JOURNAL OF BIOTECHNOLOGY
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2013
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IF 3.183
Peiliang Xiao,Suoqin Zhang,Huayu Ma,Aijun Zhang,Xiaoli Lv,Liangyu Zheng
In this study, a new method was developed to prepare enantiopure caffeic acid amides by enzyme-catalyzed asymmetric aminolysis reaction. Methoxymethyl chloride (MOMCl) was first introduced as a protective and esterified reagent to obtain the MOM-protected caffeic acid MOM ester 1d . Aminolysis reaction occurred between 1d and ( R , S )-α-phenylethylamine in the presence of an immobilized lipase ( Novozym 435) from Candida antarctica . Compared with the methyl-protected caffeic acid methyl ester 1c , 1d as substrate improved the lipase-catalyzed reaction rate by 5.5-fold. After Novozym 435-catalyzed aminolysis reaction was established, we evaluated the effects of synthesis parameters on the catalytic activity and enantioselectivity of Novozym 435. A reaction conversion rate of 25.5% and an E value of >100 were achieved under the following optimum conditions: reaction solvent, anhydrous isooctane; reaction temperature, 70 °C; reaction time, 24 h; ester-to-amine substrate molar ratio, 1:40; and enzyme additive amount, 40 mg. Kinetic and thermodynamic analyses were conducted to determine the main factors affecting enantiomeric discrimination. Novozym 435 still showed 80% of its initial activity after recycling five times. Highly optically pure caffeic acid amides with an enantiomeric excess of 98.5% were finally obtained by HCl deprotection. The established enzyme-catalyzed asymmetric aminolysis method in this study might be used to prepare other caffeic acid amides.
研究领域:
有机化学
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生物催化
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药物合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
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2015
·Vol. 5
·期 55
·44571-44577
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IF 3.84
Shuang-Shuang Zhang,Kun Cui,Jin Huang,Qiao-Ling Zhao,Shao-Kui Cao,Zhi Ma
A thiol–ene “click” reaction proceeds with facile reaction conditions for complete conversion, and displays a higher tolerance to various backbones and functional groups compared with traditional coupling and functionalization strategies. Herein, well-defined α,ω-telechelic polystyrenes with trithiocarbonate and carboxyl terminal groups (PS-CTA) were firstly synthesized via reversible addition-fragmentation chain transfer (RAFT) radical polymerization. Then, the terminal thiol group was converted from the thiocarbonylthio end group of PS-CTA and subsequently reacted with n-butyl acrylate and vinyl ferrocene, respectively, through thiol–ene “click” chemistry, to achieve α,ω-telechelic polystyrenes with difunctionality. Alternatively, a facile one-pot simultaneous aminolysis and thiol–ene “click” reaction using PS-CTA and various ene-bearing compounds as reactants was found to have high efficiency in synthesizing diverse α,ω-telechelic polystyrenes with di- and tri-functionality. Various functional groups such as hydroxyl, acrylate, fluorinated acrylate, ferrocene and allyl, etc. can be successfully incorporated as terminal groups of α,ω-telechelic polystyrenes.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2019
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IF 4.745
Jian Fan,Yinshan Ye,Guochao Chu,Zhongping Zhang,Yao Fu,Yi-Ming Li,Jing Shi
Ubiquitin (Ub)-based fluorescent reagents are crucial to explore the activity of deubiquitinases (DUBs). Ub-Rho110-G is one of the preferred tools, whereas the current synthetic route is time-consuming. Here, we report a new semisynthetic strategy to produce Ub-Rho110-G through direct aminolysis of Boc-protected Ub-Mesna using bisglycyl-rhodamine 110. We also applied this strategy to synthesize active SUMO2-Rho110-G for the first time. Biochemical analysis demonstrated that semisynthetic Ub or SUMO-Rho110-G can be effectively used for the detection of the activity of DUBs or SUMO-specific enzymes.
研究领域:
生物化学
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分子生物学
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蛋白质组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Zishang Tian,Qi Zhao,Xingchen Liu,Yingxiong Wang,Jie Zhao,Yuqi Wang,Xianglin Hou
Aromatic polyimide (PI) is characterized by rigid chains and strong interchain interactions, resulting in poor solubility and non-melting of polymers, so chemical recovery of PI is challenging. Herein, ethylenediamine (EDA) was successfully used for the aminolysis of PI on the surface of flexible printed circuit boards (FPCBs). The PI can be completely degraded at 50 °C for 40 min at a revolution speed of 200 rpm, and the epoxy adhesive and flexible copper clad laminate sheet were separated by simple filtration. The degradation mechanism of PI was proposed and verified by the density functional theory (DFT) method. Intermolecular hydrogen bonding and the vicinal amino moiety of EDA play an important role in activating nucleophiles. DFT calculations show that the formation of the six-membered ring transition state is the rate-determining step during the breaking of the amide bonds. The Gibbs activation energy and the Gibbs reaction energy are 22.90 and 11.73 kcal/mol, respectively. This study provides guidance for the degradation of PI and the recovery of FPCBs.
研究领域:
材料科学
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化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2024
·
IF 5.4
Yu Zhao,Yunyun Xue,Chuyao Wang,Zihao Zhao,Ronglu Cui,Baoku Zhu
Polymethacrylate and its derivatives are widely used in food industry and biomedical applications for their plasticity, biocompatibility and optical transparency. However, susceptibility to bacterial growth on their surfaces limits their applications. In this study, linear and branched polyethyleneimine (PEI) molecules were grafted onto poly(ethyl methacrylate) (PEMA) via aminolysis using a simple one-step method to enhance the antibacterial properties of PEMA films. PEI-modified PEMA films were characterized by ATR-FTIR, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA). The modified films exhibited optimal bactericidal efficiency of 98.0% against Escherichia coli (E. coli) and over 99.9% against Staphylococcus aureus (S. aureus) . Furthermore, hydrolysis was found to contribute to anchoring PEI onto PEMA as well. Though branched PEI exhibited a higher grafting amount than the linear ones under same conditions, PEMA modified with linear PEI presented a similar or even higher antibacterial efficiency than those grafted with branched PEI. Overall, PEI-grafted PEMA films prepared with simple one-step method exhibit effective antibacterial properties and good biocompatibilities, making them promising candidates for biomedical devices and other applications.
研究领域:
材料科学
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生物医学工程
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高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2022
·
IF 4.855
Qichen Yin,Bowen Xu,Yao Qin,Jingbo Zhao,Jue Cheng,Junying Zhang
Diglycerol and dimer acid (DA) are used as precursors for the solvent- and catalyst-free synthesis of fully biobased non-isocyanate polyurethanes to replace toxic isocyanates and petroleum-based reactants. Linear polyhydroxy(amide-urethane)s (L-NIPHAUs) were synthesized via the melt aminolysis copolymerization between diglycerol dicarbonate (DGDC) and diamino-telechelicoligoamides (DAPAhs) from DA and hexamethylenediamine (HDA). By changing the DA/HDA molar ratios, the structures of DAPAhs and L-NIPHAUs were regulated in a simple and straightforward manner. Atomic force microscopy (AFM) and dynamic mechanical analysis (DMA) of the L-NIPHAUs reveal that the huge polarity difference between the hard segments (HSs) and soft segments (SSs) leads to nanophase separation. The N-amidohexylene-diglycerolbis(hydroxyurethane)-N′-amidohexylene and N-amido-hexylene-N′-amido segments form double HSs, while the bulky nonpolar DA residues serve as SSs. L-NIPHAUs also exhibit semicrystalline structures with good thermal stability evidenced by wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). They possess Tm ranging from 94 to 110 °C and tunable mechanical properties with a tensile strength of 7.3–12.1 MPa and strain at break of 311–858%. Introducing DA segments increases the hydrophobicity of L-NIPHAUs and the water contact angle and decreases the surface energy. L-NIPHAUs also show excellent solvent resistance in organic solvents, thanks to their intramolecular hydroxyurethane hydrogen bonding, three-dimensional inherent intermolecular hydrogen bonding networks, and the modification of bulky nonpolar DA SSs.
研究领域:
材料科学
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聚合物化学
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可持续材料
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生物基聚合物
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR BIOSCIENCE
·
2022
·Vol. 22
·期 9
·2200179
·
IF 5.859
Meng Wang,Jianping Zhao,Yixuan Luo,Qianyi Liang,Yisi Liu,Gang Zhong,Yin Yu,Fei Chen
Bioprinting is an emerging technology for fabricating cell-laden scaffolds with custom shapes that resemble the complex architecture of human tissues, however, construction of mechanically competent tissue grafts which mimic irregular cartilage defect is still a big challenge. Here, 3D printing of short fiber-reinforced double-network bioink to generate anatomically accurate and mechanical tunable scaffold for cartilage regeneration is reported. Poly(lactic acid) (PLLA) short fibers are first prepared by electrospinning and then fragmented through aminolysis reaction. Composite inks are constructed with an incorporation of fragmented microfibers with varied amounts and lengths into oxidized alginate bioink. The results show that incorporation of PLLA short fibers not only improves the printing fidelity but also facilitates in generating mechanically strong constructs. By incorporating gelatin methacryloyl (GelMA) and optimizing the bioink composition, the fabricated constructs with a compressive stress of ≈150 kPa even after 100 cyclical compression loading (up to 40% of strain) are achieved. In addition, this mechanically reinforced alginate/GelMA double-network bioink displays good biocompatibility and supports bone marrow-derived stromal cell chondrogenesis in vitro. Collectively, these findings demonstrate this approach is capable of printing engineered grafts which resemble the irregular size and mechanical properties of cartilage and thus hold potential for functional tissue regeneration.
研究领域:
生物打印
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组织工程
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生物材料
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再生医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）