Thermal Expansion Properties and Mechanochemical Synthesis of Stoichiometric Cocrystals Containing Tetrabromobenzene as a Hydrogen- and Halogen-Bond Donor

The solution and mechanochemical synthesis of two cocrystals that differ in the stoichiometric ratio of the components (stoichiometric cocrystals) is reported. The components in the stoichiometric cocrystals interact through hydrogen or hydrogen/halogen bonds and differ in π-stacking arrangements. The difference in structure and noncovalent interactions affords dramatically different thermal expansion behaviors in the two cocrystals. At certain molar ratios, the cocrystals are obtained concomitantly; however, by varying the ratios, a single stoichiometric cocrystal is achieved using mechanochemistry.     

Toxicology Assessment of a Dual-Function Peptide 5rolGLP-HV in Mice

5rolGLP-HV had an ideal therapeutic potential in the prevention of hyperglycemia in type 2 diabetes and delay of the thrombosis. The objective of the study was to investigate the toxicology effects of 5rolGLP-HV and guarantee its safety. In acute toxicity test, the mice were orally receiving 5rolGLP-HV at a single dose of 300 mg/kg or 2000 mg/kg. For sub-chronic toxicity study, the mice received 5rolGLP-HV at doses of 800 mg/kg or 1600 mg/kg for 9 weeks. No significant adverse effects were evident in acute and sub-chronic toxicity tests, indicating that the LD50 value is greater than 2000 mg/kg. Although the liver and kidney exhibited a little abnormal in sub-chronic toxicity study, they could recovery to normal after withdrawal 5rolGLP-HV for 2 weeks. In micronucleus assay, the mice received 5rolGLP-HV at doses of 250, 500, or 1000 mg/kg for two consecutive days. The micronucleus numbers and the polychromatic erythrocytes to normochromatic erythrocytes (PCE/NCE) ratios among 5rolGLP-HV groups were within the normal range. Similarly, sperm aberration test demonstrated that 5rolGLP-HV had no teratogenic effect on the mice sperm. In conclusion, the combined results clearly demonstrated the safety of 5rolGLP-HV and support its use as a drug to treat diabetes and thrombosis.     

An integrated sample pretreatment platform for quantitative N-glycoproteome analysis with combination of on-line glycopeptide enrichment,deglycosylation and dimethyl labeling

Relative quantification of N-glycoproteomes shows great promise for the discovery of candidate biomarkers and therapeutic targets. The traditional protocol for quantitative analysis of glycoproteomes is usually off-line performed, and suffers from long sample preparation time, and the risk of sample loss or contamination due to manual manipulation. In this study, a novel integrated sample preparation platform for quantitative N-glycoproteome analysis was established, with combination of online N-glycopeptide capture by a HILIC column, sample buffer exchange by a N₂-assisted HILIC–RPLC interface, deglycosylation by a hydrophilic PNGase F immobilized enzymatic reactor (hIMER) and solid dimethyl labeling on a C18 precolumn. To evaluate the performance of such a platform, two equal aliquots of immunoglobulin G (IgG) digests were sequentially pretreated, followed by MALDI-TOF MS analysis. The signal intensity ratio of heavy/light (H/L) labeled deglycosylated peptides with the equal aliquots was 1.00 (RSD = 6.2%, n = 3), much better than those obtained by the offline protocol, with H/L ratio as 0.76 (RSD = 11.6%, n = 3). Additionally, the total on-line sample preparation time was greatly shortened to 160 min, much faster than that of offline approach (24 h). Furthermore, such an integrated pretreatment platform was successfully applied to analyze the two kinds of hepatocarcinoma ascites syngeneic cell lines with high (Hca-F) and low (Hca-P) lymph node metastasis rates. For H/L labeled Hca-P lysates with the equal aliquots, 99.6% of log 2 ratios (H/L) of quantified glycopeptides ranged from −1 to 1, demonstrating high accuracy of the developed sample preparation strategy. By triplicated analysis of glycopeptides and non-glycopeptides of Hca-F and Hca-P lysates, 43 up-regulated and 30 down-regulated (Hca-F/P) N-glycosylation sites, and 11 significantly changed N-glycoproteins were successfully quantified, and most of them were related to tumorigenesis and tumor metastasis. All these results demonstrate the developed integrated N-glycoprotein pretreatment platform is of great power for the accurate, precise and high-throughput analysis of N-glycoproteomes.     

Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes by Chiral Sulfide‐Catalyzed Electrophilic Carbothiolation of Alkynes

The enantioselective construction of axially chiral compounds by electrophilic carbothiolation of alkynes is disclosed for the first time. This enantioselective transformation is enabled by the use of a Ts‐protected bifunctional sulfide catalyst and Ms‐protected ortho‐alkynylaryl amines (Ts=tosyl; Ms=mesyl). Both electrophilic arylthiolating and electrophilic trifluoromethylthiolating reagents are suitable for this reaction. The obtained products of axially chiral vinyl–aryl amino sulfides can be easily converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl–aryl amines, and other valuable difunctionalized compounds.     

Metal ion extraction by cone p-tert-butylcalix[4]arene-1,3-crown-5 with two N-(X)sulfonyl carbamoylmethoxy side arms and -1,3-monothiacrown-5 analogues

Four cone p-tert-butylcalix[4]arene-1,3-monothiacrown-5 ligands each with two N-(X)sulfonyl carbamoylmethoxy side arms are synthesized for comparison with analogs having only oxygen heteroatoms in the crown ether ring. Solvent extractions of hard alkali metal and alkaline earth metal cations, intermediate Pb²⁺, and soft Hg²⁺ from aqueous solutions into chloroform by these ligands are utilized to probe the effects of sulfur replacement in the crown ether ring on metal ion complexation.     

Hierarchical meso–macroporous bioglass for bone tissue engineering

A novel meso–macroporous bioglass has been synthesized based on a sol–gel technique. This method used mushroom stalk as macroporous template and EO₂₀PO₇₀EO₂₀ as the mesoporous template. The final sample has copied the macroporous structure of the plant template, precisely. Ibuprofen was used as the model drug, and the drug loading and release test indicated the loading amount of the sample could reach 33.59 wt% and the releasing amount closed 75 wt% after 48 h. The excellent biomineralization and bioactive are also confirmed in vitro tests. It takes only 4 h to induce the formation of hydroxyapatite. Notably, the biocompatibility assessment confirmed that the obtained materials presented good biocompatibility and the enhanced adherence of HeLa cells. The exquisite mesoporous structure of the sample would be propitious to storage and transport guest molecule, making the hierarchical porous materials have more distinctive performance and application on bone tissue regeneration and drug delivery, etc.     

Combination of dispersive solid‐phase extraction and salting‐out homogeneous liquid–liquid extraction for the determination of organophosphorus pesticides in cereal grains

A new analytical method for the determination of organophosphorus pesticides in cereal samples was developed by combining dispersive SPE (d‐SPE) and salting‐out homogeneous liquid–liquid extraction (SHLLE). The pesticides were first extracted from cereal grains with acetonitrile, followed by d‐SPE cleanup. A 2 mL aliquot of the extract was then added to a centrifuge tube containing 9.2 mL water and 3.3 g NaCl for SHLLE. Analysis of the extract was carried out by gas chromatography coupled with flame photometric detection. The d‐SPE procedure effectively provides the necessary cleanup of the extract while SHLLE is used as an efficient concentration technique. Experimental parameters influencing the extraction efficiency including amounts of added water and salt were investigated. Recovery studies were carried out at three fortification levels, yielding recoveries in the range of 57.7–98.1% with the RSD from 3.7 to 10.9%. The reported limits of determination obtained from this study were 1 μg/kg, which is better than the conventional methods. In the analysis of 40 wheat and corn samples taken from Beijing suburbs, only two wheat samples have chlorpyrifos residue over the limits of determination.     

高分子科学的发展与百年诺贝尔化学奖

在100多年来的诺贝尔化学奖中,有7次颁发给了10位直接或间接对高分子科学发展做出杰出贡献的科学家。通过这7次颁奖,可以看出高分子科学经历了3个发展阶段：确立阶段、完善发展阶段和多向发展阶段。这3个阶段也体现了高分子科学研究领域和研究方法及技术手段的变化发展历程。