Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• antioxidant properties were determined by oxygen radical absorbance capacity assay (ORAC-FL), expressed as Trolox equivalents (TE) and using fluorescein as probe. Additionally, the study investigated the ability of the compounds to activate the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway in

Cage-like microstructures via sequential Ugi reactions in aqueous emulsions

• Rita S. Alqubelat,
• Yaroslava A. Menzorova and
• Maxim A. Mironov

Beilstein J. Org. Chem. 2024, 20, 2078–2083, doi:10.3762/bjoc.20.179

• presence of dicyclohexylcarbodiimide in dimethylformamide. The resulting product was precipitated with acetonitrile, dried, and redissolved in water. Fluorescein-labelled cellulose was used to produce submicron particles according to our previously described method via the Ugi reaction in water (Scheme 1

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• resuspended in 200 µL of MeOH. The sample was injected (6 µL) onto UPLC-MS using the same conditions and instrument as the amino acids standards. To normalize the retention time, 1 µM of fluorescein was added to the standard and peptide samples before injection onto the UPLC-MS. The retention time for the

• fluorescein sample was adjusted to 6.30 min to correct for run to run drifts in retention time. Biosynthetic scheme for the formation of burpitides using a split (top) or fused (bottom) pathway. RS is recognition sequence. Peptide modifications are shown in red. Cladogram made from 647 plant species surveyed

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• protein and different amounts of the test compound in a total volume of 100 µL. FP was measured with a BMG CLARIOstar microtiter plate reader using the FP filter set for fluorescein (Ex 482-16, Em 530-40, LP504). FP is the difference between wells containing LpFAT A and wells containing only tracer. The

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• a similar synthetic protocol to link porphyrin 71 to a fluorescein 72 through a 1,2,3-triazole linker to form the porphyrin-fluorescein conjugate 73 in 91% yield (Scheme 14). Furthermore, the fluorescence study of conjugate 73 revealed an intramolecular energy transfer between fluorescein and

• . The CuAAC click reaction has been shown to bind a variety of chromophores bearing azide or alkyne groups to the porphyrin periphery, including coumarin, xanthone, DNA, ferrocene, corrole, fluorescein, carborane, BODIPY, graphene, carboline, fullerene, NDI, β-cyclodextrin, cholic acid, quinolone, etc

• -fluorescein dyad 73. Synthesis of meso-triazole-linked porphyrin-carborane conjugates 76a,b. Synthesis of meso-triazole-bridged porphyrin-BODIPY conjugates 78 and 80. Synthesis of meso-triazole-linked cationic porphyrin conjugates 85 and 87. Reaction conditions: (i) Zn(OAc)2, CHCl3, MeOH, reflux, 2 h (ii

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands

• Janina-Miriam Noy,
• Fan Chen and
• Martina Stenzel

Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148

• -((phenylcarbonothioyl)thio)pentanoic acid, but it was modified with ethylene glycol. During the polymerization of the water-soluble polymers, fluorescein O-methacrylate was added at a ratio of CTA to fluorescent monomer of 1:0.3. This means more that three out of ten polymer chains will be labelled, which is sufficient

• nuclei of SW982 cells. The particles carry fluorescein (green), the mitochondria and lysosomes were stain with Mito and Lyso Tracker, respectively (red) and the nuclei was stained with Hoechst 33342 (blue). Merged images show co-localisation (yellow fluorescence). Cytotoxicity study of PPM-NP4-TPP and

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• uptake assay was conducted between two 12-mer poly-T ASOs, one being an α-ASO with a fully modified guanidinobutyl phosphoramidate backbone and the other a PS-β-ASO control, both fluorescein-labelled at the 5’-end. The study found that the guanidinium modification increased the cellular uptake. However

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

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

• –fluorescein isothiocyanate and fluorescein isothiocyanate–dextran fluorescent probes were subjected to HGCM and HGCM-vTA samples with a comparatively shorter releasing experiment than the one performed for RhB dye (Supporting Information File 1, Figure S4a). The static experiment principally relies on

• . Experimental Materials: 4-Methyl-5-vinylthiazole (vTA, 97%, Sigma-Aldrich), ʟ-(+)-ascorbic acid (AsA, 98+%, Alfa Aesar), N,N-dimethylacrylamide (99.0+%, TCI), N,N′-methylenebis(acrylamide) (MBA, 99%, Sigma-Aldrich ), acrylic acid (AA, 99%, Sigma-Aldrich), acrylamide (AAM, 98.5%, Acros), albumin–fluorescein

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

• the ligands on the quadruplex melting temperature, Tm, of the labeled G4-DNA F21T [fluo-G3(TTAG3)3-tamra; fluo = fluorescein, tamra = tetramethylrhodamine], Fa2T [fluo-(ACAG3TGT)2-tamra], FmycT [fluo-TGAG3TG3TAG3TG3TA-tamra] and FkitT [fluo-AG3AG3CGCTG3AG2AG3-tamra] was determined by fluorimetric

• buffer solution. Oligodeoxyribonucleotides (HPLC purified) d[A(GGGTAA)3GGG] (22AG), F21T [fluo-G3(TTAG3)3-tamra; fluo = fluorescein, tamra = tetramethylrhodamine], Fa2T [fluo-(ACAG3TGT)2-tamra], FmycT [fluo-TGAG3TG3TAG3TG3TA-tamra] and FkitT [fluo-AG3AG3CGCTG3AG2AG3-tamra] were purchased from Biomers.net

Incorporation of a metal-mediated base pair into an ATP aptamer – using silver(I) ions to modulate aptamer function

• Marius H. Heddinga and
• Jens Müller

Beilstein J. Org. Chem. 2020, 16, 2870–2879, doi:10.3762/bjoc.16.236

• favoured by the chelate effect, compared to the binding to ATP, the combination of ATP-binding aptamer and Im–Ag(I)–Im base pair was finally selected for this study. Results and Discussion Four ATP/AMP aptamer derivatives were synthesized and terminally labeled with a fluorescein moiety. Three of these

• have Im:Im pairs inserted at different positions into the sequence (Figure 2). The oligonucleotide 1af is essentially identical to the established ATP/AMP-binding aptamer, with the attached fluorescein moiety representing the sole difference. The oligonucleotide 1bf bears one Im:Im pair located two

• applied in combination with a fluorophore (fluorescein), a quencher (DABCYL), and complementary oligonucleotides to devise a system referred to as structure-switching signaling aptamer [40]. Based on this concept, two systems were devised to investigate whether the Im–Ag(I)–Im base pairs could be applied

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

• -cacodylate buffer (cK+ = 10 mM, pH 7.2); estimated error ±0.5 °C. F21T: fluo-d[(G3TTA)3G3]-tamra; Fa2T: fluo-d[(ACAG4TGTG4)2-tamra; FmycT: fluo-d(TGAG3TG3TAG3TG3TA2)-tamra; FkrasT: fluo-d(AG3CG2TGTG3A2GAG2A)-tamra]; FkitT: fluo-d(AG3AG3CGCTG3AG2AG3)-tamra], fluo = fluorescein, tamra = tetramethylrhodamine

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• of all dyes was high in solvents with low polarities such as PhMe and THF, while it decreased with increasing solvent polarities such as DMSO and MeOH. The fluorescence quantum yields of the dyes were found to be very low as compared to fluorescein (ΦF= 0.95 at pH 9). For example, the quantum yield

Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• crosslinker. The polymer obtained exhibited the same characteristics as a CD-based carbonate NS synthesized in a solvent. Moreover, after the synthesis, the polymer was easily functionalized through the reaction of the nucleophilic carboxylic group with three different organic dyes (fluorescein, methyl red

• nanosponges with selected organic dyes that are used as probe molecules with different structures (methyl red, rhodamine B, and fluorescein). The simple functionalization of the cyclodextrin NS, in this case via reactive imidazole moieties, is particularly interesting for a variety of applications. For

• anhydrous environment as in this case with organic dyes. The choice fell on three common, well known and widely investigated organic dyes, i.e., fluorescein, methyl red, and rhodamine B. They have a slightly different structures (and color), and also different surface charges but share a reactive

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• light ray and the structures often include fluorescein, rhodamine, or 7-amino-4-methylcoumarin (7-AMC) scaffolds as fluorophores. These fluorophores usually exhibit strong fluorescence in dilute solutions, but most of their emissions are partially or completely quenched in the solid state or in highly

Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts

• David Schönbauer,
• Carlo Sambiagio,
• Timothy Noël and
• Michael Schnürch

Beilstein J. Org. Chem. 2020, 16, 809–817, doi:10.3762/bjoc.16.74

• obtained with [Ru(bpy)3]Cl2, albeit the reaction was still low-yielding (29%, Table 1, entry 1) and was accompanied with substantial decomposition of the starting material. Eosin Y, fluorescein, and [Ir(dtbbpy)(ppy)2]PF6 gave lower yields in comparison (Table 1, entries 2, 3 and 4). Applying strictly inert

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• biological labelling and are known photostable substitutes for fluorescein, giving them applications in cell imaging [20]. Due to the conjugated π-electron system present in BODIPYs they are more electron rich than porphyrins and possess an intense UV–vis absorption at approximately 400 nm, making them ideal

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• shown to realize photoinitiated controlled/living radical polymerization of various monomers in metal free conditions. In the visible region, several dyes (fluorescein, eosin Y, erythrosin B) worked well to mediate ATRP in the presence of amines [72]. The reversibility of the electron transfer steps

α,ß-Didehydrosuberoylanilide hydroxamic acid (DDSAHA) as precursor and possible analogue of the anticancer drug SAHA

• Shital K. Chattopadhyay,
• Subhankar Ghosh,
• Sarita Sarkar and
• Kakali Bhadra

Beilstein J. Org. Chem. 2019, 15, 2524–2533, doi:10.3762/bjoc.15.245

• 11b has been studied since it was the most cytotoxic among all. FITC (fluorescein-5-isothiocyanate)–annexin V/PI flow cytometry of HepG2 cells On HeLa cells, the efficacy of 11b was measured through the application of other apoptotic parameters like phosphatidylserine (PS) externalization, a known

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

• Lei Zhang,
• Greta Linden and
• Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

• quencher (BHQ)-labelled single-strand (ss) DNA template, a complementary fluorescein (FAM)-labelled ssDNA and the PNA of interest. In this framework, the PNA could bind the BHQ-ssDNA; thus, its addition to the quenched BHQ/FAM-DNA duplex would trigger an exchange reaction and the release of the FAM-ssDNA

• (TM) obtained by the first derivative of the data in A. Outline of the displacement assay principle, in which a photoswitchable PNA probe (blue) hybridizes to a complementary quencher-labelled single-stranded (ss) DNA (black) and replaces a fluorescent-labelled ssDNA (grey); F = fluorescein; Q = black

Fluorescent phosphorus dendrimers excited by two photons: synthesis, two-photon absorption properties and biological uses

• Anne-Marie Caminade,
• Artem Zibarov,
• Eduardo Cueto Diaz,
• Aurélien Hameau,
• Maxime Klausen,
• Kathleen Moineau-Chane Ching,
• Jean-Pierre Majoral,
• Jean-Baptiste Verlhac,
• Olivier Mongin and
• Mireille Blanchard-Desce

Beilstein J. Org. Chem. 2019, 15, 2287–2303, doi:10.3762/bjoc.15.221

• instance, fluorescein, which is a widely used fluorescent tracer for many applications, was synthesized for the first time in 1871 [1]. Besides this classical type of one-photon-induced fluorescence, a theoretical work by M. Göppert-Mayer in 1931 [2] predicted the possibility of the simultaneous absorption

Synthesis and properties of sulfur-functionalized triarylmethylium, acridinium and triangulenium dyes

• Marco Santella,
• Eduardo Della Pia,
• Jakob Kryger Sørensen and
• Bo W. Laursen

Beilstein J. Org. Chem. 2019, 15, 2133–2141, doi:10.3762/bjoc.15.210

• analogues of aminoacridinium dyes (acridine orange-like structures), 7 a fluorescein-like xanthenium dye, 5a and 5b are sulfur-substituted ADOTA+ dyes, and finally the three sulfur-substituted TOTA+ dyes 6, 8 and 9. Now the relevant questions are: how do the -SR donor groups influence transition energies

• efficiency was observed by Kotaskova et al. for fluorescein derivatives with one alkylthio group in the 3 position replacing an -OH/-O− group [51]. The origin of reduced fluorescence quantum yields in dyes with alkylthio donor groups in their chromophores is not clear at this point. It may result from

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• luminescent dyes. Fluorescein, eosin Y, rose bengal, tetraphenylporphine sulfonate and sulfonated aluminum phthalocyanine were employed as classical aggregation-induced quenching dyes. 2-(p-Toluidinyl)naphthalene-6-sulfonic acid and 1-anilinonaphthalene-8-sulfonic acid were selected as representatives of

• fluorescent IDA with guanidinium-modified calix[5]arene pentaisohexyl ether (GC5A) and fluorescein (Fl) as the reporter pair [26]. The ultrasensitive detection is feasible for diagnosing ovarian and other gynecologic cancers at their early stages. Also, we proposed a nanoplatform where the fluorescence and

• and used as received unless otherwise specified. Fluorescein (Fl) was purchased from Sigma-Aldrich, 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS) and 2-(p-toluidinyl)naphthalene-6-sulfonic acid (2,6-TNS) were purchased from Tokyo Chemical Industry. Ru(dcbpy)3 was purchased from Yuanye Bio-Technology

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

• Alexander Dahlqvist,
• Axel Furevi,
• Niklas Warlin,
• Hakon Leffler and
• Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102