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菊粉酶中色氨酸残基的化学修饰及其荧光光谱 总被引:2,自引:0,他引:2
用N-溴代琥珀酰亚胺为修饰剂, 研究菊粉酶中的Trp残基的分布及其对酶生物学功能的影响, 为进一步研究菊粉酶结构与其功能之间的关系提供了新的信息. 相似文献
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人纤维蛋白溶酶原中色氨酸残基的化学修饰 总被引:3,自引:1,他引:3
以N-溴代琥珀酰亚胺为修饰剂,对人纤维蛋白溶酶原(HPg)中色氨酸(Trp)残基的分布及其与酶活力的关系进行了研究,发现每个HPg分子有19个Trp残基,5个位于分子表面:有2个是快反应残基,其中1个是活性必需的氨基酸,酶被修饰后其荧光光谱及圆二色谱发生了变化。 相似文献
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用化学修饰法以N-溴代琥珀酰亚胺作修饰剂,对聚半乳糖醛酸酶(PG2)中色氨酸(Trp)残基与酶活性的关系进行研究,发现1个PG2分子中有6个Trp残基,其中4个位于酶分子内部,2个位于酶分子表面,该发现通过表面荧光猝灭实验得到进一步证明,酶分子表面的2个Trp残基中,有1个为活性必需的氨基酸,它的修饰导致大部分酶活力丧失,底物保护实验进一步证明该活性必需的Trp可能位于酶的活性部位,酶被修饰后其圆 相似文献
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当Pd(Ⅱ)与色氨酸(Trp)、酪氨酸(Tyr)及苯丙氨酸(Phe)等芳香族氨基酸相互作用时,能观察到3种氨基酸的荧光均发生猝灭. 从吸收光谱的变化,温度对猝灭作用的影响以及猝灭常数Ksv,可以判定荧光猝灭作用是由于Pd(Ⅱ)与上述氨基酸形成基态配合物而导致的静态猝灭过程. 并认为在一定浓度的Cl-存在下,Pd(Ⅱ)与氨基酸分别以N, N配位和N, O配位形成以下混配型三元配合物Pd(HR)Cl2 (Trp和Phe体系)和Pd(H2R)Cl2(Tyr体系),并推测了配合物相应的结构. 该荧光猝灭体系不仅可用于研究钯(Ⅱ)与上述芳香族氨基酸的相互作用,也可成为以氨基酸(特别是Trp)作探针高灵敏荧光猝灭法测定钯的基础. 相似文献
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荧光光谱研究喹诺酮抗菌素与过氧化氢酶的相互作用 总被引:3,自引:0,他引:3
应用荧光光谱法研究了水溶液中喹诺酮抗菌素氧氟沙星、环丙沙星与过氧化氢酶分子间的结合反应。结果表明:药物对过氧化物酶的内源荧光有较强的猝灭作用,形成复合物所产生的静态猝灭是引起过氧化氢酶荧光猝灭的主要原因。进一步依据荧光猝灭结果确定了药物-酶复合物的形成常数和结合位点数。 相似文献
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本文运用荧光光谱法研究亚甲蓝(MB)分别与色氨酸(Trp)、酪氨酸(Tyr)和苯丙氨酸(Phe)三种芳香族氨基酸的相互作用。在pH 7.4 Tris-HCl缓冲溶液中,MB引起上述三种氨基酸明显的荧光猝灭现象,最大荧光猝灭波长分别位于346、303和282nm。其荧光猝灭值(F0-F)在一定范围内与MB成正比,用于测定MB具有高灵敏度。通过Stern-Volmer作图及温度的影响,表明MB与三种芳香族氨基酸之间以摩尔比1∶1形成基态复合物,均产生显著的静态猝灭,相互作用力较强,其中MB主要通过疏水作用与Trp结合,与Tyr和Phe之间的结合过程以静电作用力为主。 相似文献
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酪氨酸,色氨酸荧光光谱计算解析与同时测定新方法研究 总被引:4,自引:0,他引:4
本文用多波长生回归、双峰倍增配平和拟面积多波长数据线性双组合等3种计算方法解析酪氨酸、色氨酸荧光光谱、,建立了3种新的同时测定2种氨基酸分析方法,考察了3种分析方法的精密度、回收率和组分间浓度比范围。 相似文献
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A new lignan named schilignan F (1), together with twelve known ones (2–13), were isolated from the rattan stems of Schisandra chinensis. Their chemical structures were elucidated by spectroscopic methods including one and two-dimensional NMR spectra referring to the literatures as well as high-resolution mass spectrometric analysis. All compounds were evaluated for their cytotoxicities against human Hela cancer cell lines in vitro. The results showed that compounds 2, 6 and 8 exhibited weak cytotoxic activity with IC50 values of 30.6, 86.3 and 41.0 μM, and cisplatin showed cytotoxic activity with IC50 value of 27.3 μM. 相似文献
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Metabolomics analysis reveals variation in Schisandra chinensis metabolites from different origins
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Yinan Zhang Fen Li Fengjie Huang Guoxiang Xie Runmin Wei Tianlu Chen Jiajian Liu Aihua Zhao Wei Jia 《Journal of separation science》2014,37(6):731-737
Wu Wei Zi (Schisandra chinensis), an important herbal medicine, is mainly distributed in the northeast of China. Its phytochemical compositions, which depend on geographical origin, climatic conditions and cultural practices, may vary largely among Wu Wei Zi from different areas. In this study, we applied a comprehensive metabolite profiling approach using GC–TOF‐MS, ultra‐performance LC (UPLC) quadrupole TOF (QTOF) MS and inductively coupled plasma MS to systematically investigate the metabolite variations of S. chinensis from four different areas including Heilongjiang, Liaoning, Jilin, and Shanxi of China. A total of 65 primary metabolites, 35 secondary metabolites and 64 inorganic elements were identified. Several primary metabolites, including shikimic acid and tricarboxylic acid cycle intermediates, were abundant in those located in Heilongjiang, Jilin, and Liaoning. Besides, bioactive lignans are also highly abundant in those from northeastern China than those from northwestern China. Inorganic elements varied significantly among the different locations. Our results suggested that the metabolite profiling approach using GC–TOF‐MS, ultra‐performance LC quadrupole TOF MS, and inductively coupled plasma MS is a robust and reliable method that can be effectively used to explore subtle variations among plants from different geographical locations. 相似文献
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A new cirmamic acid monoterpenoid ester, intermedin C (1), was isolated from the aerial parts of Schisandra propinqua vat. intermedia. The structure of 1 was elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. 相似文献
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A new bianthraquinone glycoside, 8-O-β-D-glucopyranosyl-2,7'-bi(1,8-dihydroxy-3-methyl-9,10-anthraquinonyl) 1 was isolated from Eremurus chinensis Fedtch. Its structure was established by spectroscopic techniques including 2D-NMR and chemical methods. 相似文献
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Chemical constituents from Schisandra sphenanthera 总被引:1,自引:0,他引:1
The chemical constituents of the stems of Schisandra sphenanthera are described for the first time. This investigation has resulted in the isolation of a new phenolic glycoside (1), along with seven known compounds. The structure of 1 was assigned by using spectroscopic techniques, including 2D NMR spectra. 相似文献
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Eremurus chinensis Fedtch has a wide distribution in the western part of China; it hasbeen used in Chinese folk medicine for the treatment of rheumatism and physicalweaknessl. Only few reports describe polysaccharides'-' rather than other chemicalconstituents from the genus Eremurus. We report here the isolation and structuralelucidation of a new bianthraquinone glycoside, 8-O- P -D-glucopyranosyl-2,7'-hi(l,8dihydroxy-3-methyl-9,10-anthraqu 1 from E. chinensis.The EtOAc soluble fraction ob… 相似文献
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New flavone and isoflavone glycoside from Belamcanda chinensis 总被引:2,自引:0,他引:2
Li Jin Hai Sheng Chen Zhao Bao Xiang Shuang Liang Yong Sheng Jin Jian Guo Liu College of Pharmacy Second Military Medical University Shanghai China College of Bio-information Chongqing University of Posts Telecommunications Chongqing China 《中国化学快报》2007,18(2):158-160
The new flavone, 5,4'-dihydroxy-6,7-methylenedioxy-3'-methoxyflavone, and one new isoflavone glycoside, 3',5'-dimethoxy irisolone-4'-O-β-D-glucoside were isolated from the rhizomes of Belamcanda chinensis. Their structures were established based on the spectroscopic methods. 相似文献
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线叶紫菀中一个单萜酸的化学结构王明安,陈耀祖(北京农业大学应用化学系,北京,100094)(兰州大学化学系)关键词线叶紫菀,单萜,结构分析线叶紫菀(AsterfarreriW.W.SmithetJ.F.Jeffery)系菊科紫菀属多年生草本植物,用于... 相似文献
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应用自主研发的具有分离-富集模式的制备色谱工厂,建立了分离制备五味子木脂素有效部位及其单体化合物的方法。该方法首先以C18(250 mm×4.6 mm,5 μm)为色谱柱,水和甲醇为流动相,分离度和保留时间为考察指标,采集4个不同梯度的色谱信息,通过XTool色谱专家系统软件模拟,确定五味子木脂素第一、二维色谱条件;然后采用线性放大的方法,以C18(250 mm×30 mm,10 μm)为第一、二维分离柱,C18(80 mm×30 mm,10 μm)为富集柱,水为富集稀释液,对五味子木脂素进行二维色谱分离纯化;最后第一维分离得到9个可重复组分,第二维分离得到20个高纯度化合物,其中有6个单体化合物。结果表明该法重现性良好,可以实现五味子木脂素的系统性分离,对五味子化学成分的研究具有重要意义。 相似文献
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XingGenTAI~ ShuLinPENG XunLIAO JianLIANG LiShengDING 《中国化学快报》2003,14(10):1027-1028
A novel pregnane glycoside, biondianoside E, was isolated from the roots of Biondia chinensis. By the spectroscopic and chemical methods, this structure was elucidated as 3β, 5β,14β, 20S, 21-pentahydroxypregnane 3-O-β-D-glucopyranosyl-(1→4)-β-D-cymaropyranoside. 相似文献