纳米图案化高分子凝胶的制备

A new method was proposed to prepare binary composite colloidal crystal hydrogels by interlocking the as-prepared polystyrene/sulfonated polystyrene core/shell colloidal crystal hydrogel with a second responsive gel. The shell thickness thus the core size were synchronously controlled by altering the sulfonation time and temperature. The proper monomers were radically polymerized forming the second gel within the first gel network. The composition and structure were confirmed. Nanopatterued hydrogel including porous bulk hydrogels and surface patterned hydrogels were derived by properly treating the binary composite hydrogels. Specially, some typical patterns such as arrays of “nano-bowls” ,arrays of “nano-ribbons” and “nano-mask” were achieved by changing the treatment method such as by immersion in the solvent, after solvent evaporation from the sample surface during high rate rotation. This work provides a method to prepare nanopatterued hydrogels.     

UPLC–MS/MS simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma and its integrated pharmacokinetic application

A reliable and sensitive UPLC–MS/MS method was first established and validated for the simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma: ginsenoside Rg1, ginsenoside Rb1, osthole, tetrahydropalmatine, paeoniflorin, albiflorin, and ferulic acid. And this method was further applied for the integrated pharmacokinetic study of Yaobitong capsule in rats after oral administration. Plasma samples (100 μL) were precipitated with 300 μL of methanol using carbamazepine as internal standard. Chromatographic separation was achieved using an Aquity UPLC BEH C18 column (100 × 2.1 mm, 1.7 μm), with the mobile phase consisting of 0.1% formic acid and acetonitrile. The method was validated using a good linear relationship (r ≥ 0.991), and the lower limit of quantification of the analytes ranged from 0.5 to 40 ng/mL. In the integrated pharmacokinetic study, the weight coefficient was calculated by the ratio of AUC_0–∞ of each component to the total AUC_0–∞ of the seven active ingredients. The integrated pharmacokinetic parameters C_max, T_max, and t_1/2 were 81.54 ± 9.62 ng/mL, 1.00 ± 0.21 h, and 3.26 ± 1.14 h, respectively. The integration of pharmacokinetic parameters showed a shorter t_1/2 because of fully considering the contribution of the characteristics of each active ingredient to the overall pharmacokinetics.     

Chemical Fingerprint for Identification and Quality Control of Saccharides in Danhong Injection Based on HPLC-ELSD with Chemometrics

Chemical fingerprinting has been widely used for the quality control of complex natural products including traditional Chinese medicines and botanical drugs. However, there is still lack of appropriate method to monitor the batch-to-batch consistency of hydrophilic constituents, such as saccharides and oligosaccharides. In the present study, we developed a novel approach based on high performance liquid chromatography with evaporative light scattering detector(HPLC-ELSD) for establishing saccharide fingerprinting of Danhong Injection(DHI), which is a widely used botanical drug for treating cardiovascular diseases. Major saccharides in DHI were isolated and four compounds including fructose, glucose and two oligosaccharides were identified. The structures of two novel saccharides named glycerol-1-O-galactfpyranosyl-(1→4)-O-arabmofuranoside, and glycerol-1-O-galactpyranosyl-(1→4)[O-arabmfuranosyl-(1→3)]-O-arabinofuranoside were confirmed by NMR, HR-ESI-MS and GC-MS for the first time. The establishment approach was successfully applied to distinguishing 12 batches of DHI from other botanical drugs with the aid of principle component analysis as well as to evaluating batch-to-batch consistency with the help of calculating similarity of tmgerprints. Our findings indicate that the chemical fingerprint of saccharides can be a useful tool for the quality control of complex natural products.     

一种可用于直接检测空气中异氰酸酯的比率型荧光探针

异氰酸酯是一类广泛使用的化工原料，但容易挥发到空气中对人体健康造成危害.因此，建立一种快速、方便检测空气中异氰酸酯的方法具有重要的意义.合成了一种荧光探针（N-正丁基-4-羟基-1，8萘二酰亚胺），能与异氰酸酯快速反应，从而使探针的荧光颜色由黄绿色转变为蓝色，实现对异氰酸酯的比率型荧光检测.同时，该探针对异氰酸酯的响应具有灵敏性和选择性.反应机理研究表明，探针萘环4位上的羟基与异氰酸酯基（-NCO）反应生成了氨基甲酸酯基团.为了直接检测空气中的异氰酸酯，制备了一种基于该探针的检测试纸，实现对空气中异氰酸酯高灵敏性、高选择性的检测.该方法对空气中异氰酸酯的检测具有实际意义，同时也为挥发性有机物的检测提供了参考.     

Programmable Exposure of Pt Active Facets for Efficient Oxygen Reduction

To produce efficient ORR catalysts with low Pt content, PtNi porous films (PFs) with sufficiently exposed Pt active sites were designed by an approach combining electrochemical bottom‐up (electrodeposition) and top‐down (anodization) processes. The dynamic oxygen‐bubble template (DOBT) programmably controlled by a square‐wave potential was used to tune the catalyst morphology and expose Pt active facets in PtNi PFs. Surface‐bounded species, such as hydroxyl (OH^*, *=surface site) on the exposed PtNi PFs surfaces were adjusted by the applied anodic voltage, further affecting the dynamic oxygen (O₂) bubbles adsorption on Pt. As a result, PtNi PF with enriched Pt(111) facets (denoted as Pt_{3.5 %}Ni PF) was obtained, showing prominent ORR activity with an onset potential of 0.92 V (vs. RHE) at an ultra‐low Pt loading (0.015 mg cm^?2).     

Meso—四—（3,5—二溴—4—羟基苯）卟啉分光光度测定食品中微量铅

研究了溴代卟啉试剂（ＤＢＨＰ）Ｐ分光光度法测定食品中微量铅。在０．０８ｍｏｌ／ＬＮａＯＨ介质中,铅与Ｔ（ＤＢＨＰ）Ｐ反应生成一橙黄色配合物,λｍａｘ＝４７９ｎｍ,ε＝２．２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。铅在０－１２μｇ／２５ｍＬ范围内符合比耳定律,用于食品中微量铅的测定,获得满意结果。     

An ultrafiltration high-performance liquid chromatography coupled with diode array detector and mass spectrometry approach for screening and characterising tyrosinase inhibitors from mulberry leaves

Tyrosinase is a key enzyme in melanin synthesis. Its inhibitor may be used to efficiently treat hyperpigmentation and widely applied in cosmetic products and food supplements. In the present study, a new assay based on ultrafiltration high-performance liquid chromatography coupled with diode array detector and mass spectrometry (HPLC–DAD–MS) was developed for the rapid screening and identification of ligands for tyrosinase. Experiments were carried out to select the optimal binding conditions, tyrosinase concentration, and incubation time. Non-specific binding to the denatured tyrosinase was also investigated. Twelve compounds with tyrosinase binding activity were found in mulberry leaf extracts. The identities of these compounds were characterised by HPLC–DAD–MSⁿ. Particularly, two compounds, namely, quercetin-3-O-(6-O-malonyl)-β-d-glucopyranoside and kaempferol-3-O-(6-O-malonyl)-β-d-glucopyranoside, were identified as new tyrosinase inhibitors. The screening results were verified by tyrosinase inhibition assays. Experimental results proved that the proposed method could rapidly screen tyrosinase inhibitors in complex mixtures.     

Amphiphilic Patchy Composite Colloids

A new approach to fabricate patchy silica/polymeric gel composite colloids with amphiphilic performance is reported. The amphiphilic performance is rendered by selectively modifying the silica framework with a silane that contains an oleophilic alkyl chain. The patchy composite colloids are dispersible in both water and oil, and may be used as a solid particle surfactant. The modified silica framework can also assist other functional materials to disperse in a desired media. The corresponding silica/carbon composite colloids become amphiphilic after a sequential activation of carbon and modification of silica, and meanwhile possess as good electron conductivity as the as‐prepared silica/carbon composite colloids.

     

Simultaneous determination of seven main alkaloids of Chelidonium majus L. by ultra‐performance LC with photodiode‐array detection

A simple and rapid method for the simultaneous determination of seven isoquinoline alkaloids, protopine, chelidonine, coptisine, stylopine, sanguinarine, berberine, and chelerythrine, in Chelidonium majus L. (Ch. majus) samples by ultra‐performance LC method with photodiode array detection is described. The baseline separation of these compounds was performed with (A) acetonitrile–(B) ammonium acetate (10 mM, adjusted to pH 3.0 with acetic acid) as the mobile phase using a C18 RP column (2.1×100 mm, 1.7 μm). Optimized conditions resulted in excellent peak shapes. The seven alkaloids were completely separated within 20 min. Good linear behaviors (r≥0.9992) over the investigated concentration ranges were observed for all the analytes. Validation proved the repeatability of the method was good and recovery was satisfactory. The validated method was successfully applied for 20 batches of Ch. majus. These results demonstrated that the ultra‐performance LC photodiode array method proposed was very useful in the analysis and quality control of Ch. majus.     

Simultaneous determination of neochlorogenic acid,chlorogenic acid,cryptochlorogenic acid and geniposide in rat plasma by UPLC‐MS/MS and its application to a pharmacokinetic study after administration of Reduning injection

A simple, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one‐step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C₁₈ column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid–methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra‐ and inter‐day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection. Copyright © 2014 John Wiley & Sons, Ltd.