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1.
多甲氧基黄酮(PMFs)是一类存在于柑橘属植物中具有显著抗癌、抗炎和抗氧化等生物活性的天然产物。为了提高多甲氧基黄酮类化合物的水溶性和药用价值,以2种来源丰富且抗癌活性高的多甲氧基黄酮橘皮素和川陈皮素为底物,分别经过氧丙酮氧化得到多甲氧基黄酮醇[3-羟基橘皮素(7)和3-羟基川陈皮素(8)],化合物7和化合物8分别在K2CO3和N,N-二甲基甲酰胺条件下与氯乙酸乙酯进行Williamson反应,生成了多甲氧基黄酮羧酸酯类衍生物,再经碱性水解合成了2种未见文献报道的多甲氧基黄酮羧酸衍生物[橘皮素-3-O-乙酸(1)和川陈皮素-3-O-乙酸(2)]。化合物1和化合物2在CH2Cl2作溶剂、1-(3-二甲基丙胺)-3-乙基碳二亚胺盐酸盐为缩合剂和4-N,N-二甲氨基吡啶为辅助剂的条件下,分别与2种不同的氨基酸甲酯盐酸盐发生缩合反应,得橘皮素和川陈皮素的氨基酸甲酯衍生物,然后经水解反应得到了4种新型多甲氧基黄酮氨基酸衍生物3~6。对所合成的化合物用1H NMR、13C NMR和MS等方法进行了结构表征。  相似文献   

2.
应用一条新的合成路线合成了尚未见文献报导的黄酮 4′ O 糖苷8:先由庚二酰氯1与对甲氧基苯乙酮的烯胺2反应生成4′ 甲氧基四氢黄酮3,再经脱氢、脱甲基得到4′ 羟基黄酮5,最后与1 溴 2,3,4,6 O 四乙酰基 α D 吡喃葡萄糖进行缩合生成了黄酮 4′ O 糖苷8.  相似文献   

3.
应用一条新的合成路线合成了尚未见文献报导的黄酮—4’O糖苷8:先由庚二酰氯l与对甲氧基苯乙酮的烯胺2反应生成4’—甲氧基四氢黄酮3,再经脱氢、脱甲基得到4’-羟基黄酮5,最后与l—溴—2,3,4,6—O四乙酰基—α-D-吡喃葡萄糖进行缩合生成了黄酮—4’—O-糖苷8.  相似文献   

4.
对傣药决明属植物神黄豆(Cassia agnes Brenan)茎叶的化学成分进行研究.运用硅胶、HPLC等多种色谱技术从傣药神黄豆90%乙醇提取物中分离得到10个单体化合物.化合物1~9为黄酮类化合物.根据化合物的理化性质及波谱数据分析,将其分别鉴定为:山奈酚-3-O-α-L-鼠李糖苷(1),桑色素-3-O-α-鼠李糖苷(2),山奈酚(3), 5, 7, 3′, 4′-四羟基黄酮(4), 3-甲氧基槲皮素(5), 3, 5, 7, 3′, 4′-五羟基黄酮(6),表阿夫儿茶精(7),表儿茶素(8),表儿茶素-(4β→8′)-表儿茶素(9),原儿茶酸(10).其中,1~6、8和10为首次从该植物中分离得到.  相似文献   

5.
运用硅胶、HPLC等多种色谱技术对决明属植物粉花山扁豆(Cassia nodosa Buch.-Ham.ex Boxb)茎叶的化学成分进行分离纯化,根据理化性质和波谱数据鉴定化合物的结构.从粉花山扁豆茎叶中分离鉴定了5个黄酮类化合物,包括1个未见报道的黄酮类化合物,命名为山奈酚-3-O-[(4″,5″-O-异丙叉基)-α-L-吡喃鼠李糖苷(1);以及4个已知的黄酮类化合物,分别鉴定为山奈酚-3-O-β-D-吡喃鼠李糖苷(2)、3,5,7,3',4'-五羟基黄酮(3)、高山黄芩素(4)、5,7,3',4'-四羟基黄酮(5).其中,化合物1为新化合物,化合物2~5为已知化合物.  相似文献   

6.
通过Hoesch反应和Friedel-Craft反应分别合成了金雀花异黄素和芒柄花素两种异黄酮化合物,同时采用十六烷基三甲基溴化铵为相转移催化剂,研究了该类化合物与1-溴-2,3,4,6-O-四乙酰基-α-D-吡喃葡萄糖缩合制备7-O-糖苷的合成工艺,其合成收率分别为43%和51%.  相似文献   

7.
在糖类化合物合成中,微波辅助技术是一种有效手段.应用微波辅助技术研究了五乙酰基保护葡萄糖与直链醇在固体酸蒙脱石K-10和4×10-10m的分子筛作用下的烷基氧糖苷化合物的合成,实现了对糖苷化反应产物构型的有效控制,并推测烷基糖苷类衍生物的合成反应机理.  相似文献   

8.
以[(CH3OCH2CH2OCH2CH2)3N]为相转移催化剂,白杨素和鸡豆黄素为苷元,研究了黄酮和异黄酮类化合物分别与1-溴-2,3,4,6-O-四乙酰基-α-D-吡喃葡萄糖进行缩合反应制备糖苷的合成工艺.其合成收率分别为60%和54%.  相似文献   

9.
鬼箭锦鸡儿细胞毒活性成分研究   总被引:2,自引:0,他引:2  
 运用中压柱色谱和高效制备液相色谱方法对藏药鬼箭锦鸡儿的化学成分进行分离纯化,利用现代波谱技术鉴定所分离化合物的结构,并对所得到的化合物进行体外抗肝癌活性测试.从鬼箭锦鸡儿乙醇提取物中分离得到8个单体化合物,分别鉴定为6,7,3′-三羟基-4′-甲氧基异黄酮(1)、3,7-二羟基-4′-甲氧基黄酮(2)、3-甲氧基-4,9-二羟基紫檀素(3)、7,3′-二羟基-5′-甲氧基异黄酮(4)、6,7-二羟基-4′-甲氧基异黄酮(5)、3,9-二甲氧基-8-羟基紫檀素(6)、3,9-二甲氧基-4-羟基紫檀素(7)和3-甲氧基-4-羟基高丽槐素(8),所有的化合物为首次从该植物中分离得到.采用MTT法对化合物1~8进行体外抗肝癌活性测试,结果显示所有的化合物对2个肝癌细胞株HepG2和Hep3B均有抑制作用,它们的IC50值范围为22.5~104.7μg/mL.  相似文献   

10.
樟树叶化学成分研究   总被引:1,自引:0,他引:1  
为研究樟属植物香樟树叶的化学成分,运用正相和反相硅胶柱层析、半制备型高效液相色谱法对樟树叶提取分离纯化,用波谱技术鉴定其结构.结果表明:从该植物中分离得到5个化合物,其中1个为木脂素类化合物,4个为黄酮苷类化合物,分别为(8R,8'R)-3,3',4,4'-四甲氧基-9-氧代-8-8',9-O-9'-木脂素(I),槲皮素-3-Ο-α-L-鼠李糖苷(II),山奈酚-3-Ο-β-D-葡萄糖基(6→1)-α-L-鼠李糖苷(III),芦丁(IV),槲皮素-3-Ο-β-D-葡萄糖苷(V).  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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