共查询到20条相似文献,搜索用时 203 毫秒
1.
Rong ZHENG Chang Jin ZHU Yi LIU Dong WANG 《中国化学快报》2006,17(4):434-436
A pair of derivatives of tetrameric N-methylpyrrole polyamide were synthesized in order to develop a new method for the study of interaction of the polyamide derivatives with DNA. Indole acetic acid and nicotinic acid were introduced to the polyamide in the synthesized compound, which showed an expected red shift in the UV spectrum. These compounds may function as a potential tool in the detection of the polyamide binding to DNA. 相似文献
2.
《Electrochemistry communications》1999,1(1):10-13
The synthesis and molecular recognition properties of a new sulfur containing β-cyclodextrin (β-CD) derivative chemisorbed on a silver surface are described. Hepta-6-amino-6-deoxy-β-CD was allowed to react with CS2 in the presence of ammonia to give a mixture of partially substituted dithiocarbamate derivatives with an average degree of substitution of 4.5. A modified silver electrode with this derivative is capable of discriminating between the three positional isomers of nitrobenzoate ion and nitrophenol, as determined by cyclic voltammetry. Only the meta- and para-isomers give a signal corresponding to the reduction of the nitro group. This is attributed to the different orientations of the nitro group with respect to the silver surface after inclusion in the CD cavity. Experiments in the presence of cyclohexanol showed a decrease in signal intensity of the meta- and para-isomers which is associated with the competitive complexation of this guest, suggesting that the electroactive probe is complexed to the cavity. 相似文献
3.
A. B. Golovanchikov A. A. Shagarova N. A. Dul’kina 《Russian Journal of Applied Chemistry》2009,82(4):741-747
A transition to a flow virtually non-gradient in a screw reactors of heavy sedate liquid with thin wall layer is considered. The graphs of the differential response functions of the known models based on the ideal gas law for structures of flows (ideal mixture, ideal displacement, laminar and turbulent flows) in comparison with the response function of the sedate reaction mass were presented. The flow structure corresponds to the regime of the ideal displacement in the screw reactor at a treatment of the sedate reaction mass when air, water or other thin liquid are fed as lubricant in the wall layer. 相似文献
4.
Chui Lin RONG Xin Cheng LIAO Jian Chen ZHANG Shu Xia CAO Lun LIU Yu Fen ZHAO 《中国化学快报》2005,16(9):1140-1142
Different hydroxy substituted coumarins were successfully phosphorylated with diisopropylphophite (DIPPH) by the Atherton-Todd reaction in 76-89% yields. Moreover, the reaction activities of different hydroxys of the coumarins in the Atherton-Todd reaction were studied. 相似文献
5.
A series of novel type of glycophosphate mimics are synthesized by Todd reaction and their structure were determined on the basis of NMR,ESI-MS. 相似文献
6.
Shi Yong Fan Chun Lai Mi Jun Yang Song Li Zhi Bing Zheng 《中国化学快报》2007,18(4):400-402
The synthesis of a series of 3,6-dichloropyridazine derivatives was described.In vitro experiment,all compounds exhibited ananti-rhinovirus activity,and one of the compounds 6g showed the comparable activity as our lead compound pirodavir. 相似文献
7.
Alvarez Mauro Costa Silvio C. Huber Anton Baron Madalena Fontana José D. 《Applied biochemistry and biotechnology》1995,(1):367-377
The waxy pecto-cellulosic cuticle of cladodes of the columnar cactusCereus peruvianus (19% of the whole phytobiomass; dry wt) is a source of an α-d-polygalacturonic or pectic acid (35–40% yield, on a dry wt based on the wax-free pectocellulose layer). Warm EDTA/oxalate
or room temperature strong acid/alkali cycles are efficient for pectic acid extraction, since divalent cation (mainly Ca2+) is a barrier to be removed within the native and compact architecture of the cuticle. Despite some molecular dispersion
arising from the application of strong mineral acid in the first extraction step, the pectic material appears to be quite
homogeneous and, on acid or enzymatic analyses, was shown to contain onlyd-galacturonic acid as its monomer.Cereus cuticle pectate (sodium salt) tends to gel above a concentration of 1%, a useful property that can be more easily obtained
by the inclusion of sucrose, light addition of calcium salt, and/or mild acidification. 相似文献
8.
《Green Chemistry Letters and Reviews》2013,6(1):31-35
Abstract The synthesis in water of a series of tetradentate amine-phenol ligands derived from formaldehyde, 2,4-disubstituted phenols and amines is presented. These molecules, which are used in catalyst development, include 4,6-di-alkyl-2-bis(2-methoxyethyl)aminomethylphenols and 4,6-di-tert-amyl-2-bis(3-(dimethylamino)propyl)aminomethylphenols. Yields were generally greater than reactions performed in methanol and near quantitative for hydrophobic phenols. 相似文献
9.
《Tetrahedron: Asymmetry》1998,9(17):2999-3009
The synthesis of non racemic chiral γ-lactone 7 from α-D-isosaccharino-1,4-lactone (+)-8, as a precursor of the A-ring of the targeted 3′-morpholinyl-9-pentyl anthracycline 6, is described. 相似文献
10.
The aim of this study was to evaluate the primary experience of implementing a quality system in a clinical laboratory. The
second interrelated aim was to evaluate the quality and financial indicators needed for continuous measurement of quality,
decision making in the laboratory management and everyday process control in analytical work. The quality process itself should
be evaluated because the building up of a quality system requires a considerable amount of resources. The most effective and
practical ways of using a quality system as a management tool should be found and the need for financial appraisal when the
quality system is implemented is stressed. According to our study, when the effects of the quality system were evaluated,
the managers of the laboratory had not considered the appropriate financial indicators. The quality indicators considered
to be the best were internal quality control, external quality assessment and customer satisfaction surveys. The first benefits
of the quality system evaluated by the personnel were other than the purely financial benefits, they include a more systematic
and empowering approach to laboratory management, better working instructions, better knowledge of the methods and equipment,
and fewer errors. The financial evaluation of a quality process in a public-owned clinical laboratory is complicated due to
the fact that financial indicators are not as far developed and diverse as in industrial organisations. When starting to implement
a quality system, it is important to pay attention to all measures that motivate the staff and help them benefit from the
practical effects of the system.
Received: 10 November 1999 / Accepted: 12 January 2000 相似文献
11.
Alkyl glucoside 1 and aryl glycosides 2-4 were highly stereospecifically synthesized over 4-6 steps from commercially available starting materials. The coupling reaction of the acetobromo-α-D-glucose with the unprotective dihydroxy aglycon in the presence of silver oxide, or with aromatic aglycon in the presence of sodium hydroxide produced the key intermediate. Only β-configuration glycosides were formed in this procedure. The synthesis of all these glycosides was reported for the first time. 相似文献
12.
Synthesis of 2,15-Hexadecanedione as a Precursor of Muscone 总被引:5,自引:0,他引:5
Muscone is a precious fragrant compound scarce in nature. Many synthetic attempts for this unique natural product have been carried out. In this work, the one-carbon unit transfer reaction of tetrahydrofolate coenzyme was initialed. Bisbenzimidazolium salt was used as tetrahydrofolate coenzyme model, and thus the biomimetic synthesis of 2,15-hexadecanedione, a precursor of muscone, was successfully accomplished by using the addition-hydrolysis reaction of bisbenzimidazolium salt with methyl magnesium iodide. 相似文献
13.
Synthesis of a New Series of Bone Affinity Compounds 总被引:3,自引:0,他引:3
Ying WANG Hong CHEN Zong Ming WAN Mao Sheng CHENG Xue Chao WANG Guo Liang CONG Sheng JING Zi Ping YAN Bo WU 《中国化学快报》2006,17(3):310-312
As known that tetracycline possesses bone affinity1, which can be used as carrier of bone-targeting drugs. Chrysophanol is one of the anthraquinone components isolated from Rheum palmatum L., its structure is similar to tetracycline. The bone affinity of … 相似文献
14.
Triammonium-N-dithiocarboxyiminodiacetate,
(NH4)3L, a new dithiocarbamato
derivative of iminodiacetate, has been synthesized. The coordination properties
of the ligand were tested in reactions with copper(II), nickel(II) and palladium(II)
salts in acidic solutions. Complexes with a general formula M(H2L)2
were obtained, with the coordination taking place through the sulfur atoms
of the dithiocarbamate moiety. The new compounds were characterized by elemental
analysis, UV/VIS and IR spectroscopy, thermal analysis and magnetic measurements.
In addition, the ligand was characterized by 1H-
and 13C-NMR spectroscopy and molar conductivity
measurements. The copper(II) complex is paramagnetic, while the nickel(II)
and palladium(II) compounds are diamagnetic. The thermal decomposition of
all compounds is continuous and the thermal stability of the complexes is
higher than that of the ligand, as expected. 相似文献
15.
YeWANG ZhanZhuLIU ShiZhiCHEN 《中国化学快报》2005,16(6):713-715
L-DOPA has gained widespread credit over the past decades as being the mainstay of the pharmacological treatment of Parkinson‘s disease. However, there are many adverse effects associated with the use of L-DOPA. The prodrug approach is the most promising way to solve the problem. In this article, a thionated dipeptide prodrug of L-DOPA 11 was synthesized via 10 steps in a total yield of 26.5% from L-DOPA. 相似文献
16.
α-Alkylidene-β-hydroxy butyrolactones have been attractive and challenging targets for organic synthesis in various laboratories because that not only they are rich in skeletal diversity and stereochemistry complexity but also many of them possess quite intriguing and wide biological activities.[1] A novel class of the phytane-type diterpenoid named Tuxpanolide, bearing α-alkylidene-β-hydroxy-γ-butyrolactone skeleton, was isolated from Perymenium hintonii in Central Mexico by Maldonado and co-wokers in 1998.[2] Now we firstly report the efficient strategy of the stereocontrolled total synthesis of a diastereisomer A of Tuxpanolide. 相似文献
17.
XiaoHongWANG FengLI JingFuLIU M.T.POPE 《中国化学快报》2004,15(6):714-716
Polyoxometalates (POMs) α-K8H6[Si2W18Ti6O77] (Si2W18Ti6) loaded starch nanoparticles have been prepared and structurally characterized by elemental analyses, IR spectra and ^29Si spectroscopy. The particle size of Si2W18Ti6/starch was estimated by a Transmission electron microscope (TEM) and a 1000HSA MALVIRN Zetasizer instrttment. The result shows that the polyoxometalate retained the parent structure after encapsulated by starch microspheres. 相似文献
18.
A. N. Filippov 《Colloid Journal》2016,78(3):397-406
The asymmetry of the current–voltage characteristics of ion-exchange membranes is explained in terms of the model of a bilayer fine porous membrane with constant charge distributions over the thickness of layers. This model has previously been proposed for determining diffusion permeability of membranes. In the case of one uncharged (neutral) layer, a set of two implicit algebraic equations is derived for determining the total current–voltage characteristics (CVC) of a membrane. For the first time, implicit algebraic equations are obtained for calculating the limiting currents at different orientations of an anisotropic membrane in an electrodialysis cell and explicit expressions are derived for determining specific conductivity of the membrane from the slope of the ohmic region of a CVC under the approximation of “excluded coions.” The model may be successfully used for describing the CVCs of perfluorinated MF-4SC sulfonic cation-exchange membranes, the surface layers of which are modified with polyaniline or halloysite. 相似文献
19.
Organic photovoltaic (OPV) cells were fabricated via vacuum vapor deposition with {4-[2-(3-di-cyanomethylidene-5,5-dimethylcyclohexenyl)vinyl]phenyl}di(1-naphthyl)amine (DNP-2CN) as the electron donor, and fullerene (C60) as the electron acceptor. A thin film (10 nm) of tris(8-quinolinolato)aluminum (Alq3) was adopted as the buffer layer. A device based on this DNP-2CN exhibited an open circuit voltage (Voc) of 370 mV, a short-circuit current density (Jsc) of 0.61 mAocm 2, and a white-light power conversion efficiency ( η) of 0.09% (AM1.5, 75 mW.cm^- 2). 相似文献