Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• , which revealed that host–guest complex aggregated to form a stable structural assembly, then a dye-loaded composite system [32]. The energy transfer efficiency of the supramolecular m-TPEWP5G-EsY self-assembled composite system was examined by using m-TPEWP5G and EsY as an ideal donor and acceptor

• chromophoric dye molecules can be utilized in photoredox reactions under the irradiation of light with suitable wavelength [6]. However, in the case of the m-TPEWP5G-EsY nanosystem, which contains conjugated molecules and displays harvesting antenna effects from ultraviolet to visible light wavelengths, solar

• aqueous environment. Overall, the m-TPEWP5G-EsY system showed high catalytic efficiency within a short time of light irradiation in aqueous solution, which was due to the fact that the loaded EsY dye molecules on the surface of the TPEWP5G nanorod assembly significantly decreased photobleaching during

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• by measuring the absorbance at 630 nm by a microplate reader. The results were translated into ratios of Fe3+-complexed dye at each concentration, which were plotted on single-logarithmic charts to deduce IC50 values. The tests were run in triplicate for compounds 1, 3, and deferoxamine mesylate

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• long periods of time. Thus, the photostability parameter is an important characteristic considering that photogenerated singlet oxygen (1O2) can react with a dye molecule, promoting its degradation [32]. Based on the changes in the UV–vis absorption spectra as a function of time, the Schiff base

• was studied in DMSO solution using a 1,3-diphenylisobenzofuran (DPBF) photooxidation assay and the adequate equation as described by Pivetta and co-workers [33]. In this study, the methylene blue dye (MB) was used as a reference. The photooxidation rate constants (k) and 1O2 yield of derivatives (ΦΔ

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• compounds 2a–f, 3a–c and 4 regarding their P-glycoprotein blocking potential. For that, we used the P-glycoprotein substrate calcein as reporter dye and analyzed intracellular calcein fluorescence of P-glycoprotein overexpressing VCR-R CEM cells by flow cytometry. An increase of the calcein-positive

• after substraction of the basal value. Flow cytometry P-glycoprotein activity was assessed using the reporter dye calcein acetoxymethyl ester (AM) as described previously [59]. To assess apoptosis, VCR-R CEM cells were seeded at 0.125 × 106 cells/well, incubated for 4 h and stimulated as indicated for

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• perspectives in medicinal chemistry [15][16][17][18][19][20][21][22][23], dye industries [24][25][26], and metal chemo sensing [27][28][29]. More recently, acridines have received growing attention in organic electronics [30][31][32], due to their strong electron-donating ability [33][34] and remarkable

Phenolic constituents from twigs of Aleurites fordii and their biological activities

• Kyoung Jin Park,
• Won Se Suh,
• Da Hye Yoon,
• Chung Sub Kim,
• Sun Yeou Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2021, 17, 2329–2339, doi:10.3762/bjoc.17.151

• washed with tap water, the cells were stained with 0.4% SRB solution and incubated for 30 min at room temperature. These cells were washed to remove the unbound dye and subsequently solubilized with 10 mM unbuffered Tris base solution (pH 10.5). The absorbance was measured spectrophotometrically at 520

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• anticarcinogenic [1][2], antiviral [3], antibacterial [4][5], and anti-inflammatory [6]. Because of their pharmaceutical activity, they are used in photodynamic therapy [7][8][9]. In addition, they have an important place in the dye industry due to their photochemical and photophysical properties. They are also

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• , the developed GA-polyHMPA initially exhibits UCST responsiveness, but can subsequently be slowly biodegraded to a fully water-soluble polymer (polyHMPA) via hydrolysis. Initial in vivo studies of a sustained release of either a hydrophilic model protein or a hydrophobic dye entrapped within the

Towards new NIR dyes for free radical photopolymerization processes

• Haifaa Mokbel,
• Guillaume Noirbent,
• Didier Gigmes,
• Frédéric Dumur and
• Jacques Lalevée

Beilstein J. Org. Chem. 2021, 17, 2067–2076, doi:10.3762/bjoc.17.133

• abilities were found for some reported dyes when used in combination with iodonium salt and amine. Markedly, photothermal effects with a huge heater behavior were also observed for different NIR dye structures. Interestingly, the synthesis of interpenetrating polymer networks (IPNs, e.g., for the

• described in detail in [16]). Interestingly, a high polymerization-initiating ability was found with different dyes as well as photothermal effects with heater behaviors where the NIR dye acts as a light-to-heat convertor and transferred enough heat to the system to initiate the polymerization. The effects

• ). Interestingly, no effect of the counter anion was observed (some of the dyes with two different counter ions were prepared and compared). In each case, we observed that the maximum absorption wavelength depends on the structure of the dye and not of the counter anion: i) λmax = 798 nm for CBPh1 and CI1; ii

Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves

• Christin Walther,
• Pamela Baumann,
• Katrin Luck,
• Beate Rothe,
• Peter H. W. Biedermann,
• Jonathan Gershenzon,
• Tobias G. Köllner and
• Sybille B. Unsicker

Beilstein J. Org. Chem. 2021, 17, 1698–1711, doi:10.3762/bjoc.17.118

• : initiation and activation of polymerase (95 °C/5 min); followed by 35 cycles of denaturation (95 °C/30 s), annealing (65 °C/30 s) and elongation (72 °C/90 s) and a single, final elongation step (72 °C/10 min). For gel electrophoresis, 4 µL PCR product was mixed with one drop loading dye (0.3 mL 30% glycerol

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

• modified natural nucleobase that did not quench the fluorescence upon hybridization [148]. Köhler and Seitz introduced thiazole orange (TO, Figure 10), an intercalator dye originally designed for DNA [149], as a forced intercalation (FIT) probe in PNA. Because of rotation around the methine bond connecting

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• applications ranging from organic thin‐film transistors (OTFTs), organic light-emitting diodes (OLEDs), dye‐sensitized solar cells (DSSCs), fluorescent probes, organic photovoltaics (OPVs) to the high hole mobility semiconductors, blue light-emitting materials, nonlinear optical materials and so forth [5][6][7

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• , generating the colored anion of a diphenylmethane dye that could be isolated after acidification and characterized from the reaction of thymol (3) and of charvachrol. The Guareschi reaction was then applied by Lustgarten to a host of medicinal phenols, and the test is included in various pharmacopoeias for

• reacts with aldehydes and eventually regenerates a triphenylmethane dye from the sulfite adduct [22]. The study of old color reactions has not only mechanistic interest but can lead to new drug candidates, as shown by the

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• analysis to evaluate the vTA incorporation, and microscopy techniques were employed to examine the impact on their morphology. In terms of applicability, water contact angle measurement, equilibrium swelling ratio analysis, and dye releasing efficiency experiment were also conducted. All hydrogel samples

• physicochemical nature of hydrophilic hydrogels. After the swelling experiment, samples were contacted to an aqueous RhB dye solution to investigate their dye releasing efficiency by gradually washing out the samples, in order to mimic a drug or nutrient release. One of the attractive applications of g-CN relies

• profiles of RhB swollen hydrogels. HG, HGCM, and HGCM-vTA have been immersed in RhB solution for 24 hours, then washed with distilled water every 24 hours, and all collected samples were investigated by UV–vis spectroscopy until reaching the minimum dye absorbance (Figure 3c,d, Supporting Information File

Synthesis of 10-O-aryl-substituted berberine derivatives by Chan–Evans–Lam coupling and investigation of their DNA-binding properties

• Peter Jonas Wickhorst,
• Mathilda Blachnik,
• Denisa Lagumdzija and
• Heiko Ihmels

Beilstein J. Org. Chem. 2021, 17, 991–1000, doi:10.3762/bjoc.17.81

• forms, the effect of thermally induced unfolding of dye-labeled, quadruplex-forming oligonucleotides in the presence of the ligands was studied. In general, the binding of the ligand to the G4-DNA leads to a stabilization and thus to an increasing melting temperature of the DNA (Table 2). This effect of

Synthesis of dibenzosuberenone-based novel polycyclic π-conjugated dihydropyridazines, pyridazines and pyrroles

• Ramazan Koçak and
• Arif Daştan

Beilstein J. Org. Chem. 2021, 17, 719–729, doi:10.3762/bjoc.17.61

• calculated by comparison with a well-known reference, quinine sulfate, in 0.5 M H2SO4 solution (ФF = 0.546) as the standard dye (Table 2). When the UV–vis and fluorescence spectra of pyridazines and pyrroles were examined, it was seen that generally, they did not have effective absorbance or emission

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• in chloroform shows typical resonance signals of six hydrogen-bonded protons (Scheme 44) [162]. In order to improve the optical absorption of fullerene acceptors for utilization in solar cells with a bulk heterojunction, a series of dye–fullerene dyads with strong absorption in the visible region was

Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases

• Olga Gherbovet,
• Fernando Ferreira,
• Apolline Clément,
• Mélanie Ragon,
• Julien Durand,
• Sophie Bozonnet,
• Michael J. O'Donohue and
• Régis Fauré

Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30

• ] and (ii) spontaneous oxidation and subsequent dimerization forming the insoluble blue 5-bromo-4-chloro-substituted indigo dye [15]. In an alternative demonstration, 1a was also used for colony level detection of FAE using yeast cells (Yarrowia lipolytica [30]) that actually coexpressed AnFaeA and

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• -difluorocyclopentenes 131 in good to excellent yields [106]. A convenient route to 2,2-difluoro-homoallylic alcohols 133 occurred by photo-irradiative aerobic oxidation (Scheme 57) [107]. The reaction proceeded by the light-mediated ring-opening reaction of gem-difluorocyclopropane 132 in the presence of an organic dye

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• combining a polyelectrolyte and an ionic azo dye [4]. Moreover, recently we have developed a switchable nano-assembly system based on photoacids [66][67]. Photoacids are molecules for which light irradiation leads to an enhanced proton dissociation and thus to a more highly charged molecule. Furthermore

• substituents. Previously we have shown for a simpler model system that the PSA correlates with the interaction of the molecules, in particular, the dye–dye electrostatic repulsion [31]. Hence, the lower the PSA the better the dye molecules can interact with each other through π–π interactions. Comparing the

• prepared at l = 0.9 and k = 1.0. For the binary polyelectrolyte–dye assemblies studied previously it was found that the overall loading ratio significantly determines the properties of the nano-assemblies [4][34][40][86]. In addition, due to the combination of two switchable molecules with the polymer it

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• materials that have been exploited for photocatalytic applications, including photocatalytic dye degradations and hydrogen evolution. To successfully perform supramolecular photocatalytic reactions, various photophysical and photochemical properties of the host–guest system need to be considered [4]: i) the

• physical barrier in photocatalytic reactions. To address this issue, Chen and co-workers prepared a TiO2–AuNCs@β-CD-based hybrid material on TiO2 and β-CD-protected AuNCs, which can potentially be used for the photocatalytic degradation of methyl orange (MO) dye (Figure 8) [28]. Upon UV-light irradiation

• center for dye degradation. Interestingly, the photodegradation rate was significantly improved (≈95%) by adding ethylenediaminetetraacetic acid (EDTA, 0.02 mM) as the hole scavenger. To evaluate the stability of the TiO2–AuNCs@β-CD catalyst, recycling experiments were conducted. These results implied

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• complexes where the dyes bind non-covalently to solvent-accessible surfaces. The protein–protein interface is not solvent-accessible, and thus the dye molecules do not bind to this region. The protein complex is first “painted” with the dyes and digested using proteases, such as trypsin. Different proteases

• provide different specificities, and thereby enabling different protein regions to be studied. Due to the dye molecules, dye-masked regions cannot be digested by the protease, leaving only the protein–protein interface and the solvent-inaccessible regions to be digested and detected by a mass spectrometer

Synthesis and investigation of quadruplex-DNA-binding, 9-O-substituted berberine derivatives

• Jonas Becher,
• Daria V. Berdnikova,
• Heiko Ihmels and
• Christopher Stremmel

Beilstein J. Org. Chem. 2020, 16, 2795–2806, doi:10.3762/bjoc.16.230

• experiments. For that purpose, the DNA melting temperature Tm of the dye-labeled oligonucleotides F21T and Fa2T (for sequence see caption of Figure 2) was monitored by fluorescence spectroscopy, as the thermally induced unfolding of the quadruplex disrupts the Förster resonance energy transfer (FRET) between

• with the loops assist the binding to the loops, there is no clear experimental evidence for this binding mode. This observation is in contrast to the report about an arylalkyl-substituted cyanine dye, that has been shown to bind with a high selectivity to particular G4-DNA forms because of additional

Encrypting messages with artificial bacterial receptors

• Pragati Kishore Prasad,
• Naama Lahav-Mankovski,
• Leila Motiei and
• David Margulies

Beilstein J. Org. Chem. 2020, 16, 2749–2756, doi:10.3762/bjoc.16.225

• selectively bind a hexa-histidine tag (His-tag). ODN-1 can also be modified with a second functional group (X), such as a fluorescent dye, to afford X-ODN-1 (Figure 1A and Figure 1B). In this way, the binding of X-ODN-1 to the bacteria will lead to the presentation of X on the cell surface (Figure 1A). A

• approach can be used to fluorescently label the His-tagged proteins with different colors, simply by changing the dye (Y) on Y-ODN-2. An interesting difference between the synthetic and the natural cell surface receptors, which is in the focus of this study, is that the number of artificial receptors per

• colors, the individual bacteria were only labeled with a single dye (Figure 2). We hypothesized that incubating the bacteria with a mixture of three artificial receptors, each of which is appended with a distinct dye, should lead to a mixed labeling of each bacterium and to the generation of unique

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• bis(carbazolyl)urea-derived receptor allowed the sensitive detection of diphosphate in water by surface plasmon resonance (SPR) [29]. Silica nanoparticles containing a dye coordinated to a bis(zinc(II)–DPA) receptor released the dye upon diphosphate binding [30], and thus producing an optical signal