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Liana Orola Mikelis V. Veidis Ilpo Mutikainen Reinis Arajs 《Journal of chemical crystallography》2010,40(4):302-305
Abstract
Crystal structures of alpha2-adrenergic antagonist atipamezole base (1) and its hydrochloric acid salt (2) have been determined using X-ray diffraction methods. Atipamezole base crystallized in the monoclinic space group P21, with unit cell parameters a = 13.238(4), b = 9.747(4), c = 14.609(5) ?, β = 107.75(4)o, V = 1,795.3(12) ?3 and Z = 6 (three independent molecules of 1). Atipamezole hydrochloride crystallized in the monoclinic space group Cc, with unit cell parameters a = 12.052(1), b = 32.561(9), c = 13.668(5) ?, β = 102.64(1)o, V = 5,233(2) ?3 and Z = 16 (four independent molecules of 2). Each of the three atipamezole moieties in 1 has an intramolecular C–H···N H-bond. In both structures the molecules are H-bonded to form extended chains. 相似文献2.
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Stepniewski M Pasenkiewicz-Gierula M Róg T Danne R Orlowski A Karttunen M Urtti A Yliperttula M Vuorimaa E Bunker A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(12):7788-7798
We have combined Langmuir monolayer film experiments and all-atom molecular dynamics (MD) simulation of a bilayer to study the surface structure of a PEGylated liposome and its interaction with the ionic environment present under physiological conditions. Lipids that form both gel and liquid-crystalline membranes have been used in our study. By varying the salt concentration in the Langmuir film experiment and including salt at the physiological level in the simulation, we have studied the effect of salt ions present in the blood plasma on the structure of the poly(ethylene glycol) (PEG) layer. We have also studied the interaction between the PEG layer and the lipid bilayer in both the liquid-crystalline and gel states. The MD simulation shows two clear results: (a) The Na(+) ions form close interactions with the PEG oxygens, with the PEG chains forming loops around them and (b) PEG penetrates the lipid core of the membrane for the case of a liquid-crystalline membrane but is excluded from the tighter structure of the gel membrane. The Langmuir monolayer results indicate that the salt concentration affects the PEGylated lipid system, and these results can be interpreted in a fashion that is in agreement with the results of our MD simulation. We conclude that the currently accepted picture of the PEG surface layer acting as a generic neutral hydrophilic polymer entirely outside the membrane, with its effect explained through steric interactions, is not sufficient. The phenomena we have observed may affect both the interaction between the liposome and bloodstream proteins and the liquid-crystalline-gel transition and is thus relevant to nanotechnological drug delivery device design. 相似文献
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Brigita Cekavicus Brigita Vigante Edvards Liepinsh Reinis Vilskersts Arkadij Sobolev Sergey Belyakov Aiva Plotniece Kristaps Mekss Gunars Duburs 《Tetrahedron》2008,64(42):9947-9952
New applications of benzo[b]thiophen-3(2H)-one 1,1-dioxide have been investigated. The synthesis of a new heterocyclic system 3H,2′H-spiro[benzo[b]thieno[3,2-b]pyridine-3,2′-benzo[b]thiophene] is described and a mechanism for the cyclisation is proposed. 相似文献
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Andris Actins Reinis Arajs Sergejs Belakovs Liana Orola Mikelis Valdis Veidis 《Journal of chemical crystallography》2008,38(3):169-174
Abstract Crystals of two crystal modifications of droperidol: a hemihydrate (1) and the z polymorph (2), have been isolated and their structure determined using X-ray diffraction methods. Droperidol hemihydrate crystallized
in the triclinic space group P − 1, with unit cell parameters a = 6.2842(15), b = 10.1473(8), c = 16.1850(2) ?; α = 102.554(9); β = 91.917(14); γ = 99.316(12)°; V = 991.6(3) ?3, and Z = 2. The droperidol z polymorph crystallized in the monoclinic space group P21/c, with unit cell parameters a = 20.0406(8), b = 7.4955(4), c = 12.9733(5) ?; β = 98.089(2)°; V = 1929.39(15) ?3, and Z = 4. In 1 and 2 two molecules of droperidol are joined by two N–H···O hydrogen bonds. The structure of 1 shows a possible additional hydrogen bond linking the two droperidol molecules via the water molecule.
Graphical Abstract
The crystal and molecular structure of a polymorph and a pseudo-polymorph of droperidol
A. Actins, R. Arajs, S. Belakovs, L. Orola, and M. V. Veidis
Crystals of two crystal modifications of droperidol: a hemihydrate and the z polymorph have been isolated and their structure determined using single crystal X-ray diffraction methods.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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