采用紫外光谱定性定量分析野生植物茅莓主要有效成分黄酮化合物,并对其进行液相色谱-电喷雾质谱联用、薄层色谱原位表面增强拉曼散射研究。液相色谱流动相A:CH3OH,B:H2O+1%乙酸,液相色谱流出时间16.21 m in的化合物为六羟基双氢黄酮醇...采用紫外光谱定性定量分析野生植物茅莓主要有效成分黄酮化合物,并对其进行液相色谱-电喷雾质谱联用、薄层色谱原位表面增强拉曼散射研究。液相色谱流动相A:CH3OH,B:H2O+1%乙酸,液相色谱流出时间16.21 m in的化合物为六羟基双氢黄酮醇二聚体形式,分子量640,占总黄酮的91.71%;流出时间19.61 m in的化合物分子量448,为槲皮甙,占总黄酮的8.29%。茅莓总黄酮经聚酰胺薄层色谱板分离,获得两个斑点:R f1=0.14,R f2=0.47;分别制备灰银胶和溴化银光致还原银溶胶表面增强基底,在样品薄层色谱两个斑点原位分别获得2种黄酮化合物的表面增强拉曼光谱,在2种表面增强基底作用下,都能观察到μg量黄酮化合物特征拉曼光谱,并比较了2种色谱分离与指纹检测联用技术。展开更多
Polyamides containing N-methylpyrrole and N-methylimidazole amino acids have attracted considerable attention from biological chemists because they can permeate living cell membrane and have the potential to control s...Polyamides containing N-methylpyrrole and N-methylimidazole amino acids have attracted considerable attention from biological chemists because they can permeate living cell membrane and have the potential to control specific gene expression.In this article,three polyamides containing N-methylpyrrole rings were synthesized by the chloroform reaction and the DCC/HOBT coupling reaction,and the interaction between the polyamides and DNA was investigated by electrospray ionization mass spectroscopy.The results of the experiments indicate that the designed polyamides can effectively bind the target DNA,and ESI mass spectrometry is an excellent tool for the analysis of the interactions between DNA and the polyamides.展开更多
针对某炼厂酮苯脱蜡装置原料油(减三线)中酸性物质组成特殊(对装置产生严重的腐蚀)的情况,采用碱醇法提取其中的酸性物质,借助负离子电喷雾-傅里叶变换离子回旋共振质谱(negative-ion ESI FT-ICR MS)研究其酸性组分的组成及分布,并与工...针对某炼厂酮苯脱蜡装置原料油(减三线)中酸性物质组成特殊(对装置产生严重的腐蚀)的情况,采用碱醇法提取其中的酸性物质,借助负离子电喷雾-傅里叶变换离子回旋共振质谱(negative-ion ESI FT-ICR MS)研究其酸性组分的组成及分布,并与工业级脱脂环酸进行比较,从分子层面上揭示了其特殊之处。Negative-ion ESI FT-ICR MS结果表明,减三线酸性化合物主要的特点为O2类化合物中脂肪酸(Z=0)占明显优势,缩合度较大的Z=-8和Z=-10的O2类化合物中有些碳数的物质相对丰度也比较大,碳数分布有两个中心;O1类杂原子化合物的相对丰度仅次于O2类化合物,且大大高出其他类杂原子化合物,O1类化合物中,烷基酚类化合物占绝对优势。减三线酸性化合物的特殊组成将对进一步探究腐蚀机理和寻求解决设备腐蚀的途径有重要的指导意义。展开更多
Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploy...Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploying Pd（OAc）2 as catalyst since 2004. However, until now, the speculated reactive Pd（Ⅳ） transient intermedi-ates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry （ESI-MS/MS） was used to intercept and characterize the reactive Pd（Ⅳ） transient inter-mediates in the solutions of Pd（OAc）2-catalyzed oxidative coupling reactions. In this study, the Pd（IV） transient in-termediates were detected from the solution of Pd（OAc）2-catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd（IV） transient intermediate in reaction system was the same with the synthesized au-thentic Pd（Ⅳ） complex. Our ESI-MS（/MS） studies confirmed the presence of Pd（Ⅳ） reaction transient intermedi-ates. Most interestingly, the MS/MS of Pd（Ⅳ） transient intermediates showed the reductive elimination reactivity to Pd（Ⅱ） complexes with new C-O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd（Ⅳ） transient intermediates in solution.展开更多
Phosphorous (P) is a major contributor to eutrophication of surface waters, yet a complete understanding of the P cycle remains elusive. Inositol hexa-kis phosphate (IHP) is the primary form of organic (PO) in the env...Phosphorous (P) is a major contributor to eutrophication of surface waters, yet a complete understanding of the P cycle remains elusive. Inositol hexa-kis phosphate (IHP) is the primary form of organic (PO) in the environment and has been implicated as an important sink in aquatic and terrestrial samples. IHP readily forms complexes in the environment due to the 12 acidic sites on the molecule. Quantification of IHP in environmental samples has typically relied on harsh extraction methods that limit understanding of IHP interactions with potential soil and aquatic complexation partners. The ability to quantify IHP in-situ at the pH of existing soils provides direct access to the role of IHP in the P cycle. Since it is itself a buffer, adjusting the pH correspondingly alters charged species of IHP present in soil. Density Functional Theory (DFT) calculations support the charged species assignments made based pKas associated with the IHP molecule. Raman spectroscopy was used to generate pH dependent spectra of inorganic (PI) and IHP as well as (PO) from IHP and (PI) in soil samples. Electro-spray ionization mass spectroscopy (ESI-MS) was used to quantify IHP-Iron complexes in two soil samples using a neutral aqueous extraction.展开更多
N-Phosphoryl peptide libraries were constructed by transformation from homo-oligopeptide libraries, which was synthesized by self-assembly of amino acids with the assistance of phosphorus oxychloride. Electrospray ion...N-Phosphoryl peptide libraries were constructed by transformation from homo-oligopeptide libraries, which was synthesized by self-assembly of amino acids with the assistance of phosphorus oxychloride. Electrospray ionization mass spectrometry (ESI-MS) was used to monitor the reaction.展开更多
The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport...The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport of the ginsenoside compatibility with Veratrum nigrum in different proportions. A specific high performance liquid chro- matography-electrospray ionization-mass spectrometry（HPLC-ESI-MS） method was developed for the semiquantita- tive determination of ginsenoside in intestinal transport with Dioscin as an internal standard. For the Caco-2 model constructed, two influencing factors were investigated, including time and concentration. The results suggest that the absorption of ginsenoside Re, Rgl, Rbl, Rc, Rb2 and Rd are time- and concentration-dependent and the excretions of Rbl, Rc, Rb2 and Rd have a relatronship with some transport proteins. The bioavailability of the ginsenosides has reduced compared to the single Panax ginseng extract when compatibility with a certain amount of Veratrum nigrum.展开更多
文摘采用紫外光谱定性定量分析野生植物茅莓主要有效成分黄酮化合物,并对其进行液相色谱-电喷雾质谱联用、薄层色谱原位表面增强拉曼散射研究。液相色谱流动相A:CH3OH,B:H2O+1%乙酸,液相色谱流出时间16.21 m in的化合物为六羟基双氢黄酮醇二聚体形式,分子量640,占总黄酮的91.71%;流出时间19.61 m in的化合物分子量448,为槲皮甙,占总黄酮的8.29%。茅莓总黄酮经聚酰胺薄层色谱板分离,获得两个斑点:R f1=0.14,R f2=0.47;分别制备灰银胶和溴化银光致还原银溶胶表面增强基底,在样品薄层色谱两个斑点原位分别获得2种黄酮化合物的表面增强拉曼光谱,在2种表面增强基底作用下,都能观察到μg量黄酮化合物特征拉曼光谱,并比较了2种色谱分离与指纹检测联用技术。
文摘建立了分离鉴定牛蒡叶中微量木脂体牛蒡子甙(arctiin)和牛蒡子甙元(arctigenin)的方法。牛蒡叶粗提物经聚酰胺柱提取,浓缩其甲醇洗脱液并于低温下静置析出白色沉淀物。沉淀物用甲醇溶解后经反相高效液相色谱(RP HPLC)分离,纯化得到两个主要组分。经紫外光谱(UV)、红外光谱(FTIR)及电喷雾质谱(ESI MS)检测,并与牛蒡子甙和牛蒡子甙元对照品的UV,LC ESI MS,HPLC及FTIR图谱比较,鉴定两个主要成分为牛蒡子甙和牛蒡子甙元。
文摘Polyamides containing N-methylpyrrole and N-methylimidazole amino acids have attracted considerable attention from biological chemists because they can permeate living cell membrane and have the potential to control specific gene expression.In this article,three polyamides containing N-methylpyrrole rings were synthesized by the chloroform reaction and the DCC/HOBT coupling reaction,and the interaction between the polyamides and DNA was investigated by electrospray ionization mass spectroscopy.The results of the experiments indicate that the designed polyamides can effectively bind the target DNA,and ESI mass spectrometry is an excellent tool for the analysis of the interactions between DNA and the polyamides.
文摘针对某炼厂酮苯脱蜡装置原料油(减三线)中酸性物质组成特殊(对装置产生严重的腐蚀)的情况,采用碱醇法提取其中的酸性物质,借助负离子电喷雾-傅里叶变换离子回旋共振质谱(negative-ion ESI FT-ICR MS)研究其酸性组分的组成及分布,并与工业级脱脂环酸进行比较,从分子层面上揭示了其特殊之处。Negative-ion ESI FT-ICR MS结果表明,减三线酸性化合物主要的特点为O2类化合物中脂肪酸(Z=0)占明显优势,缩合度较大的Z=-8和Z=-10的O2类化合物中有些碳数的物质相对丰度也比较大,碳数分布有两个中心;O1类杂原子化合物的相对丰度仅次于O2类化合物,且大大高出其他类杂原子化合物,O1类化合物中,烷基酚类化合物占绝对优势。减三线酸性化合物的特殊组成将对进一步探究腐蚀机理和寻求解决设备腐蚀的途径有重要的指导意义。
文摘Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploying Pd（OAc）2 as catalyst since 2004. However, until now, the speculated reactive Pd（Ⅳ） transient intermedi-ates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry （ESI-MS/MS） was used to intercept and characterize the reactive Pd（Ⅳ） transient inter-mediates in the solutions of Pd（OAc）2-catalyzed oxidative coupling reactions. In this study, the Pd（IV） transient in-termediates were detected from the solution of Pd（OAc）2-catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd（IV） transient intermediate in reaction system was the same with the synthesized au-thentic Pd（Ⅳ） complex. Our ESI-MS（/MS） studies confirmed the presence of Pd（Ⅳ） reaction transient intermedi-ates. Most interestingly, the MS/MS of Pd（Ⅳ） transient intermediates showed the reductive elimination reactivity to Pd（Ⅱ） complexes with new C-O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd（Ⅳ） transient intermediates in solution.
文摘Phosphorous (P) is a major contributor to eutrophication of surface waters, yet a complete understanding of the P cycle remains elusive. Inositol hexa-kis phosphate (IHP) is the primary form of organic (PO) in the environment and has been implicated as an important sink in aquatic and terrestrial samples. IHP readily forms complexes in the environment due to the 12 acidic sites on the molecule. Quantification of IHP in environmental samples has typically relied on harsh extraction methods that limit understanding of IHP interactions with potential soil and aquatic complexation partners. The ability to quantify IHP in-situ at the pH of existing soils provides direct access to the role of IHP in the P cycle. Since it is itself a buffer, adjusting the pH correspondingly alters charged species of IHP present in soil. Density Functional Theory (DFT) calculations support the charged species assignments made based pKas associated with the IHP molecule. Raman spectroscopy was used to generate pH dependent spectra of inorganic (PI) and IHP as well as (PO) from IHP and (PI) in soil samples. Electro-spray ionization mass spectroscopy (ESI-MS) was used to quantify IHP-Iron complexes in two soil samples using a neutral aqueous extraction.
文摘N-Phosphoryl peptide libraries were constructed by transformation from homo-oligopeptide libraries, which was synthesized by self-assembly of amino acids with the assistance of phosphorus oxychloride. Electrospray ionization mass spectrometry (ESI-MS) was used to monitor the reaction.
基金Supported by the National Natural Science Foundation of China（Nos.81073040, 81274046, 81173507）, the Jilin Provincial Science and Technology Agency-funded Projects, China（No.20150414040GH） and the National Basic Research Program of China（Nos.2011 CB505300, 2011 CB505305）.
文摘The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport of the ginsenoside compatibility with Veratrum nigrum in different proportions. A specific high performance liquid chro- matography-electrospray ionization-mass spectrometry（HPLC-ESI-MS） method was developed for the semiquantita- tive determination of ginsenoside in intestinal transport with Dioscin as an internal standard. For the Caco-2 model constructed, two influencing factors were investigated, including time and concentration. The results suggest that the absorption of ginsenoside Re, Rgl, Rbl, Rc, Rb2 and Rd are time- and concentration-dependent and the excretions of Rbl, Rc, Rb2 and Rd have a relatronship with some transport proteins. The bioavailability of the ginsenosides has reduced compared to the single Panax ginseng extract when compatibility with a certain amount of Veratrum nigrum.
