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Chiral recognition of carbohydrate

Kajetan Dąbrowa, Patryk Niedbała, Janusz Jurczak
The symmetrical molecular receptors 1a and 1b consisting of a photochemically addressable azobenzene tether functionalized with urea hydrogen-bonding groups and d-carbohydrates as chiral selectors were developed to achieve control over the chiral recognition of α-amino acid-derived carboxylates. The photo- and thermally interconvertible planar E-1 and concaved Z-1 were found to exhibit different affinities, selectivities, and binding modes toward these biologically important anions in a highly polar medium (DMSO + 0...
May 6, 2016: Journal of Organic Chemistry
Sara Lefevre, Alexandre Héloin, Delphine Pitrat, Jean-Christophe Mulatier, Nicolas Vanthuyne, Marion Jean, Jean-Pierre Dutasta, Laure Guy, Alexandre Martinez
New host compounds combining a cyclotriveratrylene (CTV) unit and three binaphthol moieties have been synthesized enantiomerically and diastereomerically pure. The use of a chemical correlation allows for the assignment of their absolute configuration. The energy barrier of epimerization was measured, suggesting that no intramolecular hydrogen bonding occurs between the hydroxyl groups of the binaphthols. These open-shell host compounds were then tested in the recognition of carbohydrates; a preferential binding of mannose toward glucose was observed, and good diastereoselectivities were reached (up to 1:10)...
April 15, 2016: Journal of Organic Chemistry
Ziyu Lv, Xiuling Li, Zhonghui Chen, Ji Chen, Cheng Chen, Peng Xiong, Taolei Sun, Guangyan Qing
Surface stiffness is considered a key parameter for designing high-performance implantable materials and artificial extracellular matrices because of its substantial effects on cell behavior. How to transform biomolecule recognition events, particularly chiral recognition, into stiffness change on material surfaces is biologically essential but very challenging for chemists. Here, we report a chirality-triggered stiffness transition on a smart polymer film, which consists of flexible polyethylenimine (PEI) main chains grafted with dipeptide units capable of discriminating chiral monosaccharides...
December 16, 2015: ACS Applied Materials & Interfaces
Jonas Altnöder, Juhyon J Lee, Katharina E Otto, Martin A Suhm
Carbohydrates are used in nature as molecular recognition tools. Understanding their conformational behavior upon aggregation helps in rationalizing the way in which cells and bacteria use sugars to communicate. Here, the simplest α-hydroxy carbonyl compound, glycolaldehyde, was used as a model system. It was shown to form compact polar C 2-symmetric dimers with intermolecular O-H⋅⋅⋅O=C bonds, while sacrificing the corresponding intramolecular hydrogen bonds. Supersonic jet infrared (IR) and Raman spectra combined with high-level quantum chemical calculations provide a consistent picture for the preference over more typical hydrogen bond insertion and addition patterns...
December 2012: ChemistryOpen
Xixi Sun, Hyelee Lee, Sunggi Lee, Kian L Tan
Carbohydrates and natural products serve essential roles in nature, and also provide core scaffolds for pharmaceutical agents and vaccines. However, the inherent complexity of these molecules imposes significant synthetic hurdles for their selective functionalization and derivatization. Nature has, in part, addressed these issues by employing enzymes that are able to orient and activate substrates within a chiral pocket, which increases dramatically both the rate and selectivity of organic transformations. In this article we show that similar proximity effects can be utilized in the context of synthetic catalysts to achieve general and predictable site-selective functionalization of complex molecules...
September 2013: Nature Chemistry
Hajime Abe, Kotaro Okada, Hiroki Makida, Masahiko Inouye
Amphiphilic 2,6-pyridylene ethynylene "meta-ethynylpyridine" polymers having chiral oligo(oxyethylene) side chains were developed as hosts for saccharide recognition. The polymers were prepared via a Sonogashira reaction and fractionated by gel permeation chromatography (GPC). They showed circular dichroism (CD) activity due to their higher-order chiral helical structures, and their CD and UV-vis spectra changed depending on not only saccharide recognition but also molecular size, temperature, and metal cation recognition...
September 14, 2012: Organic & Biomolecular Chemistry
Stephen Hanessian
A retrospective account of natural products synthesis adopting the Chiral Synthon (Chiron) Approach and spanning nearly 50 years of personal research activity is presented highlighting the interplay between the eye and the mind's eye. Synthesis planning is discussed in terms of visual relational and visual reflexive thinking modalities relying on the recognition of naturally occurring nonracemic starting materials such as amino acids, carbohydrates, hydroxy acids, and terpenes in the carbon framework of target molecules...
August 17, 2012: Journal of Organic Chemistry
Yukiko Ogawa, Chiharu Yoshiyama, Takuya Kitaoka
Carbohydrate-mediated interactions are involved in various biological processes via specific molecular assembly and recognition. Such interactions are enhanced by multivalent effects of the sugar moieties, and thus supramolecular sugar-assembly, i.e., spontaneous association of glycoamphiphiles, is a promising approach to tailor glycocluster formation. In this study, novel sugar-decorated nanofibers were successfully prepared by self-assembly of low molecular weight hydrogelators composed of azobenzene and disaccharide lactones...
March 6, 2012: Langmuir: the ACS Journal of Surfaces and Colloids
Jens Voskuhl, Kira Schaepe, Bart Jan Ravoo
In this article we investigate the effect of multivalency in chiral recognition. To this end, we measured the host-guest interaction of a β-cyclodextrin dimer with divalent chiral guests. We report the synthesis of carbohydrate-based water soluble chiral guests functionalized with two borneol, menthol, or isopinocampheol units in either (+) or (-) configuration. We determined the interaction of these divalent guests with a β-cyclodextrin dimer using isothermal titration calorimetry. It was found that-in spite of a highly unfavorable conformation-the cyclodextrin dimer binds to guest dimers with an increased enantioselectivity, which clearly reflects the effect of multivalency...
2011: International Journal of Molecular Sciences
Jie-Hua Shi, Zuo-Jing Ding, Ying Hu
Host-guest interactions of permethylated β-cyclodextrin (PM-β-CD) with methyl mandelate enantiomers ((R/S)-MMA) were simulated using semiempirical PM3 and ONIOM (B3LYP/6-31G(d):PM3) method. The chiral recognition mechanism of (R/S)-MMA enantiomers on PM-β-CD was investigated. The binding energies for all orientations considered in this research are reported. The most stable geometry structures of the two complexes are different. The benzene ring of (R)-MMA locates horizontally approximately on the wider edge of the PM-β-CD cavity, but the aromatic ring of (S)-MMA is deeply included into the hydrophobic cavity...
February 2012: Journal of Molecular Modeling
Xia Li, Zhi-Ming Zhou, Di Xu, Jun Zhang
Two new chiral stationary phases (CSP) were successfully prepared through bonding β-cyclodextrin (CD) derivatives modified by R-configuration groups (R-CPGCD, R-HMPGCD) to silica gel. Nineteen chiral nitro aromatic alcohol derivatives were separated under the polar organic and the reversed phase modes. Better enantioseparation was obtained in the reversed phase mode. The resolution values of the analytes ranged from 1.98 to 7.57 and from 2.19 to 8.14 on R-CPGCD and R-HMPGCD CSPs, respectively, using a mobile phase composed of methanol/water (v/v, 40/60)...
May 30, 2011: Talanta
Cristina Nativi, Oscar Francesconi, Gabriele Gabrielli, Alberto Vacca, Stefano Roelens
A new generation of chiral tripodal receptors for recognition of carbohydrates, featuring trans-1,2-diaminocyclohexane as a key structural element, and their recognition properties toward a set of glycosides of biologically relevant monosaccharides is described. The introduction of a chelating diamino unit into the pyrrolic tripodal architecture markedly enhanced their binding abilities compared with the parent aminopyrrolic receptors previously reported by our group. In addition, the chirality of the structure had a clear impact on affinities, as well as on selectivities, displaying high enantiodiscrimination levels...
April 18, 2011: Chemistry: a European Journal
Wen-Wu Li, Timothy D W Claridge, Qiuhong Li, Mark R Wormald, Benjamin G Davis, Hagan Bayley
Cyclodextrins (CDs) have been widely used in host-guest molecular recognition because of their chiral and hydrophobic cavities. For example, β-cyclodextrin (βCD) lodged as a molecular adaptor in protein pores such as α-hemolysin (αHL) is used for stochastic sensing. Here, we have tuned the cavity and overall size of βCD by replacing a single oxygen atom in its ring skeleton by a disulfide unit in two different configurations to both expand our ability to detect analytes and understand the interactions of βCD with protein pores...
February 16, 2011: Journal of the American Chemical Society
Weili Wei, Baoyuan Guo, Jin-Ming Lin
The present study discovered that helical structures of amylose were not always responsible for its chiral recognition abilities in CE. Several enantiomers with different structures were selected as models. Based on ultraviolet-visible spectroscopy and (13)C NMR measurements, it was found that helical structures were gradually destroyed by temperature elevation and almost entirely transformed to extended ahelical structures above 60 degrees C. Then, CE and (1)H NMR chiral recognitions were investigated at different temperatures; chiral selectivity of the enantiomers varied in two different ways...
April 2009: Electrophoresis
Gerald Gübitz, Martin G Schmid
This review gives an overview of chiral separation principles and their applications in capillary electromigration techniques. The basic chiral separation principles are explained and the mechanisms discussed. Recent developments and new techniques in CZE and capillary electrochromatography (CEC) are highlighted. New chiral selectors among cyclodextrins, crown ethers, carbohydrates, macrocyclic antibiotics, proteins, chiral ion-pairing reagents, chiral surfactants and chiral metal ion complexes and their chiral recognition ability are discussed...
September 19, 2008: Journal of Chromatography. A
Alain Berthod
Macrocyclic glycopeptide selectors are naturally occurring antibiotics produced by microorganisms. They were found to be excellent chiral selectors for a wide range of enantiomers, including amino acids. Four selectors are commercialized as chiral stationary phases (CSP) for chromatography. They are ristocetin, teicoplanin, vancomycin, and the teicoplanin aglycone (TAG). The key docking interaction for amino acid recognition was established to be a charge-charge interaction between the anionic carboxylate group of the amino acid and a cationic amine group of the macrocyclic peptidic selector basket...
January 2009: Chirality
Hajime Abe, Hiroshi Machiguchi, Shinya Matsumoto, Masahiko Inouye
Co-oligomers involving (1H)-4-pyridone and 4-alkoxypyridine rings were studied, and it was found that their supramolecular transformation was caused by saccharide recognition. In the co-oligomers, pyridone and pyridine rings are alternately linked at their 2,6-position with an acetylene bond. The pyridine rings behave as a hydrogen bonding acceptor, and the pyridone rings and tautomerized 4-pyridinol work as a donor. Pyridine-pyridone-pyridine 3-mer was found to self-dimerize on the basis of vapor pressure osmometry in CHCl(3), and the association constant was obtained as 2...
June 20, 2008: Journal of Organic Chemistry
Zsolt Bikádi, Róbert Iványi, Lajos Szente, István Ilisz, Eszter Hazai
Cyclodextrins are well known in supramolecular chemistry as host molecules capable of engulfing molecules in their hydrophobic cavity via noncovalent interactions. Although cyclodextrins are frequently used for chiral separation of racemates, the mechanism of chiral recognition has not yet been fully characterised. The current investigation was aimed at examining chiral recognition mechanism in order to construct an in silico method for prediction of chiral recognition. Amino acids were selected as model guest, whereas alphaCD was used as model host...
December 2007: Current Drug Discovery Technologies
Petr Niederhafner, Jaroslav Sebestík, Jan Jezek
Glycopeptide dendrimers are regularly branched structures containing both carbohydrates and peptides. Various types of these compounds differing in composition and structure are mentioned, together with their practical use spanning from catalysis, transport vehicles to synthetic vaccines. This Part II (for Part I see JeZek J, et al., J. Pept. Sci. 2008; 14: 2-43) covers linear oligomers with variable valency (brush dendrimers, comb dendrimers), sequential oligopeptide carriers SOCn-I and SOCn-II, chitosan-based dendrimers, and brush dendrimers...
January 2008: Journal of Peptide Science: An Official Publication of the European Peptide Society
Marcus A Boone, Hugh Nymeyer, André M Striegel
The physiological functions of oligosaccharides are influenced by a number of structural parameters such as anomeric configuration, glycosidic linkage, and degree of polymerization. These parameters affect the conformation of the oligosaccharides which, in turn, is responsible for characteristics such as aptameric and enzymatic binding, chiral recognition, and the structural targeting of bacterial and parasitic recognition events. Here, we measure the solution conformational entropy (DeltaS) of two series of oligosaccharides, linear malto- and cellooligosaccharides, using size-exclusion chromatography (SEC)...
January 14, 2008: Carbohydrate Research
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