A novel and original strategy to obtain rapidly a large diversity of C-8 and N-9 substituted purines was developed. The present procedure describes annulation reactions in one or two steps starting from 5-aminoimidazole-4-carbonitriles 1-8 in moderate to good yields. 8,9-Disubstituted-6,9-dihydro-1H-purin-6-ones 9-14, 6-amino-8,9-disubstituted-3,9-dihydro-2H-purin-2-ones 15-20, 8,9-disubstituted-3,9-dihydro-2H-purin-2,6-diamines 21-24 and 6-imino-1-phenyl-8,9-disubstituted-6,9-dihydro-1H-purin-2-(3H)-ones 25-26 were synthesized in one step using formic acid, urea, guanidine carbonate, and phenylisocyanate, respectively, whereas 8,9-disubstituted-9H-purin-6-amines 27-31 and 6-imino-8,9-disubstituted-6,9-dihydro-1H-purin-1-amines 32-33 were obtained in two steps using formamide and hydrazine, respectively.
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http://dx.doi.org/10.1021/acs.joc.7b02269 | DOI Listing |
Environ Int
June 2024
School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
Anal Chem
March 2024
Oniris, INRAE, LABERCA, 44307 Nantes, France.
J Phys Chem A
July 2023
Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.
We report experimental and computational studies of protonated adenine C-8 σ-radicals that are presumed yet elusive reactive intermediates of oxidative damage to nucleic acids. The radicals were generated in the gas phase by the collision-induced dissociation of C-8-Br and C-8-I bonds in protonated 8-bromo- and 8-iodoadenine as well as by 8-bromo- and 8-iodo-9-methyladenine. Protonation by electrospray of 8-bromo- and 8-iodoadenine was shown by cyclic-ion mobility mass spectrometry (c-IMS) to form the N-1-H, N-9-H and N-3-H, N-7-H protomers in 85:15 and 81:19 ratios, respectively, in accordance with the equilibrium populations of these protomers in water-solvated ions that were calculated by density functional theory (DFT).
View Article and Find Full Text PDFPhysiol Behav
October 2023
School of Health and Sport Sciences, Liverpool Hope University, Liverpool, UK.
Introduction: Prolonged exercise has been linked to a decline in cognitive function due to a variety of factors, such as a drop in oxygen in the prefrontal cortex and an increase in stress hormones and neurotransmitters. Medium chain triglycerides (MCTs) may possibly offset this decline as they provide energy for the brain via both direct and indirect pathways, alongside promoting chronic physiological adaptations within the brain.
Methods: Participants were divided into two groups; MCT (n = 9) and Placebo (n = 10).
J Chem Inf Model
December 2022
LCT, UMR7616 CNRS, Sorbonne Université Paris, 75005 Paris, France.
GC-rich sequences are recurring motifs in oncogenes and retroviruses and could be targeted by noncovalent major-groove therapeutic ligands. We considered the palindromic sequence d(GGCGCC), and designed several oligopeptide derivatives of the anticancer intercalator mitoxantrone. The stability of their complexes with an 18-mer oligonucleotide encompassing this sequence in its center was validated using polarizable molecular dynamics.
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