Sodium Bismuthate Mediated Oxidation of Allylic and Benzylic Alcohols

A simple and readily available oxidation of primary allylic and benzylic alcohols to the corresponding aldehydes is carried out by sodium bismuthate in acetic acid.     

Method development for simultaneous analysis of HBCD,TBBPA, and dimethyl-TBBPA in marine biota from Greenland and the Faroe Islands

The brominated flame retardants hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are high-production-volume chemicals. In recent years, their presence has been reported in sediment and biota from the marine environment. In this study, an analytical method was developed for the simultaneous determination of HBCD, TBBPA, and the possible metabolite dimethyl-TBBPA. The method was applied in a preliminary screening of egg, liver, and adipose tissue of marine biota from Greenland and the Faroe Islands. α-HBCD was detected in 35 of 36 analysed samples from the Arctic, indicating a ubiquitous presence of α-HBCD in the environment. β- and γ-HBCD were found in 10 and 14 samples, respectively. TBBPA and dimethyl-TBBPA were not detected in any of the samples indicating limited or no transport of these compounds to remote areas.     

Nanoparticles from conventional cellulose esters: evaluation of preparation methods

Nano-scaled particles were obtained from two different cellulose acetates, cellulose acetate propionate, and cellulose acetate butyrate using the emulsification solvent evaporation procedure and the low energy methods of solvent displacement (dialysis and controlled precipitation). The relationship between the formulation parameters and the particle properties were evaluated in case of the emulsification-evaporation technique. For the solvent displacement procedures, the influence of the formulation parameters, and the intrinsic polymer properties like the hydrophilic-hydrophobic balance was evaluated. Comparing the methods, it could be shown that large amounts of small and uniform nanoparticles can be obtained by the emulsification solvent evaporation procedure. The solvent displacement techniques turned out to be very easy to use and to yield narrowly distributed particles as well.     

Polymer Chain Conformation on Deuterated Polystyrene Nanoparticles Investigated by SANS

We previously reported that grafted polystyrene (PS) chains on silica nanoparticles at a low grafting density show similar conformations to free PS chains in the same solvent, THF (diameter ?50 nm, Colloid.poly.Sci. (2013), 291, 9, 2087–2099). As an extension of our previous study we choose an organic nanoparticle (deuterated polystyrene, dPS) instead of inorganic nanoparticle to see the impact of the substrate material on chain conformation. Additionally, a wider range of molecular weights were prepared to investigate the conformation feature of grafted PS chains more in detail. Small angle neutron scattering (SANS) experiments were performed to characterize PS grafted dPS particles in good solvent condition, with deuterated toluene and deuterated THF as solvent. To get insight into the conformation of the grafted PS layer we apply a scaling law describing the dimension of free PS polymer in good solvent condition to the obtained thickness of the grafted PS layer. We find an overall agreement with the scaling law where the thickness of the grafted PS layer is slightly larger than 2R_g of the free polymer chains in the respective solvent giving hint for semi dilute polymer brush (SDPB) situation.     

Size does matter! Label-free detection of small molecule–protein interaction

This review is focused on methods for detecting small molecules and, in particular, the characterisation of their interaction with natural proteins (e.g. receptors, ion channels). Because there are intrinsic advantages to using label-free methods over labelled methods (e.g. fluorescence, radioactivity), this review only covers label-free techniques. We briefly discuss available techniques and their advantages and disadvantages, especially as related to investigating the interaction between small molecules and proteins. The reviewed techniques include well-known and widely used standard analytical methods (e.g. HPLC-MS, NMR, calorimetry, and X-ray diffraction), newer and more specialised analytical methods (e.g. biosensors), biological systems (e.g. cell lines and animal models), and in-silico approaches.     

Clickable report tags for identification of modified peptides by mass spectrometry

The identification and quantification of modified peptides are critical for the functional characterization of post-translational protein modifications (PTMs) to elucidate their biological function. Nowadays, quantitative mass spectrometry coupled with various bioinformatic pipelines has been successfully used for the determination of a wide range of PTMs. However, direct characterization of low abundant protein PTMs in bottom-up proteomic workflow remains challenging. Here, we present the synthesis and evaluation of tandem mass spectrometry tags (TMT) which are introduced via click-chemistry into peptides bearing alkyne handles. The fragmentation properties of the two mass tags were validated and used for screening in a model system and analysis of AMPylated proteins. The presented tags provide a valuable tool for diagnostic peak generation to increase confidence in the identification of modified peptides and potentially for direct peptide-PTM quantification from various experimental conditions.     

Microwave-Assisted One-Pot Lipid Extraction and Glycolipid Production from Oleaginous Yeast Saitozyma podzolica in Sugar Alcohol-Based Media

Glycolipids are non-ionic surfactants occurring in numerous products of daily life. Due to their surface-activity, emulsifying properties, and foaming abilities, they can be applied in food, cosmetics, and pharmaceuticals. Enzymatic synthesis of glycolipids based on carbohydrates and free fatty acids or esters is often catalyzed using certain acyltransferases in reaction media of low water activity, e.g., organic solvents or notably Deep Eutectic Systems (DESs). Existing reports describing integrated processes for glycolipid production from renewables use many reaction steps, therefore this study aims at simplifying the procedure. By using microwave dielectric heating, DESs preparation was first accelerated considerably. A comparative study revealed a preparation time on average 16-fold faster than the conventional heating method in an incubator. Furthermore, lipids from robust oleaginous yeast biomass were successfully extracted up to 70% without using the pre-treatment method for cell disruption, limiting logically the energy input necessary for such process. Acidified DESs consisting of either xylitol or sorbitol and choline chloride mediated the one-pot process, allowing subsequent conversion of the lipids into mono-acylated palmitate, oleate, linoleate, and stearate sugar alcohol esters. Thus, we show strong evidence that addition of immobilized Candida antarctica Lipase B (Novozym 435^®), in acidified DES mixture, enables a simplified and fast glycolipid synthesis using directly oleaginous yeast biomass.     

AgNP-decorated SBA-15 for MWCNT Paste Modified Electrode: A Sensor for Simultaneous Voltammetric Determination of Paracetamol and Sulfamethoxazole

A new electrochemical sensor based on a carbon nanotube paste electrode modified with a Santa Barbara Amorphous material (SBA-15) decorated with silver nanoparticles, namely CNT/SBA/Ag-PE, was developed. It was successfully applied for individual and simultaneous determination of both paracetamol (PC) and sulfamethoxazole (SMZ) medicines. The electrode exhibited a linear dynamic range of 0.12–110 μmol L⁻¹ for paracetamol and 0.06–70 μmol L⁻¹ for sulfamethoxazole, and detection limits of 38 and 19 nmol L⁻¹, respectively. The proposed sensor offered high sensitivity, fast response time and the potential for detecting both drugs simultaneously. The CNT/SBA/Ag-PE enabled the simultaneous determination of PC and SMZ in urine samples with high recovery rates.