Two Pd-catalyzed methods to access 6-heteroaryl 2-aminopurine ribonucleosides from 6-chloroguanosine are described. First, Pd-132-catalyzed Suzuki-Miyaura cross-coupling using a series of boron substrates and 6-chloroguanosine forms 6-heteroaryl-2-aminopurines in a single step. The versatility of 6-chloroguanosine is further demonstrated using a modified Sonogashira coupling employing potassium iodide as an additive. Finally, the utility of the 6-alkynyl-2-aminopurine ribonucleoside as a dipolarophile in [3 + 2] cycloadditions is presented, affording triazoles and isoxazoles when reacted with azide and isonitrile 1,3-dipoles, respectively.
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http://dx.doi.org/10.1021/acs.orglett.7b01602 | DOI Listing |
J Biol Chem
November 2024
Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China; Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, China. Electronic address:
The methyltransferase ribozyme SMRZ-1 utilizes S-adenosyl-methionine (SAM) and Cu (II) ions to methylate RNA. A comparison of the SAM-bound and unbound RNA structures has shown a conformational change in the RNA. However, the contribution of specific interactions and the role of a pseudo-triplex motif in the catalytic center on the methylation reaction is not completely understood.
View Article and Find Full Text PDFAcc Chem Res
May 2024
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.
In 1960, Weber prophesied that "There are many ways in which the properties of the excited state can be utilized to study points of ignorance of the structure and function of proteins". This has been realized, illustrating that an intrinsic and highly responsive fluorophore such as tryptophan can alter the course of an entire scientific discipline. But what about RNA and DNA? Adapting Weber's protein photophysics prophecy to nucleic acids requires the development of intrinsically emissive nucleoside surrogates as, unlike Trp, the canonical nucleobases display unusually low emission quantum yields, which render nucleosides, nucleotides, and oligonucleotides practically dark for most fluorescence-based applications.
View Article and Find Full Text PDFMutat Res
March 2022
Department of Microbiology, Immunology, and Molecular Genetics, and The Molecular Biology Institute, University of California, and the David Geffen School of Medicine, Los Angeles, CA 90095, United States. Electronic address:
We have extensively characterized base substitution mutations in the 795 base pair (bp) long E. coli thyA gene to define as many of the base substitution mutational sites that inactivate the gene as possible. The resulting catalog of mutational sites constitutes a system with up to 5 times as many sites for monitoring each of the six base substitution mutations as the widely used rpoB/Rif system.
View Article and Find Full Text PDFMolecules
February 2020
Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 5 Pasteura St., 02-093 Warsaw, Poland.
Etheno-derivatives of 2-aminopurine, 2-aminopurine riboside, and 7-deazaadenosine (tubercidine) were prepared and purified using standard methods. 2-Aminopurine reacted with aqueous chloroacetaldehyde to give two products, both exhibiting substrate activity towards bacterial () purine-nucleoside phosphorylase (PNP) in the reverse (synthetic) pathway. The major product of the chemical synthesis, identified as 1,N-etheno-2-aminopurine, reacted slowly, while the second, minor, but highly fluorescent product, reacted rapidly.
View Article and Find Full Text PDFCurr Protoc Nucleic Acid Chem
March 2020
Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota.
4-Cyanoindole-2'-deoxyribonucleoside (4CIN) is a fluorescent isomorphic nucleoside analogue with superior spectroscopic properties in terms of Stokes shift and quantum yield in comparison to the widely utilized isomorphic nucleoside analogue, 2-aminopurine-2'-deoxyribonucleoside (2APN). Notably, when inserted into single- or double-stranded DNA, 4CIN experiences substantially less in-strand fluorescence quenching compared to 2APN. Given the utility of these properties for a spectrum of research applications involving oligonucleotides and oligonucleotide-protein interactions (e.
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