Eu-functionalized covalent organic framework for ratiometric fluorescence detection and adsorption of tetracycline and information steganography.

Functional materials with organic/inorganic composites as the main matrix and rare earth ion complexes as the guest have shown a very broad application prospect for antibiotic sensors. However, Eu-complex often relies on a single fluorescence response signal, which is susceptible to changes in the detection environment and cannot simultaneously detect and remove tetracycline (TC). Herein, green fluorescent covalent two-dimensional organic framework (COF-TD) is synthesized, followed by modification of Eu to synthesize COF-TD@Eu.

Integrated Eu loaded covalent organic framework with smartphone for ratiometric fluorescence detection of tetracycline.

Developing rapid tetracycline sensing system is of great significance to monitor the illegal addition to drugs and pollution to food and ecosystem. By loading covalent organic frameworks (COFs) with Eu, a new hybridized material (COF@Eu) was prepared for tetracycline determination. Based on the Schiff base reaction, the COFs were by synthesized through solvent evaporation in 30 min at room temperature.

Ratiometric optical detection of pyrophosphate based on aggregation-caused dual-signal response of gold nanoclusters.

Sensing of pyrophosphate ion (PPi) has received much attention due to the strong demand for clinical diagnostics. Here, based on gold nanoclusters (Au NCs), a ratiometric optical detection method for PPi is developed by simultaneously detecting the dual signals of fluorescence (FL) and second-order scattering (SOS). The PPi is detected by inhibiting the formation of aggregates of Fe with Au NCs.

Exploring the Inhibition of Quercetin on Acetylcholinesterase by Multispectroscopic and In Silico Approaches and Evaluation of Its Neuroprotective Effects on PC12 Cells.

This study investigated the inhibitory mechanism of quercetin in acetylcholinesterase (AChE) and its neuroprotective effects on β-amyloid-induced oxidative stress injury in PC12 cells. Quercetin inhibited AChE in a reversible mixed manner with an IC of 4.59 ± 0.

Chemiluminescent detection of platelet derived growth factor-BB based on sandwich label-free aptasensor and biotin-streptavidin strategy.

We reported an aptamer-based sandwich-type biosensor to detect the platelet derived growth factor-BB (PDGF-BB) by chemiluminescence (CL). Employing magnetic beads as a peculiar immobilizing carriers, a sandwich-type biosensor for detection of PDGF-BB had developed. Firstly, Anti-PDGF-BB was immobilized on the surface of magnetic beads to serve as capture antibody.

Utilizing dual carriers assisted by enzyme digestion chemiluminescence signal enhancement strategy simultaneously detect tumor markers CEA and AFP.

To measure two tumor biomarkers, alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), a dual-carrier CL sensor with restriction enzyme digestion (Exo I) and aptamer technology utilizing gold nanoparticles (hydroxylamine amplification) and horseradish peroxidase (HRP) as the CL signal enhancement in the sensing strategy was formed. These nanoparticles and nano-enzyme were precisely detected and tagged to the appropriate position attributable to the particular recognition of biotin and streptavidin. In this sensing strategy, target markers were further enriched and recognized sensitively by CL following enrichment, and matching strong chemical signals were collected under luminol catalysis, allowing for marker identification.

Antipyretic Mechanism Exploration of HuanglianShangqing Pill Based on Metabolomics and Network Pharmacology.

Background And Objective: HuanglianShangqing pill (HLSQ), a well-known traditional Chinese medicine (TCM), has been used to treat fever in China for a long time. Our previous study had demonstrated that a total of 45 prototype components of HLSQ could be absorbed into the plasma of rats after intragastric administration. However, the detailed mechanisms related to the antipyretic effects of HLSQ were still unclear.

Synthesis and biological evaluation of aminobenzamides containing purine moiety as class I histone deacetylases inhibitors.

The aminobenzamide is selective to class I histone deacetylases (HDACs) and displays unique tight-binding/slow-off HDAC-binding mechanism. Herein, we report a series of 9-substituted purine aminobenzamides that selectively inhibit class I HDACs. The activities in vitro showed compound 9d exhibited 12 folds more potent than MS-275 against HDAC1 isoform and showed excellent inhibitory activity on cancer cells, including HCT-116, MDA-MB-231, K562 cell lines.

Smartphone assisted colorimetric and fluorescent triple-channel signal sensor for ascorbic acid assay based on oxidase-like CoOOH nanoflakes.

Ascorbic acid (AA) is an important diet-derived antioxidant to human body. Thus, efficient and accurate detection of AA is of considerable significance in food analysis. Herein, smartphone assisted colorimetric and fluorescent triple-channel signal sensor has been developed for AA monitoring based on oxidase-like CoOOH nanoflakes.

Resonance Rayleigh Scattering as a Tool for Isoelectric Point Monitoring and Iron(III) Cation Determination.

A resonance Rayleigh scattering (RRS) technique was utilized as a tool for isoelectric point monitoring and iron(III) cation determination. The spectral properties of some amphoteric molecules (proteins and a DNA sequence) were investigated using the RRS technique. When the pH values were kept at around their isoelectric points, especially high RRS signals could be obtained, which were much stronger than those at other pH values.

Use of UHPLC-QTOF-MS/MS with combination of in silico approach for distributions and metabolites profile of flavonoids after oral administration of Niuhuang Shangqing tablets in rats.

Niuhuang Shangqing tablet (NHSQT), a well-known traditional Chinese medicine preparation, has been used as an over- the- counter drug for the treatment of headache, dizziness in China. The flavonoids are the main active components in NHSQT, however, there have no reports about their distribution and metabolic fate in vivo after oral administration of NHSQTs so far. An novel UHPLC-QTOF-MS/MS method combined with in silico approach was applied to identify the flavonoids and metabolites profiling in biological samples following oral administration NHSQTs for the first time.

Syntheses and Biological Evaluation of Novel Hydroxamic Acid Derivatives Containing Purine Moiety as Histone Deacetylase Inhibitors.

The novel hydroxamates containing purine scaffold were designed, synthesized and screened for their biological activities as histone deacetylase (HDAC) inhibitors. Some of them exhibited excellent acti-HDACs activities and antiproliferative activities, the most promising compound was 7m'. Western blot analysis indicated the compounds 7f', 7l', 7m', 7o' could increase histone H3 acetylation levels in HCT116 and K562 cell lines, and 7m' increased the level of acetyl histone H3 in a dose-dependent manner, which is similar to the behavior of suberoylanilide hydroxamic acid (SAHA).

Identification of the constituents and metabolites in rat plasma after oral administration of HuanglianShangqing pills by ultra high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

An ultra high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry method was established to detect and identify the chemical constituents and metabolites of HuanglianShangqing pill (HLSQ) in vitro and in vivo. A total of 96 compounds were characterized in HLSQ extracts. In vivo, 45 prototype components and 53 metabolites of HLSQ were detected in rat plasma and tentatively identified, three of which are new.

[Study on HPLC Fingerprint of Kanggongyan Series].

Objective: To establish analysis methods for fingerprint of Kanggongyan series by HPLC.

Methods: A Shiseido CAP-CELL PAK C18(250 mm x 4. 6 mm, 3 µm) column was used with acetonitrile-0.

Synthesis, Anticancer Evaluation and Docking Study of 3- Benzyloxyhydantoin Derivatives.

A series of 3-benzyloxyhydantoin derivatives were designed and synthesized by introducing hydroxyurea pharmacophore into hydantoin rigid scaffold. The cytotoxic activities of the target compounds were evaluated in vitro against three cancer cell lines. Compounds 5b, 5c, 5e, 5g, 6c and 6g displayed high activity on all of the three cancer cell lines and the most promising compounds were 5g, 6g with IC50 values of 0.

Synthesis and anticancer evaluation of benzyloxyurea derivatives.

A series of novel benzyloxyurea derivatives was designed, synthesized by substituting different benzyls or phenyls on N,N'-positions of the hydroxyurea (HU). These target compounds were evaluated for their anticancer activity in vitro against human leukemia cell line K562 and murine leukemia cell line L1210 in comparison with HU by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Some of the compounds showed promising anticancer activity against the cells.

[Chemical constituents of the roots of Vaccinium bracteatum].

Objective: To study the chemical constituents of the roots of Vaccinium bracteatum.

Methods: The constituents were separated and purified with chromatographic methods (including silica gel, Sephadex LH-20 and RP-18 column chromatography), and their structures were determined by spectroscopic methods (including MS, 1H-NMR and 13C-NMR).

Results: 10 compounds were isolated from the roots of Vaccinium bracteatu and were elucidated as chlorogenic acid (1), pinoresinol (2), ferulic acid (3), kaempferol (4), trans-caffeic acid (5), beta-sitosterol (6), quercetin (7), oleanolic acid (8), apigenin (9) and luteolin (10).

[FTIR fingerprints-chemical pattern recognition research of three kinds of Chimonanthus and fried samples].

Objective: To classify the leaves of Chimonanthus nitens, Chimonanthus Salicifolius, Chimonanthus zhejiang and their fried samples, Discriminating equation was established to distinguish categories of raw materials.

Methods: The spectra of three kinds of Chimonanthus and fried samples were determined by FTIR. Principal component analysis, clustering analysis and discriminative analysis were applied to classify three kinds of Chimonanthus leaves and fried samples from different areas according to the relative absorbance of common peaks between 400 to 4000 cm(-1).

[Analysis of the chemical constituents of essential oil from Chimonanthus zhejiangensis by GC-MS].

Objective: To analyze the chemical constituents of the essential oil from Chimonanthus zhejiangensis.

Methods: Steam distillation was employed to extract volatile compounds of essential oil from Chimonanthus zhejiangensis. Volatile compounds of essential oil were isolated and identified by capillary GC-MS-DS.

Synthesis, antitumor evaluation and crystal structure of hydroxyurea derivatives.

A series of hydroxyurea derivatives have been synthesized and elucidated by means of FT-IR, (1)H-, (13)C-NMR and MS. The exact stereostructures of representative compounds have been determined by X-ray crystal structure analysis. In the crystals, inversion dimers linked by pairs of N-H.

Synthesis of 1,3,4-thiadiazole derivatives as aminopeptidase N inhibitors.

Aminopeptidase N (APN) is a zinc-dependent ectopeptidase which plays an important role in the invasion of metastatic tumors. In this study, we report the synthesis and in vitro enzyme inhibition assay of 1,3,4-thiadiazole scaffold compounds. These new compounds have potent inhibitory activities toward APN with IC50 values in the micromolar range.

1-(2-Fluoro-benz-yl)-1-(2-fluoro-benz-yl-oxy)urea.

In the title hydroxy-urea derivative, C(15)H(14)F(2)N(2)O(2), the dihedral angle between the two benzene rings is 48.64 (19)°. The urea group forms dihedral angles of 48.

1-(3-Chloro-benz-yloxy)urea.

The asymmetric unit of the crystal structure of the title compound, C(8)H(9)ClN(2)O(2), contains four independent mol-ecules. The dihedral angles between the urea N-(C=O)-N planes and the benzene rings are 83.3 (3), 87.