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Search for "chemically modified" in Full Text gives 49 result(s) in Beilstein Journal of Organic Chemistry.
Synthesis and photophysical characteristics of polyfluorene polyrotaxanes
Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288
- architectures [39]. The second most investigated group of host molecules in the synthesis of conjugated polyrotaxanes is comprised of chemically-modified CDs. They are less hydrophilic than native CDs, and should exhibit a significantly increased ability to bind aromatic guests through ionic, ion-dipole, as
- the lower surface parameters clearly evidenced that the encapsulation with chemically-modified CDs leads to better film forming ability with a smoother surface. Conclusion TM-βCD or TM-γCD encapsulations of PF backbones lead to distinct improvements in the solubility and transparency of the solid
Synthesis, structure, and mechanical properties of silica nanocomposite polyrotaxane gels
Beilstein J. Org. Chem. 2015, 11, 2194–2201, doi:10.3762/bjoc.11.238
- , formation of chemical bonds between the cyclic components of polyrotaxanes to the surface of a nanoparticle may result in a network structure where the nanoparticle acts as a cross-linker. As the first model system, we employed a silica nanoparticle and a CD-based polyrotaxane whose rings were chemically
- modified to react with the surface of silica. The inner structure and the mechanical properties of the silica nanocomposite polyrotaxane gels were studied by small-angle X-ray scattering and viscoelastic measurements, respectively. Results and Discussion To achieve a covalent bond between the cyclic
Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners
Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208
- cytotoxicity of a lactose scaffold with a cholesterol moiety at the C-3 carbon of the B ring of the lactose. This is because chemically modified 3β-lactosides were emerged as potential galectin-3 inhibitors. Galectin-3 is a member of the protein family known as galectins and this subfamily is believed to be
Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ
Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120
Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection
Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86
- more are being developed [1]. Although a direct delivery of “naked” siRNA or chemically modified oligonucleotides [2] has been studied, delivery vectors are typically required for efficient siRNA delivery in vivo due to unmodified siRNA’s low stability towards endogenous enzymes, poor cellular uptake
Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption
Beilstein J. Org. Chem. 2015, 11, 473–480, doi:10.3762/bjoc.11.53
- electrolysis the electrolyte contains large amounts of unreacted, respectively chemically modified lignin. A conventional approach for product recovery includes acidification of the mixture, which leads to precipitation of lignin. Filtration followed by liquid–liquid extraction results in the clean product 1
Cyclodextrin–polysaccharide-based, in situ-gelled system for ocular antifungal delivery
Beilstein J. Org. Chem. 2014, 10, 2903–2911, doi:10.3762/bjoc.10.308
- -Hydroxypropyl-β-cyclodextrin (HPBCD) and sulfobutyl ether-β-cyclodextrin (SBECD) are two chemically modified cyclodextrins frequently used as vehicles to improve drug solubility. The aim of this work is to obtain an ophthalmic drug delivery system for the release of fluconazole (FC) based on the use of ion
Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)
Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307
- using pure samples of pre-halogenated cyclopropyl chains, with deposition directly onto the surface. This presents the obvious challenge of obtaining highly ordered films after direct deposition. The current approach establishes films of good integrity, which then become chemically modified. There is
- good evidence that this is less straightforward with functionalised surfactants [32]. Conclusion In summary we have been able to demonstrate that vinyl-terminated SAMs can be chemically modified by a range of dihalocarbenes to generate surfaces carrying the corresponding dihalocyclopropane motifs. The
Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens
Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273
- hydroxyl groups allow the introduction of various functional groups [8]. As example, some native and chemically modified CDs are presented in Table 1. The main reasons why CDs are popular for inclusion of various molecules are the following: i) they are produced from a renewable natural material (i.e
- technologies and textile industry [9][10][11][12][13]. Although the application of CDs to the biocide field is not really new, there is still room for the development of new systems with advanced properties. The objective of this contribution is to focus on the use of natural and chemically modified CDs to
Versatile synthesis of amino acid functionalized nucleosides via a domino carboxamidation reaction
Beilstein J. Org. Chem. 2014, 10, 2566–2572, doi:10.3762/bjoc.10.268
- -intermediates in DNA- and RNAzymes via an efficient and straightforward domino carboxamidation reaction. Keywords: amino acids; bioorganic chemistry; carboxamidation reaction; chemically modified; DNA nucleosides; nucleic acids; Introduction For decades DNA has been known as the carrier of the genetic
Expanding the scope of cyclopropene reporters for the detection of metabolically engineered glycoproteins by Diels–Alder reactions
Beilstein J. Org. Chem. 2014, 10, 2235–2242, doi:10.3762/bjoc.10.232
- naturally biotinylated proteins. Principle of MOE with Ac4GlcNCyoc (1) and subsequent ligation by a DAinv reaction: The chemically modified sugar is fed to cells, taken up by the cells and deacetylated by non-specific esterases. The monosaccharide is metabolized and incorporated into glycoproteins (i.e., O
The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units
Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222
- been applied for the synthesis of polyrotaxanes by incorporating chemically modified CDs as host molecules [11][26][27][28][29][30]. Due to lower tendency to aggregate formations of functionalized CDs [31], polyrotaxanes with permodified CDs are characterized by a better solubility in common organic
A complete series of 6-deoxy-monosubstituted tetraalkylammonium derivatives of α-, β-, and γ-cyclodextrin with 1, 2, and 3 permanent positive charges
Beilstein J. Org. Chem. 2014, 10, 1390–1396, doi:10.3762/bjoc.10.142
- [3]. The main areas of use of native CDs and their derivatives are drug transportation [4] and solubilization [5], catalysis [6] and enzyme mimics [7]. Chemically modified CDs [5][8] are prepared in order to reach specific chemical and physical properties, e.g., solubility or their binding behavior
Automated solid-phase peptide synthesis to obtain therapeutic peptides
Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118
- , demonstrating a prolonged action profile of the acylated conjugates. Thus, the extended action was proposed to be facilitated by serum albumin binding, which leads to gradual peptide release and an prolonged circulation time [91]. Since then, many biological relevant peptides and proteins were chemically
- modified by fatty acid acylation [97]. The synthesis of these lipidated peptides can be performed by amidation, S- or O-esterification as well as thioether or -sulfide formation. Owing to the strength of the covalent bonds, amidation and O-esterfication are preferred over the other strategies [97
Atherton–Todd reaction: mechanism, scope and applications
Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117
A new building block for DNA network formation by self-assembly and polymerase chain reaction
Beilstein J. Org. Chem. 2014, 10, 1037–1046, doi:10.3762/bjoc.10.104
- different shapes which are further characterized in solution by DLS. EPR measurements further corroborate network formation and suggest rather rigid DNA networks. As demonstrated, the approach allows to additionally modify the networks by using chemically modified nucleotides during PCR. The depicted
Theoretical study on β-cyclodextrin inclusion complexes with propiconazole and protonated propiconazole
Beilstein J. Org. Chem. 2012, 8, 2191–2201, doi:10.3762/bjoc.8.247
- . Bearing in mind that the CD cavity cannot fully incorporate the guest molecule, the aim of this work is to identify the part of the molecular cavity that is more suitable for complexation with the PPH+. This information can be useful to predict which of the hydroxy groups of cyclodextrin can be chemically
- modified (by pegylation for example) in order to avoid the shielding of the cavity during the inclusion process, and, as a consequence, to improve the systemic bioavailability and pharmacokinetics of the inclusion complexes. Results and Discussions The most stable conformations of the β-CD/PP and β-CD/PPH
Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin
Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170
- photophysical properties of PFs by using persilylated γ-CD as a new host molecule [33]. Inclusion of bithiophene into persilylated β-cyclodextrin, randomly methylated β-cyclodextrin, or chemically modified CD derivatives, followed by copolymerization with fluorene monomers results in significant changes in the
A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)
Beilstein J. Org. Chem. 2012, 8, 1352–1357, doi:10.3762/bjoc.8.155
- ]. Lately, the chemodosimeter-based sensing has gained increasing popularity on account of the irreversible chemical intervention of analytes with the probe molecules. Since the metal ions are disengaged from the chemically modified dosimeters, the process results in the more reliable fluorescence
Chemo-enzymatic modification of poly-N-acetyllactosamine (LacNAc) oligomers and N,N-diacetyllactosamine (LacDiNAc) based on galactose oxidase treatment
Beilstein J. Org. Chem. 2012, 8, 712–725, doi:10.3762/bjoc.8.80
- ]. Efforts have especially been made regarding the development and evaluation of galectin inhibitors as therapeutic agents [20][21][22][23]. For example, chemically modified mono- and disaccharides as well as thiodigalactosides have been investigated [21][24][25][26][27]. Another modification strategy is the
Michael-type addition of azoles of broad-scale acidity to methyl acrylate
Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24
- and which, after acidic hydrolysis [43], can be anchored to drug delivery systems, including, e.g., chemically modified carbon nanotubes, via amide bonds. Examples of azole derivatives as important therapeutic agents. Michael-type addition of azoles of broad-scale acidity 1a–h to methyl acrylate (2
Functionalized polymers: synthesis and properties
Beilstein J. Org. Chem. 2010, 6, No. 55, doi:10.3762/bjoc.6.55
- , naturally occurring polymers as cellulose or polyisoprene were simply modified, for example by esterification or cross-linking to obtain the desired properties. Hermann Staudinger, for instance, chemically modified starch to prove the existence of high molecular weight substances. Nowadays, the development
Synthesis of glycosylated β3-homo-threonine conjugates for mucin-like glycopeptide antigen analogues
Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47
- solid-phase peptide synthesis. By appropriate conjugation, the resulting α/β-hybrid glycopeptide conjugate could be used as an antigen surrogate to elucidate the effects of chemically modified antibody determinants on the immunological properties of glycopeptide antigen analogues. Experimental General
Asymmetric reactions in continuous flow
Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19
- aqueous solution, then acidified with HCl subsequent to reaction completion, and combined with ethyl acetate organic phase for the extraction step. A chemically modified channel with hydrophobic/hydrophilic surfaces was used for the microextractor in order to maintain consistent laminar flow. Laminar flow
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