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1.
采用溶剂萃取、硅胶色谱柱、C18反相色谱柱、LH-20凝胶色谱柱、高效液相色谱等方法分离纯化,通过核磁共振波谱和质谱及旋光仪等仪器鉴定忧遁草化合物的结构.从忧遁草的95%乙醇提取液中分离鉴定9个化合物,分别鉴定为黑麦草内酯(1),异黑麦草内酯(2),3-羟基-9甲氧基紫檀烷(3),蚱蜢酮(4),(-)evofolin B(5),3-羟基-1-(4-羟基-3,5-二甲氧基苯)-1-丙酮(6),吲唑(7),吲哚-3-甲醛(8),entadamide A(9).其中化合物3-6,9为首次从忧遁草中分离得到.  相似文献   

2.
通过溶剂提取法和多种色谱方法对宜昌润楠(Machilus ichangensis Rehd.et Wils.)的干燥茎枝进行分离纯化,利用现代波谱技术(MS、1H NMR、13C NMR、DEPT、CD)和理化性质进行结构鉴定.从宜昌润楠95%乙醇提取物中分离得到16个酚类化合物,分别鉴定为(2R,3R)-4'-羟基-5,7,3'-三甲氧基黄烷-3-醇(1),(2R,3R)-3-羟基-5,7-二甲氧基-4',5'-亚甲二氧基黄烷(2),(+)-儿茶素(3),(-)-表儿茶素(4),柚皮素(5),达维荚蒾苷元(6),反式对香豆酸(7),咖啡酸(8),阿魏酸(9),异阿魏酸(10),东莨菪素(11),异东莨菪素(12),胡椒基酸(13),香草酸(14),原儿茶酸(15),丁香酸(16).所有化合物均为首次从该植物中分离得到.  相似文献   

3.
从豆科植物九龙藤(Bauhinia championii Benth)的乙醇提取物中分离出7个已知黄酮类化合物,经过核磁共振谱(NMR)和质谱(MS)分析及标准品对照,鉴定了它们的结构,分别为:5,6,7,5′-四甲氧基-3′,4′-亚甲二氧基黄酮(1),5,6,7,3′,4′,5′-六甲氧基黄酮(2),5,7,3′,4′,5′-五甲氧基黄酮(3),5,6,7,3′,4′-五甲氧基黄酮(甜橙素)(4),5,7,4′-三甲氧基黄酮(5),5,7,3′,4′-四甲氧基黄酮(6),(-)-表阿夫儿茶素(7).其中化合物5,7为首次从该植物中分离得到.  相似文献   

4.
研究红树林真菌Alternaria sp.R6固相培养代谢产物,用硅胶和Sephadex LH-20柱层析手段从甲醇提取物分离单体,波谱技术鉴定结构,二倍稀释法测试抗菌活性。分离到(4R,5R)-4,5-二羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(1),(4R,5S,6R)-4,5,6-三羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(2),xylariacyclone B(3),(4S,5S,6S)-5,6-环氧-4-羟基-3-甲氧基-5-甲基-环己-2-烯-1-酮(4),LL-C10037α(5),1-羟基-8-(羟甲基)-6-甲氧基-3-甲基-9H-呫吨-9-酮(6),6-甲基-1-甲氧羰基-8-羟基呫吨-9-酮(7),6-羧基-1-甲氧羰基-2,8-二羟基呫吨-9-酮(8),麦角甾醇和过氧化麦角甾醇共10个化合物。化合物1,2,3,4,5,6和8为首次从Alternaria属分离到。化合物6和8对小麦赤霉、香蕉炭疽,化合物2对香蕉炭疽显示良好抗菌活性。  相似文献   

5.
对元宝草Hypericum sampsonii的化学成分进行研究。应用硅胶、Sephadex LH-20和C-18反相色谱柱等柱色谱技术进行分离纯化,并运用现代波谱分析技术(ESI-MS,1 H NMR,13 C NMR)进行结构鉴定。从元宝草全草(体积分数为95%的乙醇)提取物之乙酸乙酯部分离得到12个化合物,经结构鉴定,确定为:1-羟基-7-甲氧基酮(1),2-羟基-5-甲氧基酮(2),1,3-二羟基-2-甲氧基酮(3),1,7-二羟基-2-甲氧基酮(4),1,7-二羟基-4-甲氧基酮(5),槲皮素(6),山柰酚(7),3,8"-biapigenin(8),阿魏酸(9),咖啡酸甲酯(10),香草酸(11),β-谷甾醇(12)。其中,化合物2、8-11为首次从该植物中分离得到。  相似文献   

6.
采用硅胶、Sephadex LH-20和反相RP C18等柱色谱技术,从云南剑叶龙血树(Dracaena cochinchinensis)树叶甲醇和石油醚提取物中分离了7个化合物,包括3个黄酮类化合物,1个三萜和3个甾体化合物,经综合波谱分析分别鉴定为:4',7-二羟基-3'-甲氧基-8-甲基黄烷(1),7-羟基-4'-甲氧基高异黄烷(2),2',4,4'-三羟基查尔酮(3),(22E)-3β-acetoxystigmasta-5,22-diene(4),lanost-9-en-3β-ol(5),β-谷甾醇(6),胡萝卜苷(7).测定了化合物1~3改善Hep G-2细胞对胰岛素抵抗的作用,化合物1~3能显著增加细胞的葡萄糖消耗量.  相似文献   

7.
利用溶剂提取和正、反相色谱法、Sephadex LH-20凝胶柱色谱等技术对泰国产东革阿里(Eurycoma longifolia)树皮的化学成分进行分离纯化.采用核磁共振、质谱等波谱技术鉴定化合物的结构.从泰国产东革阿里树皮提取物中分离得到8个化合物,分别鉴定为铁屎米酮(1),铁屎米酮-N(3)-氧化物(2),9-羟基铁屎米酮(3),9-甲氧基铁屎米酮(4),9,10-二甲氧基铁屎米酮(5),东哥内酯(6),宽缨酮(7),豆甾-4,22-二烯-3-酮(8).化合物1~5为β-咔巴啉类生物碱,化合物6~7为苦木萜类成分,化合物8为甾体化合物,除化合物5和6外,其他6个化合物均为首次从该植物树皮中分离得到.  相似文献   

8.
对采自云南省香格里拉县海拔4 000 m的龙胆科(Gentianaceae)獐牙菜属植物高獐牙菜(Swertia elata)的化学成分进行研究.方法采用正相硅胶柱色谱,Sephadex LH-20凝胶柱色谱,HPLC,Zorbax PrepHT GF反相柱色谱及MCI等现代分离分析技术进行分离和纯化,并用95%的乙醇对该植物全株进行超声提取,在其正丁醇萃取部分分离出10个已知的化合物.并根据理化性质和波谱数据鉴定化合物结构分别为:1-羟基-3,5,8-三甲氧基酮(1),1-羟基-3,5-二甲氧基酮(2),1,7-二羟基-3,8-二甲氧基酮(3),1-羟基-3,7,8-三甲氧基酮(4),1,5-二羟基-3,8-二甲氧基酮(5),1,8-二羟基-3,7-二甲氧基酮(6),1,3-二羟基-7,8-二甲氧基酮(7),獐牙菜苷(8),(E)-aldosecologanin(9),葡萄糖香草醛苷(10),其中化合物9为首次从獐牙菜属植物中提取分离得到.  相似文献   

9.
目的:研究虫类中药蛴螬Holotrichia diomphalia Bates的化学成分。方法:采用各种色谱材料和技术(包括硅胶、RP-18反相硅胶、Sephadex LH-20、MCI gel CHP 20P、D101大孔吸附树脂柱色谱及高效液相色谱),结合谱学方法(NMR、MS、ORD)分离鉴定蛴螬的化学成分。结果:从蛴螬的乙醇提取物中分离得到10个化合物,其结构经波谱鉴定为反-1,2-环己二醇(1),甘油醇-1-单油酸酯(2),水杨苷(3),对甲氧基苯乙酸(4),苯甲酸甘油-1-酯(5),Yangjinhualine A(6),(±)2-羟基戊二酸二甲酯(7),邻羟基苯甲醇(8),对羟基苯乙酸(9)和oxiran-2-ylmethano(l 10)。结论:化合物1~10均为首次从该种虫类中药中分离得到。  相似文献   

10.
综合运用多种柱色谱技术从越南红土沉香乙醇提取物中分离得到13个化合物,经过现代波谱学技术鉴定其结构为:7-甲氧基-2-[2-(4-甲氧基苯基)乙基]色酮(1),6-甲氧基-2-(2-苯乙基)色酮(2),6,7-二甲氧基-2-(2-苯乙基)色酮(3),6-甲氧基-2-[2-(4-甲氧基苯基)乙基]色酮(4),6-甲氧基-2-[2-(3-甲氧基苯基)乙基]色酮(5),5-羟基-6-甲氧基-2-[2-(4-甲氧基苯基)乙基]色酮(6),6,8-二羟基-2-(2-苯乙基)色酮(7),(1β,3α,4aβ,5β,8aα)-4a,5-dimethyl-3-(prop-1-en-2-yl)octahydronaphthalene-1,8a(1H)-diol(8),rel-(4S,5R,7R,8R,11R)-eremophil-9-en-12,8-olide(9),cyclodebneyol(10),柯拉斯那酸甲酯(11),白木香醇(12)和4-表-15-羟基菖蒲螺烯酮(13).其中,化合物1为新天然产物,所有化合物均为首次从红土沉香中分离得到.以上化合物的抗炎活性测试结果表明,化合物3、8和13具有一定的抗炎活性,IC50值分别为81.23 ± 2.83、39.55 ± 3.75和72.63 ± 2.87 μmol·L-1.  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.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

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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