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1.
Previous studies have reported that Hedyotis diffusa Willdenow extract shows various biological activities on cerebropathia, such as neuroprotection and short-term memory enhancement. However, there has been a lack of studies on the inhibitory activity on neurodegenerative diseases such as Alzheimer’s disease (AD) through enzyme assays of H. diffusa. Therefore, H. diffusa extract and fractions were evaluated for their inhibitory effects through assays of enzymes related to AD, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and β-site amyloid precursor protein cleaving enzyme 1 (BACE1), and on the formation of advanced glycation end-product (AGE). In this study, ten bioactive compounds, including nine iridoid glycosides 1–9 and one flavonol glycoside 10, were isolated from the ethyl acetate and n-butanol fractions of H. diffusa using a bioassay-guided approach. Compound 10 was the strongest inhibitor of cholinesterase, BACE1, and the formation of AGEs of all isolated compounds, while compound 5 had the lowest inhibitory activity. Compounds 3, 6, and 9 exhibited better inhibitory activity than other compounds on AChE, and two pairs of diastereomeric iridoid glycoside structures (compounds 4, 8, and 6, 7) showed higher inhibitory activity than others on BChE. In the BACE1 inhibitory assay, compounds 1–3 were good inhibitors, and compound 10 showed higher inhibitory activity than quercetin, the positive control. Moreover, compounds 1 and 3 were stronger inhibitors of the formation of AGE than aminoguanidine (AMG), the positive control. In conclusion, this study is significant since it demonstrated that the potential inhibitory activity of H. diffusa on enzymes related to AD and showed the potential use for further study as a natural medicine for AD treatment on the basis of the bioactive components isolated from H. diffusa.  相似文献   

2.
Panax ginseng was employed in the treatment of “Xiao-Ke” symptom, which nowadays known as diabetes mellitus, in traditional Chinese medicine for more than a thousand years. Ginsenoside Re was the major pharmacologic ingredient found abundantly in ginseng. However, the anti-diabetic of Ginsenoside Re and its underlying mechanism in metabolic level are still unclear. Serum and urine metabolomic method was carried out to investigate the anti-diabetic pharmacological effects and the potential mechanism of Ginsenoside Re on high-fat diet combined streptozotocin-induced type 2 diabetes mellitus (T2DM) rats based on ultra-high-performance liquid chromatography coupled with quadrupole exactive orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap/MS). Serum and urine samples were collected from the control group (CON), T2DM group, metformin (MET) treatment group, and ginsenoside Re treatment group after intervention. The biochemical parameters of serum were firstly analyzed. The endogenous metabolites in serum and urine were detected by UHPLC-MS. The potential metabolites were screened by multivariate statistical analysis and identified by accurate mass measurement, MS/MS, and metabolite databases. The anti-diabetic-related metabolites were analyzed by KEGG metabolic pathway, and its potential mechanism was discussed. The treatment of ginsenoside Re significantly reduced the blood glucose and serum lipid level improved the oxidative stress caused by T2DM. Biochemical parameters (urea nitrogen, uric acid) showed that ginsenoside Re could improve renal function in T2DM rats. Respective 2 and 6 differential metabolites were found and identified in serum and urine of ginsenoside Re compared with T2DM group and enriched in KEGG pathway. Metabolic pathways analysis indicated that the differential metabolites related to T2DM were mainly involved in arachidonic acid metabolism, Vitamin B6, steroid hormone biosynthesis, and bile secretion metabolic pathways. This study verified the anti-diabetic and anti-oxidation effects of ginsenoside Re, elaborated that ginsenoside Re has a good regulation of the metabolic disorder in T2DM rats, which could promote insulin secretion, stimulated cannabinoid type 1 receptor (CB1), and CaMKK β to activate AMPK signaling pathway, inhibited insulin resistance, and improved blood glucose uptake and diabetic nephropathy, so as to play the role of anti-diabetic.  相似文献   

3.
多组分分析的连续波长紫外分光光度法   总被引:2,自引:0,他引:2  
提出了一种利用紫外光谱连续波长吸光度数据对多组分混合物定量分析的方法:把吸光系数和待测浓度同时作为自变量,优化分析出待测浓度。对多种物系实验数据的分析结果表明,该法稳定、准确度高。  相似文献   

4.
Piper betle L. is widely distributed and commonly used medicinally important herb. It can also be used as a medication for type 2 diabetes patients. In this study, compounds of P. betle were screened to investigate the inhibitory action of alpha-amylase and alpha-glucosidase against type 2 diabetes through molecular docking, molecular dynamics simulation, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis. The molecule apigenin-7-O-glucoside showed the highest binding affinity among 123 (one hundred twenty-three) tested compounds. This compound simultaneously bound with the two-target proteins alpha-amylase and alpha-glucosidase, with high molecular mechanics-generalized born surface area (MM/GBSA) values (ΔG Bind = −45.02 kcal mol−1 for alpha-amylase and −38.288 for alpha-glucosidase) compared with control inhibitor acarbose, which had binding affinities of −36.796 kcal mol−1 for alpha-amylase and −29.622 kcal mol−1 for alpha-glucosidase. The apigenin-7-O-glucoside was revealed to be the most stable molecule with the highest binding free energy through molecular dynamics simulation, indicating that it could compete with the inhibitors’ native ligand. Based on ADMET analysis, this phytochemical exhibited a wide range of physicochemical, pharmacokinetic, and drug-like qualities and had no significant side effects, making them prospective drug candidates for type 2 diabetes. Additional in vitro, in vivo, and clinical investigations are needed to determine the precise efficacy of drugs.  相似文献   

5.
镀铜锌粒还原-流动注射-化学发光同时测定两种价态的铁   总被引:5,自引:0,他引:5  
建立了镀铜的锌粒在线还原微柱,还原Fe3+成Fe2+,鲁米诺中加EDTA增强鲁米诺-溶解氧-铁(Ⅱ)系统的发光强度,同时测两种价态的铁,提高灵敏度160倍,线性范围均为1×10-9~1×10-5mol/L.RSD≤6.0%,Fe3+和Fe2+的检出限分别为3.5×10-10和2.7×10-10mol/L。每小时可测定60个试样,测定结果与标准方法无显著差异。  相似文献   

6.
Abstract

A method is reported for the simultaneous determination of phosphate and silicate by flow injection analysis based on the different rate of formation of the heteromolybdic acids of the two anions. Measurements are based on the colour of the ion-pairs formed between the said molybdic acids and Rhodamine B. The method allows the determination of the two anions at a rate of 20 samples/h over the ranges 0.05–2.5 ppm (phosphate) and 0.8–15 ppm (silicate), which allows application to a variety of waters.  相似文献   

7.
停流流动注射分析同时测定碘离子和亚硝酸根的研究   总被引:10,自引:0,他引:10  
柳仁民  刘桂华 《分析化学》1995,23(4):407-409
基于铁(Ⅲ)-硫氰酸根络合物褪色动力学反应,利用流动注射分析停流技术,建立了流动注射动力学分析法同时测定碘离子和亚硝酸根离子的新方法,方法对碘离子的线性范围为2×10^--1.6×10-4mol/L,对亚硝酸根的线性范围为4×10^-7-1×10mol/L。应用于全成混合液中碘离子和亚硝酸根的测定,结果满意。  相似文献   

8.
Simultaneous TG and DSC analyses of n-butylamine adsorption/desorption were carried out over several zeolites with different degrees of dealumination. The samples used consisted of high crystalline zeolites, preparedvia steam/leaching sequential treatments, and characterized by various techniques. Catalyticactivity measured as the initial rate of cracking of 1,3,5-triisopropylbenzene did not correlate with total acidity, however, the energy required to the complete desorption of the probe molecule, determined by integration of DSC curves, correlates with the catalytic activity of zeolites with any or little extra-framework alumina content. High amounts of extra-framework alumina give significant constraint effect to acessibility to acid sites as shown by applying the Crank's method to the TG curves. This method allowed to determine the intra-crystalline diffusivity of the probe molecule, which seems to be the controlling step to the cracking reaction. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
Chemiluminescence (CL) is well known to be an important and powerful analytical technique owing to its lower detection limits, higher sensitivity and wider linear ranges can be achieved with simpler instrument1. CL analysis has been used for determination…  相似文献   

10.
化学法同时测定含氮有机化合物的碳和氮   总被引:3,自引:0,他引:3  
建立了一个新的化学分析方法,即含氮有机化合物与催化剂、氧化剂相混和,在氧气流下于空气浴上加热分解,C转变成CO2,用稀NaOH溶液吸收,以标准HCl溶液滴定;N转变成NH3,以克达尔定氮法测定,测定误差都小于±0.5%。  相似文献   

11.
Development of efficient methods for isolation and separation of biologically active compounds remains an important challenge for researchers. Designing systems such as organomineral composite materials that allow extraction of a wide range of biologically active compounds, acting as broad-utility solid-phase extraction agents, remains an important and necessary task. Selective sorbents can be easily used for highly selective and reliable extraction of specific components present in complex matrices. Herein, state-of-the-art approaches for selective isolation, preconcentration, and separation of biologically active compounds from a range of matrices are discussed. Primary focus is given to novel extraction methods for some biologically active compounds including cyclic polyols, flavonoids, and oligosaccharides from plants. In addition, application of silica-, carbon-, and polymer-based solid-phase extraction adsorbents and membrane extraction for selective separation of these compounds is discussed. Potential separation process interactions are recommended; their understanding is of utmost importance for the creation of optimal conditions to extract biologically active compounds including those with estrogenic properties.  相似文献   

12.
建立了舒血宁注射剂中16种黄酮及4种萜类内酯同时定量的超高效液相色谱-质谱分析方法,并采用所建立的方法同时测定了不同厂家舒血宁注射剂产品中上述20种化合物的含量。注射剂样品经甲醇-水(体积比1∶1)稀释后,在Acquity UPLC BEH Shield RP18(2.1 mm×100 mm,1.7μm)色谱柱上分析,以0.1%(体积分数)甲酸水溶液-乙腈为流动相进行梯度洗脱,以电喷雾离子源负离子多反应监测(MRM)模式进行质谱监测。结果表明:20种化合物可在10 min内完成色谱分离分析,检出限和定量下限分别为0.02~1.59 ng/mL和0.07~5.30 ng/mL,16种黄酮及4种萜类内酯在各自的线性范围内线性关系良好,在低、中、高3个加标水平下的回收率为85.9%~109%。该方法前处理简单、快速高效、准确性高,为舒血宁注射剂的质量控制提供了参考。  相似文献   

13.
《Analytical letters》2012,45(6):695-705
Abstract

Flow injection analysis (FIA) with a double injection technique was applied to catalytic determination of thiocyanate and iodide in the redox reaction between cerium (IV) and arsenic (III). Selective inactivation of the catalytic activity of thiocyanate was investigated. Amounts of only iodide and amounts of both thiocyanate and iodide were simultaneously determined by the FIA. Detection limits of the method were 0.2 ppm SCN? and 0.1 ppm I?.  相似文献   

14.
The present research aimed to enhance the pharmaceutically active compounds’ (PhACs’) productivity from Streptomyces SUK 25 in submerged fermentation using response surface methodology (RSM) as a tool for optimization. Besides, the characteristics and mechanism of PhACs against methicillin-resistant Staphylococcus aureus were determined. Further, the techno-economic analysis of PhACs production was estimated. The independent factors include the following: incubation time, pH, temperature, shaker rotation speed, the concentration of glucose, mannitol, and asparagine, although the responses were the dry weight of crude extracts, minimum inhibitory concentration, and inhibition zone and were determined by RSM. The PhACs were characterized using GC-MS and FTIR, while the mechanism of action was determined using gene ontology extracted from DNA microarray data. The results revealed that the best operating parameters for the dry mass crude extracts production were 8.20 mg/L, the minimum inhibitory concentrations (MIC) value was 8.00 µg/mL, and an inhibition zone of 17.60 mm was determined after 12 days, pH 7, temperature 28 °C, shaker rotation speed 120 rpm, 1 g glucose /L, 3 g mannitol/L, and 0.5 g asparagine/L with R2 coefficient value of 0.70. The GC-MS and FTIR spectra confirmed the presence of 21 PhACs, and several functional groups were detected. The gene ontology revealed that 485 genes were upregulated and nine genes were downregulated. The specific and annual operation cost of the production of PhACs was U.S. Dollar (U.S.D) 48.61 per 100 mg compared to U.S.D 164.3/100 mg of the market price, indicating that it is economically cheaper than that at the market price.  相似文献   

15.
A highly sensitive double artificial neural network (DANN) analysis with flow-injection chemiluminescence (FI-CL) has been developed to simultaneously determine the trace amounts of the gold and platinum in simulated mixed samples, without the boring process.  相似文献   

16.
Tetrastigmae Radix, also known as Sanyeqing (SYQ) in Chinese, is an important traditional Chinese medicine with a long history. Tetrastigma hemsleyanum Diels et Gilg mainly grows in the south of the Yangtze River and is widely distributed. The content of bioactive constituents in SYQ varies greatly in different habitats, and there are obvious differences in the content of bioactive constituents between southwestern SYQ (WS) and southeastern SYQ (ES). To distinguish and evaluate the quality of ES and WS, an analytical method based on ultrafast performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS) was established for the simultaneous determination of 60 constituents including 25 flavonoids, 9 phenolic acids, 15 amino acids, and 11 nucleosides in 47 samples from ES and WS. In addition, orthogonal partial least squares discriminant analysis (OPLS-DA), t-test, and gray correlation analysis (GRA) were used to discriminate and evaluate the ES and WS samples based on the contents of 60 constituents. The results showed that there were significant differences in the bioactive constituents between ES and WS, and ES was superior to WS in terms of quality evaluation. This study not only provides basic information for differentiating ES and WS but also provides a new perspective for the comprehensive evaluation and quality control of SYQ from two different habitats.  相似文献   

17.
本文利用流动注射-分光光度-火焰光度串联技术,使磷生成磷钼兰以721型分光光度计检测,钾、钠以6400型火焰光度计检测,从而建立了磷、钾和钠三元素同时快速测定的新方法,该方法操作简单、方便、快速,每小时可进行60次测定,磷、钾、钠兰元素的线性范围分别为1.0~4.0μg/ml、3.0~60μg/ml和6.0~40μg/ml。利用该方法测定了植物样品中的磷、钾和钠,获得了良好的结果。  相似文献   

18.
A rapid and sensitive liquid chromatography with tandem mass spectrometry method was developed and validated for simultaneous determination of puerarin, daidzin, daidzein, 3′‐hydroxy puerarin, and genistein in rat plasma after oral administration of Puerariae lobatae radix extract. The method of protein precipitation with acetonitrile was used for sample preparation. Chromatographic separation was achieved on a C18 column with the mobile phases of acetonitrile/water containing 0.1% formic acid. The analytes were detected by mass spectrometer with an electrospray ionization source operating in the negative ion mode. The linearity, precision, accuracy, dilution reliability, recovery, matrix effects, and stability of the method were within acceptable ranges. The developed method was successfully used to compare the pharmacokinetic characteristics of five analytes in normal and type 2 diabetics rats after oral administration of Puerariae lobatae radix extract. Several pharmacokinetic alterations were observed and this might be caused by the pathological state of type 2 diabetes.  相似文献   

19.
Abstract

Trace amounts (ppb or less) of phosphorus containing compounds present in aqueous samples are adsorbed on XAD-4 and subsequently eluted by means of ethyl acetate. The solvent and the eluted compounds are evaporated and swept over a Tenax-GC tube. This gas stripping method traps the phosphorus containing compounds together with only a small amount of the solvent whereas the water entrapped in the XAD step is removed simultaneously. The compounds are desorbed from the Tenax-GC tube and injected into the gas chromatograph using the combination of thermal desorption, cold trapping and flash heating. The subsequent analysis is carried out on a capillary column and the compounds are detected by means of a flame photometric detector. The various steps of the analytical procedure are discussed, including the recoveries of the different compounds studied and some instrumental aspects.  相似文献   

20.
王凡凡  任守信  孟和  高玲 《分析化学》2011,39(6):915-919
根据正交信号校正(OSC)、小波包变换(WPT)及偏最小二乘法(PLS)的算法原理,编制了名为POSC-WPTPLS的程序,结合荧光分析法快速、灵敏、选择性较好的优点,将该程序用于同时测定荧光光谱严重重叠的萘、1-萘酚和2-萘酚多组分体系,并将3种化学计量学方法(OSC-WPT-PLS、WPT-PLS和PLS)进行比较...  相似文献   

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