Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• displacement parameter restraints. View of the packing of the unit cells of a) Me2B viewed normal to the c-axis and b) Me4B viewed normal to (110). Only the majority occupied moiety of the N–N bridge is shown in Me4B. UV–vis spectrum of Cl2B after irradiation in DCM. Proposed mechanism for the topochemical [2

Synthesis of electrophile-tethered preQ₁ analogs for covalent attachment to preQ₁ RNA

• Laurin Flemmich and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

• vitro and in living cells using rationally designed electrophile-tethered derivatives of preQ1 (1) and its Watson–Crick diamino-faced counterpart DPQ1 (2, Scheme 1A). These ligands (compound classes 3 and 4, Scheme 1A) were tailored to target a conserved guanine nucleobase within a natural preQ1-binding

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• achieve better stereocontrol and to facilitate the formation of synthetically challenging glycosidic linkages. Keywords: chemical O-glycosylation; neighbouring group participation; remote group participation; solvent effect; stereocontrol; Introduction Cell surface glycans in living cells have

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• MTT assay was used to determine the anticancer activity of compound 7a against these cultures (Figure 6). The viability test is an important method to determine which new compounds are able to target cancer cells. The results of this test (IC50 value ± 95% confidence interval) allow us to evaluate the

• cell culture, at which the number of live cells was reduced by 50%, was 0.172 ± 0.029 μM. For the H1299 culture, this value was 2.18 ± 0.7 μM. In comparison, the IC50 value of the standard anticancer drug cisplatin at 24 hour incubation is 137 ± 12 μM for the A431 culture [31] and 34.9 μM for the H1299

• , CN) (Aldrich) were used to prepare the solutions. Spectral fluorescent experiments were performed using quartz cells (lcuvette 1.0 cm, volume V 2 mL). Stock solutions of compounds 7 or 8 (c 5.0 × 10−5 mol L−1) and tetrabutylammonium salts (c 1.0 × 10−4 mol L−1) in acetonitrile were used. The

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• prepared in DMSO and cancer cells were treated with 10 μM doses of compounds using the apoptosis inducing standard mensacarcin (10 μM) as a positive control [56]. Only compound 7l decreased cell viability to 63%, while the rest of the compounds showed very low to no significant decrease in cell viability

• mammalian cells in vitro. Results of the microbroth single-dose assays revealed that two of the synthesized compounds have selective antibiotic activity against S. aureus. Subsequently, MIC90 values were calculated by performing microbroth dilution assays using serial dilutions of these two compounds

• against three different strains of S. aureus. Compound 7b has a MIC90 of 16 μg/mL, and 7h exhibited a MIC90 of 8 μg/mL against susceptible, methicillin-resistant, and multidrug-resistant S. aureus. So, it was observed that both of these compounds destroyed designated bacterial cells in a competitive

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• activity, inhibiting approximately 70% of Staphylococcus aureus biofilms at concentrations as low as 3.9 µg/mL. Keywords: antibiofilm; antiproliferative; beauvericin; insect pathogen; Samsoniella; Introduction A microbial biofilm represents an assemblage of planktonic cells to overcome hostile living

• . aureus biofilms with farinosones D (1) and A (2). This distinction is pivotal in the evaluation of compounds for their antibiofilm efficacy, considering the potential scenario wherein a compound may affect the growth dynamics of cells without substantially disrupting the biofilm architecture or

• dispersing the encapsulated cells [16]. The results (Figure 6) yielded striking significance, revealing that the biomass remained metabolically inactive in biofilms treated with 1 and 2 low to concentrations of 3.9 and 1.9 µg/mL, respectively. It is worth noting here that both compounds followed a similar

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• -established for their use in organic photovoltaic cells and as efficient photosensitizers for singlet oxygen generation. In 2022, Goddard et al. have reported the groundbreaking use of squaraine derivatives as novel organic NIR photocatalysts for various chemical transformations, marking the first application

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• improving the stability of inverted perovskite solar cells [23]. On the other hand, benzo[rst]pentaphene-5,8-dione (BPP-dione) is known as an oxidation product of BPP [24][25], but to the best of our knowledge, the detailed optical properties of this BPP derivative have not been previously described in the

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• enantiopurity at 130 °C for 48 h in toluene. Investigating the biological activity for a number of compounds, good cytotoxicity was reported for five kinds of cancer cells. The mechanistic study suggests that the indole ring of the substrate is having a crucial role in the reaction mechanism because replacing

Hot shape transformation: the role of PSar dehydration in stomatocyte morphogenesis

• Remi Peters,
• Levy A. Charleston,
• Karinan van Eck,
• Teun van Berlo and
• Daniela A. Wilson

Beilstein J. Org. Chem. 2025, 21, 47–54, doi:10.3762/bjoc.21.5

• , which results in more rigid domains. The anomalous shapes observed, with bending starting from seemingly random positions, support this hypothesis (Supporting Information File 1, Figure S36). These irregular shapes are reminiscent of some anomalous shapes observed in red blood cells [25]. It was also

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

• Merve Yence,
• Dilgam Ahmadli,
• Damla Surmeli,
• Umut Mert Karacaoğlu,
• Sujit Pal and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

• fluorescent chemosensors and probes [4][5][6], as well as materials for applications in organic light-emitting diodes (OLEDs) [7][8][9], organic field-effect transistors (OFETs) [10], and perovskite solar cells [11]. In this respect, replacing either one or more of the carbons or rings of a fluoranthene with

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• cytotoxicity against L1210 murine leukemia cells and KB epidermoid carcinoma cells. Keywords: ceratinadin; cytotoxicity; marine sponge; psammaplysin; Pseudoceratina sp.; Introduction Marine sponges are widely recognized as a rich source of unique bioactive natural products. For instance, marine sponges

• ceratinadin G (1) was evaluated against L1210 murine leukemia cells and KB epidermoid carcinoma cells. Ceratinadin G (1) showed moderate cytotoxic activity against L1210 cells (IC50 = 4.7 μM) and KB cells (IC50 = 15.1 μM). Conclusion Ceratinadin G (1) is the first psammaplysin derivative identified to contain

• -1500 spectropolarimeter. 1H and 13C NMR spectra were acquired on a Bruker Avance II 600 MHz NMR spectrometer equipped with a cryoplatform, using 3.0 mm micro cells (Shigemi Co., Ltd.) for CD3OD. The 1H NMR chemical shift of residual CD2HOD in CD3OD at 3.35 ppm and the 13C NMR chemical shift of CD3OD at

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• cultures at 37 °C in LB medium were washed once with sterile saline 0.9% (w/v) and adjusted to an OD600 of 0.05. Then, 1% inoculum was transferred into fresh LB medium. Following the incubation at 37 °C, 200 rpm for 5–6 h to reach the mid-log phase, the cells were washed once with sterile saline 0.9% (w/v

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

• cells containing the Nrf2/antioxidant response element (ARE). The melatonin–lipoic acid (LA) hybrids 3a and 3b emerged as potent antioxidants, successfully inducing the Nrf2 transcriptional pathway at concentrations of 10, 30, and 100 μM (Figure 5). Notably, these hybrids exhibited lower CD values (28.1

• donepezil, employing a widely accepted tauopathy model in SH-SY5Y cells. Notably, compound 7a was identified as the most promising multitarget-directed ligand in the study, exhibiting superior neuroprotection compared to both MK-886 and the commercial drug donepezil in a cell viability MTT assay. These

• , inspired by natural alkaloids such as deoxyvasicinone and evodiamine with promising inhibition of ChEs and antioxidant and neuroprotective effects against glutamate-induced OS in HT-22 cells [41]. In 2016, Dgachi et al. [42] applied a Knoevenagel-based multicomponent approach to further explore the

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• applied in various fields, including organometallic catalysis, dye-sensitized solar cells, sensing, artificial olfactory systems, photodynamic therapy (PDT), anticancer drugs, biochemical probes, and electrochemical devices. Relevant examples of these two pyrrolic macrocycles as metal-free organocatalysts

• , cyclam (tetraazacyclotetradecane), phthalocyanines, corroles and their supramolecular frameworks have been widely used as both homogeneous and heterogeneous electrocatalysts for various energy conversion and storage techniques, such as fuel cells, water splitting devices, and rechargeable metal–air

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• efficiency and creating six new bonds (two C–C, three C–N, and one N–N). Additionally, the products were evaluated against breast cancer MCF-7 cells, finding moderate activity in the compounds substituted with fluorine and chlorine. Keywords: 1,5-disubstituted tetrazoles; high-order multicomponent reaction

• cytotoxic compounds. For example, a cytotoxic effect was found in CAL 27 cells, presumably through a mechanism of TNF-α inhibition in vitro, which could be related to the anti-inflammatory effect identified in several studies of NSAIDs that inhibit cancer cell viability in vitro [37][38]. In another study

• aimed at inhibiting tubulin assembly, N-mesyl-2-(1-phenylvinyl)indoles were active against HCT-116 cells on the order of a GI50 of 10 mM, although the mechanism originally sought was not demonstrated [39]. Therefore, in this work, the cytotoxic activity of methanesulfonylindoles 18a–j was explored

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• materials [14][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. For example, organic π-systems whose main structural unit is stilbazole are used as active compounds in organic light-emitting diodes (OLEDs) [20], dye-sensitized solar cells (DSSCs) [21], nonlinear optics (NLO) materials [22][23

• ], positron emission tomography (PET) imaging [24], fluorescent probes and labels [25][26][27] detecting H2S in foodstuff, water, and living cells [28], Fe3+ ions [29], Hg2+ ions [30], and cyanide anions [31], for acid–base vapor sensing [32], and as candidate material for photonics devices, optical switches

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• numerous reports, quantum yield is one of the most important photophysical parameters for describing luminescent molecules and materials since high quantum efficiency is important for a wide range of applications, including displays, lasers, bio-imaging, solar cells, and accurate measurement of the quantum

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• cytotoxic activity against melanoma and squamous cell carcinoma cells, lung cancer and glioblastoma cells [30]. It was shown in a WST-1 assay that these compounds exhibit a concentration-dependent inhibition of the metabolic activity of A375 and A431 cells, while the non-glycosylated derivative 34 proved to

• be inactive. The activities of β-33b and 34 on the cell viability was independently studied by using crystal violet as a dye for viable cells following a 48 h incubation of A375 melanoma cells and A431 squamous carcinoma cells. Interestingly, a concentration-dependent cytotoxicity was again observed

• for β-33b, but not for 35 in both cell lines. The IC50 values of β-33b were similar to those obtained by the WST-1 assay. A related proapoptotic effect was not observed for 35 in A375 cells. However, in case of A431 cells, a significant increase in caspase activity was observed for 35, but at a much

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• membrane potential (Vm) in living cells. These previous studies indicated that the localization of the triad molecules in a specific intra-membrane orientation and the suppression of the photodynamic actions of the [60]fullerene (C60) moiety are likely important to achieve fast and safe control of Vm

• , respectively. In this study, by mimicking our previous system of triad molecules and living cells, we report a simplified model system with a cationic C60 derivative (catC60) and a liposome with embedded 1-pyrenebutyric acid (PyBA) to demonstrate that the addition of PyBA was important to achieve fast and

• an acceptor in photoinduced charge-separation systems, we have previously employed ferrocene-porphyrin-C60 triad molecules (Figure 1a) in a biological system to control the plasma membrane potential (Vm) of living mammalian neuronal cells under photoirradiation [4][5][6]. Generally, Vm originates

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• , and 4ma. Whereas compound 4ja and 4ma showed an ideal single crystal behavior, compound 4fb showed a dynamic disordered structure due to intramolecular vibrations in the unit cells, particularly because of the presence of the tert-butyl group, which can assume any rotation angle [24]. Nevertheless

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• minimal change to the materials environment. This allows for structures that are more representative of their typical environment. To achieve this, many specialised cells have been developed to control various environmental parameters including temperature, pressure, irradiation, electromagnetic fields

• , cells that allow for the coupling of SAS with non-X-ray techniques continue to be developed; these include spectroscopy, rheology, and electrochemistry [62][63][64]. Ascribing changes in properties of interest directly to changes in the structure further elucidates the interesting properties of self

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• and breast carcinoma MCF7. In parallel, human skin fibroblasts were used as reference for non-tumor cells and roscovitine (ROSCO), doxorubicin (DOXO) and Taxol as positive controls. For details see: ref. [2] and Supporting Information File 1, Table S1. Compounds 4a–f, 4h, 4i, 4k, 4l, 4o and 4q that

• particular for 4a which has demonstrated low micromolar toxicities (IC50 from 1.7 to 6 μM) against HuH-7, Caco-2, MDA-MB-468 and HCT-116 cells, with low to no action, on the other cells. Similarly, the meta-fluoro analogue 4i is active only on Caco-2, MDA-MB-468, HCT-116 and MCF7 (IC50 from 2 to 6 μM) while

• , 272.1181 (0 ppm); mp: 195–197 °C. Protocole ImPACell for cytotoxicity studies Cell culture. Skin normal fibroblastic cells are purchased from Lonza (Basel, Switzerland), HuH-7, Caco-2, MDA-MB-231, HCT-116, PC3, MCF7 and NCI-H727 cancer cell lines were obtained from ATCC (American Type Culture Collection

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• ), HRMS, and elemental analysis. The molecular structures of compounds 5, 6 and 8 in crystal state were determined by single-crystal X-ray analysis. X-ray data The X-ray suitable crystals 5, 6·0.5CH3CN, and 8 were grown by slow recrystallization of the compounds from acetonitrile solutions. The unit cells

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• probe–protein interaction in native conditions in living cells. Taken together, the linkers used in chemical proteomics workflows are applied broadly in many research areas including screening of fragment libraries, covalent modifiers, protein PTMs, protein–protein interactions, protein–nucleic acid

• CuAAC due to its rapid reaction kinetics, robustness, and relatively small steric hindrance of the terminal alkyne, which is usually attached to the probe core scaffold to form an alkyne probe [5][63]. Once the covalent bond between the probe and protein is formed, the cells are lysed, and the probe

• of the probe is necessary to identify any unspecific bands stemming from side reactivity of the azide–protein conjugate. In case a photo-crosslinker is used, another control experiment needs to be included, in which the cells/lysate are treated with the probe but not UV-irradiated. The non-covalent