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.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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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.
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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.
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JOURNAL OF ORGANIC CHEMISTRY
·
2020
·
IF 4.335
Zhiwei Chen,Xiang Bai,Jie Sun,Yicheng Xu
A facile Fe(III)-catalyzed oxidative decarboxylative radical coupling reaction of α,α-difluoroarylacetic acids with coumarins has been developed. This transformation, which provides a series of C-3 difluoroarylmethylated coumarins containing various functional groups in moderate-to-good yields, features easily accessible starting materials and operational simplicity.
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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.
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Journal of Spectroscopy
·
2026
·Vol. 2026
·期 1
·5791311
·
IF 1.7
Xue Zhang,Di Lian,Yuan Li,Yutong Du,Zihan Qu,YuXin Cui,Li Li
Studies indicated that some active flavonoids combined with acarbose could reduce the side effects of acarbose and enhance its efficacy. Isorhamnetin-3-O-rutinoside (IOR) is a flavonoid found in many edible herbs. In this work, the synergistic effects of IOR and acarbose on α -amylase/α-glucosidase (PA/AG) were evaluated using ZIP score analysis. In the presence of IOR, the binding constant K b values of acarbose with PA/AG were significantly improved, indicating that IOR exhibited synergistic effect with acarbose by increasing its K b values. Furthermore, in the presence of IOR, acarbose resulted in greater changes in microenvironment and secondary structure of PA/AG. The docking analysis confirmed that IOR and acarbose bound to the different sites of PA/AG. Compared with pure enzyme, the complexes formed by IOR/acarbose with two enzymes were more stable based on dynamics simulations. This study suggested that IOR might be used as a potential synergistic inhibitor of acarbose.
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Journal of the Australian Ceramic Society
·
2018
·Vol. 55
·期 1
·71-76
·
IF 0.587
Du Xiaoni,Liu Yang,Wang Xiaohong,Feng Jingqing,Ren Chaofei
α-Bi 2 O 3 and β-Bi 2 O 3 nanoparticles were selectively synthesized via one-step solution combustion synthesis (SCS) using bismuth nitrate (Bi(NO 3 ) 3 ·5H 2 O) as the oxidant and tartaric acid (C 4 H 6 O 6 ) as the fuel, and α/β-Bi 2 O 3 heterojunction was rapidly prepared by treating SCS β-Bi 2 O 3 powders with NaOH solution. The physical and chemical properties of as-prepared samples were characterized by XRD, SEM, TEM, PL, and UV-vis techniques. The formation of α/β-Bi 2 O 3 heterojunction can be proven by TEM, UV-vis diffuse reflectance spectra, and PL spectra results. The band gap energies of α-Bi 2 O 3 , β-Bi 2 O 3 , and α/β-Bi 2 O 3 measured by UV-vis diffuse reflectance spectra were estimated to be about 2.9, 2.48, and 2.7 eV, respectively. The PL spectra of α/β-Bi 2 O 3 heterojunction showed higher efficiency of charge separation and transfer across the α–β phase junction than those of α-Bi 2 O 3 and β-Bi 2 O 3 , leading to the enhancement of photocatalytic activity. The synthesized α/β-Bi 2 O 3 heterojunction can degrade 86% of rhodamin B (RhB) after 180 min under visible-light irradiation, better than those of pure α-Bi 2 O 3 (24%, 180 min) and pure β-Bi 2 O 3 (60%, 180 min). Consequently, α/β-Bi 2 O 3 heterojunction is a promising photocatalyst, which can be easily prepared by SCS and post-treatment of NaOH solution.
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JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2014
·
IF 2.745
Long-Hua Zhou,Na Wang,Guan-Nan Chen,Qi Yang,Sheng-Yong Yang,Wei Zhang,Yang Zhang,Xiao-Qi Yu
Lipase-catalyzed direct vinylogous Michael addition reactions of electron-deficient vinyl malononitriles to nitroalkenes are reported for the first time. A series of nitroalkenes reacting with vinyl malononitriles generate the corresponding products with moderate to high yields in the presence of Lipozyme ® (immobilized lipase from Mucor miehei ) with excellent diastereoselectivities in all reactions under optimized conditions. Docking studies were performed to further elucidate the differences between the various enzymes and substrates. Furthermore, we demonstrated the synthetic potential of the multi-functional products by performing reactions that employed the electron-deficient alkylidene double bond.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2016
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IF 2.687
Yejuan Xiong,Qingshan Liu,Xiaoying Yin
In order to rapidly and accurately screen compounds present in Chinese herbal medicines for α-glucosidase inhibition activity, we have developed a screening strategy which couples the immobilized enzymes with HPLC analysis. First, the core-shell PMMA/CS nanoparticle carrier was prepared by graft polymerization method. Subsequently, α-glucosidase was loaded on the nanoparticles to prepare the immobilized enzyme and construct a screening model. Secondly, the morphology and structure of the core-shell PMMA/CS material were characterized by transmission electron microscopy (TEM) and infrared spectroscopy (IR). The results indicate that the size distribution was uniform for the α-glucosidase-immobilized nanoparticles, with an average particle size of about 239 nm. Finally, the α-glucosidase-immobilized nanoparticles were used to screen α-glucosidase inhibitors from extracts of traditional Chinese medicine and from a mixture of pharmacologically active compounds. Extracts of traditional Chinese medicines were analyzed by HPLC method before and after incubation with the immobilized enzyme nanoparticles. Using this method, magnoflorine was selectively separated from methanol extracts of Magnoliae Officinalis Cortex and genistein was selectively separated from a mixture of isoflavone compounds. Both the two compounds have previously been reported to have α-glucosidase inhibitory activity. These results demonstrate that this screening strategy represents a rapid and highly efficient method for the identification of α-glucosidase inhibitors in complex extracts of Chinese herbal medicines.
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JOURNAL OF MICROENCAPSULATION
·
2019
·
IF 2.04
Yingting Wang,Along Zuo,Xiaoyan Huang,Ying Ying,Xinsheng Shu,Xianxiong Chen,Yatao Yang,Junxian Ma,Guimiao Lin,Xiaomei Wang,Lin Mei,Gan Liu,Yingying Zhao
Taxane-based chemotherapy-loaded drug delivery systems have great potential for cancer treatment. The docetaxel (DTX)-loaded PAMAM-based poly (γ-benzyl-l-glutamate)-b-d-α-tocopheryl polyethylene glycol 1000 succinate (PAM-PBLG-b-TPGS) nanoparticles and the docetaxel (DTX)-loaded PAMAM-based poly (γ-benzyl-l-glutamate) (PAM-PBLG) nanoparticles were designed using a modified nanoprecipitation method. The particle size, encapsulation efficiency (EE), and in vitro release characteristics of the nanoparticles were tested. The effects of the two nanoparticles on the cellular uptake and cell viability on human cervical cancer cell line Hela and the human breast cancer cell line MCF-7 were compared. Furthermore, their antitumor efficiency was evaluated through in vivo tumour growth experiment in comparison with free DTX. PAM-PBLG-b-TPGS nanoparticles displayed high EE, smaller diameter, and a nice releasing profile. Besides, based on the high EE and ‘self-controlled’ drug release of the DTX-loaded PAM-PBLG-b-TPGS nanoparticles, they exhibited stronger cytotoxicity (lower survival rate) and higher uptake rate than DTX-loaded PAM-PBLG nanoparticles in Hela cells and MCF-7 cells. Furthermore, compared with DTX-loaded PAM-PBLG nanoparticles and free DTX, DTX-loaded PAM-PBLG-b-TPGS nanoparticles produced a potent anti-tumour effect. Thus, the DTX-loaded PAM-PBLG-b-TPGS nanoparticles provide a novel attractive nanocarrier for the DTX delivery of chemotherapy to human breast cancer cells and human cervical cancer cells.
研究领域:
药剂学
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肿瘤学
·
纳米技术
·
药物递送系统
·
癌症治疗
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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.
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JOURNAL OF APPLIED TOXICOLOGY
·
2020
·Vol. 40
·期 11
·1526-1533
·
IF 2.997
Yalei Yu,Youyou Zhang,Jie Zhang,Chuhuai Guan,Liang Liu,Liang Ren
Cantharidin is of high medicinal value but has strong toxicity. Nowadays, multiple research has focused on the mechanism of its antitumor activity while research on toxicological profiles associated with cantharidin poisoning is still limited. Its hepatotoxicity has attracted attention recently for the crucial role of the liver in detoxification. Here, we aim to find a potential mechanism for cantharidin-induced acute hepatotoxicity with a view to assisting subsequent research or clinical use or detoxification. Twenty-one male Sprague-Dawley rats were randomly divided into control, low-dose (1.34 mg/kg) and high-dose (2.67 mg/kg) cantharidin exposure groups. We used hematoxylin-eosin to observe pathological changes and used immunofluorescent staining, western blotting and real-time quantitative polymerase chain reaction to detect the expression of the markers. The main pathological changes in livers of cantharidin-treated rats were necrosis, inflammatory infiltration and hemorrhage. We found coexpression of tumor necrosis factor alpha (TNF-α), IkappaB kinase-alpha (IKK-α) and caspase3 by immunofluorescent staining in livers of cantharidin-treated rats. Compared with the control, the levels of TNF-α, IKK-α and caspase3 increased significantly in the experimental groups ( P < .05). The ratio of B-cell lymphoma-2 (Bcl-2)/Bax increased in the low-dose group but decreased in the high-dose group ( P < .05). Cantharidin exposure raised IKK-α mRNA and caspase3 mRNA levels ( P < .05). In conclusion, the participation of TNF-α, IKK-α, Bcl-2, Bax and caspase3 uncovered a novel mechanism underlying cantharidin-induced acute hepatotoxicity, and the mechanism needs to be studied further.
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