Effect of additives on the structure and electrochemical performance of mesoporous nickel hydroxide

Nickel hydroxide mesoporous structures are synthesized by a simple method in the presence of different additives (oxalic acid, aminoacetic acid, and sulfosalicylic acid). Structural characterizations reveal that the additives can affect the crystal structure, increase the specific surface area, and reduce the pore size of the products. The electrochemical properties of the synthesized Ni(OH)₂ samples are dependent on their crystal phase, surface area, and pore size distribution. Mesoporous β-Ni(OH)₂ with poor crystallinity shows high specific capacitances at different current densities and excellent cycling ability. A highest specific capacitance of 1,693 F?g^?1 can be achieved at a scan rate of 5 mV?s^?1. The results suggest its potential application in electrochemical supercapacitors.     

Diethyl phenylphosphonite contributing to solid electrolyte interphase and cathode electrolyte interphase for lithium metal batteries

Lithium metal batteries have obtained increasing interest due to their high specific capacity.Nonetheless,the growth of lithium dendrites brings safety risks to...     

Substrate-controlled and highly stereoselective synthesis of 2-aminobut-2-ene-1, 4-diones

2-Methylthio-substituted 1,4-enediones, obtained from readily available aryl methyl ketones, were reacted with primary or secondary amines to afford the desired 1,4-diaryl-2-aminobut-2-ene-1,4-diones in excellent yields with high Z/E-stereoselectivity.     

Highly efficient oxidation of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives by dioxygen

A highly efficient and environmental-benign oxidation by dioxygen (or air) as the sole oxidant was first applied for the conversion of 2-imidazoline-5-carboxylic derivatives to imidazole-5-carboxylic derivatives in very good and excellent yields. The substituent effect on 2-imidazoline ring was investigated. This protocol was also suitable for the synthesis of 2-imidazoles in relatively large scale.     

UPLC-ELSD Determination of 1-Octacosanol in Raw Material and Health Products

Determination of the levels of 1-octacosanol is important in food stuff for the study of its pharmacological activities and health benefits. In this study, a novel, simple and fast internal standard method for the non-derivatization ultra-performance liquid chromatographic determination of 1-octacosanol in raw materials and health products was developed and validated based on evaporative light scattering detection. The linearity (r ² > 0.998), recovery (99.1–100.2%, RSD <2.7%), intra- and inter-day precision (RSD <3.8%), limit of detection (1.0 mg/L), limit of quantification (2.2 mg/L) of the 1-octacosanol were determined. The method was successfully applied to nine real 1-octacosanol products. The results of analyses had close agreement with the labeled claims of 1-octacosanol content in these products. Compared with the classical gas chromatography method, the developed method was simpler, faster and more environmentally friendly due to avoiding any derivatization step. This protocol represents a rapid and feasible method for quality control of 1-octacosanol products.

     

Sortase-Mediated Transpeptidation for Site-Specific Modification of Peptides, Glycopeptides, and Proteins

Sortases are a family of transpeptidases found in Gram-positive bacteria responsible for covalent anchoring of cell surface proteins to bacterial cell walls. It has been discovered that sortase A (SrtA) of Staphylococcus aureus origin is rather promiscuous and can accept various molecules as substrates. As a result, SrtA has been widely used to ligate peptides and proteins with a variety of nucleophiles, and the ligation products are useful for research in chemical biology, proteomics, biomedicine, etc. This review summarizes the recent applications of SrtA with special emphasis on SrtA-catalyzed ligation of carbohydrates with peptides and proteins.