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Search for "concentration" in Full Text gives 1426 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

  • Ruiyan Wang and
  • Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

Graphical Abstract
  • tetrahydrofuran (THF) solution at a concentration of 1.0 × 10−5 M, the steady-state fluorescence spectrum of 1 was recorded, and its phosphorescence spectrum was subsequently measured at a temperature of 77 K to investigate its low-temperature behavior (Figure 3). Following the established spectroscopic
  • carbonate (K2CO3) with a concentration of 1 g/mL (3 mL) was added. Subsequently, tetrakis(triphenylphosphine)palladium(0) (0.07 g, 0.06 mmol) was introduced to the reaction mixture to promote the coupling reaction. The mixture was then heated to reflux and maintained at this temperature for an overnight
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Published 02 Feb 2026

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

  • Kazuya Asao,
  • Seika Matsumoto,
  • Haruka Mori,
  • Riku Yoshimura,
  • Takeshi Sasaki,
  • Naoya Hirata,
  • Yasuyuki Hayakawa and
  • Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

Graphical Abstract
  • potassium peroxodisulfate aqueous solution (4.0 w/v %, 5 mL) was added to the diluted phytic acid solution (25 mL), and the resulting mixture was autoclaved (121 °C, 30 min). Thereafter, the solution was diluted with deionized water to a concentration of approximately 1 µg P/mL. Step 3 (measurements): The
  • total P concentration was measured via absorption spectrophotometry. The coloring agent (2 mL) was added to the diluted samples (25 mL), thoroughly mixed, and left for 15 min. After 15 min, the absorbance of each sample was measured at 880 nm using a V-650 spectrophotometer (JASCO, Tokyo, Japan). A
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Published 30 Jan 2026

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

  • Akiho Yagi,
  • Hitomi Tomura,
  • Ami Konno and
  • Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

Graphical Abstract
  • incubated at 37 °C for 24 hours. Bacterial growth was assessed by measuring turbidity at 550 nm using a spectrophotometer. The MIC was defined as the lowest concentration of the test compound that inhibited ≥90% of bacterial growth relative to the control (no compound). Structures of streptoquinolines A (1
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Published 27 Jan 2026

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

  • Adrian G. Rossebø,
  • Hannah G. Kolberg,
  • Anders E. Tønder,
  • Louise Kjaerulff,
  • Poul Erik Hansen,
  • Karla A. Frydenvang,
  • Jesper Østergaard and
  • Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

Graphical Abstract
  • sufficient for most biological applications given the high potency of the compound both in vitro and in vivo [6]. Here, we show that if solutions with a higher concentration are needed, pure water could be considered. According to HPLC analysis, 1·HCl was found to be stable in solution in phosphate buffer at
  • aqueous solutions of 1·HCl may be prepared and stored well in advance of any application or investigation. Subsequently, the apparent pKa values (concentration-based) for 1 were determined to be 8.4 ± 0.1 and 10.7 ± 0.1 for the protonated amine and phenol, respectively, and the calculated pH-dependent
  • h in a temperature-controlled incubator at 25 °C. The concentration of 1 in the buffer solution before and after partitioning, ci and cw, respectively, was determined by HPLC, from which distribution coefficients, D, were calculated according to where Vw and Vo are the volume of the buffer solution
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Published 22 Jan 2026

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

  • Ergin Keleş,
  • Alberto Barsella,
  • Nurgül Seferoğlu,
  • Zeynel Seferoğlu and
  • Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

Graphical Abstract
  • −, signals of 2b protons have completely disappeared, and the protons of the new species become apparent. An increase in cyanide concentration did not cause any further changes in spectra. This result indicates that cyanide gives a mono-addition to the vinyl group (Scheme 2). DFT results To further confirm
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Published 14 Jan 2026

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

  • Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

Graphical Abstract
  • caliche deposits in Chile [2]. This concentration of supply raises potential concerns regarding long-term availability and geopolitical vulnerability. Recent interest in alkenyl chlorides has been driven by their occurrence in bioactive natural products (Figure 1) [3][4][5], pharmaceuticals (Figure 2) [6
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Published 02 Jan 2026

Chemoenzymatic synthesis of the cardenolide rhodexin A and its aglycone sarmentogenin

  • Fuzhen Song,
  • Mengmeng Zheng,
  • Dongkai Wang,
  • Xudong Qu and
  • Qianghui Zhou

Beilstein J. Org. Chem. 2025, 21, 2637–2644, doi:10.3762/bjoc.21.204

Graphical Abstract
  • , affording 4 in 64% yield (Table 1, entry 2). However, at a higher concentration (0.5 g/L), a significant amount of starting compound 5 remained unconverted even after 4 days, and only 30% of 4 was isolated (Table 1, entry 3). To our delight, upon adding 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) [29] as the
  • (Table 1, entry 5). Delightfully, after adding 1% Tween 80 to the above fermentation broth, a complete conversion was observed in 4 days, and compound 4 was obtained in 64% yield (Table 1, entry 6). However, further increasing the substrate concentration to 2.0 g/L resulted in a much lower conversion
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Published 03 Dec 2025

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

  • Luan A. Martinho,
  • Victor H. J. G. Praciano,
  • Guilherme D. R. Matos,
  • Claudia C. Gatto and
  • Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

Graphical Abstract
  • scans) and 151 MHz for 13C NMR (20,480 scans), using an overnight experiment in DMSO-d6 at a concentration of 0.1 M. Specifically, the spectra showed either an absence of expected signals or a lack of signal multiplicity, which was apparent in both the 1H NMR and, more prominently, in the 13C NMR
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Published 28 Nov 2025

Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

  • Liangyu Liu,
  • Wanqiu Lu,
  • Quanping Guo and
  • Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

Graphical Abstract
  • , successful macrocyclization was achieved by employing benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBOP) as the coupling reagent in DMF at a concentration of 10−3 M. After cleavage from the resin and global side-chain deprotection, the crude cyclic peptides were purified by preparative
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Published 27 Nov 2025

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

  • Michaela Šusterová and
  • Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

Graphical Abstract
  • concentration in solution reached equilibrium after 15 minutes, consistent with the equilibration time previously established for the non-covalent system SG-BnBU (Supporting Information File 1, Figure S5). Therefore, all subsequent sorption experiments were performed with an equilibration time of 15 minutes
  • carried out in nitrogen atmosphere. The dicyanoaurate concentration in solution was determined according to UV–vis spectra recorded with a CARY 60 spectrophotometer (Agilent Technologies). NMR spectra were recorded on a Bruker Avance III 300 spectrometer (300.15 Hz, 298.15 K). Preparation of SG-NHCO-BU1
  • min at 250 rpm. Afterwards, SG-NHCO-BU1 or SG-BU1 was left to settle and the supernatant was analyzed. The actual concentration of the anion left in the solution was calculated from a calibration curve. A) Thermogravimetric analyses of BU1, SG, a-SG, and SG-NHCO-BU1. B) UV–vis titration of K[Au(CN)2
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Published 24 Nov 2025

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

  • Giuseppe Granata,
  • Loredana Ferreri,
  • Claudia Giovanna Leotta,
  • Giovanni Mario Pitari and
  • Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

Graphical Abstract
  • responsiveness to conventional chemotherapy. To the best of our knowledge, calixarene derivatives have not been previously tested as anticancer agents against human renal carcinoma cells. Compound 3 suppressed the proliferation of the renal cancer cells (Figure 3) with a calculated 50% inhibitory concentration
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Published 14 Nov 2025

Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

  • Kaylen D. Lathrum,
  • Emily M. Hanneken,
  • Katelyn R. Grzelak and
  • James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

Graphical Abstract
  • sharing structural similarity regarding N center placement showed antimicrobial activity, as measured by minimum inhibitory concentration assays. MIC values of 2–16 μM towards Gram-positive bacteria Staphylococcus epidermidis and Bacillus subtilis and 8–16 μM towards Saccharomyces cerevisiae yeast were
  • bacteria Escherichia coli and Klebsiella aerogenes, and yeast Candida albicans and Saccharomyces cerevisiae was determined using minimum inhibitory concentration (MIC) assays [55][56]. As summarized in Table 4, only five of the twenty-four compounds tested displayed an ability to suppress microbial growth
  • control compounds 37–42 (blue lines) in acetonitrile solvent. Synthesis of pentacyclic aromatic heterocycles from varying alkynes.a Synthesis of pentacyclic aromatic heterocycles from varying azides.a Summary of UV–vis absorbance/emission signals. Minimum inhibitory concentration assay results.a
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Published 13 Nov 2025

Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

  • Udyogi N. K. Conthagamage,
  • Lilia Lopez,
  • Zuliah A. Abdulsalam and
  • Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

Graphical Abstract
  • structure, and saturation, can result in different membrane mechanics, hydration, thickness, intermolecular spacing, and non-covalent interactions with the rotaxane. For example, EYPC bilayer thickness increases linearly with cholesterol concentration and can induce the formation of nanodomains [16]. Such
  • S13, respectively. We investigated whether reducing the concentration of rotaxane 1 from 10 mol % to 5 mol % could provide better control over membrane changes in the more fluid bilayers, specifically in pure EYPC and EYPC/Chol 8:2 LUVs. In pure EYPC, both rotaxanes 1 and 2 induced similar levels of
  • release at 5 mol % and 10 mol %, reflecting the high intrinsic permeability of this membrane and the difficulty in modulating it (Supporting Information File 1, Table S30 and Figure S21a). As expected, total release in EYPC/Chol 8:2 LUVs decreased significantly at the lower concentration of the molecules
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Published 11 Nov 2025

Ex-situ generation of gaseous nitriles in two-chamber glassware for facile haloacetimidate synthesis

  • Nikolai B. Akselvoll,
  • Jonas T. Larsen and
  • Christian M. Pedersen

Beilstein J. Org. Chem. 2025, 21, 2465–2469, doi:10.3762/bjoc.21.188

Graphical Abstract
  • is not easily done as the system is now under pressure. The chamber was then opened to release excess gas (on small scale) and the product in chamber B can be obtained by concentration and purification. The use of other bases than DBU, was also investigated. Similar to the synthesis of
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Published 07 Nov 2025

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

  • Elizaveta V. Gradova,
  • Nikita A. Ozhegov,
  • Roman O. Shcherbakov,
  • Alexander G. Tkachenko,
  • Larisa Y. Nesterova,
  • Elena Y. Mendogralo and
  • Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

Graphical Abstract
  • synthesized spiro[indoline-3,2'-pyrrolidine] derivatives 4 were evaluated for antimicrobial activity via serial dilution assays across a concentration range of 0.5–1000 µg/mL. The minimum inhibitory concentration (MIC) and minimum bactericidal (fungicidal) concentration (MBC/MFC) against a diverse spectrum of
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Published 05 Nov 2025

Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs

  • Guang-Wei Zhang,
  • Yong Zhang,
  • Le Shi,
  • Chuang Gao,
  • Hong-Yu Li and
  • Lei Xue

Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181

Graphical Abstract
  • spectroscopy. Results and Discussion Partial 1H NMR spectra of PBG and WDG after binding to tetrabutylammonium iodide (TBAI) are presented in Figure 2a and 2b, respectively. All 1H NMR titrations were conducted at a fixed concentration of 8.7 mM. With the addition of 2 equivalents TBAI, the NH peak on the PBG
  • shifts down by 0.1902 ppm. When the concentration was increased to 5 equivalents, the NH signal peak of carbazole continued to move towards downfield, with a displacement of 0.4004 ppm to 8.3929 ppm. When the concentration was increased to 10 equivalents, the NH signal peak of carbazole continued to move
  • the acceptor. For WDG, the carbazole NH peak on WDG was shifted 0.1725 ppm downfield when 2 equivalents TBAI was added. When the concentration increased to 5 equivalents, the NH signal peak of carbazole continued to move downfield, with a displacement of 0.3649 ppm to 8.2273 ppm, while proton signals
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Published 03 Nov 2025

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

  • Suvenika Perera,
  • Peter Y. Zavalij and
  • Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

Graphical Abstract
  • , rhodamine 6G, methyl violet 6B; 7500 rpm, 5 min for acridine orange and methylene violet), and the supernatants were analyzed by UV–vis spectroscopy. To determine the dye concentration remaining in the aqueous solutions, appropriate calibration curves were employed (Figure S12 in Supporting Information File
  •  1). The removal efficiency was calculated using Equation 1, where c0 is the initial dye concentration, and ct is the dye concentration after sequestration. The results of these experiments are shown in Figure 4. Quite disappointingly, Figure 4 shows that the benzene, naphthalene, and triphenylene
  • could be successfully fitted into the Langmuir isotherm model. Figure 7c shows a plot of the data fitted using Equation 2, where qe (mg g−1) represents the amount of methylene violet adsorbed at equilibrium, c (mol L−1) denotes the residual methylene violet concentration at equilibrium, and K (mol−1
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Published 29 Oct 2025

Research towards selective inhibition of the CLK3 kinase

  • Vinay Kumar Singh,
  • Frédéric Justaud,
  • Dabbugoddu Brahmaiah,
  • Nangunoori Sampath Kumar,
  • Blandine Baratte,
  • Thomas Robert,
  • Stéphane Bach,
  • Chada Raji Reddy,
  • Nicolas Levoin and
  • René L. Grée

Beilstein J. Org. Chem. 2025, 21, 2250–2259, doi:10.3762/bjoc.21.172

Graphical Abstract
  • kinase activities are expressed in % of maximal activity, i.e., measured in the absence of inhibitor but with an equivalent dose of DMSO (solvent of the tested compounds). ATP concentration used in the kinase assays was 10 µM (values are means, n = 2). Kinases are from human origin (Homo sapiens) except
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Published 24 Oct 2025

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

  • Gyöngyvér Pusztai,
  • László Poszávácz,
  • Anna Vincze,
  • András Marton,
  • Ahmed Qasim Abdulhussein,
  • Judit Halász,
  • András Dancsó,
  • Gyula Simig,
  • György Tibor Balogh and
  • Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

Graphical Abstract
  • Table 3. The preliminary ADME investigation, characterized by first-order kinetics due to low substrate concentration (≤10 µM), aids in establishing intrinsic clearance (Clint), which indicates the predicted elimination efficacy of drugs [43]. According to the generally accepted Clint ≈ 10 μL/min/kg (or
  • KGaA, Darmstadt, Germany), adjusting the pH with HCl. Water for buffer and eluent preparation were provided by a Millipore Milli-Q water purification system. Kinetic aqueous solubility assay. All compounds were dissolved in DMSO to make stock solutions at 10 mM concentration. In the case of 7i, 7j, and
  • (E)-9b, the highest concentration achieved in DMSO was 0.5 mM, while for (E)-9a it was 1 mM (DMSO solubility results of the compounds can be found in Supporting Information File 1). 5 μL of the stock solutions was pipetted into a 96-well plate containing 495 μL PBS (pH 6.5) in each well to achieve
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Published 21 Oct 2025

C2 to C6 biobased carbonyl platforms for fine chemistry

  • Jingjing Jiang,
  • Muhammad Noman Haider Tariq,
  • Florence Popowycz,
  • Yanlong Gu and
  • Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

Graphical Abstract
  • acid (ALA), and benzylic acid (BA). These acids were oxidized and gave formaldehyde, acetaldehyde, acetone, benzaldehyde, acetophenone, and benzophenone, respectively. By increasing pH and concentration, the rate of the reactions increased, but decreased upon increasing the amount of Cl− ions (Scheme
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Published 15 Oct 2025

Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis

  • Rasma Kroņkalne,
  • Rūdolfs Beļaunieks,
  • Armands Sebris,
  • Anatoly Mishnev and
  • Māris Turks

Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154

Graphical Abstract
  • and 17). The obtained diene 10a contained 13–15% of silylindene 11a as impurity. Products 10a and 11a are separable by preparative HPLC. Lowering the starting material concentration in the reaction mixture to 0.05 mmol/mL significantly decreased the diene 10a yield due to the formation of other
  • in the context of 1,2-silyl shift and potential cyclization. Competing mechanistic pathways for diene 10 and indene 11 formation. Reaction scope for the synthesis of arylated tetrahydrofurans 8. Conditions: All reactions were performed on a 0.47 mmol scale. aStarting material 7d concentration: 0.1
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Published 26 Sep 2025

Photochemical reduction of acylimidazolium salts

  • Michael Jakob,
  • Nick Bechler,
  • Hassan Abdelwahab,
  • Fabian Weber,
  • Janos Wasternack,
  • Leonardo Kleebauer,
  • Jan P. Götze and
  • Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

Graphical Abstract
  • followed by 1H NMR over the course of 48 h. As shown in Figure 3, at the start of the reaction, rapid consumption of the benzoylazolium starting material was observed with concomitant formation of O-benzoylated product 3. The concentration of this species then slowly decreased over the remaining reaction
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Published 25 Sep 2025

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

  • Scott Rice,
  • Julian Chesti,
  • William R. T. Mosedale,
  • Megan H. Wright,
  • Stephen P. Marsden,
  • Terry K. Smith and
  • Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

Graphical Abstract
  • products were obtained (see Figure 3 and Table 2). The marked improvement in product yields, compared to those observed with D1–3, may reflect the change to the workflow, i.e., variation in stock concentration to improve solubility. The diversity of the obtained products was increased by the multiple
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Published 17 Sep 2025

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

  • Shuhai Qiu and
  • Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

Graphical Abstract
  • (c) MC3. (d) Molecular arrangements of MC3. Hydrogen atoms are omitted for clarity. (a) Absorptions and (b) emissions of compounds 3a, 3b, MC1, MC2, and MC3 measured in dichloromethane at room temperature. The inset shows the photographs under UV light at 365 nm. The concentration is 10 μM
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Published 15 Sep 2025

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

  • Almaz A. Zagidullin,
  • Emil R. Bulatov,
  • Mikhail N. Khrizanforov,
  • Damir R. Davletshin,
  • Elvina M. Gilyazova,
  • Ivan A. Strelkov and
  • Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

Graphical Abstract
  • glycidyl esters of phosphorus acids 1–3, their cytotoxic effects were assessed using the MTT assay on two tumor cell lines (PC-3 and MCF7) and one non-cancerous line (HSF). The assay measures the concentration of each compound required to inhibit cellular metabolic activity by 50% (IC50). All experiments
  • dissolving the compounds in the culture medium to a final concentration of 25 mM. These stock solutions were stored and used for subsequent treatments. Cell treatment. 24 hours after seeding, cells were treated with the test compounds at final concentrations of 25 μM, 50 μM, 100 μM, 250 μM, 500 μM, 750 μM
  • , 1,000 μM, 2,500 μM, and 5,000 μM. Each concentration was tested in triplicate. Control wells received an equivalent volume of culture medium without compounds and served as untreated negative controls. Cytotoxicity analysis of compounds. After 48 hours of treatment, MTT reagent was added to each well at
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Published 15 Sep 2025
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