Sulfonyl fluorides as privileged warheads in chemical biology

Sulfonyl fluoride electrophiles have found significant utility as reactive probes in chemical biology and molecular pharmacology. As warheads they possess the right balance of biocompatibility (including aqueous stability) and protein reactivity. Their functionality is privileged in this regard as they are known to modify not only reactive serines (resulting in their common use as protease inhibitors), but also context-specific threonine, lysine, tyrosine, cysteine and histidine residues. This review describes the application of sulfonyl fluoride probes across various areas of research and explores new approaches that could further enhance the chemical biology toolkit. We believe that sulfonyl fluoride probes will find greater utility in areas such as covalent enzyme inhibition, target identification and validation, and the mapping of enzyme binding sites, substrates and protein–protein interactions.     

Wavelength selection framework for classifying food and pharmaceutical samples into multiple classes

Near infrared (NIR) spectroscopy is an efficient, low‐cost analytical technique widely applied to identify the origin of food and pharmaceutical products. NIR spectra‐based classification strategies typically use thousands of equally spaced wavelengths as input information, some of which may not carry relevant information for product classification. When that is the case, the performance of predictive and exploratory multivariate techniques may be undermined by such noisy information. In this paper, we propose an iterative framework for selecting subsets of NIR wavelengths aimed at classifying samples into categories. For that matter, we integrate Principal Components Analysis (PCA) and three classification techniques: k‐Nearest Neighbor (KNN), Probabilistic Neural Network (PNN) and Linear Discriminant Analysis (LDA). PCA is first applied to NIR data, and a wavelength importance index is derived based on the PCA loadings. Samples are then categorized using the wavelength with the highest index and the classification accuracy is calculated; next, the wavelength with the second highest index is inserted into the dataset and a new classification is performed. This forward‐based iterative procedure is carried out until all original wavelengths are inserted into the dataset used for classification. The subset of wavelengths leading to the maximum accuracy is chosen as the recommended subset. Our propositions performed remarkably well when applied to four datasets related to food and pharmaceutical products. Copyright © 2016 John Wiley & Sons, Ltd.     

Imaging and quantitative analysis of water evaporation process using spectral-domain optical coherence tomography under illumination with two near-infrared wavelengths

Optical Review - Dynamics of water content in a biological tissue is an important information of a biological activity. However, although the conventional measurement method measures the total...     

Physical Chemistry of the Interaction of Cellulose with Lignin during Wood Surface Treatment with a Phosphate Flame Retardant

Russian Journal of General Chemistry - A phosphate flame-retardant hardener (PFH) produced on the basis of industrial orthophosphoric acid and acetic anhydride was proposed for reducing the...     

Some Transformations of 3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one

Russian Journal of Organic Chemistry - Starting from 3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one, a series of...     

Green and Catalyst-Free Synthesis of Some New Benzo[4,5]imidazo[1,2-a]pyrimidine Derivatives as Antimicrobial and Antitubercular Agents

Russian Journal of Organic Chemistry - A new series of 4-(1H-imidazol-4-yl)-2-(substituted phenyl)-1,4-dihydrobenzo[4,5]imidazo[1,2-a]­pyrimidines have been synthesized via a one-pot reaction...     

Convenient Microwave-Assisted Chlorosulfonic Acid-Catalyzed Synthesis of Some Quinazolinones from 2-Phenylindole

Russian Journal of Organic Chemistry - A new convenient method has been developed for the synthesis of quinazolinones from 2-phenyl-1H-indole and substituted amines under catalysis by...     

Comparison of the Reactivities of Tyrosine–Proline-Based Dipeptides toward Acylation with Nitrophenyl Benzoates

Russian Journal of Organic Chemistry - The reactivities of the L-Tyr–L-Pro dipeptide and its analog with a hydroxymethyl group instead of carboxy group in the proline moiety were compared by...     

Biradical with a polyfluorinated terphenylene backbone

Russian Chemical Bulletin - A method was developed for the synthesis of perfluoro-1,1′:4′,1″-terphenyl by the reaction of chloroperfluorobenzene with zinc dust followed by the...     

Synthesis and study of interconversions of new indoline spiropyrans based on 4-hydroxy-3,5-diformylbenzoic acid

The synthesis of new indoline spiropyran by the cyclocondensation in methanol revealed that the free aldehyde group of the target spiropyran is easily converted into the dimethyl acetal moiety without the addition of an acid catalyst, giving 8′-dimethoxymethyl-1,3,3-trimethylspiro[indoline-2,2′-2H-chromene]-5,6′-dicarboxylic acid as a single reaction product. The structure of this compound was confirmed by NMR spectroscopy and mass spectrometry. The molecular structure was also established by single-crystal X-ray diffraction. The Hirshfeld surfaces were generated and analyzed and intermolecular interactions in the crystal were investigated using the CrystalExplorer software package. The reverse hydrolysis reaction of dimethyl acetal to the aldehyde group proceeds under mild conditions in dimethyl sulfoxide, as shown by NMR spectroscopy.