Wyniki wyszukiwania - BazTech

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Zastosowanie cieczy jonowych jako modyfikatorów fazy ruchomej w chromatografii cieczowej

Kilanowska Anna, Zielak Judyta, Studzińska Sylwia

Wiadomości Chemiczne

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2020

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[Z] 74, 7-8

507--525

EN

Ionic liquids are molten salts composed of large, asymmetric, organic cations (e.g. imidazolium or piperidine) and inorganic anions such as e.g chloride or fluoroborate. These compounds are characterized by low melting point, below 1000C, however, they also have other interesting properties including high thermal stability, minor vapor pressure or negligible volatility. Moreover, by the appropriate selection of the cation and anion building the ionic liquid, it is possible to obtain the desired physicochemical properties of these salts. For this reason, ionic liquids are applied to the synthesis, catalysis, electrochemical methods, extraction methods, etc. Application of these compounds in separation techniques merits special attention, especially considering liquid chromatography. Ionic liquids are commonly used in this technique as free silanols suppressors, especially regarding the analysis of basic compounds. Moreover, the excess amount of ionic liquids ions may adsorb on the hydrophobic ligands present at the stationary phase surface, which also plays a significant role in the retention of analytes. Besides their application as silanols suppressors, these compounds were also used as ion pair reagents in the analysis of antisense oligonucleotides, which are short nucleic acid fragments with therapeutic potential due to the ability to bind with complementary sequences of ribonucleic acid. For this reason, antisense oligonucleotides are used in the treatment of several diseases. This article briefly presents structures, properties and the application of ionic liquids as mobile phase modifiers for the analysis of the wide range of different analytes using liquid chromatography. Moreover, a part of this paper was devoted to the analysis of antisense oligonucleotides with the use of the different chromatographic techniques, including the application of ionic liquids as mobile phase additives in ion pair chromatography.

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Analiza oligonukleotydów antysensownych pierwszej i drugiej generacji za pomocą chromatografii par jonowych

Kaczmarkiewicz Anna, Nuckowski Łukasz, Studzińska Sylwia, Buszewski Bogusław

Analityka : nauka i praktyka

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2019

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nr 2

4--11

PL

Rosnące zainteresowanie badaczy potencjalnymi terapeutykami, jakimi są oligonukleotydy antysensowne, sprawia, że wymagana jest ich czuła analiza na różnych etapach badań klinicznych.

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Synteza modyfikowanych oligonukleotydów zawierających stereozdefiniowane internukleotydowe wiązania tiofosforanowe

Radzikowska E., Kaczmarek R., Baraniak J.

Wiadomości Chemiczne

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2015

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[Z] 69, 11-12

957--981

EN

Synthetic oligonucleotides constitute an important class of compounds which can exhibit biological activity. As potential drugs they could be employed in antisense strategy by acting on the pathogenic mRNA, causing inactivation of the target molecules during the translation process [1]. Ideal antisense agent (ASO) should be resistant to exo and/or endonucleases, exhibit a suitable pharmacological and pharmacokinetic profile and exhibits high binding affinity towards the target mRNA. To improve some properties of the ASO plethora of the chemical modifications introduced within the nucleobase, sugar unit and internucleotide linkage are investigated [3]. Among them, phosphorothioate oligonucleotides (PS-oligo), created by replacing one of the nonbridging oxygen atoms with a sulfur atom, are the major representatives of DNA analogs. PS-oligo display several attractive features like nuclease resistance, activation of RNase H, and good pharmacokinetic properties [1]. Replacement of one of two nonbridging oxygens at phosphorus by sulfur induces asymmetry at the phosphorus atom. Hence, the synthesized oligo(nucleoside phosphorothioate) is a mixture of 2n diastereomers (where n is the number of internucleotide phosphorothioate functions). Therefore the actual biological activity of the P-chiral oligonucleotide analogues, (e.g., interactions with proteins or nucleic acids) may depend on stereochemical factors [7]. One has to keep in mind that the phosphoramidite [5] and H-phosphonate [32] methodologies (commonly used to prepare PS-oligo) are nonstereospecific and give a mixture of 2n diastereomers. Thus, various methods have been elaborated to synthesize these P-chiral oligonucleotide analogs in a stereocontrolled manner [15, 17], among them the oxathiaphospholane method developed by Stec et al. [18], the method utilizing nucleoside 3’-O-(3-N-acyl)oxazaphospholidine derivatives as monomer units [19], and the method based on a stereoselective synthesis of nucleoside 3’-O-oxazaphospholidine monomers [21, 22] are the most significant.