Active Ester Groups Research Articles

Non-food renewable and bioactive products for pesticides: Synthesis, anti-oomycete and anti-fungal activities of 9R-acyloxyquinine derivatives bearing an 1,3,4-oxadiazole moiety

Quinine is the main alkaloids in the bark of Cinchona and its homologous plants of Rubiaceae. To discover biorational natural product-based pesticides, a series of 9R-acyloxyquinine derivatives containing 1,3,4-oxadiazole moieties were prepared by ingeniously introducing an active ester group and a 1,3,4-oxadiazole five membered heterocyclic ring at its C-9 position, and their structures were well characterized by 1H NMR, 13C NMR, HRMS, and m.p. The stereochemical configuration of target compound 6 t was unambiguously subjected to single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete and anti-fungal agents against two serious agricultural diseases, Phytophthora capsici and Fusarium graminearum we assessed. Among all tested compounds, 1) Compounds 6c and 6d displayed promising anti-oomycete against P. capsici, with EC50 values of 38.42 and 35.49 mg/L, respectively. 2) Compound 6i exhibited promising anti-fungal against F. graminearum, with an EC50 value of 29.92 mg/L. Moreover, some interesting results of structure-activity relationships were also observed. The results of this study pave the way for further design, structural modification, and development of quinine derivatives as plant anti-oomycetes and anti-fungal agents in crop protection.

Preparation and Properties of Epoxy Adhesives with Fast Curing at Room Temperature and Low-Temperature Resistance.

Developing a highly efficient multifunctional epoxy adhesive is still an enormous challenge, which can rapidly cure at room temperature and has excellent low-temperature resistance performance and is crucial for the epoxy adhesive and electrical sealing fields during severe cold seasons. Herein, diglycidyl phthalate (DP) was synthesized with phthalic anhydride (PA) and epichlorohydrin (ECH) to enhance the curing rate and low-temperature resistance of bisphenol A diglycidyl ether (DGEBA) adhesive. The modified DP/DGEBA adhesives were systematically analyzed by gel time, mechanical properties, and aging resistance (time, temperature, and dry/wet treatment). The results showed that DP with highly active ester groups significantly accelerates the curing speed of DP/DGEBA. DP's rigid aromatic ring-benzene ring and flexible group-ester group gave the adhesive better low-temperature resistance. When the addition of DP was 10 wt % (based on the mass of DGEBA), the gel time of DP/DGEBA epoxy adhesives was reduced by 58 min compared to unmodified DGEBA epoxy adhesive, and after aging at low temperature (-20 °C) for 7 days, the tensile shear strengths of polyvinyl chloride (PVC) and aluminum plate increased by 76.2 and 80.6%, respectively. The results of non-isothermal curing kinetics and dynamic mechanical analysis suggested that when the amount of DP was 10 wt %, the reaction activation energy of DP/DGEBA epoxy adhesive decreased by 4.0%, and the cross-linking density increased by 8.9%. Moreover, the toughness of the modified adhesive was also improved. This study opens up a feasible way for the development of a low temperature-resistant epoxy adhesive cured rapidly at room temperature in practical application.

Redox dual-responsive diaryl ditelluride-containing nanoparticles as peroxidase mimetics

Polymeric nanoparticles with peroxidase-like enzyme mimetic activity were developed by incorporating catalytically active tellurium (Te) functionalities into cross-linked block copolymers. Bis(2-aminophenyl) ditelluride was used as a cross-linker to react with a diblock copolymer bearing pendent activated ester groups to generate of core-cross-linked nanoparticles (DiTe-NP) containing diaryl ditelluride bonds. DiTe-NP nanoparticles exhibit dual redox-responsiveness inherited from the sensitivity of ditelluride to both oxidants and reductants. When DiTe-NP nanoparticles were treated with H2O2, the oxidation of the ditellurides triggered the cleavage of Te-Te bonds to form Te(IV)-associated species. The oxidation-responsiveness endows DiTe-NP nanoparticles with haloperoxidase (HPO)-mimic activity. With NaBr and hydrogen peroxide, they catalyzed the oxidative bromination of phenol red, bromolactonization of 4-pentenoic acid, and bromination of 1,3,5-trimethoxybenzene due to the in-situ generation of hypobromous acid (HOBr) for halogenations. These ditelluride-containing nanoparticles also exhibited glutathione peroxidase (GPx)-like activity and accelerated the reduction of hydroperoxide by a thiol substrate. The cleavage of ditelluride bonds by a thiol substrate leads to the formation of key intermediates in the catalytic cycle of DiTe-NP nanoparticles. DiTe-NP nanoparticles showed enhanced activity for the reduction of hydrophobic cumene peroxide by 4-nitrothiophenol. These dual redox-responsive ditelluride-containing nanoparticles are promising candidates as peroxidase mimetics to apply as catalysts for green halogenation reactions and decompositions of toxic peroxides.

Site-Selective C-O Bond Editing of Unprotected Saccharides.

Glucose and its polyhydroxy saccharide analogs are complex molecules that serve as essential structural components in biomacromolecules, natural products, medicines, and agrochemicals. Within the expansive realm of saccharides, a significant area of research revolves around chemically transforming naturally abundant saccharide units to intricate or uncommon molecules such as oligosaccharides or rare sugars. However, partly due to the presence of multiple hydroxyl groups with similar reactivities and the structural complexities arising from stereochemistry, the transformation of unprotected sugars to the desired target molecules remains challenging. One such formidable challenge lies in the efficient and selective activation and modification of the C-O bonds in saccharides. In this study, we disclose a modular 2-fold "tagging-editing" strategy that allows for direct and selective editing of C-O bonds of saccharides, enabling rapid preparation of valuable molecules such as rare sugars and drug derivatives. The first step, referred to as "tagging", involves catalytic site-selective installation of a photoredox active carboxylic ester group to a specific hydroxyl unit of an unprotected sugar. The second step, namely, "editing", features a C-O bond cleavage to form a carbon radical intermediate that undergoes further transformations such as C-H and C-C bond formations. Our strategy constitutes the most effective and shortest route in direct transformation and modification of medicines and other molecules bearing unprotected sugars.

Single-molecule multi-target fluorescent imaging for latent fingerprints based on aggregation-induced emission

Existing latent fingerprint developers achieve marvelous progress during the past decades. However, most of these methods mainly consider single target substance, which may face difficulties in latent fingerprint imaging when the corresponding substance is absent from latent fingerprint traces. To alleviate this issue, we propose a novel single-molecule multi-target green fluorescent probe, TPE-NI-NHS, which could target both lipids and amino acids through physical adsorption and chemically bonding under mild conditions, respectively. Specifically, tetraphenylethylene and active ester group in TPE-NI-NHS are connected at two ends of the naphthalimide core, which provide perfect aggregation-induced emission, accurate and quick reaction with amino acids, lipophilic properties, and green fluorescence emission. As expected, TPE-NI-NHS achieves green fluorescent imaging for latent fingerprints contained different contents of lipids and amino acids with high quality, high sensitivity, and high contrast under mild conditions. In summary, TPE-NI-NHS developer provides multiple targeting features, novel imaging principles and mild imaging process to latent fingerprint detections.

Polymer Vesicles with Integrated Photothermal Responsiveness.

Functionalized polymer vesicles have been proven to be highly promising in biomedical applications due to their good biocompatibility, easy processability, and multifunctional responsive capacities. However, photothermal-responsive polymer vesicles triggered by near-infrared (NIR) light have not been widely reported until now. Herein, we propose a new strategy for designing NIR light-mediated photothermal polymer vesicles. A small molecule (PTA) with NIR-triggered photothermal features was synthesized by combining a D-D'-A-D'-D configuration framework with a molecular rotor function (TPE). The feasibility of the design strategy was demonstrated through density functional theory calculations. PTA moieties were introduced in the hydrophobic segment of a poly(ethylene glycol)-poly(trimethylene carbonate) block copolymer, of which the carbonate monomers were modified in the side chain with an active ester group. The amphiphilic block copolymers (PEG44-PTA2) were then used as building blocks for the self-assembly of photothermal-responsive polymer vesicles. The new class of functionalized polymer vesicles inherited the NIR-mediated high photothermal performance of the photothermal agent (PTA). After NIR laser irradiation for 10 min, the temperature of the PTA-Ps aqueous solution was raised to 56 °C. The photothermal properties and bilayer structure of PTA-Ps after laser irradiation were still intact, which demonstrated that they could be applied as a robust platform in photothermal therapy. Besides their photothermal performance, the loading capacity of PTA-Ps was investigated as well. Hydrophobic cargo (Cy7) and hydrophilic cargo (Sulfo-Cy5) were successfully encapsulated in the PTA-Ps. These properties make this new class of functionalized polymer vesicles an interesting platform for synergistic therapy in anticancer treatment.

A Manufacturing Strategy Utilizing a Continuous-Mode Reactor toward Homogeneous PEGylated Bioconjugate Production

AbstractProtein PEGylation is a traditional bioconjugation technology that enhances the therapeutic efficacy and in vivo half-life of proteins by the formation of covalent bonds with highly activated ester group linked polyethylene glycol (PEG). However, the high reactivity of these reagents induces a random reaction with lysine residues on the protein surface, resulting in a heterogeneous mixture of PEGylated proteins. Moreover, the traditional batch-mode reaction has risks relating to scalability and aggregation. To overcome these risks of traditional batch-mode PEGylation, a manufacturing strategy utilizing structural analysis and a continuous-flow-mode reaction was examined. A solvent exposure analysis revealed the most reactive lysine of a protein, and the continuous-flow mode modified this lysine to achieve the mono-PEGylation of two different proteins within 2 seconds. This ultrarapid modification reaction can be applied to the gram-scale manufacturing of PEGylated bioconjugates without generating aggregates. A similar trend of the exposure level of protein lysine and mono-selectivity performed by continuous-flow PEGylation was observed, which indicated that this manufacturing strategy has the potential to be applied to the production of a wide variety of bioconjugates.

Preparation of Narrow Pore Diameter Phosphorus Containing Cotton Stalk Carbon and Its Adsorption Mechanism for Tetracycline

Using cotton stalk as biomass raw material and phosphoric acid as a modifier, narrow pore distribution phosphorus-containing cotton stalk biochar (CSP) with a high surface area (1916 m2·g-1) and pore volume (1.3982 mL·g-1) was prepared through one-step carbonization, and the adsorption characteristics and mechanisms for tetracycline (TC) were investigated. The results showed that the TC adsorption capacity of CSP was up to 669 mg·g-1, which was 43.6 times that of unmodified cotton stalk carbon. FTIR, XPS, and isothermal adsorption studies showed that the high adsorption capacity of CSP for TC resulted from the joint action of complexation, hydrogen bonding, pore filling, and π-π dispersion forces, and the highly active phosphate ester group (P-O-C) endowed by phosphoric acid modification greatly enhanced the chemical interaction with TC molecules, which was the key factor for the significant increase in adsorption capacity. Isotherm and thermodynamic study further confirmed that chemical adsorption played a major role in the adsorption process, the adsorption process was spontaneous and endothermic, and the material had good regeneration performance. This study provides theoretical guidance for the preparation of modified biomass carbon with high adsorption performance to remove tetracycline antibiotic pollution.

Fabrication of submillimeter-sized spherical self-oscillating gels and control of their isotropic volumetric oscillatory behaviors.

In this study, we established a fabrication method and analyzed the volumetric self-oscillatory behaviors of submillimeter-sized spherical self-oscillating gels. We validated that the manufactured submillimeter-sized spherical self-oscillating gels exhibited isotropic volumetric oscillations during the Belousov-Zhabotinsky (BZ) reaction. In addition, we experimentally elucidated that the volumetric self-oscillatory behaviors (i.e., period and amplitude) and the oscillatory profiles depended on the following parameters: (1) the molar composition of N-(3-aminopropyl)methacrylamide hydrochloride (NAPMAm) in the gels and (2) the concentration of Ru(bpy)3-NHS solution containing an active ester group on conjugation. These clarified relationships imply that controlling the amount of Ru(bpy)3 in the gel network could influence the gel volumetric oscillation during the BZ reaction. These results of submillimeter-sized and spherical self-oscillating gels bridge knowledge gaps in the current field because the gels with corresponding sizes and shapes have not been systematically explored yet. Therefore, our study could be a cornerstone for diverse applications of (self-powered) gels in various scales and shapes, including soft actuators exhibiting life-like functions.

Simplified one-pot 18F-labeling of biomolecules with in situ generated fluorothiophosphate synthons in high molar activity.

Rationale: Conventional 18F-labeling methods that demand substrate pre-modification or lengthy radiosynthesis procedures have impeded the visualization and translation of numerous biomolecules, as biomarkers or ligands, using modern positron emission tomography techniques in vivo. Moreover, 18F-labeled biomolecules in high molar activity (Am) that are indispensable for sensitive imaging could be only achieved under strict labeling conditions. Methods: Herein, 18F-labeled fluorothiophosphate (FTP) synthons in high Am have been generated rapidly in situ in reaction solutions with < 5% water via nucleophilic substitution by wet [18F]F-, which required minimal processing from cyclotron target water. Results: Various 18F-labeled FTP synthons have been prepared in 30 sec at room temperature with high radiochemical yields > 75% (isolated, non-decay-corrected). FTP synthons with unsaturated hydrocarbon or activated ester group can conjugate with typical small molecules, peptides, proteins, and metallic nanoparticles. 337-517 GBq μmol-1 Am has been achieved for 18F-labeled c(RGDyK) peptide using an automatic module with 37-74 GBq initial activity. Conclusion: The combination of high 18F-fluorination efficiency of FTP synthons and following mild conjugation condition provides a universal simplified one-pot 18F-labeling method for broad unmodified biomolecular substrates.

Nickel‐Catalyzed Cascade Cyclization‐Negishi Coupling of Redox Active Esters for the Synthesis of Pyrrolidines

AbstractWe have developed a Ni‐catalyzed cascade cyclization/Negishi‐coupling reaction for the formation of pyrrolidines and pyrrolidinones starting from N‐protected allylamines and acrylamides which contain a redox active ester group. The reaction provides two C−C bonds in a single operation and takes place with both alkylzinc and arylzinc bromides as nucleophiles. Activation of RAE by low valent Ni complexes involving a radical pathway followed by a fast cyclization of intermediate carbon radicals is proposed.

Polymers with Pendant Water‐Soluble Tetrafluorobenzene Sulfonic Acid Activated Esters: Synthesis, Stability, and Use for Glycopolymers in Water

Front Cover: In article number 2200072, Tomonari Tanaka and co-workers synthesize a novel monomer and polymer bearing water-soluble activated ester groups, tetrafluorobenzene sulfonic acid esters, with a pentandiyl linker. These are stable and can be used for synthesizing glycopolymers in water. Synthesis of functional polymers in water are further developed.

Polymers with Pendant Water‐Soluble Tetrafluorobenzene Sulfonic Acid Activated Esters: Synthesis, Stability, and Use for Glycopolymers in Water

AbstractFunctional polymers can be synthesized via post‐polymerization modification with pendant‐activated ester groups on their backbones. There are, however, few reports on polymers bearing water‐soluble activated ester groups, as they are unstable in water. Herein, novel monomers and polymers bearing water‐soluble tetrafluorobenzene sulfonic acid (sulfoTFB) activated ester groups are reported. The corresponding sulfoTFB‐bearing polymers are successfully synthesized via controlled radical polymerization. The stabilities of the sulfoTFB‐bearing monomers and polymers are significantly improved by the introduction of an alkanediyl linker into sulfoTFB. The stability of sulfoTFB is found to be significantly improved when the linker is longer than a butanediyl linker, increasing in line with the length of the alkanediyl linker. The resulting sulfoTFB‐bearing polymer is used for synthesizing oligosaccharide‐grafted glycopolymers, which binds to lectin with high binding affinity, via post‐polymerization modification in water. This study thus details the preparation, investigation, and use of novel polymers with pendant water‐soluble sulfoTFB groups for post‐polymerization modification in water.

Synthesis of isoeugenol biobased epoxy polymer by forming α‐hydroxyl ester and degradation studies

AbstractThe synthesis of bio‐based monomers and polymers from renewable feedstock, such as plant biomass, is desirable because of the depletion of fossil fuel resources and the reliance of thermosetting epoxy resin on non‐renewable petrochemical monomers. Despite the excellent polymeric properties of bisphenol‐based epoxy resins, these negatively impact human health. Herein, the synthesis of self‐curable epoxy polymers from the bio‐based material isoeugenol by forming α‐hydroxyl esters is reported. The epoxides are named AB (single epoxide and ester groups) and A2B2 (double epoxide and ester groups), based on the number of active ester and epoxide groups. The materials derived from the bio‐based material, AB and A2B2, were initiated with and without the catalyst N,N′‐dimethylaminopyridine (DMAP) and curing agent diaminodiphenylmethane. Without the catalyst, AB and A2B2 self‐polymerized at 247 and 210°C, respectively. Notably, the polymerization temperatures for AB and A2B2 decreased after the addition of DMAP. The self‐cured epoxy resin without the catalyst showed the highest thermal stability and glass transition temperature (Tg = 156°C). Degradation and recovery studies suggested forward that 51% of the material could be recovered and 94% of the polymer could be degraded from the self‐cured A2B2 in 25 wt% NaOH solution.

A Ratiometric Fluorescent Conjugated Oligomer for Amyloid β Recognition, Aggregation Inhibition, and Detoxification.

The sensitive recognition and effective inhibition of toxic amyloid β protein (Aβ) aggregates play a critical role in early diagnosis and treatment of neurodegenerative diseases. In this work, a new conjugated oligo(fluorene-co-phenylene) (OFP) modified with 1,8-naphthalimide (NA) derivative OFP-NA-NO2 is designed and synthesized as a ratiometric fluorescence probe for sensing Aβ, inhibiting the assembly of Aβ, and detoxicating the cytotoxicity of Aβ aggregates. In the presence of Aβ, the active ester group on the side chain of OFP-NA-NO2 can covalently react with the amino group on Aβ, effectively inhibiting the formation of Aβ aggregates and degrading the preformed fibrils. In this case, the fluorescence intensity ratio of NA to OFP (INA /IOFP ) increases greatly. The detection limit is calculated to be 89.9nM, presenting the most sensitive ratiometric recognition of Aβ. Interestingly, OFP-NA-NO2 can dramatically recover the cell viability of PC-12 and restore the Aβ-clearing ability of microglia. Therefore, this ratiometric probe exhibits the targeted recognition of Aβ, effective inhibition of Aβ aggregates, and detox effect, which is potential for early diagnosis and treatment of neurodegenerative diseases.

Grafting of various acrylic monomers on to natural rubber: Effects of glutaraldehyde curing on mechanical and thermo-mechanical properties

Natural rubber (NR) grafted with different acrylic-monomers, namely butyl acrylate (BA), methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA), were prepared via redox polymerization. This aims to enhance the mechanical and thermal properties of pristine NR by using a novel curing system of glutaraldehye (GA). Grafting of acrylic-monomers onto NR molecular chains was clarified using ATR-FTIR and 1H-NMR. It was found that the grafted-NR vulcanizates effectively improved the mechanical properties. Here, NR-g-PBMA showed enhancement in moduli, tensile strength and elongation at break of approximately 100, 280, and 40 %, respectively, when compared to the one without modification. It was also observed that, all the grafted-NR vulcanizates exhibited an improved crosslinking. This was elucidated through the engine oil swelling and the TSSR (i.e. Temperature Scanning Stress Relaxation) measurements. The latter test was also first proposed for characterizing the grafted-NR in terms of mechanical and thermo-mechanical interpretations. The thermogram clearly exhibited that the thermal properties of NR were significantly improved after graft copolymerization owing to the presence of functional groups on the molecular chain which enhanced the intermolecular attraction of the grafted-NR molecules. It can be summarized that two possibilities of interaction were observed: (I) the chemical interaction of GA-Rubber through the CC bonds and through the active ester groups of grafted-NR molecules, and (II) the physical polar-polar interaction through the presence of carbonyl groups of grafted-NR molecules. Thus, the present work is found to be beneficial to the future applications of NR which requires high specific modulus and thermal stability at low strain in case of flexible actuators and sensors. Furthermore, the newly curing technique can be easily used to fabricate article at low temperature with greater ease of processing.

Functionalized Biodegradable Polymers via Termination of Ring-Opening Polymerization by Acyl Chlorides

Aliphatic polyesters are an important class of polymeric materials for biomedical applications due to their versatile and tunable chemistry, biocompatibility and biodegradability. A capability of direct bonding with biomedically significant molecules, provided by the presence of the reactive end functional groups (FGs), is highly desirable for prospective polymers. Among FGs, N-hydroxysuccinimidyl activated ester group (NHS) and maleimide fragment (MI) provide efficient covalent bonding with –NH– and –SH containing compounds. In our study, we found that NHS- and MI-derived acyl chlorides efficiently terminate living ring-opening polymerization of ε-caprolactone, L-lactide, ethyl ethylene phosphonate and ethyl ethylene phosphate, catalyzed by 2,6-di-tert-butyl-4-methylphenoxy magnesium complex, with a formation of NHS- and MI-functionalized polymers at a high yields. Reactivity of these polymers towards amine- and thiol-containing model substrates in organic and aqueous media was also studied.

Covalently construction of poly(hexamethylene biguanide) as high-efficiency antibacterial coating for silicone rubber

Biofilm formation on biomedical devices & implants and the resulting bacterial induced infections are remaining severe clinic issues. Here, a facile layer-by-layer strategy to covalently construct poly(hexamethylene biguanide) (PHMB) as the high-efficiency bactericidal coating on silicone rubber (SR) has been developed. Based on the NHS/NH2 chemistry (the reaction between active ester groups and amino groups), an active ester homo-polymers (pNHSMA) as the precursor layer was created on activated SR surface (SR-NH2), which followed by the immobilization of dense PHMB coating. XPS and water contact angle tests verified the successful construction of PHMB coating on the surface. Robust relationships between the contact time/initial seeding density of bacteria and the bactericidal capacity of the coating have been established based on systematical qualitative and quantitative antibacterial evaluations. Results showed that the PHMB coating is able to kill 100% of the attached S. aureus cells within 1 h with initial density below 1.18 × 105 CFU/cm2 without compromising of the cytocompatibility of the substrates. Interestingly, the coating significantly increased the mechanical property of the SR substrates due to the additional crosslinking introduced by the coating. Furthermore, the high-efficiency antibacterial property of PHMB coating (bactericidal ratio of 96.83%) and the significant suppressed implant-induced infection have been verified via the in vivo simulated infection model on rats. In the meantime, this surface modification strategy can be easily applied to SR based catheters, which is able to completely kill the surface attached bacteria when immersed in a bacterial suspension with a density of 3 × 106 CFU/mL for 30 min. These findings provide a new approach to combat the biofilm formation and devices-associated infections for general SR based biomedical devices/implants.

A simple route to functionalising electrospun polymer scaffolds with surface biomolecules

Surface functionalisation of polymeric electrospun scaffolds with therapeutic biomolecules is often explored in regenerative medicine and tissue engineering. However, the bioconjugation method must be carefully selected to prevent partial or full loss of activity of the biomolecule following chemical manipulation. Perfluorophenyl azide bearing a N‐hydroxysuccinimide (PFPA-NHS) active ester group is a versatile tool for UV-initiated covalent coupling of amine-containing molecules to hydrocarbon-based polymers, such as polydioxanone or polycaprolactone (PCL). This study therefore explored the feasibility of PFPA-NHS functionalisation of electrospun PCL scaffolds with model biomolecules. Protein conjugation was extensively explored using fluorescence staining and attachment studies, confirming the retention of amine coupling capability following photografting of PFPA-NHS to the PCL surface. The effect of the washing method used to remove unreacted PFPA was explored in Caco-2 cell viability studies, and it was determined that sonication washing is required to avoid cell death. A model enzyme, catalase, was then successfully attached to the surface of PCL scaffolds for potential applications in oncological photodynamic therapy. Catalase retained its enzymatic activity following attachment to the fibres and the majority of the enzyme (~60%) remained bound to the fibre after incubation in an aqueous environment for six days. The anticipated prolonged presentation and sustained release of proteins as a result of PFPA-NHS conjugation could be advantageous in progressing protein-based therapies.

Characterization of N-phenylmaleimide-terminated poly(ethylene glycol)s and their application to a tetra-arm poly(ethylene glycol) gel.

Tetra-arm poly(ethylene glycol) (TetraPEG) gels are tough materials whose toughness originates from their uniform network structure. They can be formed by combining the termini of tetra-arm polymers via chemical reactions with high conversion efficiency, such as the Michael addition, condensations using an active ester group, and alkyne-azide cycloadditions. Herein, we report the synthesis of a tetra-PEG gel using a tetra-arm polymer with N-phenylmaleimide moieties at the polymer ends (tetra-N-aryl MA PEG) as a scaffold. Tetra-N-aryl MA PEG can be obtained via a simple maleimidation using the modification agent p-maleimidophenyl isocyanate (PMPI), which directly transforms the hydroxy groups at the polymer ends into reactive N-aryl maleimide groups in a one-pot reaction. The thus-obtained tetra-N-aryl MA PEG was fully characterized using high-performance liquid chromatography (HPLC), matrix-assisted laser desorption ionization time of flight mass spectrometry, and proton nuclear magnetic resonance spectroscopy. HPLC analysis not only demonstrated the high purity of tetra-N-aryl MA PEG and the full conversion of the hydroxy groups, but also provided an effective characterization method for N-aryl maleimide-based PEG using a simple protocol, which enables us quantitative analysis of functionalized polymers with different N-aryl maleimide numbers. Furthermore, we fabricated a TetraPEG gel via Michael addition of the obtained tetra-N-aryl MA and thiol-terminated TetraPEGs. Thus, this report presents the application of tetra-N-aryl MA PEG as an effective precursor to obtain a uniform network structure and a method for its characterization; these results should provide support for the development of functional molecules, soft materials, and further functional materials based on the uniform-network-structure concept.