ACS Catalysis
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2021
·
IF 13.084
Li Sun,Junkang Xu,Xiaoyan Liu,Botao Qiao,Lin Li,Yujing Ren,Qiang Wan,Jian Lin,Sen Lin,Xiaodong Wang,Hua Guo,Tao Zhang
Single-atom catalysts (SACs) with complete dispersion of metal species on substrates provide the ultimate atom economy and opportunities for improved heterogenous catalysis or to develop more catalyst formulation. However, atomically dispersed dopants can also improve the catalyst in an indirect capacity. Here, we report an Ir1/α-MoC SAC that exhibits high activity for water gas shift reaction with ∼100% CO conversion at 150 °C. The reaction rate of this catalyst is orders of magnitude higher than previous Ir-based catalysts and ∼4 times that of α-MoC. Experimental characterizations combined with density functional theory (DFT) calculations reveal that such good performance originates from the effective catalysis by the α-MoC substrate with Ir1 serving as a single-atom promoter. DFT calculations also establish a correlation between the active Mo sites and the catalytic performance for water gas shift reaction. This work highlights the possibility of enhancing catalysis by single-atom promoters as a promising strategy for designing effective SACs.
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ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Mengxia Cheng,Hong Shu,Ye Peng,Xiaoxiao Feng,Guoquan Yan,Lei Zhang,Jun Yao,Huimin Bao,Haojie Lu
Sialylated N-glycan isomers with α-2,3 and α-2,6 linkages play crucial and distinctive roles in diverse physiological and pathological processes. Changes of α-2,3-linked sialic acids in sialylated N-glycans are especially important in monitoring the initiation and progression of diseases. However, the specific analysis of α-2,3-sialylated N-glycan linkage isomers remains challenging due to their extremely low abundance and technical limitations in separation and detection. Herein, we designed an integrated strategy that combines linkage-specific derivatization and a charge-sensitive separation method based on microfluidic chip capillary electrophoresis–mass spectrometry (microchip CE–MS) for specific analysis of α-2,3-sialylated N-glycan linkage isomers for the first time. The α-2,6- and α-2,3-sialic acids were selectively labeled with methylamine (MA) and N,N-dimethylethylenediamine (DMEN), respectively, which selectively makes α-2,3-sialylated N-glycans positively charged and realizes online purification, concentration, and discrimination of α-2,3-sialylated N-glycans from other N-glycans in microchip CE–MS. This new approach was demonstrated with standard multisialylated N-glycans, and it was found that only the α-2,3-sialylated N-glycans migrated and were detected in order according to the number of α-2,3-sialic acids. Finally, this strategy was successfully applied in highly sensitive profiling and reproducible quantitation of the serum α-2,3-sialylated N-glycome from ovarian cancer (OC) patients, where 7 of 33 detected α-2,3-sialylated N-glycans significantly changed in the OC group compared with healthy controls.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2021
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IF 8.128
Weilin Qi,Xuejiao Wang,Zeyu Liu,Kaerdun Liu,Yifan Long,Wanwan Zhi,Cheng Ma,Yun Yan,Jianbin Huang
Hypothesis Distinguishing substituted aromatic isomers is a challenging task because of the great similarity of their physicochemical properties. Considering xylene isomers have drastically different geometrical shapes, we predict this would show great impact on the self-assembling behavior of various xylene isomer@cyclodextrin inclusion complex. Experiments Through host–guest crystalline self-assembly, among three isomers, only ortho -xylene is capable to form hydrogels with α-cyclodextrin. ROESY NMR, molecular simulations and circular dichroism spectra suggest that the ortho selectivity comes from the difference in the conformation of host–guest building block. The larger volume, and steric hinderance of the ortho isomer make it most possibly decrease their tendency to adopt more mobile orientations in cyclodextrin-based complex as meta and para isomers do, resulting in gel formation. Findings Herein, we report a novel, facile and environmentally-friendly protocol on the recognition of ortho benzene isomers using α-cyclodextrin through host–guest crystalline self-assembly. Visual recognition of ortho -xylene is achieved through amplifying the structural difference of xylene isomers at molecular scale into macroscopic scale. We believe this work unveils subtle rules to control macroscopic assemblies at the molecular level and highlights the potential of using macrocyclic compounds to improve the quality and reduce the energy bill for separation in petrochemical industry.
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BIOORGANIC CHEMISTRY
·
2021
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IF 5.275
Jinxiang Huang,Xufeng Zang,Wuying Yang,Xiaoli Yin,Jianping Huang,Shumin Wu,Yanping Hong
Eighteen derivatives of pentacyclic triterpene carboxylic acids (Maslinic acid, Corosolic acid and Asiatic acid) have been prepared by coupling the piperazine complex of l -amino acids at the C-28 site of the parent compounds. The α-glucosidase inhibitory activities of the pristine derivatives were evaluated in vitro . The results indicated that the inhibitory activity of some compounds ( 15e IC 50 = 591 μM, 16e IC 50 = 423 μM) was closed to that of the reference acarbose (IC 50 = 347 μM) in ethanol-water system. In addition, compound 16e (IC 50 = 380 μM) showed superior inhibitory activity than acarbose (IC 50 = 493 μM) in the measurement system with DMSO as solvent. The comparison of two different solvent systems showed that the derivatives had better α-glucosidase inhibitory activity in the DMSO system than that of in ethanol-water system. Regrettably, all of the as-synthesized derivatives exhibited inferior α-glucosidase inhibitory activities than those of the parent compounds in both test solvent systems. Furthermore, the result of enzyme kinetics demonstrated that the inhibition mechanism of compound 16e was noncompetitive inhibition with the inhibition constant K i = 552 μM.
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Nanoscale Advances
·
2020
·Vol. 3
·期 3
·812-822
·
IF 0
Min Zhang,Muhammad Arif,Yuxiang Hua,Bo Qiu,Yue Mao,Xiaoheng Liu
The use of semiconductor photocatalysts to generate electrons with efficient reducing capability for organic photoreduction synthesis and the removal of harmful substances has become a hotspot in the field of green chemistry research. In this work, α-MnO2 nanocubes and α-MnO2@MnIn2S4 hybrid photocatalysts with a core–shell structure were synthesized successively by a two-step method. XRD and XPS verified the coexistence of the two substances (α-MnO2 and MnIn2S4) in hybrid systems. According to the SEM and TEM characterization, it is clearly seen that MnIn2S4 nanosheets grow on α-MnO2 nanocubes to form a hierarchical structure. Furthermore, HRTEM showed that the interface contact between α-MnO2 and MnIn2S4 resulted in an atomically defined junction. The photocatalytic performance of the composite catalyst was evaluated by reducing 4-nitroaniline to 4-phenylenediamine and Cr(VI) to Cr(III), respectively. The results show that the catalytic activity of the composite material is effectively improved compared to that of the single components. The Z-scheme electron transport mechanism was proved by ultraviolet-visible diffuse reflectance spectroscopy, valence band XPS, energy band structure calculation and active species detection experiments. The constructed Z-scheme hierarchical α-MnO2@MnIn2S4 system with an atomically defined junction can improve the redox performance of semiconductors for organic synthesis and environmental remediation.
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FOOD CHEMISTRY
·
2020
·
IF 6.306
GuiLin Hu,XingRong Peng,Ding Dong,Yin Nian,Ya Gao,XiaoYuan Wang,DeFu Hong,MingHua Qiu
Ten new ( 1 – 10 ) and five known ( 11 – 15 ) ent -kaurane diterpene derivatives were identified from the roasted beans of coffea arabica. Their structures were established by extensive spectroscopic analysis including 1D, 2D NMR (HSQC, HMBC, COSY, and ROESY), HRESIMS, and X-ray diffraction analysis. Compounds 1 – 3 were three types of rearranged ent -kaurane diterpenes, and compounds 4 and 5 were diterpene esters with a rare 6-hydroxyhexanoyl at C-17. Compounds 6 , 8 , 14 , and 15 showed moderate inhibitory effect on α -glucosidase with IC 50 values of 149.92 ± 2.52, 23.23 ± 1.03, 54.58 ± 4.21, 54.16 ± 3.95 μM, respectively, compared to the positive control (60.71 ± 16.45 μM). The results of activity assay showed that diterpenes with the double bond between C-15 and C-16 exhibited stronger α -glucosidase inhibitory activity. Further molecular docking experiments were adopted to discuss the mechanism of activity.
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ACTA BIOCHIMICA ET BIOPHYSICA SINICA
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2020
·Vol. 52
·期 12
·1420-1426
·
IF 2.836
Fei Mingyue,Mao Xudan,Chen Yiyang,Lu Yalan,Wang Lin,Yang Jie,Qiu Juanping,Sun Dongchang
β-Alanine (3-aminopropionic acid) holds great potential in industrial application. It can be obtained through a chemical synthesis route, which is hazardous to the environment. It is well known that l-aspartate-α-decarboxylase (ADC) can convert l-aspartate to β-alanine in bacteria. However, due to the low activity of ADC, industrial production of β-alanine through the green biological route remains unclear. Thus, improving the activity of ADC is critical to reduce the cost of β-alanine production. In this study, we established a dual-fluorescence high-throughput system for efficient ADC screening. By measuring the amount of β-alanine and the expression level of ADC using two different fluorescence markers, we can rapidly quantify the relative activity of ADC variants. From a mutagenesis library containing 2000 ADC variants, we obtained a mutant with 33% increased activity. Further analysis revealed that mutations of K43R and P103Q in ADC significantly improved the yield of β-alanine produced by the whole-cell biocatalysis. Compared with the previous single-fluorescence method, our system can not only quantify the amount of β-alanine but also measure the expression level of ADC with different fluorescence, making it able to effectively screen out ADC variants with improved relative activity. The dual-fluorescence high-throughput system for rapid screening of ADC provides a good strategy for industrial production of β-alanine via the biological conversion route in the future.
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JOURNAL OF FOOD PROCESSING AND PRESERVATION
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2020
·Vol. 45
·期 1
·e15087
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IF 1.405
Sizhu Tian,Xuwen Li,Shuang Zang,Yongri Jin,Ziwei Zhang,Yong Yu
The phenolic compound contents, antioxidant capacities, and α-amylase and tyrosinase inhibitory activities of 10 wild and 19 cultivated blueberries grown in northeast China were evaluated. The results showed that the α-amylase inhibitory activities of the blueberries represented, by 1/IC 50 , correlated with their total phenolic contents (TPCs). Moreover, the tyrosinase inhibitory activities correlated with the total anthocyanin contents (TACs). High-performance liquid chromatography and electrospray mass spectrometry were conducted to determine and identify seven phenolic acids. The average caffeic acid contents of the cultivated and wild blueberries were 277.37 and 17.71 μg/g, respectively. The total phenolic, anthocyanin, and flavonoid contents were determined. Wild blueberries have higher TPCs, α-amylase inhibitory activities, and antioxidant capacities. Cultivated blueberries have higher TACs and exhibit tyrosinase inhibitory activities similar to those of the wild ones. Practical applications This study revealed that wild blueberries have high α-amylase inhibitory activities and are effective as natural α-amylase inhibitors for the treatment of diabetes. In addition, wild blueberries were found to be rich in phenolics and have high antioxidant capacities. Thus, because of these properties, wild blueberry products with antidiabetic and antioxidant potential can be developed for use in biomedical and pharmaceutical industries.
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JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Xinying Zheng,Yang Qin,Xiaobing Meng,Zhengyu Jin,Liuping Fan,Jinpeng Wang
In this work, we for the first time synthesized the polyethylene glycol (PEG) bonded silica gel via KH-560 as a silane coupling reagent for column chromatography by a solid/liquid surface continuous reaction method. The molecular interaction, structure, morphology, and thermostability was characterized by fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), scanning electronic microscope (SEM) and thermogravimetric analysis (TGA). Given that PEG is capable to self-assemble with α-CD, the PEG bonded silica gel was used as packing of column chromatography to achieve the selective separation of α-cyclodextrin (α-CD) at room temperature and atmospheric pressure. The bonded silica gel column could realize the effective separation of α-CD in the enzymatic hydrolysis mixture, which provides support for industrial separation of α-CD.
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Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 33
·11441-11448
·
IF 7.059
Tuohetijiang Baiheti,Shujuan Han,Abudukadi Tudi,Zhihua Yang,Shilie Pan
To design ultraviolet (UV) nonlinear optical (NLO) materials, we focused on the combination of second-order Jahn–Teller (SOJT) cations and PO4. After systematic investigation, we discovered two polar polymorphs of KCsWP2O9, which were synthesized through a conventional high temperature method in an open system. These compounds exhibit a large second harmonic generation (SHG) response (up to 16.8 × KH2PO4, KDP) at 1064 nm. Meanwhile, high temperature phase β-KCsWP2O9 possesses a short UV cutoff edge (<270 nm) despite the presence of a d0 element W. First-principles electronic structure analyses suggest that the strong SHG response of α- and β-KCsWP2O9 is attributed to non-bonding O-2p orbitals (in the VB) and strong orbital interactions of W-5d orbitals and O-2p orbitals in WO6 (in the CB). This work may offer new guidance for the subsequent synthesis of d0 transition metal containing NLO crystals with a large SHG response.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Jie Hao,Fangxia Wu,Rong Tang,Yuanyuan Sun,Dehua Liu,Zhenqing Zhang
Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1 H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides , and in-source fragmented MS for analysis of oxidized polysaccharides . The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0.
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NANOTECHNOLOGY
·
2020
·Vol. 31
·期 13
·135403
·
IF 3.551
Taowen Dong,Ting Deng,Xianyu Chu,Tingting Qin,Haoxiang Wang,Zizhun Wang,Wei Zhang,Weitao Zheng
Earth-abundant Fe2O3 is a promising material for the negative electrode of supercapacitors by virtue of its wide potential windows. However, the unsatisfactory electrical conductivity and poor ionic diffusion rate within Fe2O3 results in degraded electrochemical performance. In this work, to address these issues, we demonstrate an easy method to synthesize Fe-based zeolitic imidazolate framework (Fe–ZIF) derived α–Fe2O3@C with remarkable supercapacitive properties. The as-obtained α–Fe2O3@C electrode, with the particular benefit of dispersed distribution of carbon, enabling fast electrochemical response, presents a prospective specific capacitance of 161 Fg−1 at a current density of 1 Ag−1. Furthermore, by using the α–Fe2O3@C architecture as the negative electrode, we fabricated a supercapacitor with Na0.5MnO2 as the positive electrode. Our supercapacitor shows a high energy density of 25 Whkg−1, while the corresponding power density is 2400 Wkg−1 at a current density of 2 Ag−1.
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