Purity Of Compounds Research Articles

Antimicrobial Test of 1-(2.5-Dihydroxi Phenyl)-(3-Pyridine-2-Il) -Propanone Compound in Enterococcus Faecalis and Escherichia Coli Bacteria Using a Well Diffusion Method

1-(2.5-dihydroxy phenyl)-(3-pyridine-2-il)-propenone compound is a compound synthesized by reacting the pyridine-2-carbaldehyde and 2.5-dihydroxyacetophenone compound without solvent with K2CO3 (Potassium Carbonate) catalyst in the microwave. The 1-(2.5-dihydroxy phenyl)-(3-pyridine-2-il)-propenone compound is a chalcone derivative compound substituted by two hydroxy groups on ring A and has 2-pyridyl groups on ring B. Chalcone is a secondary metabolite compound from the flavonoid group, which has several activities as anti-platelet, anti-bacterial, immunomodulator, anti-hyperglycemic, and anti-inflammatory. This study aims to determine the antibacterial effect of 1-(2.5-dihydroxifenil)-(3-pyridine-2-il)-propenone compound against Enterococcus faecalis and Escherichia coli bacteria. This study used TLC (Thin Layer Chromatography) and Melting Point Test to analyze the purity of 1-(2.5-dihydroxy phenyl)-(3-pyridine-2-il)-propenone compound. Meanwhile, the test for antibacterial activity used a well diffusion method. Concentration variation for 1-(2.5-dihydroxifenyl)-(3-pyridine-2-il)-propenone compound as antibacterial in Escherichia coli were 0.25 mg/100 μl, 0.5 mg/200 μl, and 0.75 mg/300 μl. Meanwhile, the concentration variation for Enterococcus faecalis bacteria was 5%, 2.5%, 1.25% and was replicated three times. The results of the compound purity test using the melting point test and Thin Layer Chromatography (TCL) showed that the 1-(2.5-dihydroxy phenyl)-(3-pyridine-2-il)-propenone compound was pure. The results of the antibacterial activity test for 1-(2.5-dihydroxiphenyl)-(3-pyridine-2-il)-propenone compound showed no zone of inhibition at each test concentration. In conclusion, the 1-(2.5-dihydroxifenyl)-(3-pyridine-2-il)-propenone compound did not have an antibacterial effect on Enterococcus faecalis and Escherichia coli bacteria.

Stereochemical aspects in the synthesis of novel N-(purin-6-yl)dipeptides as potential antimycobacterial agents.

The synthesis of purine conjugates with natural amino acids is one of the promising directions in search for novel therapeutic agents, including antimycobacterial agents. The purpose of this study was to synthesize N-(purin-6-yl)dipeptides containing the terminal fragment of (S)-glutamic acid. To obtain the target compounds, two synthetic routes were tested. The first of them is based on coupling of N-(purin-6-yl)-(S)-amino acids to dimethyl (S)-glutamate in the presence of carbodiimide coupling agent followed by the removal of ester groups. However, it turned out that this coupling process was accompanied by racemization of the chiral center of N-(purin-6-yl)-α-amino acids and in all cases led to mixtures of (S,S)- and (R,S)-diastereomers (6:4). Individual (S,S)-diastereomers were obtained using an alternative approach based on the nucleophilic substitution of chlorine in 6-chloropurine or 2-amino-6-chloropurine with corresponding dipeptides as nucleophiles. The enantiomeric purity of the target compounds was confirmed by chiral HPLC. To test the assumption that racemization of the chiral center of N-(purin-6-yl)-α-amino acids occurs with the participation of nitrogen atoms of the imidazole ring via the stage of formation of a chirally labile intermediate, we obtained such structural analogs of N-(purin-6-yl)-(S)-alanine as N-(9-benzylpurin-6-yl)-(S)-alanine and N-(7-deazapurin-6-yl)-(S)-alanine. It was found that coupling of these compounds to dimethyl (S)-glutamate was also accompanied by racemization. This indicates that the imidazole fragment does not play a crucial role in this process. When testing the antimycobacterial activity of some of the obtained compounds, conjugates with moderate activity against the laboratory Mycobacterium tuberculosis H37Rv strain (MIC 3.1–6.25 μg/mL) were identified.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00726-021-02958-0.

Development and Validation of RP-HPLC Method for the Simultaneous Estimation of Salbutamol Sulphate and Ambroxol Hydrochloride in Oral Liquid Dosage Form

Pharmaceutical analysis is imported branch of science deals with to check the identity, strength, quality and purity of chemical and herbal compounds. Qualitative analysis of drugs and pharmaceutical compounds. Quantitative analysis is of much importance and done by various methods. One of the most accurate and precise methods is spectrophotometry which comprises the measurement of intensity of electromagnetic radiation emitted or absorbed by the compound. Another most popular method of for quantitative analysis is high performance liquid chromatography (HPLC). In the present article a RP-HPLC method was developed for the simultaneous determination of salbutamol sulphate and ambroxol hydrochloride in oral liquid doses form and validation of the developed method. Developed methods include selection of mobile phase, chromatographic method, and wavelength whereas validation involves the system suitability, accuracy, precision, linearity, reproducibility, robustness, specificity and solution stability of the developed method. The result showed that the developed method is the best suited to the simultaneous determination of salbutamol sulphate and ambroxol hydrochloride and validated as per the standards.

Residual Solvent Signal of CDCl3 as a qNMR Internal Standard for Application in Organic Chemistry Laboratory

A nuclear magnetic resonance (NMR) spectrometer is a key instrument in the organic synthesis laboratory for structure determination, reaction control, and compound purity analysis. In addition to qualitative analysis, the application of NMR for quantitative analysis (qNMR) is gaining popularity. qNMR allows for simple quantification of crude product mixtures, determination of reaction yields, and purity of organic compounds. The determination of NMR yield requires the addition of an internal standard to each sample. Herein, we report a method where CDCl3 residual solvent signal is used as an internal standard for qNMR after quantification in the solvent batch. This method significantly simplifies sample preparation and allows straightforward recovery of the analyte by the simple evaporation of the NMR solvent. The accuracy of the method is comparable to qNMR with 1,3,5-trimethoxybenzene as an internal standard if the herein described guidelines are followed.

Using X-ray Diffraction Techniques for Biomimetic Drug Development, Formulation, and Polymorphic Characterization.

Drug development is a decades-long, multibillion dollar investment that often limits itself. To decrease the time to drug approval, efforts are focused on drug targets and drug formulation for optimal biocompatibility and efficacy. X-ray structural characterization approaches have catalyzed the drug discovery and design process. Single crystal X-ray diffraction (SCXRD) reveals important structural details and molecular interactions for the manifestation of a disease or for therapeutic effect. Powder X-ray diffraction (PXRD) has provided a method to determine the different phases, purity, and stability of biological drug compounds that possess crystallinity. Recently, synchrotron sources have enabled wider access to the study of noncrystalline or amorphous solids. One valuable technique employed to determine atomic arrangements and local atom ordering of amorphous materials is the pair distribution function (PDF). PDF has been used in the study of amorphous solid dispersions (ASDs). ASDs are made up of an active pharmaceutical ingredient (API) within a drug dispersed at the molecular level in an amorphous polymeric carrier. This information is vital for appropriate formulation of a drug for stability, administration, and efficacy purposes. Natural or biomimetic products are often used as the API or the formulation agent. This review profiles the deep insights that X-ray structural techniques and associated analytical methods can offer in the development of a drug.

Ionic Liquids Based on Oxidoperoxido-Molybdenum(VI) Complexes with a Chelating Picolinate Ligand for Catalytic Epoxidation

Ionic oxidoperoxido-molybdenum(VI) complexes of the type [Cat][MoO(O2)2(pic)], with pic = N,O-chelated picolinate ligand and Cat = monocation, were prepared in high yields (82–95%) from the precursor complex [H3O][MoO(O2)2(pic)] via [H]+ cation exchange for 1-ethyl-3-methylimidazolium [EMIM]+, 1-butyl-3-methylimidazolium [BMIM]+, 1-octyl-3-methylimidazolium [OMIM]+, N-cetylpyridinium [C16Py]+, and N-methyl-N,N,N-trioctylammonium [Aliquat]+. The structure and purity of the ionic compounds were assessed by 1H and 13C NMR, FT-IR, and elemental analysis (C, H, N), and the electrochemical properties were studied by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The [Cat][MoO(O2)2(pic)] compounds showed promising catalytic epoxidation activity based on the model reaction of cis-cyclooctene with tert-butyl hydroperoxide as oxidant. The type of cation influenced the physical state of the compound and the catalytic performance.

Application of capillary electrophoresis technique for the enantioseparation of bioactive ferrocene-based compounds versus DFT calculated data.

Herein, a series of bioactive ferrocene-modified N-heterocycles with alkyl linkers was prepared in good to quantitative yields starting from easy accessible ferrocene alcohols and heterocycles under acidic or neutral (for imidazole) conditions in racemic forms. The analytical resolution of a number of bioactive racemic ferrocene azoles 1-6 (where azole = imidazole, pyrazole, and benzotriazole derivatives) into enantiomers was first carried out by CE using sulfobuthylether-β-CD (captisol) as a chiral selector. The analytical approaches to highly enantiomeric-enriched ferrocene derivatives are based on the formation of their inclusion complexes. The best chiral separation was achieved using zone CE in a quartz capillary. The ACE was used to evaluate the stability constants of captisol complexes with enantiomeric forms of two ferrocene derivatives 1, FcCHMe-imidazole, and 6, FcCHMe-benzotriazole. The optimal conditions for the resolution of the studied (R, S)-ferrocene compounds 1, 2, and 6 were predicted on the basis of the performed quantum chemical calculations and then implemented by the electrophoretic method. A high correlation between density functional theory calculation results and experimental electrophoresis data were obtained. Successful enantioseparation of racemic mixtures is of great importance for the characterization and further applications of drug candidates in enantiopure forms and in the development of clinical treatment. The advantages of the CE procedure make it possible to have important practical value and significance for determining the purity and enantiomeric excess of other ferrocene-containing compounds.

Targeted isolation of 1,1-diphenyl-2-picrylhydrazyl inhibitors from Saxifraga atrata using medium- and high- pressure liquid chromatography combined with online high performance liquid chromatography–1,1-diphenyl-2- picrylhydrazyl detection

Traditional Tibetan medicine (TTM) is a valuable source of novel therapeutic lead molecules inspired by natural products (NPs). The health benefits of Saxifraga atrata are well documented in TTM, but reports on its chemical composition are limited, most likely due to the complicated purification process. Herein, target separation and identification of 4 main radical scavenging compounds from the methanolic extract of S. atrata was were performed using medium- and high-pressure liquid chromatography coupled with online HPLC-DPPH detection. The sample was pretreated using medium pressure liquid chromatography with MCI GELⓇ CHP20P styrene-divinylbenzene beads as a stationary phase, yielding 1.4 g of the target DPPH inhibitors (Fr4, 11.9% recovery). The compounds were further purified and isolated using HPLC on RP-C18 (ReproSil-Pur C18 AQ) followed by HILIC (Click XIon) column separation, resulting in 2.8 mg of fraction Fr4-1-1, 6.8 mg of fraction Fr4-2, 244.9 mg of the Fr4-3-1 sample, and 38.3 mg of Fr4-4-1. The structure and purity of the target compounds were determined, and four compounds (ethyl gallate, 11-O-galloylbergenin, rutin and isoquercitrin) were isolated with >95% purity. The developed methodology is efficient for targeted isolation of high-purity radical scavengers from NP extracts and could be used for rapid identification and isolation of DPPH inhibitors from various NPs.

Novel nitro based chalcone derivative single crystals: characterization on structural, linear optical, thermal, and third-order nonlinear optical properties

Crystals of “(2E)-1-(4-nitrophenyl)-3-(2,3,4-trimethoxyphenyl)prop-2-en-1-one” (NPTMP) are grown by slow solvent evaporation technique. The compound purity and presence of functional group elements in the material were identified from the spectroscopic techniques (FT-IR and ˡH-NMR). The single-phase formation in the bulk powder crystalline sample has been confirmed from powder XRD analysis. The intermolecular interaction and structure-related parameters were obtained and analyzed by utilizing single-crystal XRD data. Using single-crystal XRD data (CIF file), display of the intermolecular interactions and contribution of H···H and H···O/O···H interaction have been obtained. The molecule is mapped over dnorm, de, di, curvedness, shape index, and electrostatic potential by generating the Hirshfeld’s surface of NPTMP molecule. The linear optical absorbance and optical bandgap of the material have been confirmed by UV–VIS–NIR spectroscopic technique. The thermal stability of the crystal NPTMP is obtained from TGA/DTA/DSC techniques. The surface morphology of the crystal is collected from scanning electron microscopy (SEM) and the electronic contribution of hyperpolarizability parameters is obtained from MOPAC 2016 software. The third-order nonlinear optical properties were studied by the Z-scan technique using CW DPSS laser operating at 532 nm wavelength. The molecule exhibits a comparatively moderate optical limiting response due to reverse saturable absorption (RSA).

Synthesis of the ZnTiO3/TiO2 Nanocomposite Supported in Ecuadorian Clays for the Adsorption and Photocatalytic Removal of Methylene Blue Dye.

Currently, the study of semiconductor materials is very promising for the photocatalytic remediation of hazardous organic substances present in the air and water. Various semiconductors have been investigated in this interesting photo-assisted methodology, among them metal oxides such as ZnO, TiO2 and their derivatives. In this study, ZnTiO3/TiO2 was synthesized by the sol-gel method using Ti(OC3H7)4 and Zn(CH3COO)2 · 2H2O as reagents. The role of several conditions such as synthesis temperature and TiO2:ZnO proportion on the morphology and purity of compounds obtained was studied, and the suitable conditions for the synthesis of photocatalysts were determined. Various techniques were used to conduct a systematic investigation on the structural, morphological, and photocatalytic properties of ZnTiO3/TiO2. Scanning Electron Microscopy (SEM) images show that ZnTiO3/TiO2 have a typical particle size of approximately 100 nm with a quasi-spherical shape. The adsorption and photocatalytic activity were investigated by the decolorization of Methylene Blue (MB) as an organic contaminant under UV irradiation both in TiO2 and ZnTiO3/TiO2 supported over some Ecuadorian clays. The materials evaluated were prepared in the shape of 0.2 cm (diameter) and 1.0 cm (length) cylindrical extrudates. The degradation percentage of MB obtained was 85% approximately after 150 min of irradiation. The results obtained allow us to conclude that these synthesized materials can be used as adsorbents and photocatalysts.

Iodine-131 labeled genistein as a potential radiotracer for breast cancer

ObjectiveGenistein is an isoflavone compound that has been proven to have anticancer activity and is capable of binding to estrogen β receptors with Selective Estrogen Receptor Modulators (SERMs) properties, and has a strong affinity to inhibit the development of cancer cells. This study is to determine the optimum conditions of the reaction in the synthesis process of compounds labeled 131I-genestein which can be potential for application of breast cancer diagnosis. MethodsSynthesis of 131I-Genistein compound labeling using the Chloramine-T iodination method. This method uses several parameter optimizations, including: pH conditions, the amount of chloramine-T oxidizer and sodium metabisulfite reducing agent. The radiochemical purity of the 131I-Genistein compound was determined using thin layer chromatography TLC-SG F254, and measured by SCA (Single Channel Analyzer). The radiochemical purity of labeled compounds must fulfill the requirements of the United States of Pharmacopeia. ResultsOptimization of the synthesis conditions of the 131I-Genistein compound was obtained at pH 8, the amount of chloramine-T 0.225 mg, and the amount of Na-Metabisulfite 0.342 mg, with 30 min reaction time. This optimum condition produces radiochemical purity of 95.02 ± 0.76%. ConclusionProducts labeled 131I-Genistein meet radiochemical purity requirements according to USP requirements. The labeled compound is expected to be able to be used to detect breast cancer through a binding mechanism with estrogen receptors β.

Facile Synthesis of Propranolol and Novel Derivatives

Propranolol is one of the first medications of the beta-blocker used for antihypertensive drugs. This study reports the facile route for the synthesis of propranolol and its novel derivatives. Herein, propranolol synthesis proceeded from 1-naphthol and isopropylamine under mild and less toxic conditions. Novel propranolol derivatives were designed by reactions of propranolol with benzoyl chloride, pyridinium chlorochromate, and n-butyl bromide through esterification, oxidation reduction, and alkylation, respectively. The isolation and purity of compounds were conducted using column chromatography and thin-layer chromatography. Mass spectrometry and 1H-NMR spectroscopy were applied to identify new compounds structure. Propranolol derivatives from 2-chlorobenzoyl chloride (compound 3), 2-fluorobenzoyl chloride (compound 5), and especially acetic anhydride (compound 6) manifested high yields and significantly increased water solubility. Six semisynthetic propranolol derivatives promise to improve antioxidative and biological activities.

Determination of Absolute Purities of Hygroscopic Substances by Quantitative NMR Analysis for the Standardization of Quantitative Reagents in the Japanese Pharmacopoeia (Part 1)

Quantitative NMR (qNMR) has been developed as an absolute quantitation method to determine the purity or content of organic compounds including marker compounds in crude drugs. The "qNMR test" has been introduced into the crude-drug section of the Japanese Pharmacopoeia (JP) for determining the purity of reagents used for the assay in the JP. In Supplement II to the JP 17th edition published in June 2019, fifteen compounds adopted qNMR test were listed as the reagents for the assay. To establish the "qNMR test" in the crude drug section of the JP, there were several problems to be solved. Previously, we reported that the handling impurity signals from reference substances and targeted marker compounds, chemical shifts of reference substances, and peak unity of signals of targeted marker compounds are important factors to conduct qNMR measurements with intended accuracy. In this study, we investigated that the hygroscopicity of reagents could cause the changes in the compounds' purity depending on increasing their water content. Twenty-one standard products used for the crude-drug test in JP were examined by water sorption-desorption analysis, and ginsenosides and saikosaponins were found to be hygroscopic. To prepare a sample solution of saikosaponin b2 for qNMR analysis, samples need to be maintained for 18 h at 25°C and 76% relative humidity; further, samples need to be weighed at the same humidity for the qNMR analysis.

Synthesis of novel benzimidazoles at room temperature, under solvent-free condition and their biological studies

An efficient and facile synthesis of substituted novel benzimidazoles (3a–3h) mediated by fruit juices viz. Cocos nucifera L. juice, Citrus limetta juice and Citrus sinensis L. juice, via condensation of substituted aldehydes (1a–1h) and o-phenylenediammine (2a) under solvent-free condition at room temperature is presented in this paper. The purity of compounds was confirmed by melting point and thin layer chromatography. All synthesized compounds (3a–3h) were fully characterized via NMR and FTIR spectral data and evaluated for in vitro herbicidal activity against Raphanus sativus L. (Radish) seeds. The compounds (3a–3h) were also evaluated for their antibacterial activity against Erwinia cartovora and Xanthomonas citri by inhibition zone method. Antifungal activity was also determined against Rhizoctonia solani and Colletotrichum gloeosporioides by poisoned food techniques method. From activity data, it was found that compounds 3d and 3e were most active against R. sativus L. (root) and R. sativus L. (shoot), respectively. Compound 3g has shown maximum inhibition zone i.e. 8.00 mm against E. cartovora at 2000 µg/mL concentration. Maximum X. citrii growth was inhibited by compounds 3a showing inhibition zone 5.20 mm at highest concentration. Compound 3f was found most active against R. solani and C. gloeosporioides fungus at 2000 µg/mL concentration. In comparison with the conventional methods, the present method complies with several key requirements of green chemistry principles such as the utilization of renewable feedstock, auxiliary aqueous conditions and reduces waste with the use of nature-derived catalyst. Therefore, the present method offers an attractive option because of its ecological safety, environmental acceptance, cost effective and easy workup process.

Cycloarta-23-ene-3beta,25-diol a pentacyclic steroid from Euphorbia spinidens, as COX inhibitor with molecular docking, and in vivo study of its analgesic and anti-inflammatory activities in male swiss mice and wistar rats

Background and aimsEuphorbia is a large genus of flowering plants. In Iran, some plants of this family have been used in the treatment of inflammatory disorders and also to relieve back pain. Euphorbia spinidens is a rich source of Cycloarta-23-ene-3beta,25-diol. Cycloartane structures are the starting material for the synthesis of plant steroids, and the aim of this study is to demonstrate COX inhibitory activity, molecular docking and in vivo approach of anti-inflammatory activity of cycloartane compound isolated from Euphorbia spinidens.Material and Methods: Plant material was extracted with acetone-chloroform and submitted to column chromatography for fractionation. Based on preliminary 1H-NMR spectra, cycloartane fraction was selected and purified by repeated recycle HPLC system. The structure and purity of compound were determined by 1H and 13C-NMR, HPTLC, and mass spectra. Inhibitory activities of the tested compounds on COX-1 and COX-2 were evaluated by a colorimetric COX (ovine) inhibitor screening method. Vero cells were used to assess the toxicity against the normal cells, and calculate the selectivity index. COX inhibitory activity results were evaluated and confirmed by molecular docking experiments. In the in vivo approach, analgesic activity was assessed by acetic acid-induced abdominal writhing and formalin tests. Croton oil-induced ear edema in mice and carrageenan-induced rat paw edema in rats were used to evaluate anti-inflammatory activity. Pain tests were carried out on male Swiss mice (25–35 g). Male Wistar rats (160–200 g) were used for the carrageenan test. ResultsCycloart-23-ene-3β,25-diol showedin vitro cyclooxygenase 1 and 2 inhibitory activities with more selectivity for COX-2. Molecular docking by predicting binding energies in COX protein receptors confirmed in vitro COX inhibitory results, and determined the best position for ligand in COX receptors along with its residue interactions in receptor pockets, which must be considered for designing of their inhibitors. In the in vivo studies, cycloartane inhibited significantly acetic acid-induced abdominal contractions and formalin-induced licking behavior at a dose of 200 mg/kg. The same dose reduced croton oil ear edema in mice and carrageenan-induced paw edema in rats. ConclusionTherefore, according to these findings, cycloart-23-ene-3beta,25-diol showed promising analgesic and anti-inflammatory effects with low toxicity against normal cells and can be suggested as a template lead for designing anti-inflammatory compounds with good selectivity index, and potency for COX-2 inhibitory activity.

Synthesis and antibacterial activity of some new 1,2,4-triazole derivatives bearing carbohydrazide moiety

In this study, a series of 1,2,4-triazol-3-carbohydrazide derivatives and compound of 1,2,4-triazole-3-(4H)-thion have been synthesized. Structures and purity of the new compounds were confirmed by the use of their chromatographic and spectral data besides microanalysis. Four different bacterial stains for the study of the biological activity of compounds 6g, 7c, 7g and 7i; two Gram-positive strains, and two Gram-negative strains have been used. Compound 6g was found to be the most active of the four tested compounds against Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus, with an inhibition zone diameter of 16, 9, and 10 mm, respectively. Calculating the minimal inhibitory concentration value (MIC) for the positive drugs who formed an inhibition zone in the agar well diffusion method, we found that both compounds 6g and 7i were the most active of the four tested compounds against Pseudomonas aeruginosa and Bacillus cereus with an MIC value of 0.5 µg/mL for both bacteria. These results suggest that these two compounds could be considered as potential antibacterial agents against a range of bacteria.

Quinoline-3-carboxylate Derivatives: A New Hope as an Antiproliferative Agent.

The quinoline scaffold has been an attraction due to its pharmacological activities such as anti-HIV, anti-neoplastic, anti-asthmatic, anti-tuberculotic, anti-fungal, and anti-bacterial. The designed quinoline-3-carboxylate derivatives were synthesized through a two-step reaction and evaluated for antiproliferative activity against MCF-7 and K562 cell lines. Synthesized compounds were characterized by modern analytical techniques like NMR, 2DNMR, mass, and IR. Moreover, the purity of compounds was analyzed through the HPLC. In the progress of biological results, all synthesized compounds were evaluated for antiproliferative activity against MCF-7 and K562 cell lines. The synthesized compounds exhibited micromolar inhibition in all over the ranges, however, some of the compounds showed better activity than the standard anticancer drug such, as 4m and 4n with the IC50 value of 0.33μM against the MCF-7 cell line, and the compounds 4k and 4m showed potential activity against the K562 cell line with the IC50 value of 0.28μM. The anti-cancer activities of compounds were found to be through the up-regulation of intrinsic apoptosis pathways. The biological data of all compounds in both cell lines were utilized for the structural activity relationship of the quinoline-3-carboxylate pharmacophore. The active lead was further validated through rigorous in silico studies for the drug-likeness (QED) and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties. Here in the present research is utilized for the demonstration of an important pharmacophore, which could be utilized for further development to become a lead as an anticancer agent with minimal toxicity.

Spectroscopic and structural studies, thermal characterization, optical proprieties and theoretical investigation of 2-aminobenzimidazolium tetrachlorocobaltate(II).

In this study we present the crystal structure, spectroscopic and thermal behavior, Hirshfeld surface analysis, and DFT calculations of a new organic-inorganic hybrid compound (C7H8N3)2[CoCl4]. This compound crystallizes in the centrosymmetric space group P1¯. Single-crystal X-ray diffraction analysis indicates that structure consists of a succession of mixed layers formed by organic cations and inorganic anions parallel to the (001) plane and propagate according to the c-axis. Layers further are assembled into a 3D supramolecular architecture through N-H…Cl hydrogen bonds and π…π interactions. The peak positions of the experimental PXRD pattern are in agreement with the simulated ones from the crystal structure, indicating phase purity of the title compound. The presence of the different functional groups and the nature of their vibrations were identified by ATR-FTIR and FT-Raman spectroscopies. The tetrahedral environment of Co2+ was confirmed by UV-visible spectroscopy, where the spectrum shows three weak absorption bands in the visible range due to d-d electronic transitions 4A2(F) → 4T2(F), 4A2(F) → 4T1(F) and 4A2(F) → 4T1(P) typical of Co(II) coordination compounds. The direct and indirect optical band gap values were determined by Tauc method. The optimized structure and calculated vibrational frequencies were obtained by density functional theory (DFT) using B3LYP functional. TGA and DSC coupled to mass spectrometry (MS) experiments under argon atmosphere in the temperature range (25-950 °C) were carried out in order to determine the thermal stability of the title compound.

Efficient and Facile One-Pot Synthesis of Novel Benzimidazoles using Rice Husk

New and facile one-pot approach for the synthesis of substituted benzimidazoles from the reaction of substituted benzaldehyde and o-phenylenediamine room temperature using Rice Husk Ash: CaCl2 (RHA:CaCl2) as a green catalyst was presented in the paper. After the completion of the reaction, the reaction mixture was poured into ice-coldwater with stirring, and the precipitated product was filtered using the filter pump. The crude product was then recrystallized from ethanol to give analytically pure samples in good to excellent yield. The purity of compounds were characterized by melting point and thin-layer chromatography. The synthesized compounds were characterized by using 1HNMR and FTIR spectral techniques.Metal-free, short reaction time, high yields, mild reaction condition, simple work-up, high atom economy, cost-effectiveness, and no need for column purification are some beauties of this methodology.

Synthesis of deuterium-labeled 1-(4-methoxybenzyl)-3-(5-nitrothiazol-2-yl)urea (AR-A014418) as an internal standard for LC–MS analysis

AR-A014418, 1-(4-methoxybenzyl)-3-(5-nitrothiazol-2-yl)urea is a potential drug with potent activities against cancer cell, nociceptive pain and neurodegenerative disorders. In this paper, the stable deuterium-labeled [2H3]AR-A014418 was synthesized in seven steps with 21% overall yield starting from the commercially available [2H4]methanol, p-hydroxybenzaldehyde and 2-amino-5-nitrothiazole. The chemical and isotope purity of the title compound were over 99% and 98%, respectively. This labeled [2H3]AR-A014418 can be used as an internal standard for LC–MS analysis in drug absorption, distribution and other pharmacokinetics studies.