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Search for "fluorescent" in Full Text gives 392 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Impact of Pseudomonas aeruginosa quorum sensing signaling molecules on adhesion and inflammatory markers in endothelial cells
Beilstein J. Org. Chem. 2018, 14, 2580–2588, doi:10.3762/bjoc.14.235
- immediately with a fluorescent microscope (Eclipse TE300, with Digital Net Camera DN100, Nikon, Tokyo, Japan), by using the 100×, immersion oil objective. The plates were examined microscopically to evaluate the adherence index and patterns. The adherence index was expressed as the ratio between the number of
Comparative cell biological study of in vitro antitumor and antimetastatic activity on melanoma cells of GnRH-III-containing conjugates modified with short-chain fatty acids
Beilstein J. Org. Chem. 2018, 14, 2495–2509, doi:10.3762/bjoc.14.226
- capacity, this large-scale difference in the intracellular fluorescence intensity between the free Dau and the conjugates is not surprising. In addition, the free Dau has a ca. 10 times higher fluorescent intensity than the conjugates [35]. Comparing these results with the previous findings [19], [4Lys(Bu
- -250TM, ChemoMetec A/S, Lillerød, Denmark) using Vitabright-48™ (ChemoMetec A/S, Lillerød, Denmark), a cell permeable dye that reacts with thiol groups to form a fluorescent product. An inverse correlation has been shown between the concentration of thiols and progression of apoptosis; the level of
Synthesis of a water-soluble 2,2′-biphen[4]arene and its efficient complexation and sensitive fluorescence enhancement towards palmatine and berberine
Beilstein J. Org. Chem. 2018, 14, 2236–2241, doi:10.3762/bjoc.14.198
- carboxylato moieties, 2,2’-CBP4 (Scheme 1), and its binding behavior and fluorescent spectrum characteristic towards two alkaoilds, palmatine (P) and berberine (B), in water solution. In particular, the fluorescence intensities of the two guests have been considerably enhanced after complexation. As a member
Synthesis and supramolecular self-assembly of glutamic acid-based squaramides
Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180
- . Characterization methods Thin-layer chromatography (TLC) analyses were performed using fluorescent-indicating plates (aluminum sheets coated with silica gel 60 F254, thickness 0.2 mm, Merck). Visualization was achieved by UV light (λmax = 254 nm). Melting point calculations were made using a GallenKamp MPD 350 BM
Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry
Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179
- fluoroalkyl sulfinate salt as the fluoroalkyl source, in combination with TFA and Acid Red 94 as the photocatalyst, under 22 W fluorescent lamp irradiation to perform the transformation (Scheme 28) [72]. The substrate scope is limited to rather simple compounds, the most structurally complex of which is
Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates
Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173
- performed by the dye micellization method using pyrene and eosin Y (EY) as fluorescent and spectrophotometric probes, respectively (Table 1). The nonpolar pyrene can be incorporated into hydrophobic domains of the aggregates due to hydrophobic interactions. Pyrene insertion is measured by analyzing the
Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril
Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171
- motifs for CB7. The unprotonated dyes show low fluorescence due to photoinduced electron transfer (PET), whereas the protonated dyes are highly fluorescent. Encapsulation of the binding motif inside CB7 positions the aniline nitrogen at the carbonyl rim of CB7, which affects the pKa value, and leads to a
- fluorescent dyes directly enables (bio)sensing applications through the indicator displacement principle [16][17]. Therein, the fluorescence properties of a dye are altered when encapsulated by the host, and when a competitive binder displaces the dye from the cavity, the properties of the non-encapsulated
- macrocyclic hosts and dyes that have so far been reported [16] are only of limited use for these currently emerging life science applications of CBs. Many of the fluorescent dyes which bind to CBs with significant fluorescence changes have a limited photostability, in particular under intense laser light
Recent advances in materials for organic light emitting diodes
Beilstein J. Org. Chem. 2018, 14, 1944–1945, doi:10.3762/bjoc.14.168
- in design, from fluorescent compounds to phosphorescent organometallic complexes to organic thermally activated delayed fluorescence (TADF) molecules, the latter driving tremendous recent excitement within the field of organic semiconductor research. This thematic issue of the Beilstein Journal of
Strong binding and fluorescence sensing of bisphosphonates by guanidinium-modified calix[5]arene
Beilstein J. Org. Chem. 2018, 14, 1840–1845, doi:10.3762/bjoc.14.157
- diseases. Guanidinium-modified calix[5]arene (GC5A) affords strong binding on the micromolar to nanomolar level towards BPs dominantly via multiple salt bridge interactions, which was evaluated by fluorescence competitive titrations. Fluorescent IDA enables the highly sensitive and label-free detection of
- applications of them [25][26][27][28]. In this work, we report a fluorescent IDA approach for detecting BPs quantitatively in not only buffer solution but also artificial urine (Scheme 2). The rationale behind the IDA approach is the strong and selective complexation of BPs by guanidinium-modified calix[5
- recovery, offers the opportunity for fluorescence “switch-on” sensing of BPs. In general, fluorescent IDA could be operated at low μM or even nM concentrations, which is desirable with respect to sensing sensitivity. We tested the host–guest complexation of GC5A with a total number of 9 BP drugs clinically
Synthesis and photophysical studies of a multivalent photoreactive RuII-calix[4]arene complex bearing RGD-containing cyclopentapeptides
Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150
- were used without further purification. Anhydrous N,N-dimethylformamide was purchased from ACROS Organics. Reactions were magnetically stirred and monitored by thin-layer chromatography using Fluka silica gel or aluminium oxide on TLC-PET foils with fluorescent indicator at 254 nm. All reactions
Recent advances in phosphorescent platinum complexes for organic light-emitting diodes
Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124
- corresponds to purely fluorescent-based devices from a first approximation spin statistics, up to 100%. Nonetheless, EQEs are typically upper limited to values of ca. 20–25% owing to differences in the refractive index of organic materials commonly employed and suboptimal light outcoupling. In spite of that
Design and biological characterization of novel cell-penetrating peptides preferentially targeting cell nuclei and subnuclear regions
Beilstein J. Org. Chem. 2018, 14, 1378–1388, doi:10.3762/bjoc.14.116
- , Supporting Information File 1), not even after a longer incubation period of two hours (data not shown). For NrTP alone, a slight fluorescent signal was visible in the nucleoli of MCF-7 cells (Figure S6, Supporting Information File 1). Notably, N50-sC18* was distributed within the whole cell cytosol, and
- to be fluorescent [42] and this property was used to test if the peptides were able to enhance the intracellular uptake of the drug. Therefore, solutions out of DOX and the sequences N50-sC18* and NrTP-sC18* were incubated with HeLa and MCF-7 cells, respectively, and observed for red fluorescence
- in triplicate. Cells treated with medium only served as negative control and their fluorescent signal was subtracted from all other samples in each set of experiment. Circular dichroism spectra of the novel peptides solved in 10 mM phosphate buffer (pH 7) (A), or phosphate buffer with the addition of
An overview of recent advances in duplex DNA recognition by small molecules
Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93
- by reducing aggregation and also helps to conduct a detailed thermodynamic study for the 8-ring HP polyamides for the very first time. Recently, Hartley et al. designed and synthesized a hybrid fluorescent HP polyamide conjugate 22 (Figure 6) by attaching the A·T recognizing fluorophore, p
- challenging tandem hairpin Py/Im polyamides which could recognize >10 base pairs with flexible linker conjugated with a fluorescent dye (either Texas Red (TR) or Cyanine 3 (Cy3)) using a Fmoc-based solid phase synthetic approach; two of the representative conjugates 23 and 24 are shown in the Figure 8 [86][87
- telomere foci clearly because of their fluorescent nature. Later on, the authors successfully designed tandem tetramer Py–Im polyamides with 4 hairpins and 3 hinges targeting 24 bp of the human telomere sequences [88]. Thus, the authors set the new record for the longest binding site of synthetic, non
Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers
Beilstein J. Org. Chem. 2018, 14, 1046–1050, doi:10.3762/bjoc.14.92
- scale at a 0.2 or 0.4 M concentration on the benchtop with a fluorescent light on the ceiling. Yields are for isolated products. aPhI(OAc)2 (3 equiv) was used. bI2 (1 equiv) was used. cI2 (0.75 equiv) was used. Hydrolysis of acetates. Mechanistic investigations. Proposed reaction pathway. Effect of
On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site
Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80
Development of novel cyclic NGR peptide–daunomycin conjugates with dual targeting property
Beilstein J. Org. Chem. 2018, 14, 911–918, doi:10.3762/bjoc.14.78
- the smallest active Dau containing metabolite Dau=Aoa-Gly-OH. No significant difference in degradation speed of the conjugates was observed. Therefore, the replacement of Lys has no influence on the biological activity through the lysosomal degradation. Cellular uptake Daunomycin is fluorescent
An uracil-linked hydroxyflavone probe for the recognition of ATP
Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63
- made to selectively recognize and detect these analytes, especially ATP using small-molecule fluorescent chemosensors. Despite the various solutions, the selective detection of ATP is still challenging due to the structural similarity of various nucleotides. In this paper, we report the conjugation of
- . Conclusions: The first, uracil-containing fluorescent ATP probe based on a hydroxyflavone fluorophore was synthesized and evaluated. A selective complexation with ATP was observed and a ratiometric response in the excitation spectrum. Keywords: ATP sensing; base-pairing; fluorescent probes; 3-hydroxyflavone
- recognition and sensing of ATP has therefore paramount importance in the understanding of biological processes. Amongst the numerous solutions [5][6][7][8][9], fluorescent chemosensors using either indicator displacement assays [10][11][12][13][14][15], cation-based recognition units [16][17][18][19][20
D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies
Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55
- exciton utilization of TADF materials. Importantly, OLEDs based on 2 exhibited a maximum external quantum efficiency of 8.9%, which is higher than the theoretical efficiency of the OLEDs based on conventional fluorescent materials. Keywords: fluorenone acceptor; orange light emission; organic light
- previously limited by the statistic rule of spin multiplicity. For conventional fluorescent materials, only singlet excitons are involved in electroluminescence, leading to a theoretical maximal internal quantum efficiency (IQEmax) of 25% and a theoretical maximal external quantum efficiency (EQEmax) of 5
- increase the cost of the final OLEDs. Alternatively, a thermally activated delayed fluorescence (TADF) material is a kind of noble-metal-free fluorescent material able to transform triplet excitons into singlet excitons through reverse intersystem crossing (RISC) to achieve 100% IQEmax in theory [4]. On the
Synthesis of a sucrose-based macrocycle with unsymmetrical monosaccharides "arms"
Beilstein J. Org. Chem. 2018, 14, 634–641, doi:10.3762/bjoc.14.50
- V4.1 software package (Waters Inc). Thin-layer chromatography (TLC) was performed on silica gel plates coated with fluorescent indicator. Column chromatography was performed on silica gel (Merck, 230–400 mesh). Organic solutions were dried over anhydrous MgSO4. Procedure for the synthesis of nitro
Continuous multistep synthesis of 2-(azidomethyl)oxazoles
Beilstein J. Org. Chem. 2018, 14, 506–514, doi:10.3762/bjoc.14.36
- ]. Sulfamoxole is a broad-spectrum antibiotic for the treatment of bacterial infections (Figure 1b) [8]. In addition, ongoing studies show the potential of amino and amido-oxazoles to act as fluorescent dipeptidomimetics (Figure 1c) [9]. Due to their diene character, oxazoles find also use as intermediates in
- dilution was necessary to avoid clogging of the reactor. Examples of naturally occurring oxazoles (a); some drugs containing oxazole as the active moiety (b); general structure of fluorescent dipeptidomimetics derived from trisubstituted oxazoles (c); reactivity of the oxazole system as an azadiene (d
Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)
Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18
- the light-emitting ability of the emitter, which is directly related to the nature, and the photoluminescence quantum yield (PLQY) of the emitter. Based on spin statistics, upon electrical excitation, singlet and triplet excitons are formed in a 1:3 ratio [4]. In the case of fluorescent materials
- , only singlet excitons can be utilized for light emission, limiting the internal quantum efficiency (IQE) of fluorescent OLEDs to 25%. Conversely, phosphorescent materials can both harvest singlet and triplet excitons for emission by intersystem crossing (ISC), enabling to reach a theoretical IQE of 100
- ). TADF materials can also be metal-free, addressing the fabrication cost and environmental issues. Therefore, TADF emitters retain the high efficiency of the second generation of emitters (triplet emitters), the stability of the first generation of fluorescent materials while eliminating the different
Fluorogenic PNA probes
Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17
- vivo. For nucleic acids, the latter valuable information cannot be obtained by sequencing despite the tremendous advances in the field in recent years [1]. Accordingly, fluorescent oligonucleotide probes are still one of the most important tools not only for the detection of nucleic acids, but also
- proteins and other non-nucleic acid targets by employing aptamer technology [2]. However, ordinary fluorescent oligonucleotide probes generally show indistinguishable signals between the free and target-bound states. This means that additional treatments are required in order to separate the bound and
- developments in the areas of fluorogenic PNA probes. Some examples of PNA probes for nucleic acid hybridization and detection that may not be strictly fluorogenic by definition have been included where deemed suitable. Overview of PNA and fluorescent PNA probes Peptide nucleic acids (PNA) are a unique class of
Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications
Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7
- . Keywords: B-to-Z-DNA transition; fluorescent base analogues; FRET; netropsin; nucleic acid structure and dynamics; quadracyclic adenines; tricyclic cytosines; Z-DNA; Review Introduction The importance of nucleic acid structure and dynamics in the understanding of vital processes in living organisms has
- . In this review we will focus on the FRET between fluorescent base analogues, i.e., base–base FRET, the theory behind it, the increased accuracy in orientation factor κ2 as an effect of their position inside the base-stack, other advantages and disadvantages compared to FRET in nucleic acids using
- external fluorophores like Cy-, Alexa- and ATTO-dyes as well as finally summarize some of its recent applications. The field started less than a decade ago with the introduction of the first fluorescent nucleobase analogue FRET pair, tCO–tCnitro, and we divide this review into three parts: the first one
Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial
Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5
Aminosugar-based immunomodulator lipid A: synthetic approaches
Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3
- synthetic lipid A derivative had a bias towards MyD88- or TRIF-dependent immune responses [78]. 1.3. Synthesis of fluorescent-labeled lipid A analogues For studying the structural basis and the dynamics of TLR4-lipid A interplay, the application of labeled synthetic lipid A derivatives as versatile probes
- for tracking ligand–receptor interactions was exploited. However, the hydrophobic character and the large size of most fluorescent labels which could potentially compete with lipid A for the LPS binding site at the TLR4 complex, posed an additional challenge. The only optional hydroxyl group which
- could qualify as the site of attachment of a fluorescent label without hindering the biological activity would be position 6’ of the diglucosamine backbone of lipid A. When attached to position 6’ via a linker molecule, the fluorescent label would not interfere with the binding of lipid A to the MD-2
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