Reaction Products Research Articles

Rational design of anthocyanidins-directed near-infrared two-photon fluorescent probes.

Recently, two-photon fluorescent probes based on anthocyanidin molecules have attracted extensive attention due to their outstanding photophysical properties. However, there are only a few two-photon excited fluorescent probes that really meet the requirements of relatively long emission wavelengths (>600 nm), large two-photon absorption (TPA) cross-sections (300 GM), significant Stokes shift (>80 nm), and high fluorescence intensity. Herein, the photophysical properties of a series of anthocyanidins with the same substituents but different fluorophore skeletons are investigated in detail. Compared with b-series molecules, a-series molecules with a six-membered ring in the backbone have a slightly higher reorganization energy. This results in more energy loss upon light excitation, enabling the reaction products to detect NTR through a larger Stokes shift. More importantly, there is very little decrease in fluorescence intensity as the Stokes shift increases. These features are extremely valuable for high-resolution NTR detection. In light of this, novel 2a-n (n = 1-5) compounds are designed, which are accomplished by inhibiting the twisted intramolecular charge transfer (TICT) effect through alkyl cyclization, azetidine ring and extending π conjugation. Among them, 2a-3 gains a long emission spectrum (λem = 691.4 nm), noticeable TPA cross-section (957 GM), and large Stokes shift (110 nm), indicating that it serves as a promising candidate for two-photon fluorescent dyes. It is hoped that this work will offer some insightful theoretical direction for the development of novel high performance anthocyanin fluorescent materials.

Molecular modelling of luciferyl adenylate deprotonation in the active site of Photinus pyralis luciferase

Firefly bioluminescence is a product of chemical reactions that involve luciferin chromophore oxidation in the active site of luciferase proteins. We perform a series of classical molecular dynamic simulations and combined quantum and molecular mechanics (QM/MM) calculations to expose the molecular mechanism of C4 carbon atom deprotonation in luciferyl adenylate molecule. QM/MM calculations confirm that ND-protonated His245 residue is a suitable proton acceptor in the wild-type Photinus pyralis luciferase. Classical molecular dynamic simulations reveal oxygen-binding cavities inside the protein including the one located close to the C4 atom of luciferin. In mutant forms that lack direct interactions with the His245 side chain, a proton wire comprising water molecules stimulates either protonation of the phosphate group of the luciferyl adenylate forming an unstable intermediate or keto–enol tautomerisation of luciferin. The comparison of the ionisation potentials of molecular systems with the ‘deprotonated’ C4 carbon atom revealed that the ionisation energy for the enol tautomeric form is close to the system with the His245 proton acceptor. Thus, the existence of the keto–enol tautomerisation channel might explain bioluminescence in case of the absence of the amino acid proton acceptor.

Identifying Quinones in Complex Aqueous Environmental Media (Biochar Extracts) through Tagging with Cysteine and Cysteine-Contained Peptides and High Resolution Mass Spectrometry Analysis.

Quinones are among the most important components in natural organic matter (NOM) for redox reactions; however, no quinones in complex environmental media have been identified. To aid the identification of quinone-containing molecules in ultracomplex environmental samples, we developed a chemical tagging method that makes use of a Michael addition reaction between quinones and thiols (-SH) in cysteine (Cys) and cysteine-contained peptides (CCP). After the tagging, candidates of quinones in representative aqueous environmental samples (water extractions of biochar) were identified through high-resolution mass spectrometry (HRMS) analysis. The MS and UV spectra analysis showed rapid reactions between Cys/CCP and model quinones with β-carbon from the same benzene ring available for Michael addition. The tagging efficiency was not influenced by other co-occurring nonquinone representative compounds, including caffeic acid, cinnamic acid, and coumaric acid. Cys and CCP were used to tag quinones in water extractions of biochars, and possible candidates of quinones (20 and 53 based on tagging with Cys and CCP, respectively) were identified based on the HRMS features for products of reactions with Cys/CCP. This study has successfully demonstrated that such a Michael addition reaction can be used to tag quinones in complex environmental media and potentially determine their identities. The method will enable an in-depth understanding of the redox chemistry of NOM and its critical chemical compositions and structures.

DEVELOPMENT OF AN ALGORITHM FOR CALCULATING THE RATE CONSTANT OF HYDROCHLORIC ACID REACTION WITH A CARBONATE ROCK FORMATION

One of the main factors reducing acid stimulation efficiency is the intensive reaction of active acid in the immediate vicinity of the wellbore, which leads to insufficient completeness of reservoir rock dissolution in the remote reservoir zone. The reservoir hydrodynamic characteristics are not being improved properly, and the efficiency of oil production stimulation measures does not reach the planned values.To get high results of acid treatments it is necessary to achieve deep penetration of acid into the formation thickness. The reaction rate constant is used to compare the reactivity of different acid compositions and to select the most suitable acid composition for the geological and physical conditions of the treated object, which provides the highest treatment efficiency. It relates the initial substances concentrations with reaction products formation rate. To determine the reaction rate constant, a volumetric apparatus was created and methodological aspects were developed to work on it, allowing to minimize the measurement error and to achieve the greatest accuracy in determining the kinetic parameters of the reaction. But in the course of further investigations in the work of the existing algorithm for experimental data processing, a number of significant deficiencies distorting the results of calculations were revealed. The aim of the research is to develop a new improved algorithm for reaction rate constant calculation, which will improve the understanding of the process of determining the kinetic parameters of acid reaction with carbonate rock.To achieve this aim, the authors conducted a series of experiments according to the unified methodology, the results of which revealed ways to eliminate the identified deficiencies using a new algorithm. It includes obtaining and saving initial data, subsequent treatment and direct calculation of reaction kinetic parameters with results saving.The developed algorithm makes it possible to unify and automate the process of determining the kinetic parameters of the acid reaction with the formation rock, as well as to determine the reaction characteristics with higher accuracy and reduce the influence of the human factor on the research results, thus reducing the errors of the calculation results.

Reproducing Reaction Mechanisms with Machine‐Learning Models Trained on a Large‐Scale Mechanistic Dataset

AbstractMechanistic understanding of organic reactions can facilitate reaction development, impurity prediction, and in principle, reaction discovery. While several machine learning models have sought to address the task of predicting reaction products, their extension to predicting reaction mechanisms has been impeded by the lack of a corresponding mechanistic dataset. In this study, we construct such a dataset by imputing intermediates between experimentally reported reactants and products using expert reaction templates and train several machine learning models on the resulting dataset of 5,184,184 elementary steps. We explore the performance and capabilities of these models, focusing on their ability to predict reaction pathways and recapitulate the roles of catalysts and reagents. Additionally, we demonstrate the potential of mechanistic models in predicting impurities, often overlooked by conventional models. We conclude by evaluating the generalizability of mechanistic models to new reaction types, revealing challenges related to dataset diversity, consecutive predictions, and violations of atom conservation.

Trapping Highly Reactive Metal(H)2(η2‐H2) Species to Form Trihydride Complexes and Clusters

AbstractMetal dihydride dihydrogen‐derived intermediates can be short‐lived and difficult to detect despite their ubiquitous role in chemical transformations such as hydrogenation. Here, highly reactive [Ir(H)3(η2‐η2‐COD)(IMes)] forms by trapping [Ir(H)2(η2‐H2)(η2‐η2‐COD)(IMes)]X [X=Cl or MeO], resulting from reaction of the Ir(I) precatalyst [IrCl(η2‐η2‐COD)(IMes)] with a base and H2. This trihydride allows access to the unusual [Ir2(H)4(OMe)(IMes)2(pyridine)3]X, [Ir2(H)2(μ2‐H)2(η2‐η2‐COD)(IMes)2], [Ir3(H)9(IMes)3], [Ir4(H)12(IMes)4] and [Ir2(H)4(μ2‐H)2(IMes)2(pyridine)2]. A combination of 2D NMR, parahydrogen hyperpolarized NMR, MS, and XRD are used to characterise these reaction products and rationalise their formation via the moiety {Ir(H)3(IMes)}. Consequently, the results of these studies have implications for iridium‐catalyzed polarization transfer from parahydrogen via the well‐known precursor [IrCl(η2‐η2‐COD)(IMes)].

Strength characteristics and solidification carbonization mechanism of MgO based shield tunneling centrifugal waste silt

In response to the problem of the accumulation of waste silt produced by slurry shield tunneling, which is difficult to directly utilize, MgO carbonization acceleration technology is adopted. Carbonization modification equipment is used to test the water content (w) and unconfined compression strength (UCS) of waste silt produced by slurry shield tunneling under different soil curing agent content (as), curing time (T), and carbonization time (t). The strength characteristics of the process of MgO solidification carbonization shield tunneling centrifugal waste silt were clarified. The micro mechanism was revealed and its engineering usability was also explored. The results show that MgO cooperated with carbonization acceleration technology can improve the properties of waste silt, with a maximum decrease of 9.3%~31.7% and UCS can be increased to a maximum of 776.8 kPa. The maximum UCS of MgO solidified carbonized silt was higher than that of CaO solidified carbonized silt at various contents. Under the condition of T=7d, by comparing UCS, it was concluded that MgO carbonated solidified silt is more suitable for building foundation filling. And as =7% while t=1h modified silt can meet the strength requirement of 180 kPa under the condition of small MgO content. An improved three-phase model diagram of MgO solidification carbonation process based on water conversion research has been proposed for centrifugal high liquid limit silt in slurry shield tunneling. It can be divided into three stages: solidification reinforcement, carbonation reinforcement, and carbonation deepening, with strength growth mainly concentrated in the solidification reinforcement stage. During the solidification process, the hydration product Mg(OH)₂ and the reaction products MSH and MAH from the pozzolanic reaction are gradually transferred into various carbonization products, These products agglomerated and bonded with each other to form a whole, enhancing the bonding strength between particles and improving the strength of the silt. During the carbonization process, it is necessary to avoid the strength reduction caused by too long carbonization time.

Photochemical Dimerization of Indones: A DFT Study

In this study, DFT calculations were performed in order to identify the reaction products of the photochemical dimerization of indones. Calculations allowed us to assume that all tested reactions occurred in the first excited singlet state. The irradiation of 2-phenyl-5-nitroindone gave the main product, the <i>anti-cis</i> head-to-tail dimer, while the other two compounds found in the experiments were the <i>syn-cis</i> head-to-head dimer and the <i>anti-cis</i> head-to-tail dimer. The irradiation of 2-phenylindone gave the main product, <i>syn-cis</i>-head-to-tail dimer, while the minor products were <i>anti-cis</i>-head-to-tail and <i>anti-cis</i>-head-to-head dimer. The photochemical dimerization of 2-methyl-3-phenylindone gave the main product, <i>anti-cis</i>-head-to-tail dimer, while the minor component of the mixture was <i>syn-cis</i>-head- to-head dimer.

Sensorial flavor characteristics and volatile Maillard reaction products of Tenebrio molitor mealworm based-reaction flavors with beef broth-like flavor

Sensorial flavor characteristics and volatile Maillard reaction products of Tenebrio molitor mealworm based-reaction flavors with beef broth-like flavor

Reproducing Reaction Mechanisms with Machine-Learning Models Trained on a Large-Scale Mechanistic Dataset.

Mechanistic understanding of organic reactions can facilitate reaction development, impurity prediction, and in principle, reaction discovery. While several machine learning models have sought to address the task of predicting reaction products, their extension to predicting reaction mechanisms has been impeded by the lack of a corresponding mechanistic dataset. In this study, we construct such a dataset by imputing intermediates between experimentally reported reactants and products using expert reaction templates and train several machine learning models on the resulting dataset of 5,184,184 elementary steps. We explore the performance and capabilities of these models, focusing on their ability to predict reaction pathways and recapitulate the roles of catalysts and reagents. Additionally, we demonstrate the potential of mechanistic models in predicting impurities, often overlooked by conventional models. We conclude by evaluating the generalizability of mechanistic models to new reaction types, revealing challenges related to dataset diversity, consecutive predictions, and violations of atom conservation.

Effective strategy for Cr(VI) removal from water in evolution process of ferroan brucite by redox and intercalation

Cr(VI)-contaminated wastewater treatment is of great significance to ecological environment and human health. In this work, ferroan brucite with different Fe2+ doping amounts (Mg1-XFeX(OH)2, x = 0.1–0.8) were synthesized for the removal of Cr(VI) from wastewater. The effect of Fe content, initial concentration of Cr(VI), reaction time, co-existing ions and pH for Cr(VI) removal performance were examined. As Fe2+ content increased, the removal efficiency initially increased and then decreased, Mg0.4Fe0.6(OH)2 exhibited the maximum removal amount of 494.63 mg/g. Kinetic studies showed Cr(VI) removal well fitted pseudo-second-order model and achieved equilibrium at approximately 40 min. Isotherm data was well described by Langmuir model. The coexisting ions except CO32− had negligible effect, while pH had a significant influence on Cr(VI) removal since different dominated form of Cr(VI) existed at different pH. The removal mechanism towards Cr(VI) under different pH values was explored. At acidic environment, most Cr(VI) in Cr2O72− was reduced to Cr(III) by Fe2+ resulting in the precipitation of (Fe,Mg)(Cr,Fe)2O4, the remaining part was immobilized by interlayer of reaction product LDHs, and the intercalation amounts of Cr2O72− were 114.05 mg/g and 106.78 mg/g at pH of 3 and 6. While under alkaline conditions, most CrO42− entered the interlayer of LDHs with amounts of 262.3 mg/g at pH = 11, and the rest was absorbed on the surface. Furthermore, the reaction product could be recovered as chromite with recovery rate of 83.94 %. The excellent removal performance suggested a promising strategy in sewage water remediation.

Sodium Houttuyfonate Alleviates Monocrotaline-induced Pulmonary Hypertension by Regulating Orai1 and Orai2.

An increased intracellular Ca2+ concentration ([Ca2+]i) is a key trigger for pulmonary arterial smooth muscle cell (PASMC) proliferation and contributes greatly to pulmonary hypertension (PH). Extracellular Ca2+ influx via a store-operated Ca2+ channel, termed store-operated Ca2+ entry (SOCE), is a crucial mechanism for [Ca2+]i increase in PASMCs. Calcium release-activated calcium modulator (Orai) proteins, consisting of three members (Orai1-3), are the main components of the store-operated Ca2+ channel. Sodium houttuyfonate (SH) is a product of the addition reaction of sodium bisulfite and houttuynin and has antibacterial, antiinflammatory, and other properties. In this study, we assessed the contributions of Orai proteins to monocrotaline (MCT)-enhanced SOCE, [Ca2+]i, and cell proliferation in PASMCs and determined the effect of SH on MCT-PH and the underlying mechanism, focusing on Orai proteins, SOCE, and [Ca2+]i in PASMCs. Our results showed that: 1) Orai1 and Orai2 were selectively upregulated in the distal pulmonary arteries and the PASMCs of MCT-PH rats; 2) knockdown of Orai1 or Orai2 reduced SOCE, [Ca2+]i, and cell proliferation without affecting their expression in PASMCs in MCT-PH rats; 3) SH significantly normalized the characteristic parameters in a dose-dependent manner in the MCT-PH rat model; and 4) SH decreased MCT-enhanced SOCE, [Ca2+]i, and PASMC proliferation via Orai1 or Orai2. These results indicate that SH likely exerts its protective role in MCT-PH by inhibiting the Orai1,2-SOCE-[Ca2+]i signaling pathway.

Evaluation of 4-fluoro-7-nitrobenzofurazan as a dual-function chromogenic and fluorogenic probe for tulathromycin and its innovative utility for development of two eco-friendly and high-through microwell assays for analysis of pharmaceutical formulations

Tulathromycin is a triamilide antibacterial drug which has been approved for use in the European Union and the United States for the treatment and prevention of bovine respiratory diseases. The aim of this study was the development of two innovative microwell spectrometric (photometric and fluorometric) assays for determination of tulathromycin in its pharmaceutical formulations. To achieve this goal, 4-fluoro-7-nitrobenzofurazan was investigated as a dual-function chromogenic and fluorogenic probe for tulathromycin. The reaction between tulathromycin and 4-fluoro-7-nitrobenzofurazan proceeded smoothly in an alkaline medium, resulting in the formation of a colored and fluorescent product. The product displayed a maximum light absorption at 475 nm and emitted fluorescence at 545 nm when excited at 475 nm. Extensive investigations were conducted to optimize the factors affecting the tulathromycin /4-fluoro-7-nitrobenzofurazan reaction, and the optimal conditions were established. Using these optimized conditions, both microwell-based photometric and fluorometric assays were developed. The calibration curves relating the absorbance and fluorescence intensities of the reaction product with the corresponding tulathromycin concentrations were generated. The absorbance-concentration relationship was found to be linear within a tulathromycin concentration range of 10–400 µg mL−1, with a limit of quantitation of 6.2 µg mL−1. On the other hand, the fluorescence-concentration relationship was linear within a concentration range of 0.04–1.2 µg mL−1, with a limit of quantitation of 0.06 µg mL−1. Rigorous validations of both assays’ procedures were performed, and both assays were successfully employed for the analysis of tulathromycin–containing pharmaceutical formulations (injections) with satisfactory accuracy and precision. The ecologically friendly assessment of both assays demonstrated their compliance with the principles of green analytical chemistry approaches. Moreover, the proposed microwell-based assays enabled the simultaneous analysis of multiple samples using small volumes, enabling high-throughput analysis. In conclusion, this study represents the first evaluation of 4-fluoro-7-nitrobenzofurazan as a probe with dual functionality for the microwell-based photometric and fluorometric analysis of tulathromycin. The developed assays serve as valuable analytical tools for ensuring the quality of tulathromycin ’s pharmaceutical formulations.

Towards electrochemical regeneration of redox photocatalysts? The example of the tris(2,2′-bipyridine)ruthenium(II)/methylviologen system

The regeneration of redox photocatalysts usually requires the use of sacrificial reagents that are added to the medium in stoichiometric amounts, either as an electron donor or as an electron acceptor, to act as an electron relay to the photocatalyst to ensure its effective regeneration. In the present work, we consider the possibility of direct electrochemical regeneration of the catalyst using a model system made of tris(2,2′-bipyridine)ruthenium(II) ([Ru(bpy)3]2+) as photosensitizer and methylviologen (MV2+) as quenching substrate. Based on hydrodynamic amperometry experiments, we demonstrate that this can indeed be possible provided that appropriate potential values are applied to ensure the electrochemical reduction of [Ru(bpy)3]3+ back to [Ru(bpy)3]2+ while avoiding interfering processes arising from electron transfer reactions involving the quencher and/or the products/intermediates generated in the course of the photocatalytic event. Furthermore, using EDTA as a sacrificial electron donor, we show that photocurrents can also be exploited for regenerating the quenching substrate by reduction of the reaction product MV+ (back into MV2+).

Interaction mechanism of cold atmospheric plasmas and fusion peptides of spike protein in SARS-CoV-2 revealed by reactive molecular dynamics simulation

Despite the conclusion of the COVID-19 pandemic, the coronavirus-killing ability of cold atmospheric plasma (CAP) remains impressive, and investigations into its underlying mechanisms are still ongoing. The fusion peptide (FP) is a crucial site of membrane fusion and toxicity exerted by the S-protein in severe acute respiratory syndrome CoV-2 (SARS-CoV-2). In this study, reactive molecular dynamics simulations were performed to investigate the interaction mechanisms of FP and reactive oxygen species (ROS). The simulation results show that the given ROS (O atoms and OH radicals as examples) can destroy hydrophobic residues, negatively charged acidic residues, and peptide bonds through structurally altering essential sites. Furthermore, the reaction typically initiates from the H-abstraction reaction, followed by various types of oxidative modifications such as dehydrogenation, hydroxylation, carbonylation, cyclogenesis, ring cleavage, and decarboxylation, which are consistent with the experimental findings made on peptides. Therefore, it can be predicted that the membrane fusion ability of FP and the toxicity of SARS-CoV-2 will be reduced, with CAP functioning as a bactericidal disinfectant. The dose effects were also investigated, providing experimental guidance for the optimization of CAP. In this study, the interaction processes of FP and CAP are explored by revealing the chemical pathways and final reaction products from the computational data, thus providing a fundamental understanding of the mechanisms for inactivating SARS-CoV-2 by CAP.

Substitution of additives in horseradish sauce: technological strategies and efficacy

An additive-free horseradish sauce was produced by replacing citric acid and sulfites, commonly used as acidifying, and antimicrobial/anti-browning agents, respectively. Unripe grape juice was used as acidifier, while steam blanching was applied to inactivate horseradish peroxidase (HRP) to avoid browning. Unexpectedly, the heat treatment inactivated myrosinase, responsible for the release of the irritating allyl isothiocyanate from sinigrin's hydrolysis, causing undesired loss of pungency. To restore it, mustard seed powder was added as an ingredient naturally rich in myrosinase. The inactivation of HRP and restoration of myrosinase were evaluated through spectrophotometric measurements of HRP and chromatographic analysis of glucose, a reaction product of myrosinase. The experimental sauce, obtained by adding basic ingredients to horseradish, was stabilized through pasteurization and subjected to sensory analysis and colorimetric evaluation. An additive-free and sustainable horseradish sauce was obtained, using mustard seeds and exploiting thinned bunches as by-products instead of wasting them.

A preliminary evaluation of how classical separation techniques affect the solid catalyst surface features during transesterification

The aim of this study was to investigate how the classical separation methods alter the solid catalyst surface structure in heterogeneous-catalyzed transesterification, viz., centrifugal and gravitational settling-in-funnel schemes, for the first time. The FTIR spectroscopy showed that while the settling system produces vivid and smooth surface shifting as a result of long-term contact with reaction products, centrifugal separation does not entirely obliterate the identity of the post-reaction catalyst surface. In addition, the SEM analysis confirmed that smaller agglomerates, which may have resulted from the dissolution of some particles and the accumulation of organic substances that clog the catalyst pore through the formation of calcium-glycerol bonds during the decantation period, were observed in the gravitational settling system; this trait could also complicate the separation and lower the desired product recovery (biodiesel). Whereas the centrifugal separation technique revealed the presence of bigger oval-shaped agglomerates, which are anticipated to possess more unoccupied active sites for efficient catalysis. As a result, centrifugal separation produces a greater biodiesel yield (87 ± 0.9%) than the settling method (76.6 ± 2%). The fuel properties of biodiesel products were characterized in terms of acid value, kinematic viscosity, cetane number, and specific gravity, of which only the cetane number does not meet the international limit due to its aromatic content. Generally, the results of this study proved that centrifuges are a more effective method of separating heterogeneous catalysts relative to the decantation system.

Utilization of Cobalt and its Oxide/Hydroxide Mediated by Ionic Liquids/Deep Eutectic Solvents as Catalysts in Water Splitting.

With the ever-growing global demand for sustainable energy solutions, hydrogen has garnered significant attention as a clean, efficient, and renewable energy source. In the field of hydrogen production, catalyst research stands out as one of the foremost areas of focus. In recent years, the preparation of electrocatalysts using ionic liquids (ILs) and deep eutectic solvents (DESs) has attracted widespread attention. ILs and DESs possess unique physicochemical properties and are recognized as green media as well as functional materials. Cobalt-based catalysts have proven to be efficient electrocatalysts for water splitting. Incorporating ILs or DESs into the preparation of cobalt-based catalysts offers a remarkable advantage by allowing precise control over their structural design and composition. This control directly influences the adsorption properties of the catalyst's surface and the stability of reaction intermediates, thereby enabling enhanced control over reaction pathways and product selectivity. Consequently, the catalytic activity and stability of cobalt-based catalysts can be effectively improved. In the process of preparing cobalt-based catalysts, ILs and DESs can serve as solvents and templates. Owing to the good solubility of ILs and DESs, they can efficiently dissolve raw materials and provide a special nucleation and growth environment, obtaining catalysts with novel-structures. The main focus of this review is to provide a detailed introduction to metal cobalt and its oxide/hydroxide derivatives in the field of water splitting, with a particular emphasis on the research progress achieved through the utilization of IL and DES. The aim is to assist readers in designing and synthesizing novel and high-performance electrochemical catalysts.

Study on Selenium Assimilation and Transformation in Radish Sprouts Cultivated Using Maillard Reaction Products

Study on Selenium Assimilation and Transformation in Radish Sprouts Cultivated Using Maillard Reaction Products

Full green assay of rosuvastatin utilizing sulphophtalein dyes: application to tablet analysis

The aim of the work was to develop a «green» and extraction-free spectrophotometric procedure for the assay of rosuvastatin in tablets. The present work describes three new spectrophotometric procedures (A, B and C) that can be utilized for routine quality control of rosuvastatin in laboratories. Materials and methods. Analytical instrumentation: Shimadzu UV-1800 double beam UV-vis spectrophotometer (Japan) with attached UV-Probe ver. 2.62 software, RAD WAG AS 200/C precise analytical balance (Poland). Rosuvastatin calcium (purity ≥98 % (HPLC)) was bought from Sigma-Aldrich Chemicals Co. (St. Louis, MO, USA). Rosuvastatin 10 mg tablets were acquired from a nearby drugstore. All solvents used in this study, including methanol, ethanol, chloroform, acetonitrile and ethyl acetate, were produced by Honeywell and had a purity of 99.9 %. BCG, BCP and BTB were acquired from Sigma-Aldrich Chemicals Co. (USA, St. Louis). All chemicals utilized in the experiment were of analytical purity. Results and discussion. New simple «green» and extraction-free spectrophotometric procedures for assay of rosuvastatin in tablets involve the formation of ion-pair complexes with sulphophtalein dyes (BCG (Method A), BCP (Method B), BTB (Method C)) have been developed. The absorbances of the coloured reaction products were registered at 405 nm (Method A) and 400 nm (Methods B, C). The concentration was linearly proportional to absorbance values in the range of 2.51-20.08 μg/mL (method A), 2.50-24.90 μg/mL (method B) and 2.51-12.56 μg/mL (method C). Estimation of LOD and LOQ parameters were obtained as 0.67 μg/mL and 2.23 μg/mL (Method A), 0.39 μg/mL and 1.32 μg/mL (Method B), 0.30 μg/mL and 1.01 μg/mL (Method C). The stoichiometric ratio of the reactive components of rosuvastatin - BCG, BCP, and BTB corresponded 1: 1. The %RSD values of intra-day and inter-day were obtained less than < 1.5 %, which showed excellent repeatability and RE % data was ≤ 3 %. The effect on the environment of the proposed spectrophotometric procedures and their compliance with the GAC principles were endorsed by the output of AGREE, GAPI, and AES metrics tools. The values of these three «green» metrics show that the proposed spectrophotometric procedures had a low environmental impact compared with the reported ones. Conclusions. The developed fast, simple and cost-effective methods A, B, and C can be used for routine analysis of rosuvastatin in tablets