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The structural properties and Angiotensin-I converting enzyme (ACE) inhibition activities of a polysaccharide (PGE) extracted from Gastrodia elata Blume were investigated. PGE was extracted using hot water and purified by Sephadex G-200 followed by ultra-filtration. The structural characterisation of PGE was analysed by FT–IR, NMR spectroscopy, specific rotation determination, periodate oxidation-smith degradation, methylation analysis, GC–MS and Congo red test. The results revealed that PGE was composed by glucose, with an average molecular weight of 1.54 × 103 kDa. The structure of PGE was 1→3 and 1→4,6-branched-glucopyranose that had a linear backbone of (1 → 4)-linked-d-glucopyranose (Glcp). ACE-inhibitory activity results showed that PGE was efficient to inhibit ACE and the IC50 value was 0.66 mg/mL. 相似文献
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以甲酰基二茂铁6为原料, 通过与NH4OH•HCl的缩合反应得到二茂铁肟7, 再经脱水剂脱水得到二茂铁腈8, 最后在(n-C4H9)3SnCl的作用下与NaN3反应生成新化合物二茂铁四唑(9). 以甲酰基二茂铁为原料, 在对甲苯磺酸(PTSA)的催化作用下与原甲酸三甲酯反应生成二甲基二茂铁缩醛(10), 然后与(R)-(-)-3-氯-1,2-丙二醇反应得到新的二茂铁缩醛衍生物12, 12再与NaN3发生取代反应得到新的二茂铁缩醛衍生物13. 而新的二茂铁缩醛衍生物15的合成则是先由(R)-(-)-3-氯-1,2-丙二醇与CH3OH在NaOH的作用下生成(R)-(-)-1-甲氧基-2,3-丙二醇(14), 再由14与二甲基二茂铁缩醛(10)反应得到的. 所合成的新化合物都用MS, 1H NMR和IR谱确证了它们的结构. 相似文献
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合成了水溶性很好的5,3′,5′-三磺酸基-2,3,4,4′-四羟基脱氧安息香三钠盐(TTDB),采用IR、UV、1HNMR和元素分析对其结构进行了表征,并利用X射线单晶衍射仪测定了该化合物的晶体结构.使用荧光光谱法检测了化合物对羟基自由基的清除作用.用循环伏安法探讨了化合物的电化学性质.实验结果表明,5,3′,5′-三磺酸基-2,3,4,4′-四羟基脱氧安息香三钠盐[C14H17Na3O18S3]属于单斜晶系,空间群C2/c,a=1·4223(4)nm,b=2·4327(8)nm,c=1·3596(4)nm,α=90°,β=113·044(5)°,γ=90°,Z=8,V=4·329(2)nm3,Dc=1·925Mg/m3,F(000)=2568,Mr=627·43,R1=0·0950,wR2=0·2648.TTDB的抗羟基自由基的氧化作用优于其相应的脱氧安息香THDB,前者清除羟基自由基的半数有效浓度(EC50)为47·3μmol/L,而后者的EC50则为53·1μmol/L.电化学研究结果表明,THDB和TTDB的氧化还原过程有所差异,前者负扫时在-1·016和-1·228V处出现两个还原峰,正扫时在0·219V处出现一个氧化峰,但后者负扫时仅在-0·999V出现一个还原峰,正扫时在0·193V出现一个氧化峰. 相似文献
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采用模拟计算的方法,运用量子点模型对GaN基LED器件中不同尺寸量子点的电致发光光谱进行模拟分析,并对器件结构中电子空穴浓度,辐射复合强度进行了研究.分析结果显示,随着量子点尺寸的增大,量子点发光波长存在红移,当圆柱状量子点半径从1.8nm增长到13nm时,波长红移309.6meV,在量子阱中生长单一尺寸的量子点可以达到不同波长的单色发光器件,而在不同量子阱中生长不同尺寸的量子点可以实现多波长发光,以及单颗LED的白色显示,并通过调节量子点的分布密度达到调节各发光波长强度的目的.结果表明,量子点分布密度调节之后多波长发光均匀性得到有效改善. 相似文献
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The light-enhanced NO2 sensing properties of porous silicon gas sensors at room temperature
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The NO2 gas sensing behavior of porous silicon(PS) is studied at room temperature with and without ultraviolet(UV) light radiation.The PS layer is fabricated by electrochemical etching in an HF-based solution on a p +-type silicon substrate.Then,Pt electrodes are deposited on the surface of the PS to obtain the PS gas sensor.The NO2 sensing properties of the PS with different porosities are investigated under UV light radiation at room temperature.The measurement results show that the PS gas sensor has a much higher response sensitivity and faster response-recovery characteristics than NO2 under the illumination.The sensitivity of the PS sample with the largest porosity to 1 ppm NO2 is 9.9 with UV light radiation,while it is 2.4 without UV light radiation.We find that the ability to absorb UV light is enhanced with the increase in porosity.The PS sample with the highest porosity has a larger change than the other samples.Therefore,the effect of UV radiation on the NO2 sensing properties of PS is closely related to the porosity. 相似文献
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Xiao-Lan Shang Li-Chao Pan Yun Tang You Luo Hui-Qing Sun 《Natural product research》2020,34(10):1366-1372
AbstractThe crude polysaccharide was extracted from Cordyceps militaris. Material ratio of powder and water was 1:10. The polysaccharide was successively purified by Sevag and chromatography on Sephadex G-100 column to produce a polysaccharide fraction termed CBPS-II. The average molecular weight of CBPS-II was 1.273?×?103 kDa. The study was conducted to investigate the hypoglycemic effect of Cordyceps militaris polysaccharide on diabetic mice. Analysis of the clinical chemistry of the serum samples included serum creatinine (CRE), urea nitrogen (BUN), triglyceride (TG) and total cholesterol (TC). Results revealed that a certain dose of polysaccharide can alleviate the symptoms of metabolic disorders of diabetes, contributing to the body to restore the normal levels. The metabolic profiling method was adopted to find the related biomarkers and the metabolic pathway of diabetes. Moreover, results showed that 100?mg·kg?1 of Cordyceps polysaccharides can effectively reduce the blood glucose level of diabetic mice, thus regulating the metabolism of their energy, amino acids and intestinal microbes. The biomarkers noted in their metabolism were glucose, lactic acid, 3-hydroxy butyric acid, creatine, glutamate, valine, leucine, isoleucine and very low density lipoprotein (VLDL). 相似文献
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Ferrocenylimines have attracted additional interest due to their versatile utilities. They have been widely used as plant growth regulator, bactericide, fuel dope and new anticarcinogen.[1] And a large amount of ferrocenyl shiff bases were prepared in the past. However, study on ferrocenylimines as directing ortho metalation group (DMG) in the (-)-sparteine meditated synthesis of planar chiral ferrocene has not been reported. Herein, we synthesized a series of ferrocenyl schiff bases for this study. 相似文献
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