Friedlander synthesis of highly functionalized isoxazolyl quinoline libraries via addition of C(sp3)–H bond to aldehydes

A novel protocol for ionic liquid (IL)-mediated C(sp³)–H bond functionalization of 3,5-dimethyl-4-nitroisoxazoles 4 to substituted o-amino benzaldehydes 5 was developed in excellent yields. Isoxazolyl aryl ethanones 7 have been synthesized from isoxazolyl aryl ethanol synthon 6. Furthermore, utilizing the later as synthons for IL promoted Friedlander synthesis of highly functionalized isoxazole substituted quinoline libraries 9. The merit of this synthesis is easily available and economical starting materials, effective utilization of all the reactants, and simple workup procedure. It is noteworthy that ionic liquid used in C(sp³)–H bond functionalization and Friedlander synthesis reactions can be recycled and reused five times without significant decrease in activity.     

Simultaneous quantification of analytes in quaternary mixtures using dual pulse staircase voltammetry and genetically optimised neural networks

This paper describes the simultaneous quantification of four aliphatic compounds (ethanol, methanol, fructose and glucose) mixed in varying concentrations. The method used employs dual pulse staircase voltammetry (DPSV) to acquire an electrochemical voltammogram from the mixture. An artificial neural network, optimised using an elitist genetic algorithm, is then used to determine the concentration of each individual analyte from the voltammogram. The best average RMS errors achieved when testing with unseen data were 5.03%, 7.72%, 3.29% and 4.00% for maximum analyte concentrations of ethanol, methanol, fructose and glucose respectively. This work represents an important step forward because DPSV data is notoriously difficult to calibrate due to complex electrode-analyte interactions, and had not previous been shown to be amenable to quaternary mixtures.     

Production of slow singly charged fragments in 200 GeV/c hadron nucleus interactions

Measurements of slow, singly charged fragments in the target rapidity region have been performed for proton and pion induced reactions with various nuclei at 200 GeV/c. Multiplicity, angular and energy distributions are examined and used to study the effects of rescattering in the nuclear medium. Data are compared to a geometric cascade model and to simulations with the VENUS 3.11 and the FRITIOF 1.7 Monte Carlo codes.     

EGFRisopred: a machine learning-based classification model for identifying isoform-specific inhibitors against EGFR and HER2

The EGFR kinase pathway is one of the most frequently activated signaling pathways in human cancers. EGFR and HER2 are the two significant members of this pathway, which are attractive drug targets of clinical relevance in lung and breast cancer. Therefore, identifying EGFR- and HER2-specific inhibitors is one of the important challenges in cancer drug discovery. To address this issue, a dataset of 519 compounds having inhibitory activity against both the isoforms, i.e., EGFR and HER2, was collected from the literature and developed a knowledge-based computational classification model for predicting the specificity of a molecule for an isoform (EGFR/HER2) with precision. A total of seventy-two classification models using nine fingerprint types, four classifiers (IBK, NB, SMO and RF) and two different datasets (EGFR and HER2 isoform specific) were developed. It was observed that the models developed using random forest and IBK performed better for EGFR- and HER2-specific datasets, respectively. Scaffold and functional group analysis led to the identification of prevalent core and fragments in each of the datasets. The accuracy of the selected best performing models was also evaluated using the decoy dataset. We have also developed an application EGFRisopred, which integrates the best performing models and permits the user to predict the specificity of a compound as an EGFR-/HER2-specific anticancer agent. It is expected that the tool’s availability as a free utility will allow researchers to identify new inhibitors against these targets important in cancer.

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Peroxidase enzyme sensor for on-line monitoring of disinfection processes in the food industry.

For desirable environmental reasons, peroxides have replaced halogenated substances for disinfection purposes in the food and beverage industry. However, cost issues and the requirement to remove these agents completely after disinfection necessitate simple, low-cost and sensitive test methods with a wide dynamic range and on-line capability. The development and performance of such a method is detailed here. Low-cost peroxide sensors were fabricated using a single deposition procedure, in which horseradish peroxidase enzyme and dimethylferrocene mediator were entrapped within a cellulose acetate membrane, over the working electrode area of a screen-printed three-electrode assembly. Optimum performance was obtained using HRP and DMFc loadings of 25 U and 0.03 micromol per electrode, respectively, and a mean cellulose acetate molecular weight of 37,000. The device had a detection limit of 49.5 microM hydrogen peroxide and mean RSD values of 21% across the concentration range 49.5-368 microM. In laboratory studies the sensor was shown to have a stability of > or = 4 d in continuous flow-mode maintaining an accuracy of +/- 16% that was considered acceptable for the intended on-line monitoring of the disinfection process. In a field study, it was successfully used on-line within a flow-cell to measure peroxide levels during disinfection of an industrial fermentation vessel.     

Sustainable feasibility of waste printer ink to magnetically separable iron oxide–doped nanocarbons for styrene oxidation

A simpler cost-effective method for the isolation of magnetically separable ‘self-doped iron oxide nanocarbons’ (FeO-NC) from waste printer ink (used as a carbon source material which is available free of cost) is discussed here. The process involves carbonization of waste printer ink in a muffle furnace at ~600 °C to obtain FeO-NC. The as-prepared FeO-NC has been investigated as an efficient heterogeneous catalyst for the long-known important organic reaction involving transformation of styrene to benzaldehyde in a quantitative yield (~70%). Importantly, FeO-NC were magnetically separable along with good recyclability, which supports the sustainability of reported process.     

New Strategy for the Oxidation of Hantzsch 1,4‐Dihydropyridines and Dihydropyrido[2,3‐d]pyrimidines Catalyzed by DMSO under Aerobic Conditions

A novel metal‐salt‐oxidant‐free, efficient, and economical method for the oxidation of Hantzsch 1,4‐dihydropyridines that uses aerial oxygen and solvent‐grade dimethylsulfoxide is described. Also, the synthesis of pyrido[2,3‐d]pyrimidines is achieved from in situ oxidation of dihydropyrido[2,3‐d]pyrimidines that arise from the reaction of 6‐aminouracils and cyano olefins in dimethylsulfoxide.