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A fluorescent probe for phenylhydrazine detection was developed with aldehyde as the recognition group and good selectivity towards phenylhydrazine over hydrazine, hydroxylamine and other amines was observed. Its application in real water samples and fast visualization of phenylhydrazine using a probe-loaded paper strip were demonstrated. [ABSTRACT FROM AUTHOR]

Poria cocos polysaccharides (PCPs) are of high research value because of their important biological functions. However, the ways to extract a PCP are limited and its yield is relatively low in current reports. In this study, a new ternary deep eutectic solvent (DES) composed of choline chloride, 1,3-butanediol and D -sorbitol was used to efficiently extract bioactive polysaccharides from poria cocos assisted by the new tool of far infrared radiation (FIR) together with hot air circulation (HAC). The yield of a polysaccharide (PCP-DL) obtained by this new method was 55.02 ± 0.87% under the optimized conditions of sieving mesh (300 mesh), liquid–solid ratio (30 mL g−1), intensity of FIR (300 W m−2), and circulated air temperature (80 °C). Meanwhile, the extraction mechanism of PCP-DL was investigated by comprehensive characterization studies and extraction kinetics. The recovered DES still retained its performance after recycling five times by dialysis. A laboratory-scale life cycle assessment (LCA) was applied to analyze the potential environmental profiles and the results showed that this new extraction process possessed environmental impact reductions of 93.61% waste solids and 69.72% fossil fuel depletion potential in contrast to the traditional method. Furthermore, chromatographic and spectral analyses were used to analyze the product and confirm the presence of α-,β-pyranose, as well as five kinds of glycosidic linkages, in target polysaccharides with a molecular weight (Mw) of 2.05 × 104 Da. Scanning electron microscopy (SEM) revealed that it was an amorphous aggregate with an irregular spherical shape and loose porous surface. Finally, the product exhibited a similar inhibitory activity to that of donepezil against acetylcholinesterase (AChE, 73.82 ± 0.60%) and butyrylcholinesterase (BChE, 63.85 ± 0.54%) at 500 μg mL−1 as a mixed-type competitive inhibitor for these enzymes. The interaction sites between AChE and the fragment of PCP-DL were simulated by molecular docking, which provided a theoretical basis for the above inhibition assays. [ABSTRACT FROM AUTHOR]

Hydrazine is a well-known genotoxic impurity which may be present in some important drugs, such as isoniazid and hydralazine. It may be ingested along with the drug or generated as a metabolite in the human body. Hence, monitoring the level of hydrazine in the human body is of great importance. A hemicyanine-based NIR fluorescent probe, Hcy-DB, was designed and synthesized for hydrazine detection. This probe exhibited a dramatic off–on NIR fluorescence response toward hydrazine in PBS–DMSO buffer and the detection limit was calculated to be 4.38 ppb. The bioimaging of hydrazine in living H1975 cells was successfully demonstrated. Moreover, the real time imaging of hydrazine, either injected as a foreign agent or generated as a metabolite of isoniazid, was demonstrated in mice and the results clearly disclosed the hydrazine level variation in the liver and kidneys. The injected exogenous hydrazine was mainly distributed in the kidneys and then excreted slowly. After the intragastric administration of isoniazid, hydrazine was quickly generated as a metabolite in the liver and reached a maximum in about 20 min, and then it was excreted slowly through the kidneys. Generally, the investigation provided a promising tool to monitor the level of hydrazine in vivo and thus help to evaluate and control its toxicity more rationally. [ABSTRACT FROM AUTHOR]

For the first time, a new magnetic separation strategy for alkaloids from Coptis chinensis was developed in this study. For basic research, physical properties including thermal properties, solubility and magnetic properties of six Fe-containing magnetic compounds based on isoquinoline alkaloids (including isoquinoline, berberine, palmatine, tetrahydropalmatine, tetrahydropapaverine and berbamine) were characterized firstly, which showed good thermal stability (Tstart > 190 °C) and expected magnetic susceptibility (>1.35 × 10−5 emu g−1). The Gouy method measurement results were in agreement with the order determined using a vibrating sample magnetometer. Then the new integrated method of extraction–derivatization–magnetic separation was successfully applied for the target isoquinoline compounds from Coptis chinensis for the first time on the basis of the above studies, and the recovery of various samples was in the range of 96.85–101.4%. As the key operation in the whole process, derivatization/magnetization not only makes these alkaloids exhibit a good magnetic response in various states but also provides a new strategy of magnetic separation after their extraction. As a result, the effects of different extraction and derivatization conditions were investigated for target compounds from Coptis chinensis in detail. [ABSTRACT FROM AUTHOR]

A hemicyanine-based fluorescent probe, Hcy-Ac, was developed for the specific detection of hydrazine. With good water solubility and high sensitivity, Hcy-Ac has been successfully applied for the monitoring of in situ hydrazine release during the metabolism of isoniazid in mice. [ABSTRACT FROM AUTHOR]

Li-rich layered oxides hold great promise for improving the energy density of present-day Li-ion batteries. Their application is, however, limited by the voltage decay upon cycling, and the origin of such a phenomenon is poorly understood. A major issue is determining the voltage range over which detrimental reactions originate. In the present study, a unique yet effective approach was employed to probe this issue. Instead of studying the materials during the first cycle, electrochemical behavior and evolution of the atomic structures were compared in extensively cycled specimens under varied charge/discharge voltages. With the upper cutoff voltage lowered from 4.8 to 4.4 V, the voltage decay ceased to occur even after 60 cycles. In the meantime, the material maintained its layered structure without any spinel phase emerging at the surface, which is unambiguously shown by the atomic-resolution Z-contrast imaging and electron energy loss spectroscopy. These results have conclusively demonstrated that structural/chemical changes responsible for the voltage decay began between 4.4 and 4.8 V, where the layered-to-spinel transition was the most dramatic structural change observed. This discovery lays important groundwork for the mechanistic understanding of the voltage decay in Li-rich layered cathode materials. [ABSTRACT FROM AUTHOR]

A modular and convenient synthesis of ethynyl end functionalized poly(3-hexylthiophene) in high purity is reported; this material facilitated access to poly(3-hexylthiophene)-block-poly(acrylic acid) which self-assembled into hierarchical structures. [ABSTRACT FROM AUTHOR]

A modular and convenient synthesis of ethynyl end functionalized poly(3-hexylthiophene) in high purity is reported; this material facilitated access to poly(3-hexylthiophene)-block-poly(acrylic acid) which self-assembled into hierarchical structures.

Amphiphilic polymer nanoparticles loaded with silver cations or/and N-heterocyclic carbene-silver complexes were assessed as antimicrobial agents against Gram-negative pathogens Escherichia coli and Pseudomonas aeruginosa.