Analytical Methods
·
2018
·Vol. 10
·期 19
·2263-2271
·
IF 2.073
Yunmei Huang,Jidong Yang,Haiyan Yuan,Yuan Guo,Xiaoqing Zeng,Jiawei Cheng,Yuhui Zhang
D-Penicillamine (D-PA), as the dominant enantiomer, is usually used in many clinical drugs, but the other enantiomer, L-penicillamine (L-PA) is a toxic enantiomer. Therefore, it is of great significance to analyze and detect L-PA in biomedical or environmental samples. CdTe quantum dots (CdTe QDs) were modified by N-acetyl-L-cysteine (NALC) as novel fluorescent probes and were successfully utilized for the determination of L-penicillamine. The fluorescence of the CdTe QDs decreased significantly in the presence of cupric ions (Cu2+) due to the binding of Cu2+ to NALC on the surface of the CdTe QDs, but the addition of L-PA immediately resulted in efficient fluorescence recovery of the modulated CdTe QDs. The experimental results showed that the pH of the buffer solution and the concentration of Cu2+ affected the fluorescence intensity upon adding L-PA. Under the optimum conditions, the recovered fluorescence intensity was linearly proportional to the increasing L-PA concentration in the range of 2 × 10−7 to 4 × 10−6 mol L−1, with correlation coefficient R2 = 0.9980. So, a new, simple and rapid method for the determination of L-PA has been developed and its potential has been demonstrated in human serum samples and environmental samples with satisfactory results.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 38
·57823-57834
·
IF 5.19
Yi Shuang,Bao Binqin,Song Weifeng,Liu MuDdan
In this study, L-methionine and nano-Fe 3 O 4 were encapsulated and cured on sodium alginate by the ionic cross-linking method to form magnetic composite gel spheres (SML) as an adsorbent for the removal of Zn(II) from water. The influence of adsorbent dosages, pH, reaction time, and initial ion concentration on the ability of the gel spheres to adsorb Zn(II) was investigated, and the adsorption mechanism was identified. The experimental results showed that under the optimum conditions (pH = 5, t = 60 min, dosage of SML is 0.7 g·L −1 ), the maximum amount of Zn(II) adsorbed by the adsorbent gel spheres reached 86.84 mgˑg −1 . The reaction process of this adsorbent fits well with the Langmuir and pseudo-second-order kinetic models and is a heat absorption reaction. The adsorbent would preferentially adsorb Pb(II), and the adsorption efficiency of Zn(II) decreased when the concentration of interfering ions increased in the coexistence system. Further mechanistic research showed that this magnetic composite adsorbent is a mesoporous material with superior adsorption performance, and the amino and carboxyl groups on it react with Zn(II) via ligand chelation; the ion exchange effect of Ca(II) also plays a role. The adsorption amount of Zn(II) was maintained at a higher level after 5 cycles, and the loss of Fe was approximately 0.2%. In summary, SML, which is environmentally friendly, efficient, and recyclable, is an ideal adsorbent for Zn(II) removal.
研究领域:
环境科学
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材料科学
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2011
·Vol. 47
·期 2
·711-719
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IF 1.859
Jin Quan,Zheng Mingtao,Wu Yongjian,Xie Chunlin,Xiao Yong,Liu Yingliang
A facile approach was developed for synthesis of carbon hollow microspheres (CHM) via carbonization of the hollow polymer microspheres prepared from polymerization in the presence of l -lysine acted as in situ template. The physical and chemical structures of the samples were investigated by X-ray powder diffraction, Raman spectrum, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM and TEM images show that the products consist of a large scale of monodisperse CHM with a size of about 1.1–1.3 μm. Furthermore, the resulting CHMs possess a surface area of 559 m 2 g −1 and a pore volume of 0.27 cm 3 g −1 . The morphology and the size of the as-obtained samples can be controlled by the polymerization temperature, polymerization time, and the dosage of l -lysine. Moreover, a possible formation mechanism of the CHM has been put forward according to the experimental data available.
研究领域:
材料科学
·
化学工程
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高影响因子
Frontiers in Pharmacology
·
2025
·
IF 4.8
Yeshi Yin,Changhui Zhao,Qin Xiang,Zongyan Li,Xiu Liu,Changhui Hu,Rong Yu
Background: Animal and cell studies have demonstrated that Zuogui-Jiangtang-Yishen decoction (ZGJTYS) has a favorable effect on the treatment of diabetic kidney disease (DKD). Our previous clinical research also showed that ZGJTYS prevents DKD in a manner similar to that of benazepril. Nevertheless, the interactions between ZGJTYS and the human gut microbiota require further investigation, particularly its interference in the intestinal flora response to food ingredients that may increase DKD risk, such as L-α-phosphatidylcholine and L-tyrosine.Objective: The aim of this study was to evaluate the regulatory function of ZGJTYS on human gut microbiota and explore the effect of ZGJTYS on the intestinal flora response to L-α-phosphatidylcholine and L-tyrosine.Methods: ZGJTYS was prescribed from the First Affiliated Hospital of Hunan University of Chinese Medicine. High-throughput sequencing of bacterial 16S RNA genes and fungal internal transcribed spacer (ITS) sequences was used for intestinal flora analysis. An in vitro gut microbiota simulation model was used to investigate the effect of ZGJTYS on the intestinal flora’s response to L-α-phosphatidylcholine and L-tyrosine. Ultra-high-performance liquid chromatography and mass spectrometry were used for non-targeted metabolomics analysis.Results: Compared to the control group, the microbial diversity of DKD was significantly reduced by ZGJTYS treatment; three bacterial genera, including Parabacterioids, were significantly higher; eight bacterial genera, including Prevotella_9, and the linoleic acid content were significantly lower. A receiver operating characteristic curve analysis using Parabacterioids and Prevotella_9 showed an area under the curve greater than 0.75, indicating good predictive performance. ZGJTYS intervention restored some of the normal bacterial genera, such as Rickettsia and Metarhizium, which were regulated by L-α-phosphatidylcholine and L-tyrosine. Furthermore, ZGJTYS effectively restored several significantly different Kyoto Encyclopedia of Genes and Genomes metabolic pathways related to immunity and disease to normal, such as efferocytosis and tryptophan metabolism.Conclusion: ZGJTYS was found to effectively restore the microbiota that were altered by L-α-phosphatidylcholine and L-tyrosine to normal, along with their metabolites. However, the mechanism by which ZGJTYS exerts its preventive and therapeutic effects on DKD through the gut microbiota still requires further study.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Tao Sun,Ying Li,Yangyang Wang,Qing Yang,Jiahui Du,Jian Hu,Sarula,Tungalag Dong,Xueyan Yun
Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid- co -butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 °C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.
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PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2021
·
IF 4.291
Mengyang Lu,Qi Zhang,Zhicheng Zhang,Xueqi Wang,Bing Yan,Yongqian Wang
There are a variety of biological ion channels in organisms, which change under the influence of the environment and regulate the material transport at both ends of the biofilm. Inspired by this, a large number of studies on biomimetic nanochannels have been carried out. The lack of selective specificity and detection sensitivity are considered as main drawbacks in biomimetic nanochannels, and the combination of nanomaterials and biomimetic nanochannels is one of solutions. In this research, a confined self-assembly system composed of anodic aluminum oxide (AAO) templates and ZnS nanoparticles was fabricated by a negative pressure filtration method. Besides, L- Cysteine ( L- Cys) and D- Cysteine ( D- Cys) were modified into the confined self-assembly system by ultraviolet irradiation to enhance the sensitivity for biological molecules response. The confined self-assembly system showed specific selection of L- Cys and high sensitivity to biological molecules response. This work not only synthesized ZnS nanoparticles in biomimetic nanochannels controllably but also provided a new way of studying how to utilize nanomaterials to improve the response sensitivity of biomolecules in biomimetic nanochannels.
研究领域:
纳米技术
·
仿生学
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材料科学
·
生物传感
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高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 39
·e04041
·
IF 2
Xintong Huan,Mingxin Jiang,Can Gao,Meixuan Liu,Xiaohuan Sun,Jie Han
Enantioselective sensing of 3,4-dihydroxyphenylalanine (DOPA) enantiomers is highly significant in biology and pharmaceutics, yet developing sensors with high enantioselectivity and analyte-specific output signals remains challenging. In this study, we constructed an L-cysteine (Cys)-Fe 2+ nanozyme through self-assembly of L-Cys and Fe 2+ . This nanozyme exhibited efficient peroxidase-like activity, with a K cat value of 2.1 × 10 −9 M·s −1 ·µg −1 toward 3,3“,5,5”-tetramethylbenzidine (TMB). When using D/L-DOPA as a substrate, we observed higher catalytic efficiency for L-DOPA than for D-DOPA, with a selectivity factor of 1.6. Mechanistic studies revealed that this enantioselectivity originates from the preferential adsorption of D-DOPA over L-DOPA on the nanozyme surface, which impedes the oxidation kinetics by blocking substrate access to the active sites. These chirality-specific changes induced in UV–vis absorption during catalysis enabled the establishment of analyte-specific calibration curves for D-DOPA, L-DOPA, and enantiomeric compositions in D/L-DOPA mixtures, achieving highly enantioselective sensing of DOPA enantiomers. This sensing platform demonstrated high sensitivity (limit of detection: 3.6 µM), excellent selectivity, and significant potential for practical applications. These findings provide novel insights for developing superior enantioselective sensors with high accuracy. Graphical Through the self-assembly of L-cysteine (Cys) and Fe 2+ , we constructed a novel chiral L-Cys-Fe 2+ nanozyme. This nanozyme achieved high enantioselectivity in discriminating 3,4-dihydroxy-D/L-phenylalanine (D/L-DOPA) due to enantioselective adsorption. This approach constitutes a promising new platform for reliable enantiomer detection.
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CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Chenghao Fu,Wenjuan Dai,Aoxiang Liu,Yongxuan Liu,Qingshou Yao,Linghui Kong,Bo Yu,Xiuwen Wang,Jiayang Qin
ε-Poly- l -lysine (ε-PL), typically comprising 25–35 l -lysine residues, is a natural homopolymer with potent antibacterial properties. Its wider use is limited by two key challenges: precise control over peptide chain length and low production yields of low-molecular-weight (low-MW) ε-PL variants. In this study, we addressed these constraints by combining genetic engineering, carbon source modulation, and fermentation optimisation, enabling the targeted production of four well-characterised ε-PL variants. Multiple genetically engineered strains of Streptomyces albulus were developed and evaluated for ε-PL chain distribution. Particularly, S. albulus CICC-Pls880-LysP— co -overexpression of a mutated polylysine synthetase (Pls S880I) and a lysine importer (LysP)—produced ε-PL with chain lengths between 23 and 31 residues when grown in glucose-enriched fermentation broth and between 19 and 30 residues in glycerol-enriched broth. By contrast, the parental strain CICC-Pls-LysP yielded longer polymers (28–34 residues in glucose and 25–32 in glycerol), confirming the effectiveness of enzyme engineering in modulating chain length. Subsequent statistical optimisation of the fermentation medium, coupled with fed-batch cultivation strategies, enabled all four ε-PL variants (28–34, 25–32, 23–31, and 19–30 mer) to achieve production titres exceeding 50 g/L. Notably, supplementing l -lysine during fermentation significantly enhanced the yield of the low-MW variant (23–31 mer), reaching to 75.35 g/L. Antibacterial activity assays revealed a distinct correlation between chain length and efficacy, providing valuable insights into the structure–function relationships of ε-PL. This method, established for selectively synthesising ε-PL variants, overcomes historical yield bottlenecks for low-MW ε-PL, thereby broadening the applications of ε-PL.
研究领域:
生物技术
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微生物发酵
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合成生物学
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高分子科学
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应用微生物学
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高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Yating Zheng,Chunxing Pan,Zejun Zhang,Wenqian Luo,Xiaoxin Liang,Yaohui Shi,Linjie Liang,Xi Zheng,Lanyue Zhang,Zhiyun Du
Objective Essential oil derived from the rhizome of Curcumin longa (CL-EO) has marked anti-inflammatory, antioxidant, antimicrobial, anticancer, and antiviral activities. However, its effect on photodamaged skin has not yet been evaluated. In this study, the anti-skin photoaging activity of CL-EO was determined by performing an ultraviolet B (UVB)-induced skin aging assay. Methods CL-EO was extracted by hydrodistillation and characterized using gas chromatography–mass spectrometry. The anti-skin aging effect was determined by topically applying 150 μl of CL-EO diluted to 1, 5, and 10% with ethanol to the dorsal area of UVB-irradiated nude mice every day except on Sunday for 8 weeks. Histological and immunohistochemical analyses were performed. Results In total, 56 compounds, which accounted for 94.36% of the contents of CL-EO, were detected. The major compounds in CL-EO were ar-turmerone (36.04%), curlone (8.78%), β-turmerone (7.05%), 8,9-dehydro-9-formyl-cycloisolongifolene (5.69%), β-sesquiphellandrene (5.39%), germacrone (4.51%), ar-curcumene (2.19%), α-himachalene (2.14%), and ledane (2.13%). Hematoxylin and eosin staining of tissue sections revealed that CL-EO decreased epidermal skin thickness. Immunohistochemistry showed that CL-EO inhibited interleukin-1β and tumor necrosis factor-α expression. Conclusions Thus, CL-EO can reduce cutaneous photoaging in a UVB-irradiated nude mouse model. Therefore, CL-EO could be used in the formulation of skin care and functional cosmetic products.
研究领域:
药理学
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皮肤科学
·
植物化学
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高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Yuanyuan Liu,Xiyu Wang,Caihui Luo,Jie Cai,Yuting Li,Ying Cao,Yuanli Cai
Salt bridges are predominant in protein construction and stabilization, yet largely unexplored for polymer nanoparticle synthesis. We herein report the use of l-histidine salt bridges to drive monomer preassembly and two-dimensional electrostatic self-assembly in aqueous photo-RAFT polymerization. l-histidine salt bridges drive the monomer clustering nucleation, complex coacervation, and Coulombic stabilization, leading to the 2 nm ultrasmall clusters and coacervate droplets. Homopolymerization leads to a precision two-dimensional electrostatic self-assembly via a droplet-monolayer-multilayer transition, i.e., salt-bridged homo-polymerization-induced self-assembly (PISA). Block copolymerization does not disturb the “salt-bridged homo-PISA” mechanism. Enhanced Coulombic repulsion via seeded polymerization of charged monomers using as-achieved multilayer lamellae (seeds) yields supercharged 5 nm ultrathin monolayer lamellae with high colloidal stability upon dilution, salting, and long-term storage, urgently needed for bioapplications. This work opens up a new avenue to use amino acid salt bridges for PISA synthesis of biologically important, yet hitherto inaccessible, salt-resistant ultrathin polyelectrolyte complex nanomaterials.
研究领域:
聚合物化学
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材料科学
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生物医学工程
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高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2023
·Vol. 89
·期 4
·
IF 4.4
Xuling Jiang,Wanqing Wei,Yaozhong Cui,Wei Song,Yingying Li,Xiulai Chen,Cong Gao,Jia Liu,Liang Guo,Liming Liu,Jing Wu
Pyrrolidone is a high value-added monomer and an important active drug intermediate. However, the efficient enzymatic synthesis of pyrrolidone remains a challenge. Here, we developed and reconstructed a three-enzyme cascade pathway using Escherichia coli BL21(DE3) for the production of pyrrolidone from l-glutamate (l-Glu). The carnitine-CoA ligase from Escherichia coli (EcCaiC) at a low expression level and with a low activity is regarded as the rate-limiting enzyme. Here, we obtained the best EcCaiCF380M/N430D double mutant with a kcat/Km value 1.5 times higher than that of the wild type via mechanism-based protein engineering. For this, we (i) eliminated the steric hindrance of the loop ring to improve the precatalytic conformation of the adenylation intermediate and (ii) fixed the hinge region to stabilize the closed conformation of the enzyme. Furthermore, ribosome-binding site (RBS) optimization led to an increase in the expression level of EcCaiCF380M/N430D, which was then cloned into the plasmid pET-EcCaiCF380M/N430D-DegoPPK2. Finally, under optimal induction and transformation conditions, 16.62 g/L of pyrrolidone was generated from 30 g/L l-Glu (batch feeding) within 24 h with a molar conversion rate of 95.2% and the highest productivity ever obtained, to our knowledge (0.69 g/L/h). Our findings demonstrate a strategy that is potentially attractive for the industrial production of pyrrolidone.IMPORTANCE This study developed a three-enzyme cascade pathway for the production of pyrrolidone from l-Glu. The catalytic efficiency of carnitine CoA ligase from Escherichia coli (EcCaiC) was improved by mechanism-based protein engineering, and the titer of pyrrolidone was further increased by ribosome-binding site (RBS), induction conditions, and conversion conditions optimization. Finally, we efficiently produced pyrrolidone by one pot in vivo with 95.2% conversion and 0.69 g/L/h productivity. Our study provides a new possibility for the industrial production of enzymatic synthesis of pyrrolidone.
研究领域:
生物化学
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合成生物学
·
酶工程
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PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2021
·
IF 0
Tien Hieu Vu,Van Huan Bui,Ngoc Thang Nguyen
The green synthesis of silver nanoparticles (AgNPs) using herbal plants has gained much attention due to their potential widespread applications, especially in biomedical application to control pathogenic microbes. The aim of our study was to evaluate the antibacterial properties of synthesized AgNPs using aqueous leaf extract of Piper betle L., an important medicinal plant. The AgNPs were identified by UV-Visible spectrometry (UV-Vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FT-IR). The presence of surface plasmon band around 420-460 nm indicated AgNPs formation. Spherical nature, unique size-distribution and crystal structure of the AgNPs with diameter around 10-20 nm were affirmed by TEM and XRD analyses. The FTIR measurements showed the presence of bioactive compounds in the extract responsible for the efficient reduction of silver ions and stabilization of the AgNPs. The results from the antimicrobial assays suggested that the biosynthesized AgNPs were potent against pathogenic bacteria including Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.
研究领域:
纳米生物学
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药用植物学
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微生物学
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