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Wyświetlanie 1-4 z 4
Tytuł:
Zastosowania „click chemistry” w modyfikacjach nukleozydów i oligonukleotydów
Applications of click chemistry in modification of nucleosides and oligonucleotides
Autorzy:
Gładysz, M.
Milecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/171589.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
click chemistry
CuAAC
modyfikacje nukleozydów
oligonukleotydy
DNA
kwas deoksyrybonukleinowy
RNA
kwas rybonukleinowy
Click Chemistry
nucleosides modifications
oligonucleotides
deoxyribonucleic acid
ribonucleic acid
Opis:
Since the year 2001 new ideology of clean and simple synthesis in organic chemistry has been established. The outstanding scientists Meldal and Sharpless presented their concepts of Click Chemistry. Among the reactions chosen for this concept the reaction of Copper(I) Catalyzed Alkyne-Azide Cycloaddition (CuAAC) became the most popular one. It is the basis of syntheses employed for building blocks synthesis in medicinal chemistry and material science. Libraries of potentially pharmacologically active anticancer and antivirus compounds possessing neutral triazol linkage could be easily obtained. Remarkable efficiency of CuAAC reaction influenced on DNA- and RNAbased synthesis of novel oligonucleotides derivatives. Many of nucleic acid molecular modifications found applications in enzymatic transformation, nucleic acid hybridization, molecular tagging and gene silencing. The CuAAC reaction allows for introducing modifications into practically every region of nucleoside/nucleotide/ oligonucleotide. This includes versatile modifications of the base moiety both aiming at the base pairing ability or specific labeling of the nucleoside unit. Different conjugates (bio-, fluorescent-, affinity- or spin labels) are being attached to the base part of the nucleic acid taking advantage of the presence of azide or alkyne substituents, which can be installed without great difficulty. Labeling at the sugar part of the nucleoside can be realized at the position 2’, 3’ or 5’, the latter two giving rise to the end-labeled oligonucleotides and the 2’ position serving as the attachment point for labeling inside the oligonucleotide chain. These kind of nucleic acid modifications are very promising. Versatility of CuAAC reactions is demonstrated by numerous examples of introducing modifications into practically every reactive site of the nucleotide/oligonucleotide molecule. The review systematically presents application of the “click” technique for modification of nitrogenous base, sugar or pseudosugar moiety or phosphorus center. Possibility of creating new kind of chain linkage, devoid of negative charge and nuclease resistant is also shown. This allows to design a new class of nucleic acid analogues, similar in its DNA-mimicking properties to PNA’s.
Źródło:
Wiadomości Chemiczne; 2014, 68, 7-8; 617-643
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spektrometria mas w analizie białek i peptydów : znaczniki jonizacyjne
Mass spectrometry in analysis of peptides and proteins : ionization markers
Autorzy:
Bąchor, R.
Biernat, M.
Cebrat, M.
Kijewska, M.
Kluczyk, A.
Kuczer, M.
Paluch, A.
Waliczek, M.
Wierzbicka, M.
Stefanowicz, P.
Szewczuk, Z.
Powiązania:
https://bibliotekanauki.pl/articles/171509.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
spektrometria mas
modyfikacje potranslacyjne
znaczniki jonizacyjne
fosforylacja
glikacja
biblioteki kombinatoryczne
mass spectrometry
post-translational modifications
ionization markers
phosphorylation
glycation
combinatorial libraries
Opis:
High sensitivity, accuracy, and ability to provide structural information makes mass spectrometry (MS) the method of choice for both qualitative and quantitative analysis in proteome research. Peptide sequencing by tandem mass spectrometry (MS/MS) was successfully applied to discover new peptide sequences and modifications. Insufficient ionization of some peptides is one of the main limitations of MS- based peptide identification. The development of sensitive detection techniques for the efficient analysis of such samples is very important. Differences in ionizability cause difficulties in quantification studies, which could be overcome by derivatization of peptides to improve both the detectability and the selectivity of an analysis. Incorporation of ionization markers and isotopic labels (particularly the isobaric tags) is often used for this reason. Isobaric labeling reagents (including commercially available iTRAQ, TMT, DiLeu and DiART) have found a wide application in quantitative proteomics. Mass spectrometry is a very good tool for the determination of posttranslational modifications (PTMs), but the modified proteins are usually present in low concentrations. The development of ionization tags specific to a particular PTM and suitable for sensitive analysis of the modified proteins is required. For the analysis of phosphorylated peptides, a combination of β-elimination and the reaction of resulting α,β-dehydroamino acid residues with the nucleophilic thiol group could be used to detect a labile PTM. Such reaction may be used to introduce derivatizing reagents at the original site of phosphorylation, to enhance ionization in MS analysis. Glycation and glycosylation of proteins are other very important PTMs associated with many natural processes as well as diseases. We have designed and synthesized bifunctional quaternary ammonium salt derivatives of phenylboronic acids for selective detection of carbohydrates and peptide-derived Amadori products by ESI-MS. The attachment of a fixed charge (e.g. in a form of a quaternary ammonium salt) to the amino groups in peptides leads to the enhancement of a precursor ion signal in mass spectra. We have developed several new QAS-containing ionization reagents including bicyclic tags with DABCO, ABCO or azoniaspiro groups. It is worth noting that 2,4,6-substituted pyrylium salts react with amino groups in peptides introducing a stable positive charge and improve peptide detection by MS. The newly developed ionization tags were successfully applied for the analysis of OBOC combinatorial libraries as well as for studying possible biomarkers of preeclampsia, a pregnancy disorder.
Źródło:
Wiadomości Chemiczne; 2018, 72, 7-8; 609-633
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enzymatyczne i chemiczne modyfikacje fosfolipidów
Enzymatic and chemical modifications of phospholipids
Autorzy:
Chojnacka, Anna
Niezgoda, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/27310043.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
fosfolipidy strukturyzowane
koniugaty fosfolipidowe
bioaktywne kwasy tłuszczowe
modyfikacje fosfolipidów
sprzężony kwas linolowy
dehydroepiandrosteron
niesteroidowe leki przeciwzapalne
lipaza
fosfolipaza
structured phospholipids
phospholipid conjugates
bioactive fatty acids
phospholipid modification
dehydroepiandrosterone
NSAIDs
lipase
phospholipase
Opis:
At the moment, phospholipids are among the most interesting molecules. The possibilities of chemical and enzymatic modifications, while maintaining their integrity and unique nature, also contribute to these compounds' great interest. This review paper concerns the preparation of new phospholipid conjugates containing fragments of biologically active compounds not found naturally in phospholipids, and phospholipids enriched with specific fatty acids with health-promoting properties (structured phospholipids). Chemical methods for the synthesis of phospholipids containing conjugated linolenic acid (CLA), dehydroepiandrosterone (DHEA) or selected non-steroidal anti-inflammatory drugs (NSAIDs) at the sn-1 and/or sn-2 position have been described. In addition, the evaluation of the antiproliferative activity of the obtained conjugates against selected cancer cell lines was also described. Enzymatic methods of modifying natural phospholipids leading to their enrichment with bioactive polyunsaturated fatty acids and conjugated acids have also been described.
Źródło:
Wiadomości Chemiczne; 2023, 77, 5-6; 449--477
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modyfikowane oligodeoksyrybonukleotydy zawierające w wiązaniu internukleotydowym w pozycji mostkowej atom azotu
Modified oligodeoxyribonucleotides containing nitrogen at a bridging position of an internucleotide bond
Autorzy:
Radzikowska, E.
Powiązania:
https://bibliotekanauki.pl/articles/172442.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
analogi kwasów nukleinowych
modyfikacje wiązania internukleotydowego
oligodeoksyrybonukleozydo-(P3’→N5’)amidofosforany
oligodeoksyrybonukleozydo-(N3’→P5’)amido(tio)fosforany
strategia antysensowa
telomeraza
reakcja Athertona-Todda
nucleic acids analogues internucleotide linkage modifications
oligodeoxyribonucleoside-(P3’→N5’)phosphoramidates
oligodeoxyribonucleoside-
(N3’→P5’)(thio)phosphoramidates antisense strategy
telomerase
Atherton-Todd reaction
Opis:
Synthetic oligonucleotides (ONs) constitute an important class of compounds which exhibit biological activity. As potential drugs ONs are employed in the antisense strategy [1]. The antisense therapeutic agent acts on the pathogenic mRNA causing inactivation of the target. Ideal antisense agent should be resistant to exo and/or endonucleases, have a suitable pharmacological and pharmacokinetic profile and high affinity for the target. To improve some properties of antisense oligonucleotides plethora of chemical modifications introduced within both sugar unit and internucleotides linkage were investigated. Among numerous ONs modified in internucleotide phosphodiester bond, one of the most interesting are oligonucleotide phosphoramidates (NP-oligos) in which one of the bridging oxygens is replaced by nitrogen atom (at 3’ or 5’ position). Hence, two classes of compounds are formed: oligonucleotide-(N5’→P3’)phosphoramidates and oligonucleotide(N3’→P5’)-phosphoramidates. These compounds, similar to native DNA and RNA, possess an achiral phosphorous atom and all internucleotides bonds are negatively charged. Additionally, NP-oligo shows good resistance to nucleolytic degradation and can bind to the target DNA or RNA with high affinity [12]. In literature several synthetic strategies concerning both (N5’→P3’) and (N3’→P5’) NP-oligos have been described. Some of them allowed to obtain only corresponding dimers. In the light of recent discoveries the most promising candidates for therapeutic and diagnostic applications are oligonucleotide-(N3’→P5’)thiophosphoramidates. Gryaznov et al. have found that such compounds can act as potent and selective telomerase inhibitors [29]. Human telomerase (TA) is a reverse transcriptase ribonucleoprotein that synthesizes de novo d-(TTAGGG)n repeats at chromosomal DNA ends. Whereas activity of this enzyme is observed in ~85% of all human tumors, most of normal somatic cells either lack TA activity or express it only at low levels. For these reasons TA constitute an attractive and nearly universal anticancer target for rational drug development.
Źródło:
Wiadomości Chemiczne; 2013, 67, 11-12; 1003-1025
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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