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1.
采用薄层色谱,正相、反相硅胶,葡聚糖凝胶,半制备高效液相柱对中药藤梨的正丁醇部位进行了分离研究.得到8个化合物,分别为:2-β-D-葡萄糖-1,3,7-三羟基-酮(1),7-O-[β-D-吡喃木糖-(1-6)-β-D-吡喃葡萄糖苷]-1,8-二羟基-3-甲氧基-酮(2),3-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃葡萄糖]-5,7,4′-三羟基黄酮(3),6-C-葡萄糖-5,7,3′,4′-四羟基黄酮(4),6-C-葡萄糖-5,7,4′-三羟基黄酮(5),1-O-[β-D-吡喃木糖-(1-6)-β-D-吡喃葡萄糖苷]-8-羟基-3,7-二甲氧基-酮(6),3-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃半乳糖]-5,7,3′,4′-四羟基黄酮(7),7-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃葡萄糖]-5,3′-二羟基-4′-甲氧基二氢黄酮(8).所有的化合物都是首次从该植物分离得到.  相似文献   

2.
通过现代分离技术并经波普分析研究,分离得到了土贝母乙酸乙酯部位8个化合物,并鉴定为:7-羟基-6-甲氧基香豆素(1)、表儿茶素(2)、儿茶素(3)、(E)-N-(4-羟基苯乙基)-3-(4-羟基-3-甲氧基苯基)丙烯酰胺(4)、邻苯二甲酸二丁酯(5)、(Z)-3-O-咖啡酰基-4-O-甲基奎宁酸甲酯(6)、绿原酸(7)、3-O-[β-D-吡喃鼠李糖-(1-6)-β-D-吡喃葡萄糖]-5,7,4'-三羟基黄酮(8).此8个化合物均为首次从该植物中分离得到.  相似文献   

3.
采用硅胶柱色谱、Sephadex LH-20柱色谱、RP-18柱色谱方法对水青树(TetracentronsinenseOliv.)茎干进行了成分分离纯化,并利用UV、NMR、MS等波谱光谱方法对化学成分进行结构鉴定.共从水青树乙酸乙酯与正丁醇萃取部分中分离并鉴定了15个化合物,分别为2-羟基-5-(2-羟乙基)苯β-D-葡萄糖甙(1),2,6-二甲氧基-4-羟基苯1-O-β-D-吡喃葡萄糖甙(2),3,5-二甲氧基-4-羟基苯1-O-β-D-吡喃葡萄糖甙(3),丁香酸β-D-葡萄糖酯(4),丁香酸4-β-D-葡萄糖甙(5),甲氧基四氢醌-4-β-D-葡萄糖甙(6),甲氧基四氢醌-1-β-D-葡萄糖甙(7),对-羟基肉桂酸(8),β-乙酰鼠李糖甙(9),α-乙酰鼠李糖甙(10),(+)-儿茶素(11),羽扇醇(12),3β,20-羽扇二醇(13),白桦子酸(14),齐墩果酸(15).除化合物11-13和15外,其余化合物均为首次从该植物中分离得到.  相似文献   

4.
对东方草莓(Fragaria Orientalis Lozinsk.)进行了系统的化学成分研究.采用正相硅胶柱、反相硅胶柱、MCI凝胶柱、凝胶柱及高效液相色谱对东方草莓的甲醇提取物分离得到一系列化合物,通过MS、NMR等波谱技术鉴定了其中的8个化合物,分别为(+)-儿茶素(1)、山柰酚-3-O-(6″-反式-对-香豆酰基)-β-D-葡萄吡喃糖苷(2)、对羟基苯乙醇(3)、3-羟基-4-甲氧基苯乙醇(4)、芹菜素(5)、槲皮素(6)、槲皮素-3-O-β-D-葡糖苷(7)、β-谷甾醇(8).  相似文献   

5.
白蒺藜果实的化学成分研究   总被引:1,自引:1,他引:0  
采用硅胶柱层析、凝胶柱层析从白蒺藜(Tribulus terrestris L.)醇提液正丁醇萃取层中分离纯化得到8个化合物,运用核磁共振、质谱等光谱方法鉴定结构分别为:N-对羟基苯乙酮基-3-甲氧基-4-羟基取代桂皮酰胺(Ⅰ),槲皮素-3-O-β-D-葡萄糖苷 (Ⅱ),3′-甲氧基-槲皮素-3-O-β-D 葡萄糖苷(Ⅲ),3′-甲氧基-槲皮素-3-O-β-D-龙胆二糖苷(Ⅳ),海柯皂苷元-3-O-β-D-吡喃葡糖基-(1-4)-β-D-吡喃半乳糖苷(Ⅴ),海柯皂苷元-3-O-β-D-吡喃半乳糖基(1-2)-[β-D-木糖基(1-3)]-β-D-吡喃葡糖基(1-4)-β-D-吡喃-半乳糖苷(Ⅵ),苯甲酸(Ⅶ),尿嘧啶核苷(Ⅷ)。其中化合物Ⅳ,Ⅶ,Ⅷ为首次从该植物中分离得到,也是首次从该属植物中分离获得。  相似文献   

6.
采用硅胶柱色谱法对蒙古黄芪花提取物进行分离,结合MS,1 H-NMR等波谱手段鉴定化合物的结构,以紫外分光光度法测定分离化合物的抗氧化能力。共分离鉴定出8种化合物,分别为:(1)金丝桃苷,(2)异槲皮苷,(3)7-甲氧基-山萘酚-3-O-半乳糖苷,(4)7-甲氧基-山萘酚-3-O-葡萄糖苷,(5)7-甲氧基-山萘酚-3-O-(6"-O-丙二酰基)-β-D-葡萄糖苷,(6)紫云英苷,(7)异鼠李素-3-O-β-D-吡喃葡萄糖苷,(8)毛蕊异黄酮。其中化合物(3)(4)(5)(7)为首次从黄芪属中分离得到。测定了黄芪花不同粗提物及纯成分的抗氧化活性,其中金丝桃苷与异槲皮苷抗氧化活性最强。  相似文献   

7.
采用硅胶柱层析、ODS和Sephadex LH-20等色谱技术,从仔榄树叶体积分数为95%乙醇提取物的正丁醇萃取部位分离得到11个化合物;通过理化性质和波谱数据分析,鉴定它们的结构分别为(±)-赤-3-甲氧基-4-羟基苯基丙三醇(1)、(±)-苏-3-甲氧基-4-羟基苯基丙三醇(2)、(+)-syringaresinol-4,4’-O-bis-β-D-glucopyranoside(3)、1,3,5-三甲氧基苯(4)、丁香酸葡萄糖苷(5)、2,6-二甲氧基-4-羟基-1-O-β-D-吡喃葡萄糖苷(6)、3,5-二甲氧基-苄醇-4-O-β-D-吡喃葡萄糖苷(7)、(2E,6S)-8-(α-L-arabinopyranosyl-(1″fwdarw6’)-β-D-glucopyranosyloxy)-2,6-dimethyloct-2-eno-1,2″-lactone(8)、山奈酚-3-O-β-D-吡喃葡萄糖苷(9)、2-甲胺基苯甲酸(10)、D-1-O-methyl-myo-in-ositol(11).化合物1~11均为首次从该植物中分离得到.  相似文献   

8.
采用MCI柱色谱、硅胶柱色谱、Sephadex LH-20凝胶柱色谱和半制备HPLC等色谱分离手段对半育耳蕨的化学成分进行研究.利用理化性质及波谱数据(MS、NMR)对其结构进行鉴定,从半育耳蕨体积分数95%的乙醇提取物中分离并鉴定了10个化合物,分别是2R, 3R-3, 5, 6, 7, 8,4′-hexahydroxyflavane(1)、(-)-表儿茶素(2)、(+)-epicatechin(3)、arachniodesin A(4)、4β-carboxymethyl-(-)-epicatechin methyl ester(5)、eriodictyol(6)、daucosterol(7)、3, 4-二羟基苯甲酸乙酯(8)、圣草酚7-O-β-D-(6′-甲酯基)-吡喃葡萄糖醛酸苷(9)、圣草酚7-O-β-D-(6′-乙酯基)-吡喃葡萄糖醛酸苷(10).化合物1~10均为首次从耳蕨属中分离得到.活性测试结果表明,化合物4、5和6对α-葡萄糖苷酶具有较好的抑制活性,其IC_(50)分别为(26.2±1.9)、(32.6±2.5)和(51.5±3.5)μmol·L~(-1).  相似文献   

9.
目的:对思茅松松塔的化学成分进行初步研究。方法:采用溶剂法提取思茅松松塔的化学成分,运用正相硅胶、反相RP-18、Sephadex LH-20柱色谱和中压液相色谱等方法进行分离纯化,利用波谱数据鉴定化合物的结构。结果:从中分离鉴定了6个化合物,分别为:松脂醇(1),罗汉松树脂酚(2),(7S,8R)-3′,4,9,9′-四羟基-3-甲氧基-7,8-二氢苯并呋喃-1′-丙醇基新木脂素(3),dihydrodehydrodiconiferyl alcoho(l4),二氢槲皮素-3′-O-β-D-吡喃葡萄糖苷(5),3,4-二羟基苯甲酸(6)。结论:6个化合物均首次从该植物中分离得到。  相似文献   

10.
从匙萼木(Xanthophytum attopvensis Pierre)中分离提取了6种已知蒽醌化合物,用SRB法测试了它们对4种人肿瘤细胞株的体外细胞毒活性.实验结果表明,未有糖基取代的1,3-二羟基-2-醛基蒽醌(1)和1-甲氧基-2-醛基-3-羟基蒽醌(2)对4种细胞株均显示了较强的细胞毒活性,它们比具有糖基取代基的化合物1 甲氧基-2-羟化甲基-3-O-β-D-吡喃葡萄糖蒽醌(3),1-羟基-2-甲基蒽醌-3-O-β-D-吡喃木糖(1→6)-β-D- 吡喃葡萄糖苷(4),1-甲氧基-2-羟甲基蒽醌-3-O-β-D-吡喃木糖(1→6)-β-D-吡喃葡萄糖苷(5)及1,3 二羟基-2-羟甲基蒽醌-3-O-β-D- 吡喃木糖(1→6)-β-D- 吡喃葡萄糖苷(6)的细胞毒活性高约4.7~12.7倍,这可能缘于糖基取代基较大的空间位阻使得化合物与细胞中靶分子的相互作用减弱所致;仅有C-1位取代基不同的化合物1和化合物2具有相似的细胞毒活性,表明蒽醌化合物C-1位为-OH或-OCH3取代时,它们对化合物的细胞毒性贡献相似;与其它3种细胞株相比,HL 60细胞株对蒽醌化合物有更高的敏感性,其对每种蒽醌化合物的IC50值比其它3种细胞株所得IC50值低1.2~2.5倍;6种蒽醌化合物中化合物1和化合物2具有进一步研究的价值.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

14.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

16.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
1 Rise of studies on climate change's effects on biodiversity
Until the 1980s, climate change and biodiversity were studied as two independent disciplines for more than a century. In 1992, the Ecological Society of America's annual report named climate change, biodiversity, and the sustainable ecological system as the three major global environmental issues of the twenty-first century [1].  相似文献   

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