CARBOHYDRATE POLYMERS
·
2011
·
IF 3.463
Yuanfeng Wang,Fangfang Mao,Xinlin Wei
The chemical characterization and antioxidant activities of tea leaves polysaccharides (TLPS), tea seed polysaccharide (TSPS), tea flower polysaccharide (TFPS) were investigated after isolated from the leaves, flowers and seeds of camellia sinensis. Results indicated that TLPS, TFPS and TSPS were all composed of Rha, Ara, Gal, Glu, Xyl, GalA and GluA, besides, TLPS was also contained Man and Rib, and TFPS was also contained Man. The molecular weight distribution of TLPS, TFPS and TSPS ranged from 3.67 × 10 3 to 7.58 × 10 5 Da, 2.56 × 10 3 to 1.46 × 10 6 Da and 3.66 × 10 3 to 9.61 × 10 5 Da, respectively. Antioxidant activity tests revealed that TLPS, TFPS and TSPS exhibited strong antioxidation in a concentration-dependent manner. Furthermore, TLPS and TFPS had higher antioxidant activity than TSPS. The nature of monosaccharide and the higher molecular weight in TLPS and TFPS molecules probably contribute to the activities.
研究领域:
食品科学
·
药理学
·
植物学
✓ 已验证
DOI
高影响因子
Journal of Zhejiang University-SCIENCE B
·
2017
·
IF 1.676
Ju-qing Huang,Rui-ting Qi,Mei-rong Pang,Cong Liu,Guang-yu Li,Ying Zhang
Bamboo shavings, the outer or intermediate layer of bamboo stems, are the bulk of by-products produced in bamboo processing. In this study we investigated the isolation, chemical characterization, and immunostimulatory activity in vitro of the hemicelluloses from bamboo shavings. Shavings were first pretreated by steam explosion. The optimal pretreatment was found to be steam explosion at 2.2 MPa for 1 min. Following this pretreatment, the yield of hemicelluloses reached (2.05±0.22)% (based on the dry dewaxed raw materials), which was 5.7-fold higher than that of untreated samples. Bamboo-shavings hemicellulose (BSH) was then prepared by hot water extraction and ethanol precipitation from the steam-exploded shavings. Purification of BSH by anion-exchange chromatography of diethylaminoethanol (DEAE)-sepharose Fast Flow resulted in a neutral fraction (BSH-1, purity of 95.3%, yield of 1.06%) and an acidic fraction (BSH-2, purity of 92.5%, yield of 0.79%). The weight-average molecular weights ( M w ) of BSH-1 and BSH-2 were 12 800 and 11 300 g/mol, respectively. Chemical and structural analyses by Fourier transform infrared spectroscopy (FT-IR), 1D ( 1 H and 13 C) and 2D (heteronuclear single quantum correlation (HSQC)) nuclear magnetic resonance (NMR) spectra revealed that BSH-1 was O -acetylated-arabinoxylan and BSH-2 was O -acetylated-(4- O -methylglucurono)-arabinoxylan. BSH-1 had a higher content of acetyl groups than BSH-2. For the immunomodulatory activity in vitro, BSH and BSH-2 significantly stimulated mouse splenocyte proliferation while BSH-1 had no effect; BSH, BSH-1, and BSH-2 markedly enhanced the phagocytosis activity and nitric oxide production of the murine macrophage RAW264.7 in a dose-dependent manner. Our results suggest that the water-extractable hemicelluloses from steam-exploded bamboo shavings are naturally acetylated and have immunostimulatory activity.
研究领域:
生物化学
·
免疫学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2023
·
IF 3
Yue-Hua Chen,Si-Yu Li,Dan Wang,Wei Yuan,Kun Xu,Jia-Wei Wang,Ting-Guo Kang,Hui Zhang
Marsdenia tenacissima is a traditional Chinese medicinal plant used for treating cancer, and its main medicinal part is the stem. Considering the resource shortage of M. tenacissima , it is of great significance to improve its utilization efficiency. Steroids and caffeoylquinic acids, the two main components of M. tenacissima , are composed of several basic structures. Based on this rule, a novel strategy of combinatorics-based chemical characterization was proposed to analyze the constituents of roots, stems and leaves of M. tenacissima . Combinatorics was used to generate a compound library for structure alignment, which has the advantages of wide coverage and high specificity. Steroids are composed of four basic parts: core skeleton (C), substituent at position 11 (A), substituent at position 12 (B) and sugar moiety (S). Based on combinatorics, a compound library consisting of 1080 steroids was generated. Diagnostic neutral loss has been used to effectively predict the substituents at position 11 and 12 of steroids, including acetyl, 2-methylpropionyl, tigloyl, 2-methylbutyryl and benzoyl. As a result, 131, 131 and 99 components were detected from the roots, stems and leaves of M. tenacissima , respectively. Principal component analysis (PCA) was used to analyze the differences of roots, stems and leaves, and orthogonal partial least squares-discriminant analysis (OPLS-DA) was further applied to find differential components. Tenacissoside H, a critical indicator component for quality evaluation of the stem, has been proved to be a differential component between roots and stems. Notably, the relative content of tenacissoside H in the roots was significantly higher than that in the stems. The bioactivity comparison showed that roots, stems and leaves of M. tenacissima had similar scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. However, their α-glucosidase inhibitory activity was ranked as leaves > stems > roots. Therefore, besides stems, the other parts of M. tenacissima have potential medicinal value. This study not only helps to develop the resource of M. tenacissima , but also provides a paradigm for the research of other similar medicinal plants.
研究领域:
药用植物学
·
分析化学
·
中药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Tingting Zhang,Yanling Yang,Xing Li,Nan Wang,Hang Li,Peng Du,Haikuan Yu,Siyang Ji,ZhiweiZhou
In this study, an experimental study aimed at optimizing the factors affecting the regeneration amount of 4-chlorophenol (4-CP) from spent powdered activated carbon (PAC) is presented. For this response surface methodology (RSM) with Box-Behnken design was applied, which identified four variables (acoustic density, NaOH concentration, spent PAC dosage and ethanol concentration) in batch experiments. The physicochemical characteristics of the regenerated PAC under the optimal desorption condition was evaluated using thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and scanning electron microscopy, as compared with the virgin and spent PACs. Among the four variables, acoustic density and ethanol concentration (v/v, %) had stronger effect on the 4-CP desorption (p < 0.001). The predicted optimal 4-CP desorbing amount was 97.43 mg g –1 , and this matched well the observed performance of (96.94 ± 0.70) mg g –1 , obtained by acoustic density of 0.36 W mL –1 , NaOH concentration of 0.10 mol L –1 , spent PAC dosage of 0.93 g L –1 and ethanol concentration (v/v) of 24%. The result of thermogravimetric pyrolysis profiles of regenerated PAC confirmed that the adsorption behavior of 4-CP exhibited a chemisorption feature and desorption process was dominated by chemical reaction. Analysis of FTIR, pore structure and BET surface area demonstrated that ultrasound mainly acted on the surface functionalities, macro-pore and meso-pore structure of PAC. Additionally, the SEM images indicated that cavitation effect affected the surface roughness and surface cavities of PAC. The results here provided an insight into the application of ultrasound to regenerate saturated PAC with 4-CP.
研究领域:
环境工程
·
吸附与再生
·
水处理技术
·
物理化学方法
·
环境污染控制
✓ 已验证
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Qu Jiang,Sihong Wang,Ziyang Sheng,Chaoran Zhang,Haoyue Zhang,Haofei Wu,Pan Liu,Peng Fan,Fang Song
Traditional electrochemical redox assessments offer insights into material properties for charge storage and catalytic kinetics but often fail to link these to specific surfaces, obscuring the structure–performance relationship. Here, we reveal the facet-dependent electrochemical redox behaviors and their connection to oxygen evolution reaction (OER) catalysis using Co(OH)2 nanosheets and nanorods as models. By correlating redox charge storage capacity and kinetics with distinct exposed surfaces, we uncover diffusion-controlled redox processes on the basal surface and non-diffusion-controlled behavior on the lateral surface and further utilize the distinct redox charging kinetics to differentiate the two. Integrated microscopic, spectroscopic, and electrochemical analyses reveal redox-active regions with a thickness of ∼12 Co atoms on the lateral surface and 85% Co atom equivalent extension on the basal surface, yielding benchmark redox charge capabilities of 3.04 mC cm–2 for the lateral surface and 0.35 mC cm–2 for the basal surface. By linking the surface-specific redox charges to catalytic performances, we find that the catalytic activity correlates with the lateral surface exclusively, corresponding well with previous demonstration of the catalytic reactivity of the lateral surface and the inertness of the basal surface. This work clarifies dynamic, heterogeneous, and anisotropic redox behaviors and offers a fast, reliable, and simplified method to probe the facet-specific redox and catalytically active surfaces electrochemically.
研究领域:
电化学
·
材料科学
·
催化化学
·
纳米材料
·
表面科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2014
·Vol. 6
·期 19
·7801-7808
·
IF 1.938
Kunjing Li,Yinfeng Li,Lingxi Yang,Lu Wang,Baoxian Ye
A sensitive voltammetric sensor, a graphene-modified glassy carbon electrode (GR/GCE), for the detection of trace amounts of curcumin is proposed. The GR/GCE was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of curcumin at the GR/GCE was investigated by CV and liner sweep voltammetry (LSV). The reaction mechanisms of curcumin on the GR/GCE were also investigated and discussed systematically. In addition, the currents measured by LSV presented a good linear relationship with curcumin concentrations in the range of 5.0 × 10−8 to 3.0 × 10−6 mol L−1, with a low detection limit of 3.0 × 10−8 mol L−1. The method was also applied successfully to detect curcumin in a Curcuma longa L. sample with high selectivity and accuracy, as well as good recovery.
研究领域:
分析化学
·
电化学
·
药物分析
·
天然产物化学
·
生物传感器
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Keng-Qiang Zhong,Le-Yi Chen,Meng Li,Xing Chen,Xing Lu,Yu-Chen Yang,Hao-Wen He,Bao-Hua Jing,Hong-Guo Zhang,Jia Yan,Yi-Feng Zhang
Efficient and eco-friendly purification of uranium-bearing wastewater is essential for the safety of the water ecosystem and sustainable development of the nuclear energy industry. Although bioelectrochemical systems show great prospect for uranium bioremediation, the uranium removal efficiency is often limited by the ineffective quality of biofilm formation and unsatisfactory electron transfer. Here we propose a rapid self-assembled biofilm formation strategy to construct a sulfate-reducing bacteria-carbon cloth biohybrid cathode (CF-PQ7) modified with cotton-derived carbon fibers for the simultaneous removal of uranium and sulfate. Electrochemical characterizations show that pyridinic-N and graphitic-N species in highly conductive carbon fibers promote electron transfer at the uranium reduction interface between the biofilm and the electrode by optimized electron transfer dynamics. Moreover, spectroscopic and biofilm analysis demonstrate that a rapid self-assembled electroactive biofilm is formed by coating polyquaternium-7 in situ on the microbial surface to improve the viability and detoxification capacity of the biofilm. Impressively, CF-PQ7 biocathode demonstrates uranium removal efficiency of 93.8%, achieving a 7.8-fold and 3.9-fold increase compared to sulfate-reducing bacteria and bare electrode, respectively, indicating its promising potential for uranium bioremediation. This work provides a safe, clean, and sustainable uranium reduction strategy and puts forward new perspectives and opportunities for uranium-bearing wastewater remediation.
研究领域:
环境生物技术
·
电化学
·
核环境科学
·
生物杂化材料
·
废水修复
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Lecai Wang,Li Li,Xiaoxiao Zhang,Feng Wu,Renjie Chen
Compound-hierarchical-sphere-structured LiNi0.5Co0.2Mn0.3O2 was synthesized to improve the electrochemical performance of this material in lithium-ion battery cathodes. The product was found to have a large specific surface area, good electron and ion conductivities, a stable interface, and a robust nano/microhierarchical structure, all of which improved the rate capability, capacity, and cycling stability of this material. When this material was cycled between 3.0 and 4.3 V, a high discharge capacity of 180.8 mA h g–1 was obtained at 0.2C with 94.0% capacity retention after 100 cycles. In addition, a superior discharge capacity of 148.9 mA h g–1 was observed at a high current density of 1600 mA g–1. This compound-hierarchical-sphere LiNi0.5Co0.2Mn0.3O2 is readily prepared using our ternary coprecipitation method. We also propose an effector unit theory to explain the enhanced cycling stability of this substance and believe that the present results will assist in the design of cathode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Huiyuan Li,Jiabin You,Xiaojing Cheng,Xiaohui Yan,Shuiyun Shen,Junliang Zhang
Pt alloy electrocatalysts (e.g., Pt 3 Co) for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) have attracted a great deal of interest from worldwide researchers in past decades, due to the excellent ORR activity and cost-effective properties. However, the long period operation would yield sever dissolution of the non-precious metal which effects the ionomer microstructure, thus leading to significantly decreased ORR activity of catalyst and aggravated of the oxygen transport resistance in cathode catalyst layers (CCLs), especially the local oxygen transport resistance caused by the ultrathin ionomer film covering on catalyst surface. Herein, in this paper, the effects of Co 2+ contamination on structure of ionomer films and the corresponding local oxygen transport behavior in CCLs are explored via physicochemical characterizations and molecular dynamics (MD) simulations, limiting current method, as well as fuel cell performance measurement. It is found that Co 2+ contamination reduces water content and increases the modulus of the ultrathin ionomer film, while reducing the distance between the sulfonic acid groups and increasing the aggregation size of the ionomer, which is related to the volume of hydrophilic domains. Additionally, the electrochemical measurement results demonstrate that as the degree of Co 2+ contamination increases from 0 to 85 %, the local oxygen transport resistance increases from 27.74 s cm −1 to 42.43 s cm −1 , and the peak power density of fuel cell reduces from 510 mW cm −2 to 453 mW cm −2 . The reason behind lies on that contaminated Co 2+ tends to connect with sulfonate, then suppress the ionomer mobility and dislocate the local oxygen transport channels.
研究领域:
电化学
·
材料科学
·
能源工程
·
催化化学
·
高分子科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 46
·45484
·
IF 1.86
Teng Xue,Erjun Tang,Jian Zhou,Ruitao Han,Shaojie Liu
A coordinating ionic liquid (IL), 1-[(diethyl amine)amine]ethyl-3-methyl imidazolium chloride ([N 3 MIM]Cl), was prepared as an alternative to a simple organic ligand to coordinate to copper(I) bromide (CuBr). We, thereby, obtained a novel catalyst for atom transfer radical polymerization (ATRP) reactions. This catalyst was applied to the ATRP of methyl methacrylate in the IL 1-allyl-3-methyl imidazolium chloride ([AMIM]Cl). The chemical structures of the ILs obtained were confirmed by Fourier transform infrared spectroscopy, mass spectrometry, and 1 H-NMR analyses. The coordination ability of [N 3 MIM]Cl was assessed by cyclic voltammetry, and the redox potential of [N 3 MIM]Cl–CuBr was −0.507 V. The [N 3 MIM]Cl–CuBr complex was expected to be a markedly more active catalyst than the amine DETA–CuBr complex. The coordination mode toward CuBr was also examined. The [N 3 MIM]Cl–CuBr catalyst system showed good controllability in the aforementioned ATRP reaction in [AMIM]Cl. The Cu catalyst was easily separated from the obtained polymer with the coordinating IL as a ligand. Consequently, the coordinating IL overcame the shortcomings of traditional organic ligands, such as poor compatibility with IL media and poor separation of the catalyst from the polymer; this makes it highly promising for applications in the ATRP field. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45484.
研究领域:
高分子化学
·
催化化学
·
功能材料
·
绿色溶剂
·
配位化学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Liping Zhang,Yuye Cai,Qisheng Zhong,Shijing Zhang,Lingling Shen,Taohong Huang,Ting Zhou
Salvia miltiorrhiza , a widely used traditional Chinese medicine, contains a complex matrix of hydrophobic diterpenoids and hydrophilic phenolic acids, presenting significant challenges in comprehensive analysis. In this study, an online polarity-partitioned two-dimensional liquid chromatography coupled with mass spectrometry (2D-LC-MS) method was developed for comprehensive analysis of both lipophilic and hydrophilic active components in Salvia miltiorrhiza . The method integrated hydrophilic interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography (RPLC), facilitating the efficient separation of compounds across a wide range of polarities. An online dilution strategy was implemented, minimizing sample loss and enhancing the method's utility for quality control and chemical characterization of complex herbal matrices. Compared with other LC methods, this approach significantly improved analyte coverage, resolution, and analysis efficiency. Under optimal conditions, 150 active components were successfully identified, including 33 compounds newly discovered in Salvia miltiorrhiza . Additionally, the validated online method was applied to the quantitative determination of 16 quality markers of Salvia miltiorrhiza from different sources. The results demonstrated the online method's potential as a superior alternative to existing techniques, offering broader applicability in traditional Chinese medicine research.
研究领域:
分析化学
·
生药学
·
传统中药
·
药物分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2020
·Vol. 7
·期 9
·2654-2668
·
IF 7.683
Wei Li,Xiao-shan Chu,Shu-ao He,Xue-chuan Wang,Chuan-yi Wang
Tetracycline hydrochloride (TTC), a typical antibiotic with biological toxicity, is very harmful to the ecosystem. Photocatalysis is considered an effective method for solving this problem. However, traditional photocatalysts have limited light response, poor charge transport, and low adsorption ability, which substantially limit their application. Herein, gourd-like hollow mesoporous silica (HS) particles with considerable BET surface area (1181.57 m2 g−1) and enhanced light absorption were constructed to support the Ag/AgBr Schottky junction. Photoelectrochemical characterizations confirmed that the optical response and charge transfer of the fabricated photocatalysts were significantly elevated because the synergistic effect of the Ag/AgBr Schottky junction and amino-modified gourd-like HS particles facilitated the effective generation of ˙OH radicals. The optimal HS-Ag/AgBr (40 wt% HSAA) exhibited highest TTC degradation activity (3.79 × 10−2 min−1) owing to a redox reaction with O2˙−/˙OH radicals, which was about 28.3-fold greater than the commercial P25 (1.34 × 10−3 min−1) and 12.8-fold greater than the AgBr (2.96 × 10−3 min−1). Most importantly, about 72.04%/81.17% of TTC was mineralized by optimal 40 wt% HSAA after 90 min/150 min of illumination, which was higher than those with P25 and other Ag/AgBr-based photocatalysts reported in the literature. Therefore, TTC and its by-products could be completely decomposed by this novel structure, and this study provides a prospective approach for the effective handling of antibiotic pollution in the ecosystem.
研究领域:
环境科学
·
材料科学
·
化学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）