4914-73-2Relevant academic research and scientific papers
Palladium-Catalyzed Thiomethylation via a Three-Component Cross-Coupling Strategy
Wang, Ming,Qiao, Zongjun,Zhao, Jiaoyan,Jiang, Xuefeng
supporting information, p. 6193 - 6197 (2018/09/25)
In this report, the combination of masked inorganic sulfur and dimethyl carbonate was designed to achieve thiomethylated cross coupling of aryl chlorides. Remarkably, this powerful strategy realized thiomethylation of nucleosides bearing unprotected ribose, chloride-containing pharmaceuticals with late-stage coupling, and herbicides possessing multiple heteroatoms and steric hindrance. Moreover, this protocol is practically amenable to multigram-scale synthesis with a lower catalysis loading and a higher yield.
Methyl aryl thioether compound, and synthetic method and applications thereof
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Paragraph 0149; 0150; 0151, (2017/07/21)
The invention discloses a methyl aryl thioether compound represented by formula 2, and a synthetic method and applications thereof. According to the synthetic method, in a reaction solvent, an aryl halide or an aromatic halide, dimethyl carbonate, and potassium thioacetate are taken as reaction raw materials, reaction is carried out in the presence of metal palladium catalyst under the action of a ligand and an alkali so as to obtain the methyl aryl thioether compound. The reaction conditions of the synthetic method are mild; the raw materials are cheap and easily available; reaction operation is simple; yield is relatively high. The methyl aryl thioether compound can be used for providing skeleton structures for the synthesis of a plurality of natural products and medicines, and can be widely applied in industrialized large-scale production.
Production, characterization and synthetic application of a purine nucleoside phosphorylase from Aeromonas hydrophila
Ubiali, Daniela,Serra, Carla D.,Serra, Immacolata,Morelli, Carlo F.,Terreni, Marco,Albertini, Alessandra M.,Manitto, Paolo,Speranzab, Giovanna
experimental part, p. 96 - 104 (2012/04/11)
Purine nucleoside phosphorylase (PNP) from Aeromonas hydrophila encoded by the deoD gene has been over-expressed in Escherichia coli, purified, characterized about its substrate specificity and used for the preparative synthesis of some 6-substituted purine-9-ribosides. Substrate specificity towards natural nucleosides showed that this PNP catalyzes the phosphorolysis of both 6-oxo- and 6-aminopurine (deoxy)ribonucleosides. A library of nucleoside analogues was synthesized and then submitted to enzymatic phosphorolysis as well. This assay revealed that 1-, 2-, 6- and 7-modified nucleosides are accepted as substrates, whereas 8-substituted nucleosides are not. A few transglycosylation reactions were carried out using 7-methylguanosine iodide (4) as a d-ribose donor and 6-substituted purines as acceptor. In particular, following this approach, 2- amino-6-chloropurine-9-riboside (2c), 6-methoxypurine- 9-riboside (2d) and 2-amino-6-(methylthio)purine- 9-riboside (2g) were synthesized in very high yield and purity.
Evidence for the existence of a specific gprotein-coupled receptor activated by guanosine
Volpini, Rosaria,Marucci, Gabriella,Buccioni, Michela,DalBen, Diego,Lambertucci, Catia,Lammi, Carmen,Mishra, Ram C.,Thomas, Ajiroghene,Cristalli, Gloria
experimental part, p. 1074 - 1080 (2012/01/06)
Guanosine, released extracellularly from neurons and glial cells, plays important roles in the central nervous system, including neuroprotection. The innovative DELFIA Eu-GTP binding assay was optimized for characterization of the putative guanosine receptor binding site at rat brain membranes by using a series of novel and known guanosine derivatives. These nucleosides were prepared by modifying the purine and sugar moieties of guanosine at the 6- and 5'-positions, respectively. Results of these experiments prove that guanosine, 6-thioguanosine, and their derivatives activate a Gprotein-coupled receptor that is different from the well-characterized adenosine receptors. Catching the elusive guanosine receptor: The innovative DELFIA Eu-GTP binding assay was applied to characterize the guanosine binding site by using novel and known guanosine derivatives. Some of the tested compounds, which proved to be full agonists with EC50 values in the low nanomolar range, could be useful tools for further characterization of the putative guanosine receptor.
High-throughput five minute microwave accelerated glycosylation approach to the synthesis of nucleoside libraries
Bookser, Brett C.,Raffaele, Nicholas B.
, p. 173 - 179 (2007/10/03)
The Vorbrueggen glycosylation reaction was adapted into a one-step 5 min/130 °C microwave assisted reaction. Triethanolamine in acetontrile containing 2% water was determined to be optimal for the neutralization of trimethylsilyl inflate allowing for direct MPLC purification of the reaction mixture. When coupled with a NH3/methanol deprotection reaction, a high-throughput method of nucleoside library synthesis was enabled. The method was demonstrated by examining the ribosylation of 48 nitrogen containing heteroaromatic bases that included 25 purines, four pyrazolopyrimidines, two 8-azapurines, one 2-azapurine, two imidazopyridines, two benzimidazoles, three imidazoles, three 1,2,4-triazoles, two pyrimidines, two 3-deazapyrimidines, one quinazolinedione, and one alloxazine. Of these, 32 yielded single regioisomer products, and six resulted in separable mixtures. Seven examples provided inseparable regioisomer mixtures of -two to three compounds (16 nucleosides), and three examples failed to yield isolable products. For the 45 single isomers isolated, the average two-step overall yield ± SD was 26 ± 16%, and the average purity ± SD was 95 ± 6%. A total of 58 different nucleosides were prepared of which 15 had not previously been accessed directly from glycosylation/deprotection of a readily available base.
Methylation of mercaptopurine, thioguanine, and their nucleotide metabolites by heterologously expressed human thiopurine S-methyltransferase
Krynetski, Eugene Y.,Krynetskaia, Natalia F.,Yanishevski, Yuri,Evans, William E.
, p. 1141 - 1147 (2007/10/03)
Thiopurine S-methyltransferase (TPMT), a cytosolic enzyme that exhibits genetic polymorphism, catalyzes S-methylation of mercaptopurine (MP) and thioguanine (TG), yielding S-methylated nucleobases that are inactive, whereas S-methylated nucleotides of these thiopurines are cytotoxic. A yeast- based heterologous expression system was therefore used to characterize human TPMT-catalyzed methylation of MP, TG, and their principal nucleotide metabolites [thioinosine monophosphate (TIMP) and thioguanosine monophosphate (TGMP), respectively]. MP, TG, TIMP, and TGMP were all substrates for human TPMT, exhibiting similar Michaelis-Menten kinetic parameters (K(m), 10.6- 27.1 μM; V(max), 31-59 nmol/min/mg of TPMT). Consistent with these kinetic parameters, human leukemia cells (CEM) incubated for 24 hr with 10 μM MP or TG accumulated significantly higher (2.3-fold, p = 0.01) concentrations of methyl-TIMP after MP incubation than methyl-TGMP after TG incubation, due to the 2.7-fold higher concentration of TIMP after MP incubation, compared with TG nucleotides (TGN) after TG incubation. Moreover, intracellular accumulation of TGN was 2.5-fold greater after TG incubation than after MP incubation (p = 0.01). These data establish that MP, TG, and their principal nucleotide metabolites are comparable substrates for polymorphic TPMT, and they demonstrate significant differences in the accumulation of active TGN and methylated nucleotides when leukemia cells are treated with MP versus TG.
Photoinduced Alkylthiolation of Halogenated Purine Nucleosides
Nair, Vasu,Young, David A.
, p. 450 - 453 (2007/10/02)
A new highly efficient methodology for the synthesis of biologically important methylmercaptopurine nucleosides is described.The approach represents a substantial improvement over earlier reported methods for this class of compounds.
