Graphane Nanostripes

Graphane, the hydrogenated counterpart of graphene, was shown to exhibit properties such as tunable band gaps through varied degrees of hydrogenation, fluorescence, or ferromagnetism. Graphane nanostripe properties have also been theoretically predicted. Herein, we show that graphane nanostripes can be prepared by opening carbon nanotubes using Birch reduction in liquid ammonia utilizing potassium as a reducing agent and water as a proton donor. The prepared graphane nanostripes exhibit several exceptional properties when coupled with trace metal dopants. The interplay of metallic nanoparticles and defects lead to a spin polarization and induction of ferromagnetic moment, as well as to enhanced electrocatalytic properties in the hydrogen evolution reaction when compared to non‐hydrogenated carbon nanotubes.     

Amino Acid Functionalized Superparamagnetic Nanoparticles Inhibit Lysozyme Amyloid Fibrillization

Nanoparticles have great potential to be used in various biomedical applications, including therapy or diagnosis of amyloid-related diseases. The physical and chemical properties of iron oxide superparamagnetic nanoparticles (MNPs) functionalized with different amino acids (AAs), namely, with lysine (Lys), glycine (Gly), or tryptophan (Trp), have been characterized. The cytotoxicity of nanoparticles and their effect on amyloid fibrillization of lysozymes in vitro was also verified. The AA-MNPs under study are nontoxic to human SHSY5Y neuroblastoma cells. Moreover, the AA-MNPs were able to significantly inhibit lysozyme amyloid fibrillization and destroy amyloid fibrils. Kinetic studies revealed that the presence of AA-MNPs affected lysozyme fibrillization, namely, the lag phase and steady-state phase of the growth curves. The most effective activities were observed for Trp-MNPs, which revealed the importance of aromatic rings in the structure of AAs used as coating agents. The obtained results indicate the possible application of these AA-MNPs in the treatment of amyloid diseases associated with lysozyme or other amyloidogenic proteins.     

Stereoselective arylthiolation of dehydroalanine in the NiII coordination environment: the stereoinductor of choice

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Early introduction of the amino group to the C27–C35 building block of Eribulin

A new synthetic strategy towards the C27–C35 subunit of Eribulin (1) has been devised to include a protected 1,2-amino alcohol at C34–C35. Early introduction of the C35 amino group in the synthesis of 1 increases the efficiency of the route. This new approach can be accomplished on a multi-gram scale and allows for the successful synthesis of Eribulin.     

SPE and purification of DNA using magnetic particles

Superparamagnetic particles have been attractive for molecular diagnostics and analytical chemistry applications due to their unique magnetic properties and their ability to interact with various biomolecules of interest. This paper presents a critical overview of magnetic nano ‐ and microparticles used as a solid phase for extraction and purification of DNAs. The mechanisms of DNA binding to the surface of functionalised magnetic particles are described. The most widely used materials including silica supports, organic polymers and other materials, mostly containing magnetite or paramagnetic metallic elements are reviewed. The main application areas of magnetic particles for DNA separation are briefly described.     

Identification of regioisomers and enantiomers of triacylglycerols in different yeasts using reversed‐ and chiral‐phase LC–MS

LC with atmospheric pressure chemical ionization (ACPI) MS with RP and chiral phase was used for separation of triacylglycerols (TAGs) from yeasts of the genera Candida, Kluyveromyces, Rhodotorula, Saccharomyces, Torulospora, Trichosporon, and Yarrowia. Chiral LC–APCI‐MS is based on using two columns in series packed with a 3,5‐dimethylphenyl carbamate modified β‐cyclodextrin chiral phase. All regioisomers and enantiomers of TAGs containing one to five double bonds were separated. Molecular species of TAGs, i.e. regioisomers and enantiomers, were identified and quantified by MS/MS. Among the 94 identified TAGs, the most abundant were triolein, oleopalmitoleoolein, and dipalmitoleoolein. In strains producing palmitoleic acid in amounts >25% of total fatty acids (FAs), this acid, or unsaturated FA is bound in sn‐1. In strains containing palmitoleic acid at 10–25% total FAs this acid is mainly bound in sn‐3, saturated FA being bound in sn‐1. Strains containing <10% palmitoleic acid form preferentially symmetrical TAGs.     

Effects of alcohols on fluorescence intensity and color of a discharged-obelin-based biomarker

Photoproteins are responsible for bioluminescence of marine coelenterates; bioluminescent and fluorescent biomarkers based on photoproteins are useful for monitoring of calcium-dependent processes in medical investigations. Here, we present the analysis of intensity and color of light-induced fluorescence of Ca²⁺-discharged photoprotein obelin in the presence of alcohols (ethanol and glycerol). Complex obelin spectra obtained at different concentrations of the alcohols at 350- and 280-nm excitation (corresponding to polypeptide-bound coelenteramide and tryptophan absorption regions) were deconvoluted into Gaussian components; fluorescent intensity and contributions of the components to experimental spectra were analyzed. Five Gaussian components were found in different spectral regions—ultraviolet (tryptophan emission), blue-green (coelenteramide emission), and red (hypothetical indole-coelenteramide exciplex emission). Inhibition coefficients and contributions of the components to experimental fluorescent spectra showed that presence of alcohols increased contributions of ultraviolet, violet, and red components, but decreased contributions of components in the blue-green region. The effects were related to (1) changes of proton transfer efficiency in fluorescent S*₁ state of coelenteramide in the obelin active center and (2) formation of indole-coelenteramide exciplex at 280-nm photoexcitation. The data show that variation of fluorescence color and intensity in the presence of alcohols and dependence of emission spectra on excitation wavelength should be considered while applying the discharged obelin as a fluorescence biomarker.     

Kinetics of the total hydrolysis of acetyl-β-methylcholine by acetylcholinesterase

Mechanism and kinetics of in vitro hydrolysis of acetyl-β-methylcholine by acetylcholinesterase from electric eel in a mixed batch reactor at 25 and 37°C, pH 8, ionic strength 0.11 M and catalytic activity of the enzyme preparat of 3.5 U mL⁻¹ were studied. The optimal kinetic parameters were determined.