- The interplay between hydrogen bonding and π-π Stacking interactions in the crystal packing of N1-thyminyl derivatives, and implications for the photo-chemical [2π + 2π]-cycloaddition of thyminyl compounds
-
The solid-state photo-chemical dimerisation of thyminyl derivatives occurs when two thyminyl units are aligned in such a way that the olefinic moieties are separated by a distance of less than 4.2 A. When irradiated with >270 nm UV, the thyminyl olefinic groups undergo [2π + 2π]-cycloaddition to form a dimeric cyclobutane derivative. However, the design and execution of [2π + 2π]-cycloaddition reactions can be challenging due to the requirement to produce molecular crystals with the necessary olefinic alignment. In this investigation, the crystallographic and solid-state photo-chemical reactions of six N1-thyminyl derivatives are studied. Only one derivative, thyminyl propanamide (7), was found to undergo [2π + 2π]-cycloaddition in the crystalline state. As such, quantum chemical methods were employed to study the photo-chemical transition states of the derivatives, as well as the strengths of typical intermolecular interactions that were observed in their crystal structures (such as π-π stacking between the thyminyl rings, Watson and Crick style hydrogen bonding and hydrogen bonding between functional groups of N1 substituents). These results were used to rationalise the solid-state photo-reactivity of more complex bis-thyminyl monomers. The Royal Society of Chemistry and Owner Societies 2012.
- Johnston, Priscilla,Izgorodina, Ekaterina I.,Saito, Kei
-
-
Read Online
- Blocking cyclobutane pyrimidine dimer formation by steric hindrance
-
The efficiency of thymine (Thy) and uracil (Ura) to form cyclobutane pyrimidine dimers (CPDs) in solution, upon UV irradiation differs by one order of magnitude. This could to be partially related to the steric hindrance induced by the methyl at C5 in thymine. The aim of the present work is to establish the influence of a bulky moiety at this position on the photoreactivity of pyrimidines. With this purpose, photosensitization with benzophenone and acetone of a 5-tert-butyl uracil derivative (1) and the equivalent Thy (2) has been compared. Introduction of the tert-butyl group completely blocks CPD formation. Moreover, the mechanistic insight obtained by laser flash photolysis is in accordance with the observed photoreactivity.
- Vendrell-Criado, Victoria,Lhiaubet-Vallet, Virginie,Yamaji, Minoru,Cuquerella, M. Consuelo,Miranda, Miguel A.
-
-
Read Online
- Ratiometric fluorescent chemosensor for Hg2+ based on heptamethine cyanine containing a thymine moiety
-
Based on a T-Hg2+-T binding mode, a sensitive ratiometric fluorescent chemosensor for aqueous Hg2+ was developed with a heptamethine cyanine chromophore containing a thymine moiety.
- Zheng, Hong,Zhang, Xiao-Juan,Cai, Xin,Bian, Qing-Na,Yan, Min,Wu, Ge-Hui,Lai, Xue-Wang,Jiang, Yun-Bao
-
-
Read Online
- Synthesis and photochemical behavior of peptide nucleic acid dimers and analogues containing 4-thiothymine: Unprecedented (5-4) photoadduct reversion
-
Pna dimers 1, 5, containing either 4-thiothymine or N3-methyl- 4-thiothymine, were prepared, and the crystal structure of compound 3 was established. With regard to their photochemistry none of these PNA analogues were able to fully mimic the p
- Clivio, Pascale,Guillaume, Dominique,Adeline, Marie-Thérèse,Hamon, Jeanine,Riche, Claude,Fourrey, Jean-Louis
-
-
Read Online
- Thymine-based near-infrared squaraine dye probe and preparation method and application thereof
-
The invention relates to the field of dye probe preparation, particularly to a thymine-based near-infrared squaraine dye probe and a preparation method and application thereof. The preparation method comprises taking 1-(3-dimethyl aminopropyl)-3-ethyl carbodiimide and 1-hydroxybenzothioamide as catalysts, N, N-diisopropylethylamine as organic base and dimethyl formamide as solvent to perform key reaction for producing amido bonds, and taking ethylenediamine as truss arm to link thymine and unsymmetric squaraine dyes via covalent bonds to prepare the unsymmetric thymine-based near-infrared squaraine dye probe. Existing near-infrared dye probes mainly focus on recognition of ions of Fe3+, and the thymine-based near-infrared squaraine dye probe solves the problem of selective recognition of Fe2+ and Co2+ in near-infrared absorbing areas.
- -
-
Paragraph 0035; 0036
(2017/12/30)
-
- Solution-phase parallel synthesis of acyclic nucleoside libraries of purine, pyrimidine, and triazole acetamides
-
Molecular diversity plays a pivotal role in modern drug discovery against phenotypic or enzyme-based targets using high throughput screening technology. Under the auspices of the Pilot Scale Library Program of the NIH Roadmap Initiative, we produced and report herein a diverse library of 181 purine, pyrimidine, and 1,2,4-triazole-N-acetamide analogues which were prepared in a parallel high throughput solution-phase reaction format. A set of assorted amines were reacted with several nucleic acid N-acetic acids utilizing HATU as the coupling reagent to produce diverse acyclic nucleoside N-acetamide analogues. These reactions were performed using 24 well reaction blocks and an automatic reagent-dispensing platform under inert atmosphere. The targeted compounds were purified on an automated purification system using solid sample loading prepacked cartridges and prepacked silica gel columns. All compounds were characterized by NMR and HRMS, and were analyzed for purity by HPLC before submission to the Molecular Libraries Small Molecule Repository (MLSMR) at NIH. Initial screening through the Molecular Libraries Probe Production Centers Network (MLPCN) program, indicates that several analogues showed diverse and interesting biological activities.
- Pathak, Ashish K.,Pathak, Vibha,Reynolds, Robert C.
-
p. 485 - 493
(2014/12/10)
-
- Expanding the scope of PNA-encoded libraries: divergent synthesis of libraries targeting cysteine, serine and metallo-proteases as well as tyrosine phosphatases
-
Seven PNA-encoded combinatorial libraries targeting proteases and phosphatases with covalent reversible and irreversible mechanism-based inhibitors were prepared. The libraries were synthesized using modified PNA monomers, which dramatically increase the water solubility of the libraries in biologically relevant buffers. The libraries were shown to selectively inhibit targeted enzymes.
- Debaene, Fran?ois,Da Silva, Julien A.,Pianowski, Zbigniew,Duran, Fernando J.,Winssinger, Nicolas
-
p. 6577 - 6586
(2008/02/05)
-
- Dde-protected PNA monomers, orthogonal to Fmoc, for the synthesis of PNA-peptide conjugates
-
Peptide nucleic acids have become, arguably, one of the most interesting of DNA mimics. Herein the efficient solution phase synthesis of four novel 1-(4,4-dimethyl-2,6-dioxacyclohexylidene)ethyl/4-methoxytrityl (Dde/Mmt) protected PNA monomers is reported
- Bialy, Laurent,Díaz-Mochón, Juan José,Specker, Edgar,Keinicke, Lise,Bradley, Mark
-
p. 8295 - 8305
(2007/10/03)
-
- Synthesis of Peptide Nucleic Acid Monomers Containing the Four Natural Nucleobases: Thymine, Cytosine, Adenine, and Guanine and Their Oligomerization
-
The preparation of mixed-sequence PNAs (PNAs containing the four natural nucleobases; thymine, cytosine, adenine, and guanine) is described.The PNA monomers containing thymine, Cbz-protected cytosine, or adenine or benzyl-protected guanine were prepared v
- Dueholm, Kim L.,Egholm, Michael,Behrens, Carsten,Christensen, Leif,Hansen, Henrik F.,et al.
-
p. 5767 - 5773
(2007/10/02)
-