10.1016/j.carres.2007.03.029
The research focuses on the synthesis and evaluation of fluorescently labeled and internally quenched UDP-Gal probes, which are sugar nucleotide analogs with a fluorescence emitter and a quencher. These probes were designed to assess their recognition and usage by various galactosyltransferases, enzymes crucial for the biosynthesis of mammalian oligosaccharides. The study involved detailed chemical syntheses of the UDP-Gal analogs, utilizing a range of reactants such as uridine, galactose, and phosphorus oxychloride, among others, and employing techniques like palladium-catalyzed coupling, hydrogenation, and ion-exchange chromatography. The experiments aimed to determine the rate of galactose transfer by several galactosyltransferases, including blood group B a-(1!3) galactosyltransferase, a-(1!3) galactosyltransferase, and milk bovine b-(1!4) galactosyltransferase, using the synthesized UDP-Gal analogs as substrates. Analytical methods employed to monitor the reactions and characterize the products included TLC, MALDI TOF mass spectrometry, and NMR spectroscopy. The results demonstrated that the modified UDP-Gal analogs were recognized as weak substrates by the tested galactosyltransferases, with the ability to transfer their galactose unit to the acceptor molecules.
10.1002/hlca.201300043
The research focuses on the synthesis and characterization of oligonucleotide analogues with integrated bases and backbone (ONIBs), specifically targeting the self-complementary thiomethylene-linked octanucleoside. The purpose of this investigation is to demonstrate that the structural differentiation of oligonucleotides into a contiguous backbone and appended nucleobases is not a prerequisite for pairing or the formation of defined conformers. The research aims to create ONIBs that can pair in aqueous solutions, challenging the traditional structure of nucleic acids. Key chemicals used in the synthesis process include various nucleoside derivatives, such as guanosine, cytidine, and uridine, along with protecting groups like methoxytrityl (MMTr) and isopropylidene groups. The conclusions drawn from the study indicate that the pairing properties of these analogues are influenced by the sequence of nucleobases and the constitution and conformation of the linking elements. The study successfully synthesized and analyzed the structures of the target octanucleosides, revealing that the fully deprotected octanucleoside forms a duplex with complete base pairing, while the partially protected version forms a mixture of associated species with at most four Watson-Crick base pairs.
10.1016/S0040-4020(01)96481-6
The research focuses on the development of a new synthetic route to S-substituted uridines, which are important modified nucleosides found in transfer RNA. The purpose of the study was to devise a method for the transformation of uridine into these substituted derivatives, leveraging the use of lithiation, a technique that has gained recognition in nucleoside chemistry for carbon-carbon bond forming reactions. The researchers found that 2’,3’-O-isopropylidene-5’-O-methoxymethyl-5,6-dihydrouridine could serve as an "amide α-anion" upon lithiation with lithium diisopropylamide (LDA). Through a series of reactions involving anion formation, acylation, phenylselenation, and oxidative elimination, they successfully synthesized S-acyluridines and S-alkyluridines. Key chemicals used in the process included butyllithium, acid chlorides, phenylselenyl chloride, and various alkylating agents. The conclusions of the research provide a new entry to S-substituted uridines and demonstrate the effectiveness of the developed synthetic routes, offering a practical and efficient method for the preparation of these compounds.
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