FOOD CHEMISTRY
·
2020
·
IF 6.306
Yuxue Zheng,Jinhu Tian,Wenhan Yang,Shiguo Chen,Donghong Liu,Haitian Fang,Huiling Zhang,Xingqian Ye
The inhibitory mechanisms of ferulic acid against α-amylase and α-glucosidase were investigated by enzyme kinetic analysis, circular dichroism (CD), Fourier-transform infrared (FT-IR) spectroscopy, fluorescence quenching and molecular docking. Results indicated that ferulic acid strongly inhibited α-amylase (IC 50 : 0.622 mg ml −1 ) and α-glucosidase (IC 50 : 0.866 mg ml −1 ) by mixed and non-competitive mechanisms, respectively. CD spectra and fluorescence intensity measurements confirmed that the secondary structure of α-amylase and α-glucosidase were changed and the microenvironments of certain amino acid residues were modulated by the binding of ferulic acid. FT-IR spectra indicated that the interaction between ferulic acid and α-amylase/α-glucosidase mainly involved in non-covalent bonds. Molecular docking further demonstrated that the interaction forces between ferulic acid and α-amylase/α-glucosidase were hydrogen bonds, with the binding energy of −5.30 to −5.10 and −5.70 kcal mol −1 , respectively. This study might provide a theoretical basis for the designing of novel functional foods with ferulic acid.
研究领域:
食品科学
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生物化学
·
药理学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Hao Wang,Jing Wang,Yaojie Liu,Yanglin Ji,Yatu Guo,Jiang Zhao
Inhibition the activity of glycosidase is an effective method for the treatment and prevention of diabetes. In this study, enzymatic kinetics , fluorescence spectrum experiment, starch granule digestion, molecular docking studies and animal's studies were used to investigate the interaction mechanism of carnosic acid against two glycosidase (α-amylase and α-glucosidase). Enzymatic kinetics showed that carnosic acid inhibited α-amylase activity in a competitive manner and α-glucosidase activity in a non-competitive manner. The half inhibitory concentrations (IC50) of carnosic acid to α-amylase and α- glucosidase were (1.12 ± 0.31) and (0.08 ± 0.17), respectively. The fluorescence quenching experiments showed that the intrinsic fluorescence of α-amylase or α-glucosidase was quenched by forming a complex with carnosic acid, and there was only one binding site between carnosic acid and glycosidase. The starch granules were no longer hydrolyzed by α-amylase after the addition of carnosic acid, which indicated that carnosic acid inhibited the activity of α-amylase. Molecular docking study showed that carnosic acid binds to the amino acid residues of glycosidase through hydrogen bond and van der Waals force, which leads to the change of the molecular conformation of glycosidase and thus reduces the activity of glycosidase. The experiment on mice showed that carnosic acid could effectively reduce postprandial blood glucose in mice.
研究领域:
药理学
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生物化学
·
糖尿病研究
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Jingjing Cui,Di Lian,Yuan Li,Yutong Du,Zihan Qu,Xue Zhang,Li Li
Coreopsin is a flavonoid from Coreopsis tinctoria . The inhibition of coreopsin and synergy with acarbose against α-amylase (PPA) or α-glucosidase (SCG) were explored. As a result, coreopsin exhibited stronger inhibition on PPA/SCG than that of acarbose. Combination of coreopsin (4.11 μM) with acarbose (132.77 μM) had significant synergistic effect on PPA, while combination of coreopsin (5.76 μM) and acarbose (121.7 μM) had significant synergy on SCG. Coreopsin, acarbose and acarbose-coreopsin inhibited PPA in mixed-type mode. Acarbose competitively inhibited SCG, whereas coreopsin and acarbose-coreopsin inhibited SCG in mixed-type mode. Fluorescence analysis conformed that coreopsin could synergize with acarbose by increasing the binding ability of acarbose to PPA/SCG. Compared with acarbose or coreopsin, acarbose-coreopsin complexes resulted in more conformational changes of PPA/SCG, revealing that the complexes had stronger inhibitory ability than acarbose or coreopsin alone. The detail binding information of coreopsin, acarbose or acarbose-coreopsin to PPA /SCG was revealed by computer simulation.
研究领域:
药理学
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生物化学
·
酶学
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产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 24
·8114-8121
·
IF 4.174
Jing Yang,Jiaqiang Liu,Baihan Li,Le Han,Yan Xu
A rational design and directional synthesis of well-defined porous metal oxide heterostructures remains a challenge for the fabrication of new gas sensors with enhanced sensing properties. Herein, a novel hierarchical heterostructure of α-Fe2O3@α-MoO3 microcubes was prepared by applying a self-sacrifice template strategy, in which a porous metal–organic framework (MOF) was used as the precursor with the partial insertion of OH− and MoO42− and extraction of [Fe(CN)6]34− followed by heating treatment. Benefiting from the porous microcubic structural characteristic, the α-Fe2O3@α-MoO3 heterostructures exhibited excellent selectivity and high sensitivity for triethylamine gas with the highest response value (Ra/Rg) of 18.64 under the operating temperature of 240 °C. The experimental results also revealed that the material showed a fast response and recovery time (12 s/106 s) and excellent repeatability for at least 20 days. This feasible synthetic strategy may provide a versatile and controlled way to prepare other polymetal oxide-based heterostructures with improved sensing performance.
研究领域:
材料科学
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化学传感器
·
纳米技术
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DOI
高影响因子
Microbiology Spectrum
·
2021
·Vol. 9
·期 3
·
IF 7.171
Alia Rizvi Syeda Kazim,Yuting Jiang,Shengnan Li,Xiaoxiao He
α-Glucan is a major cell wall component and a virulence and adhesion factor for fungal cells. However, the biosynthetic pathway of α-glucan was still unclear. α-Glucan was shown to be composed mainly of 1,3-glycosidically linked glucose, with trace amounts of 1,4-glycosidically linked glucose. Besides the α-glucan synthetases, amylase-like proteins were also important for α-glucan synthesis. In our previous work, we showed that Aspergillus nidulans AmyG was an intracellular protein and was crucial for the proper formation of α-glucan. In the present study, we expressed and purified AmyG in an Escherichia coli system. Enzymatic characterization found that AmyG mainly functioned as an α-amylase that degraded starch into maltose. AmyG also showed weak glucanotransferase activity. Most intriguingly, supplementation with maltose in shaken liquid medium could restore the α-glucan content and the phenotypic defect of a ΔamyG strain. These data suggested that AmyG functions mainly as an intracellular α-amylase to provide maltose during α-glucan synthesis in A. nidulans.IMPORTANCE Short α-1,4-glucan was suggested as the primer structure for α-glucan synthesis. However, the exact structure and its source remain elusive. AmyG was essential to promote α-glucan synthesis and had a major impact on the structure of α-glucan in the cell wall. Data presented here revealed that AmyG belongs to the GH13_5 family and showed strong amylase function, digesting starch into maltose. Supplementation with maltose efficiently rescued the phenotypic defect and α-glucan deficiency in an ΔamyG strain but not in an ΔagsB strain. These results provide the first piece of evidence for the primer structure of α-glucan in fungal cells, although it might be specific to A. nidulans.
研究领域:
微生物学
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分子生物学
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真菌遗传学
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细胞壁生物学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Xi Peng,Kai Liu,Xing Hu,Deming Gong,Guowen Zhang
Inhibition of α-amylase and α-glucosidase activity is an effective way for controlling postprandial blood glucose-related diabetes. The study found that hesperetin-Cu(II) complex (Hsp-Cu(II)) exhibited a stronger inhibitory ability on α-amylase and α-glucosidase compared to hesperetin (Hsp), with smaller IC 50 values of Hsp-Cu(II) (60.3 ± 0.9 µM for α-amylase; 1.25 ± 0.03 µM for α-glucosidase) than Hsp (115.6 ± 1.1 µM for α-amylase; 55.2 ± 0.1 µM for α-glucosidase). Interestingly, Hsp-Cu(II) and acarbose exerted a synergistic effect on inhibition of α-glucosidase. The binding affinities of Hsp-Cu(II) to α-amylase and α-glucosidase were strong with the K a values (binding constant) in the magnitude order of 10 5 , which was 9 times larger than Hsp. After interacting, Hsp-Cu(II) reduced α-helix contents of α-amylase and α-glucosidase, resulting in a looser conformation of these two enzymes. Molecular simulations manifested that Hsp-Cu(II) bound to the active center of enzymes driven by hydrogen bonds and interacted with the key catalytic amino acids (α-amylase: Gln63, Asp300 and His305; α-glucosidase: Tyr158, Asp215, Glu277 and Glu411), altering the conformation of enzymes, blocking the entrance of substrates, ultimately reducing the activities of α-glucosidase and α-amylase. This study has demonstrated that Hsp-Cu(II) may be a promising candidate of functional nutritional additive and medicine for the prevention of diabetes.
研究领域:
生物化学
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药理学
·
糖尿病研究
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产品关联
DOI
PubMed
高影响因子
SYNTHESIS-STUTTGART
·
2015
·Vol. 47
·期 23
·3751-3757
·
IF 2.689
Zhijie Li,Quan Wen,Lihong Zhou,Xingmei Deng,Qingle Zeng
The synthesis of highly important α-hydroxycarboxylic acid anilides via copper-catalyzed chemoselective C–N coupling reactions of α-hydroxyamides and aryl halides is described. This highly selective N-arylation process demonstrates wide substrate scope, cost savings and easy operation. In addition, the chirality of l-3-phenyllactamide is preserved during the reaction.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Yejun Deng,Lixin Huang,Caihong Zhang,Pujun Xie,Jiang Cheng,Xiang Wang,Lujie Liu
Purification and structural characterization of a novel polysaccharide fraction from Chaenomeles speciosa seeds were investigated. After hot water extraction and ethanol precipitation, the crude polysaccharide was sequentially purified with Cellulose DEAE-52 and gel-filtration chromatography, and a highly purified polysaccharide fraction (F3) was obtained. The structure of F3 was characterized by high-performance gel permeation chromatography (HPGPC), high performance liquid chromatography (HPLC), ultraviolet-visible (UV), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectrum, together with methylation, scanning electron microscopy (SEM), atomic force microscope (AFM), and Congo-red test analysis. The results indicated that F3 was a homogeneous polysaccharide fraction with a molecular weight of 8.65 × 10 6 Da, and it was composed of Rha, GlcA, Gal, and Ara in a molar ratio of 6.34:5.73:47.14:40.13. The backbone of F3 was consisted of →3,6)-Gal p -(1→, and the side chains of F3 were composed of Ara f -(1→, →4)-Glc p A-(1→, →4)-Gal p -(1→ and →3)-Rha p -(1→. The hypoglycemic assays demonstrated F3 had good α-amylase and α-glucosidase inhibition activities, and their IC 50 values were 6.24 mg/mL and 4.59 mg/mL respectively. Thus, the polysaccharide from Chaenomeles speciose could be applied as a potential natural source in retarding postprandial hyperglycemia effects.
研究领域:
药学
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生物化学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2021
·
IF 4.24
Halah Aalim,Zisheng Luo
This study provides a comprehensive evaluation of the effect of the phenolic composition in addition to the thermal treatments (i.e., roasting and frying) and the subsequent cooking on the starch physicochemical characteristics of red and brown rice. Native starch (Ns) was isolated to provide a theoretical and practical basis for starch functional properties. Red rice was characterized by superior phenolic contents and the presence of proanthocyanidins , which were enhanced by roasting and declined after all cooking methods. However, brown rice showed greater phenolic stability compared with red rice. Chromatographic separation showed that red rice was dominated by protocatechuic acid and (−)-epicatechin, whereas brown rice showed high contents of p-hydroxybenzoic acid, (−)-epicatechin, and syringaldehyde. Our results showed that processing profoundly influenced the color parameters of rice grain. Fourier transform infrared spectroscopy (FTIR) indicated intermolecular hydrogen bonds formed between native starch and phenolic compounds in rice influenced by cooking methods. Brown rice showed lower amylose (AAC), which influenced the grain's thermal characteristics and digestibility . Cooking and frying enhanced the AAC while roasting led to a significant reduction. Cooked red rice phenolic extract showed higher enzyme inhibition for α-amylase and α-glucosidase compared to brown rice extract . Notably, Ns showed considerably higher AAC, gelatinization enthalpy, and digestibility rate than native rice grain. Oil-frying significantly increased damaged starch, reduced gelatinization enthalpy, enhanced resistance starch (RS), and reduced the estimated glycemic index (eGI), which are favorable nutritional qualities.
研究领域:
食品科学
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植物化学
·
营养学
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DOI
高影响因子
STARCH-STARKE
·
2021
·
IF 2.741
Jinjin Zhao,Zhangtie Wang,Emad Karrar,Deping Xu,Xiulan Sun
Berberine is separated from medical plants and food raw materials, and shows excellent anti-diabetic activity and could be used as a food additive in some countries and regions. However, its inhibitory mechanisms on α-amylase and α-glucosidase have hardly ever been revealed in vitro. In this study, enzymatic reaction kinetics, fluorescence quenching, circular dichroism spectroscopy, and molecular docking are used to study the inhibitory effects of berberine on α-amylase and α-glucosidase. Berberine has great inhibitory effects on α-amylase and α-glucosidase (IC 50 = 50.83 µg mL –1 , IC 50 = 198.4 µg mL –1 , respectively), and inhibition types of α-amylase and α-glucosidase are non-competitive inhibition and competitive inhibition, respectively. Fluorescence spectra show that there is static quenching between berberine and α-amylase or α-glucosidase. Besides, hydrophobic interaction is the main interaction type. These results are further evidenced and visualized by molecular docking. This study provides a different theoretical basis for berberine in anti-diabetic activity in vitro and expands interaction research about hydrophobic compounds and α-amylase as well as α-glucosidase.
研究领域:
药理学
·
生物化学
·
分子生物学
·
糖尿病研究
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产品关联
DOI
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Yushi Wei,Le Deng,Shuling Chen,Xing Hu,Guowen Zhang
The inhibition mechanism of starch digestion by a natural plant active ingredient isoliquiritigenin was studied. The results indicated that isoliquiritigenin effectively decreased the starch hydrolysis through increasing the content of resistant starch, and inhibiting the activities of α-amylase and α-glucosidase. The content of resistant starch increased by 18.85% with the addition of isoliquiritigenin at 8% content. Multispectral analyses showed isoliquiritigenin combined with α-amylase or α-glucosidase to form stable complexes by non-covalent bonds, leading to the enzyme's structure to be loose, which was supported by the results of unstable conformations and an increase in the freedom of amino acid residues of the enzymes in molecular dynamics simulation. Molecular docking demonstrated that isoliquiritigenin bound to the amino acid residues 304–310 nearby the active pocket of α-amylase, and inserted the active site of α-glucosidase competing with the substrate to bind the crucial amino acid residues (Asp215, Asp352 and Glu411), thereby inhibiting α-amylase and α-glucosidase activity. These findings highlight the development potential of isoliquiritigenin as a hypoglycaemic dietary supplement.
研究领域:
食品科学
·
营养学
·
药理学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 16
·9362
·
IF 6.208
Chenzhi Zhang,Dashuang Wang,Lichao Dong,Kailin Li,Yifan Zhang,Pingan Yang,Shuang Yi,Xingjian Dai,Changqing Yin,Zhilan Du,Xinfang Zhang,Quan Zhou,Zhiyu Yi,Jinsong Rao,Yuxin Zhang
A neoteric round sieve diatomite (De) decorated with sea-urchin-like alpha-type iron trioxide (α-Fe2O3) synthetics was prepared by the hydrothermal method and further calcination. The results of the electromagnetic (EM) parameters of α-Fe2O3-decorated De (α-Fe2O3@D) showed that the minimum reflection loss (RLmin) of α-Fe2O3@D could reach −54.2 dB at 11.52 GHz and the matched absorber thickness was 3 mm. The frequency bandwidth corresponding to the microwave RL value below −20 dB was up to 8.24 GHz (9.76–18 GHz). This indicates that α-Fe2O3@D composite can be a lightweight and stable material; because of the low density of De (1.9–2.3 g/cm3), the density of α-Fe2O3@D composite material is lower than that of α-Fe2O3(5.18 g/cm3). We found that the combination of the magnetic loss of sea-urchin-like α-Fe2O3and the dielectric loss of De has the most dominant role in electromagnetic wave absorption and loss. We focused on comparing the absorbing properties before and after the formation of sea-urchin-like α-Fe2O3and explain in detail the effects of the structure and crystal shape of this novel composite on the absorbing properties.Keywords:diatomite;α-Fe2O3;microwave absorption
研究领域:
材料科学
·
电磁学
✓ 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）