- Furan-PNA: A mildly inducible irreversible interstrand crosslinking system targeting single and double stranded DNA
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We here report on the design and synthesis of tailor-made furan-modified peptide nucleic acid (PNA) probes for covalent targeting of single stranded DNA through a crosslinking strategy. After introducing furan-containing building blocks into a PNA sequence, hybridization and furan-oxidation based crosslinking to DNA is investigated. The structure of the crosslinked products is characterized and preliminary investigations concerning the application of these systems to double stranded DNA are shown.
- Manicardi,Gyssels,Corradini,Madder
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Read Online
- Reversible Covalent Assembly of Nanoparticles through On-Surface Diels-Alder Reaction
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We demonstrate here a controlled assembly of individual nanoscale building blocks into defined architectures based on chemospecific covalent bonding interactions. For this purpose, α-Fe2O3, γ-Fe2O3, and SiO2 nanoparticles decorated with surface-conjugated organic ligands were used for performing on-surface Diels-Alder reactions. Driven through their chemical affinity and surface-grafted complementary functionalities, nanoparticles underwent click-reactions to produce covalently organized nanostructures. An advantage of using the Diels-Alder reaction is its reversible nature, which was used to click and unclick the nanoparticles on demand. The efficiency and chemical specificity of this approach opens up another synthetic access to unify materials with complementary properties, where the thermoresponsive nature of particle assemblies imparts to them a fully reversible character. The covalent conjugation strategies demonstrated in this work potentially allow the use of a diverse range of particles and ligands for their applications in different disciplines such as medicine, optics, or photonics. The nanoparticles morphology and crystalline nature were investigated by TEM and XRD analysis, while the presence of surface attached groups was verified by NMR, FTIR, UV-vis, and ζ potential measurements.
- Schütz, Markus B.,Lê, Khan,Ilyas, Shaista,Mathur, Sanjay
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p. 1552 - 1558
(2020/03/05)
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- Metal-Free Chemoselective Oxidative Dehomologation or Direct Oxidation of Alcohols: Implication for Biomass Conversion
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A transition metal-free, chemoselective reaction was performed using the sodium tert-butoxide-oxygen (NaOtBu-O2) system, resulting in either oxidative dehomologation or direct oxidation of alcohols. In particular, the newly developed protocol may be used to predict the major product formed, which depends on alkyl chain length of the alcohols and reaction conditions. The rational mechanism of this transformation was also demonstrated by performing an 18O isotopic labelling experiment. This protocol presents a straightforward method for biomass conversion of a lignin model compound to phenol and benzoic acid.
- Kim, Sun Min,Shin, Hun Yi,Kim, Dong Wan,Yang, Jung Woon
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p. 241 - 245
(2016/02/27)
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- A biocompatible alkene hydrogenation merges organic synthesis with microbial metabolism
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Organic chemists and metabolic engineers use orthogonal technologies to construct essential small molecules such as pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small-molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Reported herein is a method for alkene hydrogenation which utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe, and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering. Reduction to practice: A hydrogenation reaction has been developed that employs hydrogen generated in situ by a microorganism and a biocompatible palladium catalyst to reduce alkenes on a synthetically useful scale. This type of transformation, which directly combines tools from organic chemistry with the metabolism of a living organism for small-molecule production, represents a new strategy for chemical synthesis.
- Sirasani, Gopal,Tong, Liuchuan,Balskus, Emily P.
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supporting information
p. 7785 - 7788
(2014/08/05)
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- Raney nickel-catalyzed hydrogenation of unsaturated carboxylic acids with sodium borohydride in water
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A mild, selective, and green method for the reduction of unsaturated carboxylic acids with sodium borohydride-Raney nickel (W6) system in water is reported. This method is practical and safe and avoids use of organic solvents. Taylor & Francis Group, LLC.
- Rao, Gopal Krishna,Gowda, Narendra B.,Ramakrishna, Ramesha A.
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experimental part
p. 893 - 904
(2012/02/01)
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- Unprecedented C-selective interstrand cross-linking through in situ oxidation of furan-modified oligodeoxynucleotides
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Chemical reagents that form interstrand cross-links have been used for a long time in cancer therapy. They covalently link two strands of DNA, thereby blocking transcription. Cross-link repair enzymes, however, can restore the transcription processes, causing resistance to certain anti-cancer drugs. The mechanism of these cross-link repair processes has not yet been fully revealed. One of the obstacles in this study is the lack of sufficient amounts of well-defined, stable, cross-linked duplexes to study the pathways of cross-link repair enzymes. Our group has developed a cross-link strategy where a furan moiety is incorporated into oligodeoxynucleotides (ODNs). These furan-modified nucleic acids can form interstrand crosslinks upon selective furan oxidation with N-bromosuccinimide.We here report on the incorporation of the furan moiety at the 20-position of a uridine through an amido or ureido linker. The resulting modified ODNs display an unprecedented selectivity for cross-linking toward a cytidine opposite the modified residue, forming one specific cross-linked duplex, which could be isolated in good yield. Furthermore, the structure of the formed cross-linked duplexes could be unambiguously characterized.
- De Beeck, Marieke Op,Madder, Annemieke
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experimental part
p. 796 - 807
(2011/04/15)
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- QUINOLONES USEFUL AS INDUCIBLE NITRIC OXIDE SYNTHASE INHIBITORS
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The present invention relates to novel quinolones of Formula I that inhibit inducible NOS synthase together with methods of synthesizing and using the compounds including methods for inhibiting or modulating nitric oxide synthesis and/or lowering nitric oxide levels in a patient by administering the compounds for the treatment of disease.
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Page/Page column 28
(2008/12/06)
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- Heteroaromatic side-chain analogs of pregabalin
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A series of heteroaromatic analogs of pregabalin has been identified that possess anticonvulsant activity in the DBA/2 mouse model. The methods of synthesis and preliminary pharmacology are discussed herein.
- Schelkun, Robert M.,Yuen, Po-Wai,Wustrow, David J.,Kinsora, Jack,Su, Ti-Zhi,Vartanian, Mark G.
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p. 2329 - 2332
(2007/10/03)
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- Probing structural effects on replication efficiency through comparative analyses of families of potential self-replicators
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A formidable synthetic apparatus for the creation of nanoscale molecular structures and supramolecular assemblies through molecular structures can potentially be created from systems that are capable of parallel automultiplication (self-replication). In order to achieve this goal, a detailed understanding of the relationship be tween molecular structure and replication efficiency is necessary. Diastereoisomeric templates that are capable of specific and simultaneous autocatalysis have been synthesised. A systematic experimental and theoretical evaluation of their behaviour and that of structurally-related systems reveals the key determinants that dictate the emergence of self-replicative function and defines the structural space within which this behaviour is observed.
- Kassianidis, Eleftherios,Pearson, Russell J.,Philp, Douglas
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p. 8798 - 8812
(2007/10/03)
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- Fine-tuning furan toxicity: Fast and quantitative DNA interchain cross-link formation upon selective oxidation of a furan containing oligonucleotide
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Oligonucleotides containing a furan modified internal nucleoside have been synthesized; selective in situ oxidation of the furan moiety to a reactive enal species in the presence of a complementary DNA strand gives rise to fast and efficient formation of an interstrand cross-link. The Royal Society of Chemistry 2005.
- Halila, Sami,Velasco, Trinidad,De Clercq, Pierre,Madder, Annemieke
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p. 936 - 938
(2007/10/03)
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- 3-heteroarylalkyl substituted gaba analogs
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The invention is a novel series of compounds which are useful in the treatment of epilepsy, faintness attacks, neurodegenerative disorders, depression, anxiety, panic, pain, neuropathological disorders, gastrointestinal disorders such as irritable bowel syndrome (IBS), and inflammation, especially arthritis. A pharmaceutical composition containing a compound of the invention as well as methods of preparing the compounds and novel intermediates useful in the preparation of the final compounds are included.
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Page column 30-31
(2010/02/05)
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- Self-replication vs. reactive binary complexes - Manipulating recognition-mediated cycloadditions by simple structural modifications
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The rate of reaction and the selectivity of a Diels - Alder cycloaddition between a furan and a maleimide can be enhanced by the introduction of complementary recognition sites on the reactant species. Subtle manipulation of other structural elements allows the generation of the observed rate enhancements and selectivities through either self-replication or formation of a pre-reactivc binary complex.
- Pearson, Russell J.,Kassianidis, Eleftherios,Slawin, Alexandra M.Z.,Philp, Douglas
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p. 3434 - 3441
(2007/10/03)
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- Methods to improve immunogenicity of antigens and specificity of antibodies
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A method of improving specific immune responses to small immunogens, haptens, has been developed by changing the linkage between the hapten and carrier being used for immunization. High affinity antibodies to the hapten cotinine have been produced using this method. Antibodies to a glycated protein have also been developed, utilizing an immunogen which is composed of a glycated peptide mimic of the glycated peptide sequence which is the target epitope, wherein the peptide mimic is constructed to conformationally mimic the conformation of the peptide in the native protein, the peptide mimic contains no charged groups or other immunodominant group, and the peptide mimic is connected to a spacer sequence equivalent to a peptide spacer of between one and thirty amino acids in length, which serves to position the peptide epitope in a conformation that approximates its conformation in the native protein. In a further embodiment the peptide mimic and spacer are linked to a carrier molecule.
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- Dissociative cycloelimination, a new selenium based pericyclic reaction
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The stereospecific oxidation of hydrazine into cis-diimide and the catalytic disproportionation of hydrogen peroxide effected by selenoxides are suggested to involve a dissociative cycloelimination from an intermediary selenurane.
- Henriksen,Jakobsen
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p. 2448 - 2449
(2007/10/03)
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- Recognition-induced control of a Diels-Alder cycloaddition
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The rational design of systems which are capable of accelerating and/or controlling the stereochemical outcome of the Diels-Alder cycloaddition reaction between a furan and a maleimide is presented. The origins of the acceleration and control of the cycloaddition reactions are traced by kinetic studies - allied to molecular mechanics calculations - to the formation of complexes in which the dienes and the dieneophiles are placed in the appropriate arrangements for reaction, and, more importantly, to the formation of intramolecular hydrogen bonds in the cycloadducts.
- Robertson, Andrew,Philp, Douglas,Spencer, Neil
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p. 11365 - 11384
(2007/10/03)
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- Thermodynamics of Protonation of Some Five-membered Heteroarylcarboxylates, -alkanoates and -trans-propenoates
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Thermodynamic parameters for the proton complex formation of some five-membered heteroaryl-carboxylates, -alkanoates and -trans-propenoates have been determined in aqueous solution at 25 deg C and I = 0.10 mol dm-3 (KNO3) by means of potentiometric and calorimetric measurements.The acidity of heteroarylcarboxylic acids follows the order 2-furoic > 2-thenoic > selenophene-2-carboxylic > 3-furoic > 3-thenoic > pyrrole-2-carboxylic > N-methylpyrrole-2-carboxylic.Such a sequence agrees with the different effects of the heteroaryl groups on the carboxylic side chain.A similar trend is observed for the corresponding furyl- and thienyl-alkanoic acids, even though polar effects of heteroatoms on the acidity are less pronounced owing to the presence of the methylenic spacers.The pK values of trans-heteroarylpropenoic acids turn out to be independent of both the heteroatom and the carboxylic group position.Enthalpic and entropic changes are typical of a "hard-hard" interaction.
- Arena, Giuseppe,Cali, Rosario,Maccarone, Emanuele,Passerini, Amedeo
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p. 1941 - 1946
(2007/10/02)
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- Allyl cation stereochemistry in the intramolecular 4+3 cycloaddition reaction
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Initial allyl cation geometry appears to be irrelevant with respect to the stereochemistry of cycloadducts in the intramolecular 4+3 cycloaddition of alkoxyallylic cations derived from alkoxyallylic sulfones.
- Harmata,Gamlath,Barnes
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p. 5981 - 5984
(2007/10/02)
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- Tobacco smoke chemistry 3. Aromatic acids of cigarette smoke condensate.
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A fraction containing mainly aromatic acids has been isolated from cigarette smoke condensate. Gas chromatographic and mass spectral analysis of the corresponding methyl esters and comparison with reference compounds, many of which were synthesized for this purpose, made possible the identification of 27 constituents (Table 1). Eighteen of these have not been detected in tobacco smoke condensate before.
- Arnarp,Dahlin,Enzell,Pettersson
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p. 381 - 385
(2007/10/02)
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