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1.
通过壳聚糖与含双胍基结构的芳酰氯反应,得到具有抗菌活性的双胍基化壳聚糖衍生物。利用对双胍基苯甲酸盐酸盐与氯化亚砜的反应,得到盐酸对双胍基苯甲酰氯后,再在甲烷磺酸-二甲基亚砜(MeSO3H-DMSO)介质中与壳聚糖进行缩合反应,得到了O-(4-双胍基苯甲酰基)壳聚糖盐酸盐(p-BGBC)。用FT-IR、1H-NMR、GP...  相似文献   

2.
通过二乙三胺五乙酸的双N-羟基琥珀酰亚胺活性酯与含氨基的乳糖或D-半乳糖衍生物反应,合成了8种含有D-半乳糖基的二乙三胺五乙酸非离子型配体,并进一步合成了其钆(Ⅲ)配合物,配体及配合物的结构经IR,^1HNMR与元素分析表征,对配合物的体外驰豫性能和小鼠急性毒性作了初步研究,家兔在磁共振成像实验表明这种上类造影剂具有肝靶向的特性。  相似文献   

3.
采用低硒饲料饲养大鼠造成体内贫硒。14周时测定血浆中脂质过氧化物(LPO)、前列环素(PGI2)和血栓素(TXA2)的水平以及部分血液流变学指标。实验第39周,测定血管组织一氧化氮合酶(NOS)活性及一氧化氮(NO)水平。结果显示,低硒饲料组的血管NOS活性、NO水平显著低于常规饲料的对照组;而在实验第14周时,当低硒饲料组的血硒、血谷胱甘肽过氧化物酶(GSH-Px)活性显著下降、血浆LPO水平明显上升的同时,其对应的血浆6-酮-PGF1α水平也显著降低,但其TXB2与对照组无显著差异。此外,随着大鼠体内的贫硒,其红细胞变形能力下降,但红细胞聚集指数和血沉方程K值提高。因此,硒不足可能会通过影响NOS活性和PGI2的合成以及红细胞特性而损害微循环功能。  相似文献   

4.
研究了具有“推-拉”电子结构的4‘-(N,N-二羟乙基)氨基4-硝基偶氮苯(R-HANB)衍生物的光谱性质和二阶非线性光学性质,R-HANB是一类假芪型偶氮苯分子其激发态具有相似的能级结构,且在不同状态下均具有较高的二阶非线性光学活性,其粉末二次谐波信号多数强于分散红1,一阶超极化率与基太偶极矩动量 合量用溶为色法测得为〉3.4×10^82C^2m^4/V^2,其5%掺杂聚甲基丙烯酸甲酯薄膜以电晕  相似文献   

5.
Schiff碱型壳聚糖高分子冠醚的合成和表征   总被引:4,自引:0,他引:4  
将4‘-甲酰基苯并15-冠和-5和4‘-甲酰基苯并18-冠-6与矣糖分子中的氨基反应,使冠醚单元接枝到高分子壳聚糖上,合成了Schiff碱型壳聚糖冠醚,经元素分析,IR,X-粉末衍射分析和固体^13C NMR分析表征了其结构。实验结果表明壳聚糖冠醚与预期结构相符。并初步考究他其对某些金属离子的吸附选择性。  相似文献   

6.
把硫原子引入液晶分子,取代液晶分子中的碳原子和氧原子可得到含硫代苯甲酸酯[1]、砜基[2]、亚砜基[3]和亚磺酸基[4]等结构的液晶化合物,性能独特.但含磺酸酯基的液晶化合物尚未见文献报道.本文应用N,N二环己基碳二亚胺(DCC)和4N,N二甲...  相似文献   

7.
在AM1和ZINDO方法基础上,按完全态求和公式计算分子二阶非线性光学βik和三介非线性光学系数γijki,并对含偶氮功能团的双炔类衍生物的二阶、三阶非线性光学性质进行了系统的理论研究,即在基础上,在分子在左端引入推电子基N(CH3),右端分别引入推电子基CH2OH、2,5-二氮-4-硫甲苯基,研究取代基变化时β、γ变化的规律,地计算结果所反映的规律性在微观上给予了解释。  相似文献   

8.
卢水明  毛丽娟 《合成化学》1998,6(4):335-338
利用N,N-二(2-氯乙基)氨基磷酰二异氰酸酯和胺的加成反应,合成了2,4,6三氧-1,3,5,2三氮磷杂环己烷衍生物,它们的结构经^1HNMR,IR和元素分析所证实。初步生物活性测试结果表明,部分化合物具有一定的抗肿瘤活性。  相似文献   

9.
合成了铜(Ⅱ)与苯基羧酸根[PCA-=苯甲酸根(Bz-),2-苯乙酸根(PAc-),3-苯丙酸根(PPr-),4-苯丁酸根[PBu-)]和2,2′-联吡啶衍生物(dpx:2,2′-联吡啶胺dpa、2,2′-联吡啶酮dpk、2,2′-联吡啶甲烷dpm)三大系列12种新的三元配合物。用元素分析、摩尔电导、红外光谱、1H核磁共振、差热分析等实验方法表征了它们的组成和性质。确定该系列配合物化学组成为Cu(PCA)2(dpa)、Cu(PCA)2(dpm)、Cu(PCA)2(dpk)·nH2O(n=2-4)。它们具有相似的组成和配位方式。它们的可能结构为:二个PCA-与Cu(Ⅱ)单齿配位,一个dpx与Cu(Ⅱ)N,N二齿螯合配位。dpk的羰基在金属离子Cu2+的存在下发生水化作用成dpk·H2O。用1HNMR法研究了Cu(Bz)2(dpx)·nH2O和Cu(PAc)2(dpx)·nH2O二个体系其分子内或分子间可能存在的非共价键作用。  相似文献   

10.
利用N,N-二(2-氯乙基)氨基磷酰二异氰酸酯和胺的加成反应,合成了2,4,6-三氧-1,3,5,2-三氮磷杂环己烷衍生物,它们的结构经1HNMR,IR,MS和元素分析所证实.初步生测结果表明,部分化合物具有一定的抗肿瘤活性.  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.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

13.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

14.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

15.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

16.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

17.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

18.
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   

19.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

20.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

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