipase, a ubiquitous enzyme that has considerable industrial potential and can be used as a biocatalyst in the pharmaceutical, food, and environmental industries. In this work, Yarrowia lipolytica lipase (YLL) was immobilized on Lewatit and Amberlite beads and is used in the enzymatic ring-opening polymerization (ROP) of cyclic esters in the presence of different organic solvents. YLL immobilized on Amberlite XAD7HP had the higher protein adsorption (96%) and a lipolytic activity of 35 U/g. Lewatit VPOC K2629 has the higher lipolytic activity (805 U/g) and 92% of protein adsorption. The highest molecular weight (Mn 10,685 Da) was achieved at 90 °C using YLL that was immobilized on Lewatit 1026 with decane as solvent after 60 h and 100% of monomer conversion. [ABSTRACT FROM AUTHOR]