Nucleobase-Containing Gelators

Araki, Koji; Yoshikawa, Isao

doi:10.1007/b107173

Cited by 130 publications

(78 citation statements)

References 74 publications

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“…All the intermediate products synthesised were purified by silica gel column chromatography and then fully characterised by 1 H and 13 C NMR spectroscopy and ESI mass spectrometry. Final compounds G1-G7, obtained from the corresponding nucleobase-protected precursors by a simple treatment with TFA (10 %) in CH 2 Cl 2 , followed by repeated co-evaporations from isopropanol until the excess TFA had disappeared completely, were identified on the basis of their NMR and ESI-MS spectra.…”

Section: Resultsmentioning

confidence: 99%

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Design, Synthesis and Characterisation of Guanosine‐Based Amphiphiles

Simeone

Milano

Napoli

et al. 2011

Chemistry A European J

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A small library of sugar-modified guanosine derivatives has been prepared, starting from a common intermediate, fully protected on the nucleobase. Insertion of myristoyl chains and of diverse hydrophilic groups, such as an oligoethylene glycol, an amino acid or a disaccharide chain, connected through in vivo reversible ester linkages, or of a charged functional group provided different examples of amphiphilic guanosine analogues, named G1-G7 herein. All of the sugar-modified derivatives were positive in the potassium picrate test, showing an ability to form G-tetrads. CD spectra demonstrated that, as dilute solutions in CHCl(3), distinctive G-quadruplex systems may be formed, with spatial organisations dependent upon the structural modifications. Two compounds, G1 and G2, proved to be good low-molecular-weight organogelators in polar organic solvents, such as methanol, ethanol and acetonitrile. Ion transportation experiments through phospholipid bilayers were carried out to evaluate their ability to mediate H(+) transportation, with G5 showing the highest activity within the investigated series. Moreover, G3 and G5 exhibited a significant cytotoxic profile against human MCF-7 cancer cells in in vitro bioassays.

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Section: Resultsmentioning

confidence: 99%

“…liminary studies aimed at identifying new tools with the potential to profitably complement the lipophilic congeners recently studied by the research groups of G. P. Spada, [6][7][8][9] J. T. Davis [9][10][11][12] and K. Araki [13][14][15] , among others, further expanding the chemical diversity offered by nucleosides.…”

Section: Introductionmentioning

confidence: 99%

Design, Synthesis and Characterisation of Guanosine‐Based Amphiphiles

Simeone

Milano

Napoli

et al. 2011

Chemistry A European J

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“…[15] Araki and Yoshikawa recently introduced nonpolar and flexible alkylsilyl groups into 2'-deoxyguanosine to obtain efficient organogelators for alkanes. [21] From an in-depth structural analysis, they concluded that in these gels the basic structure is a sheetlike assembly: the supramolecular structure (see Figure 2) consists of anti-parallel G ribbons like in Figure 1e linked through two additional inter-tape hydrogen bonds between NH(2) and N(3) of the two guanines belonging to adjacent ribbons. Upon heating, a gel-toliquid-crystal phase transition is observed and has been ascribed to the selective cleavage of the inter-tape H-bonds.…”

Section: Introductionmentioning

confidence: 99%

Self‐Assembly of an Alkylated Guanosine Derivative into Ordered Supramolecular Nanoribbons in Solution and on Solid Surfaces

Lena

Brancolini

Gottarelli

et al. 2007

Chemistry A European J

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We report on the synthesis and self-assembly of a guanosine derivative bearing an alkyloxy side group under different environmental conditions. This derivative was found to spontaneously form ordered supramolecular nanoribbons in which the individual nucleobases are interacting through H-bonds. In toluene and chloroform solutions the formation of gel-like liquid-crystalline phases was observed. Sub-molecularly resolved scanning tunneling microscopic imaging of monolayers physisorbed at the graphite-solution interface revealed highly ordered two-dimensional networks. The recorded intramolecular contrast can be ascribed to the electronic properties of the different moieties composing the molecule, as proven by quantum-chemical calculations. This self-assembly behavior is in excellent agreement with that of 5'-O-acylated guanosines, which are also characterized by a self-assembled motif of guanosines that resembles parallel ribbons. Therefore, for guanosine derivatives (without sterically demanding groups on the guanine base) the formation of supramolecular nanoribbons in solution, in the solid state, and on flat surfaces is universal. This result is truly important in view of the electronic properties of these supramolecular anisotropic architectures and thus for potential applications in the fields of nano- and opto-electronics.

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“…11 Among these gelators, the biocompatible and biodegradable species are particularly popular for constructing hydrogels, such as nucleobases, 12 bile salts, 13 carbohydrates 14 and peptides, 15 as they can be safely used in biological applications. 16 Bile acids and their salts belong to not only important biological surfactants, but also small-molecule biological gelators that can act as solubilizers of cholesterol, bilirubin, and various fat-soluble vitamins in the intestine of vertebrates, including humans.…”

Section: Introductionmentioning

confidence: 99%

Effects of polymers on the properties of hydrogels constructed using sodium deoxycholate and amino acid

et al. 2018

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The gelation behavior and properties of sodium deoxycholate (NaDC) and L-aspartic acid (Asp) in aqueous solution were investigated in detail at 25 C. The linear polymer poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo-(ethylene glycol) methacrylate) (P(MEO 2 MA 90 -co-OEGMA 10 )) and star-shaped polymer poly(2-(dimethylamino)ethyl methacrylate-b-2-(2-methoxyethoxy)ethyl methacrylate) (CDPDPM) were introduced in NaDC/Asp hydrogels for exploring the effects of polymers on the properties of NaDC/Asp hydrogels and the mechanism underlying gelation processes by polymers was proposed. The hydrogels were characterized by phase behavior observation, polarized optical microscopy (POM), cryogenic scanning electron microscopy (cryo-SEM), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and rheological measurements. Moreover, the adsorption performances of hydrogels with and without polymers to methylene blue (MB) were studied using a UV-vis spectrometer. The results indicated that the transition from sol to gel state was observed with an increase in the Asp concentration in the system. Both linear and star-shaped polymers can participate in the formation of a gel network structure, so that the density of network structure and the mechanical strength of hydrogels increased. Furthermore, it was found that the viscoelasticity of the CDPDPM-containing hydrogel was much higher than that of the P(MEO 2 MA 90 -co-OEGMA 10 )-containing hydrogel under the same condition, indicating that CDPDPM performed better in strengthening the network structure of the hydrogels than P(MEO 2 MA 90 -co-OEGMA 10 ) due to the special structure that provided more binding sites for hydrogen bonding and stronger hydrophobicity that inhibited the swelling and dissolution of hydrogels. On coming in contact with the MB solution, the CDPDPMcontaining hydrogel can adsorb MB and maintain the hydrogel state for recycling. On the contrary, the NaDC/Asp hydrogel dissolved and P(MEO 2 MA 90 -co-OEGMA 10 )-containing hydrogel collapsed in the MB solution. The properties of the hydrogels are expected to be tailored by introducing polymers with different properties, including the charge numbers, the number of available binding sites, and hydrophobic properties.

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Nucleobase-Containing Gelators

Cited by 130 publications

References 74 publications

Design, Synthesis and Characterisation of Guanosine‐Based Amphiphiles

Design, Synthesis and Characterisation of Guanosine‐Based Amphiphiles

Self‐Assembly of an Alkylated Guanosine Derivative into Ordered Supramolecular Nanoribbons in Solution and on Solid Surfaces

Effects of polymers on the properties of hydrogels constructed using sodium deoxycholate and amino acid

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