Target Substance Research Articles

Синтез и определение активности нового производного гидроксиоксопиримидина — потенциального объекта для изготовления противовоспалительного геля

Introduction. Compounds with a hydroxypyrimidine fragment in their structure exhibit pronounced and diverse biological activity. The low solubility of many hydroxypyrimidine derivatives in water is a significant drawback in the development of new medicines. From 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one, its water-soluble form being a sodium salt was obtained. This compound, as it was revealed during the computer screening of its possible biological acti¬vity in silico, can potentially be used as a pharmaceutical substance for the production (manufacture) of drugs. Since the line of hydroxypyrimidine drugs in the topical dosage forms is extremely limited, and the resulting compound has hydrophilic properties, it is important to enclose the substance in a gel dosage form. Aim. Synthesis of a water-soluble form of new hydroxypyrimidine derivative, determination of its acute toxicity and anti-inflammatory activity, as well as critical stages of development and further production of a topical hydrophilic dosage form based on the obtained compound. Materials and Methods. The target compound was obtained from the interaction of 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one and an equimolar amount of an aqueous solution of sodium hydroxide. Acute toxicity was determined on white mice (5 groups of 10 animals, which were injected with a solution of the study compound at a dose of 1100, 1200, 1300, 1400, and 1500 mg/kg respectively), observing the development of the main symptoms and recording the time of death of the animals within 72 h from the moment of the drug administration. For the experimental assessment of anti-inflammatory activity, two models were used: formalin-induced mice paw edema and cotton pellet implantation-induced granuloma in rats (for each model there were 3 groups with 10 animals per group: the 1st group received the reference drug diclofenac, the 2nd – the compound under study, the 3rd (control) – sodium chloride solution). Results. The yield of the obtained sodium 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidine-4-olate was 85 ± 1%. It has been proven in vivo that the test compound belongs to the 5th class of toxicity (practically non-toxic) and has a pronounced anti-inflammatory activity. An Ishikawa diagram was drawn up to determine the critical stages of the development and manufacture of a semisolid dosage form, a gel with a target substance. Conclusion. A new compound with anti-inflammatory action has been synthesized, sodium 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidin-4-olate, which has low toxicity and pronounced anti-inflammatory activity. The critical stages in the development and manufacture of a gel with synthesized compound are: preparation of the base and drug substance, introduction of the drug substance into the base, homogenization and packaging.

Blatter-type radicals as polarizing agents for electrochemical overhauser dynamic nuclear polarization.

Overhauser dynamic nuclear polarization (O-DNP) refers to a microwave-assisted process where an unpaired electron's (e.g. a radical) spin polarization is transferred to surrounding nuclei in solution, thus increasing the nuclear magnetic resonance (NMR) signal intensity of a given substance by several orders of magnitude. The presence of the unpaired electrons, which induces relaxation of the resulting hyperpolarized state when the radiation is halted, can be avoided by electrochemically removing the radicals on demand. We report the use of Blatter-type (benzo[e][1,2,4]triazinyl) radicals as polarizing agents, potentially opening the way to highly tunable radicals for electrochemical DNP.

GEANT4 Modeling of the Bremsstrahlung Converter Optimal Thickness for Studying the Radiation Damage Processes in Organic Dyes Solutions

The study of the processes occurring in a matter when ionizing radiation passes through is important for solving various problems. Examples of such problems are applied and fundamental problems in the field of radiation physics, chemistry, biology, medicine and dosimetry. This work is dedicated to computer modeling of the parameters of a tungsten converter for studying the processes of radiation damage during the interaction of ionizing radiation with solutions of organic dyes. Simulation was carried out in order to determine the optimal thickness of the converter under predetermined experimental conditions. Experimental conditions include: energies and type of primary particles, radiation intensity, target dimensions, relative position of the radiation source and target. Experimental studies of the processes of radiation damage occurring in solutions of organic dyes are planned to be carried out using the linear electron accelerator "LINAC-300" of the National Scientific Center "Kharkov Institute of Physics and Technology". Electrons with 15 MeV energy are chosen as primary particles. The interaction of electrons with the irradiated target substances is planned to be studied in the first series of experiments. Investigations of the interaction of gamma quanta with the target matter will be carried out in the second series of experiments. The tungsten converter is used to generate a flux of bremsstrahlung gamma rays. One modeling problem is determination of the converter thickness at which the flux of bremsstrahlung gamma will be maximal in front of the target. At the same time, the flow of electrons and positrons in front of the target should be as low as possible. Another important task of the work is to identify the possibility of determining the relative amount of radiation damage in the target material by the Geant4-modeling method. Radiation damage of the target substance can occur due to the effect of bremsstrahlung, as well as electrons and positrons. Computational experiments were carried out for various values of the converter thickness – from 0 mm (no converter) to 8 mm with a step of 1 mm. A detailed analysis of the obtained data has been performed. As a result of the data analysis, the optimal value of the tungsten converter thickness was obtained. The bremsstrahlung flux in front of the target is maximum at a converter thickness of 2 mm. But at the same time, the flux of electrons and positrons crossing the boundaries of the target does not significantly affect the target. The computational experiment was carried out by the Monte Carlo method. A computer program in C++ that uses the Geant4 toolkit was developed to perform calculations. The developed program operates in a multithreaded mode. The multithreaded mode is necessary to reduce the computation time when using a large number of primary electrons. The G4EmStandardPhysics_option3 model of the PhysicsList was used in the calculations. The calculations necessary for solving the problem were carried out using the educational computing cluster of the Department of Physics and Technology of V.N. Karazin Kharkiv National University.

Simultaneous determination of isoxaflutole and its two metabolites in corn under field conditions by LC-MS/MS.

An improved QuEChERS method was established and verified for simultaneous determination of isoxaflutole and its metabolites diketonitrile and benzoic acid analogue residues in corn and plants. This method was mainly used to study the digestion rule and final residue level of isoxaflutole and its metabolites in corn and plants. It was hoped that the safe use of isoxaflutole in corn can be achieved eventually. The method was completed by means of ultra-performance liquid chromatography with triple quadrupole mass spectrometry. The extraction of the target substance was through acetonitrile solution containing 1% acetic acid, and the purification was through primary secondary amine, octadecylsilane and graphitized carbon black sorbent. In the method, the quantitative limits and detection limits of the three analytes were 0.005-0.01 and 0.001-0.003 mg kg-1 respectively. The half-life of isoxaflutole in the plants in Shandong and Anhui was 36.4 and 42.1 days respectively, and the digestion dynamics all conformed to the first-order kinetics. The final residues of isoxaflutole in green corn and mature corn were less than 0.02 mg kg-1 of the maximum residue limit set by the Codex Alimentarius Commission. The residual amount of isoxaflutole in corn and plants at harvest time was acceptable when isoxaflutole was applied once at a dose of 121.5g a.i. ha-1 . © 2021 Society of Chemical Industry.

Novel adsorption material for solid phase extraction in sample pretreatment of plant hormones

植物激素在植物生长过程中具有重要作用,调节植物生长、发育及抗逆的各个过程。植物激素超微精准定量分析一直是植物生理学研究的瓶颈问题。植物激素的准确、高效检测目前大多是基于液相色谱-串联质谱联用技术。样品前处理是植物激素色谱-质谱分析中必不可少的一个步骤,直接影响后续检测方法的灵敏度和准确性。在植物激素各种前处理方法中,固相萃取(SPE)技术应用非常广泛。在萃取小柱基础上发展了多种新形式(分散固相萃取、磁性固相萃取、固相微萃取等,称之为SPE相关方法)。在上述SPE相关方法中,吸附材料的选择均是关键因素,决定了样品前处理过程的目标物提取、净化和富集效果。碳基材料(包括碳纳米管、石墨烯、碳氮化合物等)和有机骨架材料(包括金属有机骨架、共价有机材料)拥有结构可设计、比表面积大、稳定性良好等特性,非常适合作为吸附材料。分子印迹聚合物和超分子化合物依靠主-客体特异性分子识别作用,能显著提高样品前处理方法的选择性。本文重点针对植物激素样品前处理中的SPE技术,综述了近5年来上述几类功能化吸附材料的最新应用进展,并对其发展趋势进行展望。

Determination of new carmine in beverages by one step rapid solid phase extraction based on metal organic framework extractant

胭脂红是一种广泛应用的偶氮类色素,我国对其在食品中的添加量有严格规定。由于食品基质的复杂性,针对这类痕量色素很难建立一种灵敏度高、富集性强且高效便捷的检测方法。研究利用卟啉环中的羧基与金属锆离子的配位作用制备了一种高比表面积的金属有机骨架材料(PCN-222),并将纳米材料填入注射式固相萃取装置中,以简化前处理过程,用于快速萃取饮料中胭脂红色素。采用多种表征手段研究了PCN-222纳米材料的形貌、结构及性能。较高的比表面积和静电作用共同决定了新型萃取剂对胭脂红色素具有极强的富集性能。通过优化萃取剂用量、样品溶液pH值、洗脱条件和洗脱剂体积等萃取条件,使目标物实现瞬时吸附,样品前处理时间缩短至5 min。在最佳条件下,该方法可使样品在高、中、低3个水平的加标回收试验中的回收率达到99.5%~109.4%,相对标准偏差小于3%,方法的检出限为0.1 μg/L(S/N=3),定量限为0.3 μg/L(S/N=10)。此外,针对所合成的材料进行萃取-解吸后发现,PCN-222在重复使用4次后仍保持90%以上的萃取能力,表明材料具备可循环性。该方法通过制备的新型金属骨架材料建立了一种高效、便捷、绿色环保的前处理技术,极低的检出限、较高的准确度和较好的重复性表明方法适用于饮料中痕量色素胭脂红的富集和检测。新型固相萃取技术的开发为食品安全检测提供了新思路。

Droplets generation conducting during laser-plasma treating of metals in electric field

Evolution of plasma plume generation on the surface of metal irradiated by laser beam with the mean radiation flux density ~ 106 W/cm2 in the external electric field with different polarity and field strength from 0 to 106 V/m was experimentally investigated. It is shown that the mean size of metal droplets carried out from the irradiated zone of target becomes materially (in several times) smaller when of the external electric field strength amplitude grow, independently to its polarity. It is essential that the mentioned differences (at the considered parameters of laser radiation) are observed only at the initial stage of the laser plume development, because after the steam-plasma cloud reaches the electrode an electric breakdown (short-circuit) occurs, and the external field in the interelectrode gap disappears. Electric breakdown leads to the spasmodic increase of electron density and temperature of plasma and to effective absorption of laser radiation by plasma torch (shielding of the target). In consequence of shielding droplets generation happens only during electric field existence. This explains decrease by several times of the characteristic size of the target substance droplets in spite of short duration of electric field existence.

Effects of brief substance use interventions delivered in general medical settings: a systematic review and meta-analysis.

To estimate effects of brief substance use interventions delivered in general medical settings. A systematic review and meta-analysis of randomized trials conducted since 1990 of brief substance use interventions in patients of any age or severity level recruited in general medical settings. Primary outcomes were any measure of substance use or substance-related consequences (indexed with Hedges' g and risk ratios). Mixed-effects meta-regressions were used to estimate overall effects and predictors of effect variability. Analyses were conducted separately by brief intervention (BI) target substance: alcohol only or drugs. A total of 116 trials (64 439 participants) were identified; 111 (62 263 participants) provided effect size data and were included in the meta-analysis. Drug-targeted BIs yielded significant small improvements in multiple drug/mixed substance use (Hedges' g ) = 0.08; 95% CI = 0.002, 0.15), but after adjusting for multiple comparisons, they did not produce significant effects on cannabis use ( = 0.06; 95% CI = 0.001, 0.12), alcohol use ( = 0.08; 95% CI = -0.0003, 0.17), or consequences ( = 0.05; 95% CI = 0.01, 0.10). Drug-targeted BIs yielded larger improvements in multiple drug/mixed substance use when delivered by a general practitioner ( = 0.19; 95% CI = 0.187, 0.193). Alcohol-targeted BIs yielded small beneficial effects on alcohol use ( = 0.12; 95% CI 0.08, 0.16), but no evidence of an effect on consequences ( = 0.05; 95% CI = -0.04, 0.13). However, alcohol-targeted BIs only had beneficial effects on alcohol use when delivered in general medical settings = 0.17; 95% CI = 0.10, 0.24); the findings were inconclusive for those delivered in emergency department/trauma centers ( = 0.05; 95% CI = 0.00, 0.10). When delivered in general medical settings, alcohol-targeted brief interventions may produce small beneficial reductions in drinking (equivalent to a reduction in 1 drinking day per month). There is limited evidence regarding the effects of drug-targeted brief interventions on drug use.

Osmium Nanoparticles-Polypropylene Hollow Fiber Membranes Applied in Redox Processes.

Composite membranes play a very important role in the separation, concentration, and purification processes, but especially in membrane reactors and membrane bioreactors. The development of composite membranes has gained momentum especially through the involvement of various nanoparticles, polymeric, oxide, or metal, that have contributed to increasing their reactivity and selectivity. This paper presents the preparation and characterization of an active metal nanoparticle-support polymer type composite membrane, based on osmium nanoparticles obtained in situ on a polypropylene hollow fiber membrane. Osmium nanoparticles are generated from a solution of osmium tetroxide in tert-butyl alcohol by reduction with molecular hydrogen in a contactor with a polypropylene membrane. The composite osmium-polypropylene hollow fiber obtained membranes (Os-PPM) were characterized from the morphological and structural points of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX), X-ray diffraction analysis (XRD), Fourier transform Infrared (FTIR) spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry (TGA, DSC). The process performance was tested in a redox process of p-nitrophenol and 10-undecylenic (10-undecenoic) acid, as a target substance of biological or biomedical interest, in solutions of lower aliphatic alcohols in a membrane contactor with a prepared composite membrane. The characteristics of osmium nanoparticles-polypropylene hollow fiber membranes open the way to biological and biotechnological applications. These membranes do not contaminate the working environment, operate at relatively low temperatures, provide a large contact area between reactants, allow successive oxidation and reduction operations in the same module, and help to recover the reaction mass by ultrafiltration. The results obtained show that the osmium-polypropylene composite membrane allows the reduction of p-nitrophenol or the oxidation of 10-undecylenic acid, the conversion depending on the concentration in the lower aliphatic alcohol, the nature of the lower aliphatic alcohol, and the oxidant or reducing flow through the membrane contactor.

Molecular orientation and dynamics of ferricyanide ion-bearing copoly(ionic liquid) modified glassy carbon electrode towards selective mediated oxidation reaction of cysteine versus ascorbic acid: A biomimicking enzyme functionality

Understanding the electron-transfer (ET) functionality of enzymes in relation to their molecular orientation and dynamics is a cutting-edge research interest in the interdisciplinary areas of chemistry and biology. In this work, we demonstrate how the molecular structure and orientation of a redox polymer influence the ET behavior and specific catalytic functionality to target substance, ascorbic acid (AA) or cysteine (CySH) in a physiological condition. In the literature, Fe(CN)63−, a well-known benchmarking redox system, based chemically modified electrodes (CME) prepared by the ion-exchange method, has been widely used as an electrocatalyst for ascorbic acid oxidation reaction without the interference of CySH. In this work, a Fe(CN)63− bearing copoly(ionic liquid)-ethanol solution modified glassy carbon electrode, designated as GCE@{Fe(CN)63−}-coPIL, prepared as a homogenous solution followed by CME formation, has shown a unique and selective CySH oxidation reaction, rather than expected AA mediation, similar to the Thiol Oxidase enzyme-based biomimetic functionality. Andrieux and Saveant and Michaelis-Menten kinetic models were adopted to explain the reaction mechanism. The polymer network orientation and dynamics are found to influence strongly on the electrocatalytic functionality of the new CME. It has been revealed that underlying surface, functional groups, and solvent nature impact the molecular architectures of the {Fe(CN)63−}-caped polymer back-bone (insulating) network as a fully (H2O and CHCl3) or partially (C2H5-OH and CH3CN) shielded structures and decide its electron-transfer and selective mediated oxidation reaction functionalities. This observation is similar to the protein folding of enzymes at various external stimuli conditions and its unfolded structures for direct electron transfer and selective mediated oxidation/reduction reaction. As a proof of concept, electroanalytical application of thiol functional group (CySH) oxidation to disulfide bond (CyS-SyC) catalyzed by the GCE@{Fe(CN)63−}-coPIL in neutral pH solution has been demonstrated.

Promising New Salt of Oseltamivir.

A synthetic method for the promising new drug oseltamivir ethoxysuccinate is described in detail. Various conditions for obtaining the target substance are considered. Its complete physicochemical characteristics are given. The obtained agent is shown to be effective against influenza virus A (H1N1)pdm09.

Duration and distance of a laser-driven shock wave formation in a plasma with subcritical density

Theory and computational results are presented through the generation and propagation of a plane laser-driven shock wave in a substance with a density less than the critical plasma density. A model of the phenomenon is developed, the essence of which consists in the formation of pressure behind the front of the laser-driven ionization wave, which provides hydrodynamic motion with the speed exceeding the speed of the ionization wave front and the sound speed in unperturbed matter ahead of it. The dependences of the duration and distance of shock wave formation on the intensity and radiation wavelength of the impacting laser pulse, as well as on the density of the target substance, are established. The results are discussed for the conditions of irradiation of targets with a density up to 0.1 mg cm−3 by a pulse of short-wavelength radiation of the first–third harmonics of the Nd laser with an intensity of 1012−1015 W cm−2.

Material manipulation and separation using the horizontal magneto-Archimedes effect

We have studied the manipulation and the separation of substances using the horizontal magneto-Archimedes effect. By ingenerating a high magnetic field gradient in the horizontal direction, it is possible to move the target substance to a designated position in the horizontal direction. We attempted to separate several kinds of valuable metals by applying the horizontal magnetic force to the metals falling vertically into a paramagnetic medium. In order to enhance the magnetic force, we set up the ferromagnetic core array in magnetic fields. According to the trajectory analysis for the metal particles and the magnetic separation experiments, we succeeded in dynamically separating the metal mixture dropped to the vertical direction due to the strong horizontal magnetic force in relatively low magnetic fields. It is expected that this method creates a new device for the separation of substances.

Novelty Au Nanoparticles with Different Nano Sizes as an Acidity Sensor

The amazing wide range, applications of gold nanoparticles corresponding to excellent optical and electronic properties enhance utilization of Au NP as PH sensor. Gold nanoparticles were synthesized in simple and rapid Turkevich method to accomplish optical sensing technologies covalent or non-covalent, bonds formation causes, aggregation of the nanoparticles in the target substance. Au nanoparticles characterization was studied using XRD, UV-spectroscopy and SEM. XRD indicate polycrystalline. Nanoparticles with two different sizes according to reducing agent amount to obtain 20 30 nm. Optical energy gap was calculated for both particle size to find it (2.13) eV for 30nm particle size and (2.33) eV for 20nm.Scanning Electron Microscope showed spherical shape particles. PH test were performed to investigate efficiency of Au Np’s for PH sensor and that is found to be excellent results for both sizes with more efficiency for 30 nm due to its rough surface. Which is a fantastic tool and measurement device to test the pH of soil, food, and other puncture-worthy applications.

Ion therapy guideline (Version 2020)

Ion therapy guideline (Version 2020)

Leveraging Social Media Activity and Machine Learning for HIV and Substance Abuse Risk Assessment: Development and Validation Study.

BackgroundSocial media networks provide an abundance of diverse information that can be leveraged for data-driven applications across various social and physical sciences. One opportunity to utilize such data exists in the public health domain, where data collection is often constrained by organizational funding and limited user adoption. Furthermore, the efficacy of health interventions is often based on self-reported data, which are not always reliable. Health-promotion strategies for communities facing multiple vulnerabilities, such as men who have sex with men, can benefit from an automated system that not only determines health behavior risk but also suggests appropriate intervention targets.ObjectiveThis study aims to determine the value of leveraging social media messages to identify health risk behavior for men who have sex with men.MethodsThe Gay Social Networking Analysis Program was created as a preliminary framework for intelligent web-based health-promotion intervention. The program consisted of a data collection system that automatically gathered social media data, health questionnaires, and clinical results for sexually transmitted diseases and drug tests across 51 participants over 3 months. Machine learning techniques were utilized to assess the relationship between social media messages and participants' offline sexual health and substance use biological outcomes. The F1 score, a weighted average of precision and recall, was used to evaluate each algorithm. Natural language processing techniques were employed to create health behavior risk scores from participant messages.ResultsOffline HIV, amphetamine, and methamphetamine use were correctly identified using only social media data, with machine learning models obtaining F1 scores of 82.6%, 85.9%, and 85.3%, respectively. Additionally, constructed risk scores were found to be reasonably comparable to risk scores adapted from the Center for Disease Control.ConclusionsTo our knowledge, our study is the first empirical evaluation of a social media–based public health intervention framework for men who have sex with men. We found that social media data were correlated with offline sexual health and substance use, verified through biological testing. The proof of concept and initial results validate that public health interventions can indeed use social media–based systems to successfully determine offline health risk behaviors. The findings demonstrate the promise of deploying a social media–based just-in-time adaptive intervention to target substance use and HIV risk behavior.

Contact-free and fast detection of energetic materials in containments

The identification of energetic materials in containments is an important challenge for analytical methods in the field of safety and security. Opening a package without knowledge of its contents and the resulting hazards is highly involved with risks and should be avoided whenever possible. Therefore, preferable methods work non-destructive with minimal interaction and are capable of identifying target substances in a containment quickly and reliably. Most spectroscopic methods find their limits, if the target substance is shielded by a covering material. To solve this problem, a combined laser drilling method with subsequent identification of the target substance by means of Raman spectroscopic measurements through microscopic bore holes of the covering material is presented. A pulsed laser beam is used for both the drilling process and as an excitation source for Raman measurements in the same optical setup. Results show the ability of this new method to gain high-quality spectra even when performed through microscopic small bore channels. With the laser parameters chosen right, the method can even be performed on highly sensitive explosives like triacetone triperoxide (TATP). Another advantageous effect arises in an observed reduction in unwanted fluorescence signal in the spectral data, resulting from the confocal-like measurement setup with the bore hole acting as aperture.

Quantitative analysis of polycyclic aromatic hydrocarbons in soil by infrared spectroscopy combined with hybrid variable selection strategy and partial least squares

Infrared spectroscopy (IR) combined with multivariate calibration technology can be used as a potential method to quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in soil, which provides a rapid data support for soil risk assessment. However, IR spectrum contains lots of useless information, its predictive performance is poor. Variable selection is an effective strategy to eliminate irrelevant wavelengths and enhance predictive performance. In this study, IR combined with partial least squares (PLS) was proposed to quantify anthracene and fluoranthene in soil. In order to improve the predictive performance of the PLS calibration model, the synergy interval PLS (siPLS) method was first used for “rough selection” to select feature bands; on this basis, “fine selection” was performed to extract the feature variables. In “fine selection”, three different feature variables selection methods, such as successive projection algorithm (SPA), genetic algorithm (GA), and particle swarm optimization (PSO), were compared for their performance in extracting effective variables. The results show that the siPLS-GA calibration model receive a lowest root mean square error (RMSE) and a largest determination coefficient (R2). Results of external validation demonstrate an excellent predictive performance of siPLS-GA calibration model, with the R2 = 0.9830, RMSE = 0.5897 mg/g and R2 = 0.9849, RMSE = 0.4739 mg/g for anthracene and fluoranthene, respectively. In summary, siPLS combined with GA can accurately extract the effective information of the target substance and improve the predictive performance of the PLS calibration model based on IR spectroscopy.

New Process of Solidification under Low Temperature of Cation Conductive NaSn2(PO4)3 Synthesized Hydrothermally

NaSn2(PO4)3 hard bulk materials were successfully obtained by low-temperature calcination (~600 °C) from hydrothermally synthesized sols without a powder-press or sintering at high temperature. A hydrothermal reaction was performed at 250 °C for 5 h using an aqueous solution of NaOH, an aqueous solution of SnCl4, and H3PO4 as starting materials. The ratio of the starting materials was changed, and the range in which NaSn2(PO4)3 was formed was investigated. As a result, the sample hydrothermally synthesized under the synthesis conditions of Na: Sn: P = 2.75: 0.50: 1.75 was produced as a white sol in a Teflon container. In order to remove Cl from this sol, an immersion treatment with deionized water was performed. After immersion treatment for 3 h, and calcination at 600-900 °C, it was possible to obtain the target substance NaSn2(PO4)3 as a hard bulk material.

Assessing metabolic similarity for read-across predictions

Read-across is one of the most frequently used non-animal approaches for filling toxicological data gaps. There is a universal realization that considerations of the metabolic fates of the target substance and proposed source analogue(s) are important in accepting or rejecting a read-across hypothesis. Comparisons of target and source metabolic information most often suffers from the lack of experimental data. These data voids have prompted the development and use of alternative methods. With various limitations, several in silico tools are available to aid an evaluator in appraising metabolic similarity. Metabolic maps, arrays of 2D molecular structures of (a)biotic transformation products, allow for side-by-side visual comparison of stepwise routes of conversion of the target and source chemicals. There are two varieties of metabolic maps – documented and simulated. A document metabolic map is one derived for in vivo or in vitro experimental data. A simulated one is a map derived from metabolic pathway predictions of possible or probable metabolites coupled with expert judgment. Here, through a series of examples, the advantages of using the metabolic information, provided by the OASIS software, are exemplified. This will aid in establishing metabolic consistency between the chemicals used in a read-across argument (i.e., establish similarity in their (a)biotic transformations). Of particular importance are found to be the identification of common metabolic pathway(s), common metabolite(s), and similarity concerning the formation of reactive metabolites.