Overlap contribution to57Fe3+ isomer shifts in fluorides and oxides

We have calculated the overlap contribution to the contact charge density at the⁵⁷Fe³⁺ site in fluoride and oxide lattices, FeF₃, CaFe₂O₄, CaBaFe₄O₈ and KFeO₂. The trend in isomer shifts in going from one lattice to another is explained in terms of the overlap effects. The experimental values of the change in isomer shift from lattice to lattice is used to obtain the change in nuclear size. The values of r/r _N are found to lie between –0.81×10^–4 and –1.56×10^–4.     

Mass spectrometry-based glycoprofiling of biopharmaceuticals by using an automated data processing tool: SimGlycan®

The therapeutic and immunological properties of biopharmaceuticals are governed by the glycoforms contained in them. Thus, bioinformatics tools capable of performing comprehensive characterization of glycans are significantly important to the biopharma industry. The primary structural elucidation of glycans using mass spectrometry is tricky and tedious in terms of spectral interpretation. In this study, the biosimilars of a therapeutic monoclonal antibody and an Fc-fusion protein with moderate and heavy glycosylation, respectively, were employed as representative biopharmaceuticals for released glycan analysis using liquid chromatography–tandem mass spectrometry instead of conventional mass spectrometry-based analysis. SimGlycan® is a software with proven ability to process tandem MS data for released glycans could identify eight additional glycoforms in Fc-fusion protein biosimilar, which were not detected during mass spectrometry analysis of released glycans or glyco-peptide mapping of the same molecule. Thus, liquid chromatography–tandem mass spectrometry analysis of released glycans not only complements conventional liquid chromatography–mass spectrometry-based glycan profiling but can also identify additional glycan structures that may otherwise be omitted during conventional liquid chromatography–tandem mass spectrometry based analysis of mAbs. The mass spectrometry data processing tools, such as PMI Byos™, SimGlycan^®, etc., can display pivotal analytical capabilities in automated liquid chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry-based glycan analysis workflows, especially for high-throughput structural characterization of glycoforms in biopharmaceuticals.     

Kinetics and mechanism of proton transfer between disubstituted benzoic acids and carbinol base of crystal violet in chlorobenzene

An investigation on the detailed kinetics of proton transfer between a set of di- and monofluoro- and chloro- (2,3-, 2,5-, 2,6-, 3,5-, 2-, and 3-) benzoic acids (HA) and Crystal Violet carbinol base in chlorobenzene favors a mechanism in terms of fast equilibrium between HA and D to form a H-bonded complex, D...HA, followed by rate-limiting proton transfer along the H-bond to form the colored ion pair DH+A- under the combined influence of monomer HA catalyst, nonreactive cyclic dimer (HA)2 inhibitor, and hyperacidic homoconjugated complex H(HA2) catalyst through a transition state with nearly 60% charge separation.     

p-TSA-catalyzed one-pot synthesis and docking studies of some 5H-indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives as anticonvulsant agents

The present work describes a facile, one-pot three component environment friendly, green synthesis of a series of 5-(4-methoxyphenyl)-7,7-dimethyl-10-phenyl-7,8-dihydro-5H-indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives 8(a-n). 1,3-indanedione, aryl-aldehyde and enaminone was thoroughly ground in the presence of catalytic amount of p-toluene sulfonic acid (p-TSA) to give the titled compounds in good yields. All the synthesized derivatives were evaluated for their anticonvulsant activity using the maximal electroshock (MES) method with phenytoin as a standard drug along with their neurotoxicity effect. Derivatives 8b, 8e and 8k exhibited significant anticonvulsant activity (P<0.001). The neurotoxicity study clearly revealed that all the tested compounds are non-toxic at a dose of 40 mg/kg. The molecular modeling studies also predicted good binding interactions of most active molecules with the serotonin 5-HT_2A receptor. Therefore, it can be safely concluded that synthesized derivatives 8(a-n) would represent useful leads for further investigation in the development of a new class of anticonvulsant agents.     

Luminescence studies on europium- and dysprosium-doped di-strontium magnesium silicate phosphor

Research on Chemical Intermediates - Europium- and dysprosium-doped strontium magnesium silicate powder with different concentration ratios of dysprosium were synthesized using solid-state...     

Development and validation of an RP‐HPLC method for the quantitation of Orteronel (TAK‐700), a CYP17A1 enzyme inhibitor,in rat plasma and its application to a pharmacokinetic study

A novel, simple, specific, sensitive and reproducible high‐performance liquid chromatography assay method has been developed and validated for the estimation of Orteronel in rat plasma. The bioanalytical procedure involves extraction of Orteronel and phenacetin (internal standard) from rat plasma with a simple liquid–liquid extraction process. The chromatographic analysis was performed on a Waters Alliance system using a gradient mobile phase conditions at a flow rate of 1 mL/min and a C₁₈ column maintained at ambient room temperature. The eluate was monitored using a photodiode array detector set at 242. Orteronel and internal standard eluted at 4.8 and 6.2 min, respectively and the total run time was 9 min. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. The calibration curve was linear over a concentration range of 100–3149 ng/mL (r² = 0.995). The intra‐ and inter‐day precisions were in the ranges of 0.31–7.87 and 3.97–6.35, respectively, in rat plasma. The validated HPLC method was successfully applied to a pharmacokinetic study of Orteronel in rats. Copyright © 2013 John Wiley & Sons, Ltd.     

Studies on Mercury Pollution: Microdetermination of Mercury in Biological Materials by Cold Vapour Atomic Absorption Spectrometry

Abstract

A simple, rapid, precise and accurate method for the determination of mercury in biological material is described. Biological samples were digested with nitric acid and acidified potassium permanganate and determined by cold vapour analyser. The proposed method was successfully employed for the determination of mercury in samples of fish, hair and blood.