首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 265 毫秒
1.
从翠雀花根的乙醇提取物中分得两个新的C~2二萜生物碱:翠雀花定(1)和乙酰翠雀花定(2)经谱图分析(IR, ^1H和^13C NMR, )推定了它们的结构。迄今报告的C~20二萜生物碱中, 1和2在结构上是具有含氧了取代基最多的两例药理试验表明,2有镇痛作用。  相似文献   

2.
采用密闭微波辅助法(PMAE)提取还亮草中的硬飞燕草碱和巴比翠雀碱。采用单因素试验结合正交试验方法对微波实验条件进行优化。得到硬飞燕草碱和巴比翠雀碱的最佳提取方案:药物颗粒度100目,固液比1∶60,微波温度80℃,微波功率560 W,微波时间10 min。以甲醇-0.2%三乙胺(45∶55)为流动相,建立了高效液相色谱(HPLC)测定硬飞燕草碱和巴比翠雀碱含量的方法。硬飞燕草碱和巴比翠雀碱分别在0.50~50.0,0.30~30.0 mg/L范围内呈良好的线性关系,回收率为98.3%~104.5%,相对标准偏差(RSD)分别为2.0%和2.2%。与传统溶剂回流法(SRE)进行比较,该方法简单、提取率更高。  相似文献   

3.
毛莨科翠雀属(Delphinium)植物主要分布在北温带,我国约有近120种翠雀属植物[1],广泛分布在西藏、四川西部、青海和甘肃,生于海拔2100~4000米山地草坡或多石砾山坡,其中许多是著名的中药,具有镇痛、消炎、抗菌治疗心血管病、抗癌等功效[2],陈耀祖院士等曾对川西翠雀和甘肃南部的蓝翠雀中二萜生物碱的提取分离及结构鉴定进行了研究[3],考虑到同一种植物生长的环境不同,所含化学成份也不尽相同,我们选择了青海翠雀进行了研究[4],以充分利用和开发我国的药用植物资源.中药的神奇功效体现在多种成分的协调作用,对中草药进行多个部位,多种成分的综合研究是中药现代研究的发展方向[5],本文用GC-MS对青海翠雀花挥发油的化学成分进行了研究.  相似文献   

4.
两个具有特殊骨架的C_(20)-二萜生物碱北乌灵(kusnezoline)和峨翠灵( omeieline)分别分自中国特产毛茛科植物北草乌(Aconitum hkusnezoffii Paritz)、彭州岩乌头(A. racemulosum var. pengzhouense)和峨眉翠雀花( Delphinium omeiense W. T. Wang)。应用2D NMR技术(~1H-~1H COSY, HMQC, HMBC, NOESY)全面归属了这两个生物碱的~1H和~(13)C信号的化学位移。  相似文献   

5.
采用顶空固相微萃取气质联用(HS-SPME-GC-MS)法对伊犁翠雀花挥发性成分进行提取并鉴定,以色谱峰面积归一化法计算各成分的相对百分含量。结果表明,伊犁翠雀花中鉴定的挥发性成分为38个,其主要成分为(E)-2-庚烯醛(7.76%)、苯甲醛(7.62%)、正辛醇(7.16%)、3,5-辛二烯-2-酮(6.12%)、已醛(3.53%)、1,4-二甲氧基苯(3.27%)、壬醛(3.12%)、反-β-金合欢烯(2.92%)等,伊犁翠雀花的主要挥发性成分为醛类、芳香族、酮类、醇和萜类化合物。  相似文献   

6.
用柱层析、制备薄层层析等对青海翠雀的化学成份进行了分离,并用IR,FA, MS,1HNMR,13C NMR及DEPT等光谱确定了化合物的结构,共分得5种二萜生物碱, 其中一种为新化合物,还分得一种非生物碱β-谷甾醇.  相似文献   

7.
报道了盐酸帕罗西汀的分子结构解析方法,利用国产核磁共振波谱仪测试了盐酸帕罗西汀核磁氢谱(^(1)H-NMR)、核磁碳谱(^(13)C-NMR、DEPT 135°)、二维核磁相关谱(^(1)H-^(1)HCOSY、^(13)C-^(1)H HSQC、^(13)C-^(1)H HMBC),实现了盐酸帕罗西汀氢碳的全部归属.  相似文献   

8.
A novel complex of monomeric thallium (Ⅲ) with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multimuclear NMR(^1H,^13C,^205Tl). The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the ^205Tl NMR spectra. The ^1H and ^13C NMR spectra of tris-phen T1(Ⅲ) complex have been measured, where the spin-spin coupling between T1(I=1/2) and ^13C or ^1H signals were observed with the ^1H and ^13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.  相似文献   

9.
对多司马酯的紫外(UV)光谱、红外(IR)光谱、氢谱(^1HNMR)、碳谱(^13CNMR)、氢氢相关谱(^1H-^1HCOSY)、碳氢相关谱(HETCOR)及碳氢远程相关谱(COLOC)进行了解析报道,并对所有的^1HNMR,^13CNMR谱的信号进行了归属,讨论了红外吸收光谱峰所对应的官能团的振动形式。  相似文献   

10.
二醋酸纤维素接枝聚己内酯的核磁共振表征   总被引:4,自引:0,他引:4  
用^1H-NMR和^13C-NMR研究了二醋酸纤维素(CDA)和聚己内酯(PCL)的接枝共聚反应,确定了^1H-NMR和^13C-NMR谱中各谱峰的归属,为证明二醋酸纤维素和己内酯的接枝共聚反应提供了依据。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

13.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

14.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

15.
16.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

17.
Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.  相似文献   

18.
A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.  相似文献   

19.
A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).  相似文献   

20.
Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO4 oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号