CHEMICAL PAPERS
·
2019
·Vol. 74
·期 6
·1831-1838
·
IF 1.246
Cai Zhifeng,Zhang Caifeng,Jia Kang
A fast, simple, green and low-cost synthesis method in aqueous solution was successfully established for the preparation of l -tyrosine protected Cu nanoclusters (Cu NCs). Subsequently, the as-prepared Cu NCs was characterized by UV–vis absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It exhibited good water solubility, excellent photostability and high stability toward high concentration of sodium chloride. The Cu NCs revealed maximum excitation and emission peaks at 430 and 477 nm, respectively. Importantly, the Cu NCs showed a rapid response, a liner relation over the pH ranges from 5.02 to 11.92 and could be repeated for five consecutive cycles without fluorescence decay. Further, the as-prepared Cu NCs was applied for the determination of pH value in water samples. Simultaneously, all above features showed that l -tyrosine protected Cu NCs had great potential for sensing of pH in biological field.
✓ 已验证
产品关联
DOI
高影响因子
Biotechnology Journal
·
2024
·Vol. 19
·期 11
·e202400527
·
IF 3.2
Chaoqun Tang,Lu Zhang,Junyi Wang,Congjia Zou,Yalin Zhang,Jifeng Yuan
Saccharomyces boulardii , as a probiotic yeast, has shown great potential in regulating gut health and treating gastrointestinal diseases. Due to its unique antimicrobial and immune-regulating functions, it has become a significant subject of research in the field of probiotics. In this study, we aim to enhance the antioxidant properties of S. boulardii by producing l -ergothioneine (EGT). We first constructed a double knockout of ura3 and trp1 gene in S. boulardii to facilitate plasmid-based expressions. To further enable effective genome editing of S. boulardii , we implemented the PiggyBac system to transpose the heterologous gene expression cassettes into the chromosomes of S. boulardii . By using enhanced green fluorescent protein (EGFP) as the reporter gene, we achieved random chromosomal integration of EGFP expression cassette. By using PiggyBac transposon system, a great variety of EGT-producing strains was obtained, which is not possible for the conventional single target genome editing, and one best isolated top producer reached 17.50 mg/L EGT after 120 h cultivation. In summary, we have applied the PiggyBac transposon system to S. boulardii for the first time for genetic engineering. The engineered probiotic yeast S. boulardii has been endowed with new antioxidant properties and produces EGT. It has potential applications in developing novel therapeutics and dietary supplements for the prevention and treatment of gastrointestinal disorders.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xinru Tang,Hui Zhang,Shugui Huang,Zeyuan Deng,Chuan Sun,Xiaomao Sun,Hongyan Li
In our country, sodium selenite and sodium selenate are still used as nutritional fortifiers of selenium. Both of them are inorganic selenium, the absorption effect of human body is lower, the risk of toxic wind is larger, and it is easy to cause selenium poisoning. L-selenium-methylselenocysteine (L-SeMC) is a good source of organic selenium, which has higher biological activity and availability. At present, L-SeMC solid standard materials have not yet been developed, a high accuracy and low technical requirement method is needed to determine the purity of candidate reference materials (RMs). In this way, the key steps in the development of reference materials can be completed, and provide a source of high quality selenium supplement for people. In this paper, the candidate structures were identified and analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR). Homogeneity, together with stability were also measured by HPLC. The sample can be transported for a short period of one month under normal conditions, which can also be stored for a long time within the temperature range of −20 °C to room temperature for more than one year. The purity of L-SeMC measured by mass balance method and quantitative nuclear magnetic resonance (qNMR) was 99.5 % with an expanded uncertainty of 0.4 % (k = 2). However, differential scanning calorimetry (DSC) was not suitable for the purity determination of L-SeMC samples. This method has a wide range of applications and may provide a reference for the purity determination of other RMs.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Wen-Jun Yi,Li-Jun Li,Hao He,Zhen Hao,Bo Liu,Yi Shen,Zi-Sheng Chao
In this work, hydroxyapatite (HA) was modified by chelation of citric acid and Ca on the surface of HA, followed by the cross-linking between the hydroxyl groups of β -CD and citrate, and then the further in situ ring-opening polymerization (ROP) of l -lactide over the hydroxyl groups. The as-synthesized filler were characterized by FT-IR, XRD , TGA , and SEM. The results showed that HA was successfully modified with β -CD/citrate/PLA networks. The grafting amount of PLA-CD-HA-72 ( β -CD/citrate/PLA) is up to 15.0 wt%, while the amount of PLA is 11.7 wt%. The modification of HA greatly improves the bioactivity. Comparing the synthesized samples, PLA-CD-HA-72 shows a better cell adhesion and higher viability to the mesenchymal stem cells (MSCs) of Wistar rat. Also the osteoinductivity of the PLA-CD-HA-72 is much higher than the others. Various composites are prepared by PLLA filled with HA, CD-HA and PLA-CD-HA-72, respectively. Among these composites, tensile strength of the PLA-CD-HA-72/PLLA with 2.5 wt% of filler reached 41.7 ± 2.2 MPa, which is much higher than that of the pure PLLA (31.7 ± 1.3MPa). The addition of the PLA-CD-HA-72 significantly improves the bioactivity and mechanical properties of the composite simultaneously. This kind of composite with good biocompatibility and mechanical properties is a good candidate for promising bioresorbable material.
研究领域:
生物材料学
·
组织工程学
✓ 已验证
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 2
·175
·
IF 4.501
Anwen Fan,Ziyao Wang,Haojie Qu,Yao Nie,Yan Xu
l-amino acid deaminases (LAADs) are flavoenzymes that catalyze the stereospecific oxidative deamination ofl-amino acids into α-keto acids, which are widely used in the pharmaceutical, food, chemical, and cosmetic industries. However, the substrate specificity of available LAADs is limited, and most substrates are concentrated on several bulky or basicl-amino acids. In this study, we employed a LAAD fromProteus mirabilis(PmiLAAD) and broadened its substrate specificity using a semi-rational design strategy. Molecular docking and alanine scanning identified F96, Q278, and E417 as key residues around the substrate-binding pocket of PmiLAAD. Site-directed saturation mutagenesis identified E417 as the key site for substrate specificity expansion. Expansion of the substrate channel with mutations of E417 (E417L, E417A) improved activity toward the bulky substratel-Trp, and mutation of E417 to basic amino acids (E417K, E417H, E417R) enhanced the universal activity toward variousl-amino acid substrates. The variant PmiLAADE417Kshowed remarkable catalytic activity improvement on seven substrates (l-Ala,l-Asp,l-Ile,l-Leu,l-Phe,l-Trp, andl-Val). The catalytic efficiency improvement obtained by E417 mutation may be attributed to the expansion of the entrance channel and its electrostatic interactions. These PmiLAAD variants with a broadened substrate spectrum can extend the application potential of LAADs.Keywords:l-amino deaminase;amino acids;keto acids;substrate spectrum;substrate channel
研究领域:
生物化学
·
酶学
·
生物催化
·
代谢工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2026
·
IF 3.1
Haiyan Li,Kai Zhang,Shuai Zheng,Jing Ma,Long Zhao,Jialiang Wang,Lili Yin,Yulong Zou
Conventional poly( l -lactic acid) (PLLA) exhibits a relatively high switching temperature, limiting its on-demand actuation under mild biomedical conditions. Herein, poly( l -lactide-co-ε-caprolactone) (PLCL) was incorporated into PLLA to improve chain mobility and elasticity, and (MWCNTs–ZnO)@polydopamine nanoparticles (CZP) were introduced to construct a near-infrared (NIR)-responsive photothermal shape-memory system. The resulting PLLA/PLCL/CZP composites showed improved crystallinity, mechanical performance, and light-triggered actuation. At 1 wt% CZP, the film exhibited optimal tensile properties, with a tensile strength of 24.5 MPa and an elongation at break of 373%. Under 808 nm NIR irradiation, the composites rapidly recovered their original shape at approximately 55°C, enabling remote and mild-temperature actuation. Direct-ink-written 4D-printed scaffolds displayed high print fidelity and enhanced compressive properties, with 3 wt% CZP reaching a compressive strength of 5.2 MPa and a modulus of 0.6 MPa at 40% strain. The scaffolds showed shape-fixity ratios above 95% and recovery ratios above 80%. Biological evaluations revealed acceptable initial cell adhesion, concentration-dependent cytocompatibility, and antibacterial activity against E. coli and S. aureus . This work provides a tunable platform for NIR-triggered shape-memory actuation and programmable 4D-printed biomedical scaffolds.
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Ru Huan,Peigen Xu,Shuang Chen,Yao Dong,Chen Zhang,Dan Lu,Yilan Ouyang,Jiangyun Liu,Zhenyu Xuan,Chunshan Gui
Human organic anion transporting polypeptides (OATPs) 1B1 and 1B3 are two closely related transporters. However, OATP1B1- and 1B3-mediated estrone-3-sulfate (E3S) uptake can be differentially modulated by quercetin-3- O -α-L-arabinopyranosyl(1 → 2)-α-L-rhamnopyranoside (QAR), a compound found in some fruits such as jujube. In this study, we isolated QAR from jujube leaves and investigated the molecular mechanism underlying the activation of OATP1B3-mediated E3S uptake by QAR through functional characterization on a range of chimeric transporters derived from OATP1B3 and molecular modeling. Our findings revealed that the residue Ser545 in transmembrane domain 10 (TM10) is crucial for the activation of OATP1B3 by QAR. Kinetic analyses showed that QAR enhances OATP1B3-mediated E3S uptake at low substrate concentrations due to an increase in substrate binding affinity. Mutational analysis and molecular modeling suggested that amino acid residues with smaller side chains at position 545 are vital for the activation of OATP1B3, as bulkier residues could lead to steric collision with E3S. While QAR stimulates OATP1B3-mediated E3S uptake, it inhibits OATP1B3-mediated estradiol-17β-glucuronide/rosuvastatin uptake, indicating that the effect of QAR on OATP1B3's function is substrate-dependent. In summary, Ser545 within TM10 is essential for the activation of OATP1B3-mediated E3S uptake by QAR.
研究领域:
药理学
·
分子生物学
·
膜转运
·
药物代谢
·
天然产物
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2023
·Vol. 61
·期 19
·2303-2315
·
IF 3.4
Yipeng Chen,Jiangang Zhang,Yuesheng Zhang,Wen Cao,Xiong Liu,Jianna Bao,Xianming Zhang,Wenxing Chen
Copolymerizing poly(lactide) with other materials to obtain better comprehensive performance is a effective way to expand its application range. In this work, the precursors of hydroxyl terminated (poly(L-lactide) [PLLA], poly(ε-caprolactone) [PCL], poly(D,L-lactide) [PDLLA]) were prepared, and PLLA-PCL-PDLLA copolymer were synthesized by chain extension. The effects of the proportion and molecular weight of each component and the amount of chain extender on crystallization, phase structures, mechanical properties and thermal stabilities of PLLA-PCL-PDLLA copolymer were studied in detail. Based on small-angle X-ray scattering results, the competition between crystallization and microphase separation was regulated by the composition and chain length of prepolymers. As the ratio of PLLA/PDLLA was 1:1, crystallization was prevailing and no obvious peak was observed in SAXS pattern. The tensile test results showed that as the ratio of PLLA/PDLLA increased from 1:1 to 1:5, the elongation at break of the copolymer changed from 1.8% to 343%. By using shorter length of PCL and PLLA segments in chain extension, improvement in strength and flexibility were obtained due to moderate degree of crystallization and microphase separation. This work used biodegradable materials to prepare extraordinary toughness copolymers without losing the biocompatibility, which may provide a feasible method for obtaining high toughness and biodegradable PLA-based materials. Graphical
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Xue Xia,Yun Zhai,Heping Cui,Han Zhang,Khizar Hayat,Xiaoming Zhang,Chi-Tang Ho
The Amadori compound of glucose and l -alanyl- l -glutamine (Ala-Gln-ARP) was prepared and characterized by UPLC-MS/MS and NMR. There were no pyrazines produced by heated Ala-Gln-ARP alone due to the asynchronicity of regenerated l -alanyl- l -glutamine and α -dicarbonyl compounds. High temperature (130 °C) and long reaction time could facilitate the 2,5-dimethylpyrazine formation at a small concentration (33.4 ± 3.47 μg/L). The exogenous amino substrates would lower the formation temperature of pyrazines and make it to be generated effectively. Extra supplied l -alanyl- l -glutamine could generate 2,5-dimethylpyrazine at 110 °C, while higher temperature of 140 °C could strengthen the formation of 2,5-dimethylpyrazine (793 ± 119 μg/L) and stimulate the generation of other pyrazines, including methylpyrazine and 2,6-dimethylpyrazine. The exogenous alanine, glutamic acid, and glutamine was also beneficial to enhance the pyrazines formation, especially the glutamic acid. Furthermore, alkaline pH of thermal reaction made pyrazines increase significantly than in neutral medium and further enriched their species such as unsubstituted pyrazine and trimethylpyrazine.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Mengna Li,Weiwang Qiu,Qian Wang,Na Li,Xueli Wang,Jianyong Yu,Xiaoran Li,Faxue Li,Dequn Wu
Bacterial biofilm often exists in non-healing wounds, and if it cannot be removed promptly, further complications will occur. Bioactive biodegradable wound dressings with the ability to kill bacteria, eliminate biofilms and prevent infections are expected to solve this problem. This study reports the development of a new l -tryptophan and l -phenylalanine-based poly(ester urea)s which aims at fabricating electrospun composite mat with nitric oxide releasing capability for infected wound treatment. The designed l -tryptophan and l -phenylalanine based poly(ester urea)s owned adjustable degradability and good biocompatibility , indicating it could be an ideal biomaterial for wound repair. The electrospun mat was an ideal cargo for steady and continuous delivery with a total concentration of 0.8 μmol/L of NO. The mats showed obvious advantages in killing the bacteria and destructing biofilms. Such electrospun mats could promote proliferation and improve collagen deposition as well as accelerate wound healing. It suggests that the fabric mats can act as a suitable candidate in infected-wound care applications.
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2022
·
IF 7.088
Yinglu Wang,Lile Pan,Li Li,Ruipin Cao,Qian Zheng,Zuxian Xu,Chang-Jer Wu,Hu Zhu
Pseudomonas aeruginosa infections pose a huge threat to cystic fibrosis patients, as well as those suffering from immunodeficiency. Antimicrobial resistance , especially multi-drug resistance, due to its ability to aggregate the compact biofilm, makes it more inefficient to treat this pathogen with traditional antibiotics. Biofilm and quorum sensing (QS) have become the alternative targets for treating P. aeruginosa infections. Previously, a cyclic dipeptide cyclo( L -Trp- L -Ser) has been identified as a QS inhibitor of P. aeruginosa . On the other hand, some monosaccharides have been proved lectin-targeting behavior and to mediate biofilm formation and adhesion of P. aeruginosa . We constructed novel cyclic dipeptide-carbohydrate conjugates as a low molecular weight dual-functional QS inhibitor, which can not only enhance its anti -QS activity but also enable good anti -biofilm and anti-adhesion ability. The IC 50 of galactosylated c(WS) on biofilm formation and glass adhesion was 1/6 and 1/4 of that of the unmodified cyclic dipeptide, respectively. And the ability to eliminate the preformed biofilm was increased 10-fold. Furthermore, the carbohydrate conjugates can increase the germicidal efficiency of clinical antibiotic azithromycin when used synergistically. Our results provide a novel scaffold for developing anti-virulence adjuvants when taken with clinical antibiotics.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOORGANIC & MEDICINAL CHEMISTRY
·
2017
·
IF 2.93
Xiaoyan Han,Yifan Zhong,Guan Zhou,Hui Qi,Shengbin Li,Qiang Ding,Zhenming Liu,Yali Song,Xiaoqiang Qiao
A new series of thirteen N -(carbobenzyloxy)- l -phenylalanine and N -(carbobenzyloxy)- l -aspartic acid- β -benzyl ester compounds were synthesized and evaluated for antiproliferative activity against four different human cancer cell lines: cervical cancer (HeLa), lung cancer (A549), gastric cancer (MGC-803) and breast cancer (MCF-7) as well as topoisomerase I and IIα inhibitory activity. Compounds ( 5a , 5b , 5e , 8a , 8b ) showed significant antiproliferative activity with low IC 50 values against the four cancer cell lines. Equally, compounds 5a , 5b , 5e , 5f , 8a , 8d , 8e and 8f showed topoisomerase IIα inhibitory activity at 100 μM with 5b , 5e , 8f exhibiting potential topoisomerase IIα inhibitory activity compared to positive control at 100 μM and 20 μM, respectively. Conversely compounds 5e , 5f , 5g and 8a showed weaker topoisomerase I inhibitory activity compared to positive control at 100 μM. Compound 5b exhibited the most potent topoisomerase IIα inhibitory activity at low concentration and better antiproliferative activity against the four human cancer cell lines. The molecular interactions between compounds 5a – 5g , 8a – 8f and the topoisomerase IIα (PDB ID: 1ZXM ) were further investigated through molecular docking. The results indicated that these compounds could serve as promising leads for further optimization as novel antitumor agents.
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）