Investigation and optimization of the recovery of coal fines using oil agglomeration process: Use of waste oils from different sectors

The high cost of the bridging liquid subdues the implementation and commercialization of oil agglomeration process. To overcome this problem, waste oils from different sectors were used in this present study. The performance of the process was assessed based on the responses like ash rejection and organic matter recovery. The aim of the present study was to investigate the usage of waste oils from different sectors and to optimize and analyze the behavioral pattern showcased by different variables (pulp density, oil dosage, agglomeration time and oil type) using response surface methodology (Box-Behnken design). Experimental investigation shows that the optimum pulp density, oil dosage, agglomeration time and oil type condition obtained as 3%, 15%, 15?min and waste engine oil, respectively. At optimum condition, the % ash rejection and % organic matter recovery obtained as 63.94% and 81.8%, respectively.     

Novel glitazones as PPARγ agonists: molecular design,synthesis, glucose uptake activity and 3D QSAR studies

Background

An alarming requirement for finding newer antidiabetic glitazones as agonists to PPARγ are on its utmost need from past few years as the side effects associated with the available drug therapy is dreadful. In this context, herein, we have made an attempt to develop some novel glitazones as PPARγ agonists, by rational and computer aided drug design approach by implementing the principles of bioisosterism. The designed glitazones are scored for similarity with the developed 3D pharmacophore model and subjected for docking studies against PPARγ proteins. Synthesized by adopting appropriate synthetic methodology and evaluated for in vitro cytotoxicity and glucose uptake assay. Illustrations about the molecular design of glitazones, synthesis, analysis, glucose uptake activity and SAR via 3D QSAR studies are reported.

Results

The computationally designed and synthesized ligands such as 2-(4-((substituted phenylimino)methyl)phenoxy)acetic acid derivatives were analysed by IR, ¹H-NMR, ¹³C-NMR and MS-spectral techniques. The synthesized compounds were evaluated for their in vitro cytotoxicity and glucose uptake assay on 3T3-L1 and L6 cells. Further the activity data was used to develop 3D QSAR model to establish structure activity relationships for glucose uptake activity via CoMSIA studies.

Conclusion

The results of pharmacophore, molecular docking study and in vitro evaluation of synthesized compounds were found to be in good correlation. Specifically, CPD03, 07, 08, 18, 19, 21 and 24 are the candidate glitazones exhibited significant glucose uptake activity. 3D-QSAR model revealed the scope for possible further modifications as part of optimisation to find potent anti-diabetic agents.

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Highly Productive Oxidative Biocatalysis in Continuous Flow by Enhancing the Aqueous Equilibrium Solubility of Oxygen

We report a simple, mild, and synthetically clean approach to accelerate the rate of enzymatic oxidation reactions by a factor of up to 100 when compared to conventional batch gas/liquid systems. Biocatalytic decomposition of H₂O₂ is used to produce a soluble source of O₂ directly in reaction media, thereby enabling the concentration of aqueous O₂ to be increased beyond equilibrium solubility under safe and practical conditions. To best exploit this method, a novel flow reactor was developed to maximize productivity (g product L^?1 h^?1). This scalable benchtop method provides a distinct advantage over conventional bio‐oxidation in that no pressurized gas or specialist equipment is employed. The method is general across different oxidase enzymes and compatible with a variety of functional groups. These results culminate in record space‐time yields for bio‐oxidation.     

Comparative metabolic profiling of Costus speciosus leaves and rhizomes using NMR,GC-MS and UPLC/ESI-MS/MS

Costus speciosus had been used in oriental systems of medicines, to treat diverse ailments. The present study was focused on NMR, GC-MS and UPLC/ESI-MS/MS-based metabolic profiling of C. speciosus. This metabolic study resulted in the identification of 91 and quantification of 69 metabolites. Caffeic acid derivatives previously unreported in C. speciosus were also identified. High quantity of steroidal saponins namely methyl protogracillin (297.97 ± 0.07 mg/g dried wt.) and dioscin (158.72 ± 0.27 mg/g dried wt.) were observed in butanol fraction of rhizomes. Health care metabolites including caffeic acid (37.88 ± 0.04 mg/g dried wt.) and trehalose (75.12 ± 0.08 mg/g dried wt.) were also detected in ethyl acetate and aqueous fractions of rhizomes, respectively. Metabolites of nutraceutical and biological significance including eremanthine (5.14 ± 0.68%, peak area), tocopherols (~22%), sterols (~25%) were also identified from hexane fractions of rhizomes and leaves using GC-MS. The analytical techniques used had successfully differentiated metabolites composition among leaves and rhizomes.     

Validation of a Stability-Indicating LC Method for Assay of Ezetimibe in Tablets and for Determination of Content Uniformity

A simple, precise, and accurate HPLC method has been developed and validated for assay of ezetimibe in tablets and for determination of content uniformity. Reversed-phase liquid chromatographic separation was achieved by use of phosphoric acid (0.1%, v/v)–acetonitrile 50:50 (v/v) as mobile phase. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing of the drug (forced degradation). Response was a linear function of drug concentration in the range 20–80 μg mL⁻¹ (r = 0.9999). Intraday and interday system and method precision were determined. Accuracy was between 100.8 and 102.7%. The method was found to be robust, and was suitable for assay of ezetimibe in a tablet formulation and for determination of content uniformity. An erratum to this article can be found at     

Validated LC Method for Simultaneous Analysis of Tramadol Hydrochloride and Aceclofenac in a Commercial Tablet

This paper describes development and validation of a high-performance liquid chromatographic method for simultaneous analysis of tramadol hydrochloride (TR) and aceclofenac (AC) in a tablet formulation. When the combination formulation was subjected to ICH-recommended stress conditions, adequate separation of TR, AC, and the degradation products formed was achieved on a C₁₈ column with 65:35 (v/v) 0.01 M ammonium acetate buffer, pH 6.5—acetonitrile as mobile phase at a flow rate of 1 mL min^?1. UV detection was performed at 270 nm. The method was validated for specificity, linearity, LOD and LOQ, precision, accuracy, and robustness. The method was specific against placebo interference and also during forced degradation. The linearity of the method was investigated in the concentration ranges 15–60 μg mL^?1 (r = 0.9999) for TR and 40–160 μg mL^?1 (r = 0.9999) for AC. Accuracy was between 98.87 and 99.32% for TR and between 98.81 and 99.49% for AC. Because degradation products were well separated from the parent compounds, the method was stability-indicating.     

Intermolecular stacking in pyrazolo[3,4‐d]pyrimidine‐based pentamethylene‐linked flexible ­molecules

The crystal structures of 1‐{5‐[4,6‐bis­(methyl­sulfanyl)‐2H‐py­razolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐6‐methyl­sulfanyl‐4‐(pyr­rolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₂H₂₉N₉S₃, and 6‐methyl­sulfanyl‐1‐{5‐[6‐methyl­sulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₅H₃₄N₁₀S₂, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo­[3,4‐d]­pyrimidine rings.     

Chemical Degradation of Mercury Alkyls Mediated by Copper Selenide Nanosheets

Methylation and demethylation of mercury compounds are two important competing processes that control the net production of highly toxic mercury alkyls, methylmercury (MeHg⁺) and dimethylmercury (Me₂Hg), in environment. Although the microbial and the photochemical methylation and demethylation processes are well studied in recent years but the chemical methylation and demethylation processes have not been studied well. Herein, we report for the first time that the CuSe nanosheet has remarkable ability to activate the highly inert Hg?C bonds of various MeHg⁺ and Me₂Hg compounds at room temperature (21 °C). It facilitates the conversion of MeHg⁺ into Me₂Hg in the absence of any proton donors. Whereas, in the presence of any proton source, it has unique ability to degrade MeHg⁺ into CH₄ and inorganic mercury (Hg²⁺). Detailed studies revealed that the relatively fast Hg?C bond cleavage was observed in case of MeHgSPh or MeHgI in comparison to MeHgCl, indicating that the Hg?C bond in MeHgCl is relatively inert in nature. On the other hand, the Hg?C bond in Me₂Hg is considered to be exceedingly inert and, thus, difficult to cleave at room temperature. However, CuSe nanosheets showed unique ability to degrade Me₂Hg into CH₄ and Hg²⁺, via the formation of MeHg⁺, under acidic conditions at room temperature. DFT calculations revealed that the Hg?C bond activation occurs through adsorption on the surface of (100)‐faceted CuSe nanosheets.