Wyniki wyszukiwania - BazTech

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Zastosowanie cyklodekstryn w technologii wdrukowania molekularnego

Pokajewicz Katarzyna, Poliwoda Anna, Wieczorek Piotr P.

Wiadomości Chemiczne

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2022

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[Z] 76, 7-8

677--699

EN

In the last decade molecular imprinted polymers (MIP) have gained great interest in the area of selective recognition various type substances. Scientific work in this field is carried out very intensively - the methods of synthesis are modified and improved, new types of hydride materials are created, as well as new reagents for synthesis. In this case, cyclodextrins (CD) and their analogues show good molecular recognition ability for its unique physical and chemical properties and suitable cavity structure. As a result, these supramolecular ligands can perform various functions in the MIP technology, and the resulting polymeric materials are characterized by high selectivity and binding specificity (recognition) of analytes structurally matched to the MIP cavity. Of particular importance is the fact that cyclodextrins enable the imprinting not only of low-molecular-weight biologically active compounds, but also of high-molecular molecules (proteins, peptides). The numerous hydroxyl groups available in cyclodextrins are active sites that can form different types of linkages. They can be cross-linked with one another, or they can be derivatized to produce monomers that can form linear or branched networks. This article provides a detailed review of MIPs based on CD and their application in the field of separation science and analytical chemistry in recent years. The discussion is grouped according to the different role of CD in MIPs, that is, functional monomer, carrier modifier, etc.

2

W poszukiwaniu idealnego chromojonofora

Zarzeczańska Dorota, Wcisło Anna, Smułka Agata, Ossowski Tadeusz

Wiadomości Chemiczne

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2022

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[Z] 76, 7-8

663--676

EN

In pursuit for new chromoionophores, it is important to know their functioning, which depends primarily on theirstructure. The structures of chromoionophores were discussed, highlighting the elements that have a significant impact on their operation, i.e. the binding and visualization of metal ion binding. Chromoionophores are composed of a binding and signaling group. Valinomycin, salinomycin and synthetic crown ethers are presented as ionophores. Using the anthraquinone as an example, the function of the chromophore system was defined and discussed. It has been shown that an element connecting the main components of the chromoionophore may also play an important role. The action of chromoionophores is directly related to their acid-base properties, which can influence both ion binding and the visualization of interactions. The examples of aminoanthraquinone derivatives show the influence of the number of groups, position in the anthraquinone ring and the order of amino groups on the basicity of chromoionophores.

3

Od rozpoznania molekularnego do rozdziału racemicznego metodą frakcyjnej krystalizacji soli diastereomerycznych

Białońska A.

Wiadomości Chemiczne

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2014

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[Z] 68, 5-6

545--562

EN

Synthesis and isolation of enantiopure compounds remains an important challenge in medicinal, pharmaceutical, alimentary as well as material chemistry. Amongst many methods leading to enantiopure compounds, formation and fractional crystallization of diastereomeric salts of an enantiopure resolving agent is the most popular one. Since its discovery many years went by, and yet it has been performed by the trial and error method. Selection of the suitable resolving agent is crucial for racemic resolution efficiency. Hence, this review is concerned with common features of crystal structures of salts, in which resolving agents, frequently used for separation of racemic acids, are involved. Among them, there are crystal structures of salts of primary, secondary and tertiary chiral amines (1-arylethylamines, ephedrine, pseudoephedrine, deoxyephedrine, chinine, chinidine, cinchonine, cinchonidine, strychnine and brucine). In most of them, cations and anions are involved in characteristic systems of hydrogen bonds leading to formation of cationic-anionic self-assemblies. In this respect, brucine and strychnine appear as unique, because presence of anions usually does not affect formation of common cationic self-assemblies stabilized by weak hydrophobic interactions. Comparison of the common structural motifs indicates different factors being crucial in molecular recognition and in diastereomeric diversification. Formation of common hydrogen bonded cationic-anionic self-assemblies plays a dominant role in molecular recognition of a given acid by most of the studied amines. In turn, formation of common cationic self-assemblies stabilized by hydrophobic interaction plays a crucial role in molecular recognition of a given acid by brucine or strychnine. Diastereomeric diversification can be realized in various ways. In extreme cases, when molecular recognition in crystals of particular diastereomeric salts is similar, diastereomeric diversification is governed by different factors, depending on factors governing molecular recognition. Hydrophobic interactions play an important role in diastereomeric diversification when molecular recognition is governed by hydrogen bonds. In turn, when molecular recognition is governed by hydrophobic interactions, different hydrogen bond systems in crystals of particular salts are responsible for their diastereomeric deversification.

4

Trans-1,2-diaminocykloheksan – niezwykła kariera outsidera

Petryk M., Kwit M.

Wiadomości Chemiczne

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2013

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[Z] 67, 5-6

393--442

EN

An enantiopure trans-1,2-diaminocyclohexane is one of the most widely used chiral diamines in modern organic chemistry. This chiral building block, readily available from waste industrial products, emerges as a major figure in the field of asymmetric synthesis. The unique structural and conformational properties of trans-1,2-diaminocyclohexane make it very useful for the development of new synthetic strategies, taking advantage of its geometrical pre-organization. In this short article, we will highlight the utility of enantiomerically pure trans-1,2-diaminocyclohexane derivatives as broad-range chiral reagents and ligands for catalytic cycles. A brief overview of the aspects of applications in the field of molecular recognition will also be given.

5

Modelling of Molecular and Chiral Recognition by Cyclodextrins : Is It Reliable? Part 2. Molecular Dynamics Calculations in Vacuum Pertaining to the Selective Complexation of Decalins by B-Cyclodextrin

Dodziuk H., Lukin O.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 7

997-1001

EN

Molecular modelling is frequently used to rationalize experimental finding concerning molecular and chiral recognition by cyclodextrins, although the reliability of neither molecular mechanics nor molecular dynamics in this domain has been extensively analyzed. We have recently started a program aiming at the evaluation of computational methods applied in cyclodextrin research.

6

Chemical Recognition Dynamics as a Theoretical Approach to Chemical Synthesis

Kaczmarek J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2000

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Vol. 48, nr 1

11-27

EN

In this paper a concept of chemical recognition dynamics is introduced. The concept is based on the definition of the molecular recognition. An element of this definition, the range of selection set indicates tasks for chemical recognition dynamics. Chemical dynamics accentuates dynamics of processes near transition states along reaction path. Chemical recognition dynamics is viewed to be part of chemical dynamics which is also connected with dynamics of molecules in larger distances where interactions are transferred by solvent and are characterized just by introduced range of selection set. Characterization of geometrical structure of this set is carried out. Presented theoretical approach is devoted to mathematical formalization of notions related to synthesis in solution with special regard to bringing into prominense possible functions related to this process and accentuating construction of larger molecules. In particular, a concept of controlling of the whole path of reaction during synthesis in solution is considered.

7

ph Dependent Enantioselection of Amino Acids by Phosphorous-Containing Calix[4]resorcinarene in Langmuir Monolayers

Pietraszkiewicz M., Prus P., Bilewicz R.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 12

2035-2042

EN

Lipophilic calix[4]resorcinarene with phosphorous acid amide groups linking oxygen atoms is a rigid system of the cavitand type, in which conformational flexibility is strongly limited. These chiral receptors form stable Langmuir monolayers on water surface with surface area per molecule in the compressed layer being almost ph-independent.

8

pH Dependent Enantiomeric Recognition of Amino Acids by Mannich-Type Calix[4]resorcinarenes in Langmuir Monolayers

Pietraszkiewicz M., Prus P., Bilewicz R.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 11

1845-1853

EN

The surface potential of these compounds is distinctly higher in the presence of substituents and its further increase upon decreasing the pH of the subphase is observed only for the derivatized calixarenes. This means that protonation on the amine centers is the factor determining the properties of the monolayer.

9

Molecular Recognition of Pyrimidine and Xanthine Bases by Lipophilic Calixarenes Derived from Resorcinol and Pyrogallol

Pietraszkiewicz O., Brzózka Z., Pietraszkiewicz M.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 12

2043-2052

EN

Two lipophilic calixarenes, derived from resorcinol (R1) and pyrogallol (R2), were investigated as receptors for pyrimidine and xanthine bases in extraction experiments. Extraction abilities sequence for R1 in chloroform is: cytosine>uracil>thymine, whereas for R2: thymine>uracil>cytosine. Among pyrimidine bases, no clear pattern of extraction was observed: uracil was extracted most effectively to toluene phase, thymine - into diethyl sebacate, cytosine into - chloroform.