中国柞蚕肠道蛋白酶的提取与活力测定

应用丙酮沉淀法以柞蚕肠道组织为材料提取蛋白酶并进行了活力测定．这项成果为柞蚕饲养和代谢的研究提供了重要参与，并为酶在工业上的利用找到了依据．     

Rapid and specific determination of free cortisol in guinea pig urine and faeces by thin-layer chromatography-competitive protein-binding assay

Summary The present work describes a specific, rapid and sensitive determination of free cortisol in the urine and faeces of guinea pigs. This method offers some advantages over previous methods including the use of dexamethasone as a marker for cortisol localization on TLC sheets, the use of buffer instead of organic solvents to recover cortisol from silica gel 60 and the rapidity of the competitive protein-binding assay (1–2 h).     

Paclitaxel-Loaded Magnetic Nanoparticles Based on Biotinylated N-Palmitoyl Chitosan: Synthesis,Characterization and Preliminary In Vitro Studies

A considerable interest in cancer research is represented by the development of magnetic nanoparticles based on biofunctionalized polymers for controlled-release systems of hydrophobic chemotherapeutic drugs targeted only to the tumor sites, without affecting normal cells. The objective of the paper is to present the synthesis and in vitro evaluation of the nanocomposites that include a magnetic core able to direct the systems to the target, a polymeric surface shell that provides stabilization and multi-functionality, a chemotherapeutic agent, Paclitaxel (PTX), and a biotin tumor recognition layer. To our best knowledge, there are no studies concerning development of magnetic nanoparticles obtained by partial oxidation, based on biotinylated N-palmitoyl chitosan loaded with PTX. The structure, external morphology, size distribution, colloidal and magnetic properties analyses confirmed the formation of well-defined crystalline magnetite conjugates, with broad distribution, relatively high saturation magnetization and irregular shape. Even if the ability of the nanoparticles to release the drug in 72 h was demonstrated, further complex in vitro and in vivo studies will be performed in order to validate the magnetic nanoparticles as PTX delivery system.     

Assaying neurotransmitters in and around single neurons with information-rich detectors

Techniques to study the chemical environment in and around individual neurons are reviewed, with an emphasis on methods to assay single cells for neurotransmitters and neuromodulators that do not require analyte preselection. Current capabilities of capillary-based microseparations and mass spectrometry are highlighted for this application. Methods to combine multiple analytical techniques to provide chemical, spatial and temporal information are described.     

Analytical performances of validated chemiluminescent enzyme immunoassays to detect N-methylcarbamate pesticides

In the present work, enzyme-linked immunosorbent assays (ELISAs) with chemiluminescent detection for the determination of carbofuran, carbaryl and methiocarb were developed and the analytical parameters of these assays were compared with those of ELISAs with colorimetric detection. Both were conjugate-coated formats based on identical monoclonal antibodies and homologous protein conjugates. In comparison with colorimetric ELISA, the ability of the chemiluminescent reagents to detect lower concentrations of horseradish peroxidase allowed to decrease the optimal antibody and conjugate concentrations and to reach better analytical parameters. The experimental comparison of the analytical performance of the ELISAs was carried out by analysing extracts of apple-strawberry baby food and simply diluted fruit juices, both spiked at different concentration levels with the above mentioned pesticides. Recovery values for both ELISAs were around 100% and no matrix effects were observed when fruit juices were diluted 1:20 or more. Results obtained by ELISAs correlated well, both in terms of accuracy and precision, with those obtained by a liquid chromatography-electrospray mass spectrometry (LC/ESI/MS/MS) analysis, used as reference method to validate the immunoassays results. The limits of detection reached by using the chemiluminescent assay were 0.03, 0.007 and 0.004 ng ml⁻¹ for carbofuran, carbaryl and methiocarb, respectively.     

Aptamer-mediated turn-on fluorescence assay for prion protein based on guanine quenched fluophor

An aptamer-participated haprin structure was designed by employing cellular prion protein (PrP^C) as a model protein, and thus an aptamer-mediated turn-on fluorescence assay for proteins was developed in this contribution. The designed aptamer-participated haprin structure consists of three segments. Namely, an aptamer sequence located in the loop, three guanine bases at 3′-terminal, and a fluophor modified at 5′-terminal. It was found that the guanine bases at the 3′-terminal could quench the fluorescence of the fluophor such as tetramethyl-6-carboxyrhodamine (TAMRA) at the 5′-terminal about 76.6% via electron transfer if the guanine bases are close enough to the fluophor, and the quenched fluorescence could get restored when the target protein is present since the interaction, which could be confirmed by measuring fluorescence lifetime, between TAMRA-aptamer and the target protein forces the guanines away from TAMRA so that TAMRA-modified aptamer changes into turn-on state. A linear relationship was then constructed between the turn-on fluorescence intensity and the concentration of PrP^C in the range from 1.1 to 44.7 μg/mL with a limit of detection of 0.3 μg/mL (3σ).     

First total synthesis of piperodione and analogs

Piperodione (3), a secondary metabolite previously isolated from the Javanese pepper plant Piper retrofractum in 0.0002% isolated yield was synthesized in a convergent strategy utilizing a Mannich and a Stetter reaction. An over-all yield of 76% could be achieved. Several analogs were prepared by this synthetic sequence. None of the compounds showed a significant cytotoxicity for human tumor cells (photometric sulforhodamine B assay).     

紫外分光光度法表征Lipozyme TL IM脂肪酶转酯化活性

建立了一种新的有机相脂肪酶转酯化活性测定方法. 以正己烷为溶剂,脂肪酶催化棕榈酸对硝基苯酯和正丁醇的转酯化反应为模型反应,通过测定反应液中310 nm下吸光值的变化计算反应转化率. 以气相色谱法对新建的紫外分光光度法进行验证,分别采用这两种方法测定了七种商品化脂肪酶的转酯化活性,两种方法所得实验结果基本一致. 利用紫外分光光度检测法考察了Lipozyme TL IM脂肪酶催化转酯化的时间进程及合成活性与酶量的关系,并对Lipozyme TL IM催化转酯化的性质（最适溶剂、酰基受体特异性、醇耐受性、最优反应温度和热力学稳定性）进行了表征.     

Exploring beta amyloid cleavage enzyme-1 inhibition and neuroprotective role of benzimidazole analogues as anti-alzheimer agents

Beta amyloid cleavage enzyme-1 (BACE1) is the key enzyme involved in Aβ peptide formation in Alzheimer's disease pathogenesis. We intend to target this enzyme by exploring benzimidazole analogues against BACE1 as potential anti-Alzheimer agents. Docking studies were performed to determine the hydrogen bond interactions between the designed molecules and the target protein's active site. Research indicates the relationship between oxidative stress and Aβ effect in precipitating neurodegeneration; hence, the series was also studied in vitro to ascertain its neuroprotective role by performing the lipid peroxidation assay. In silico absorption, distribution, metabolism, and excretion studies were undertaken to assess the drug-like suitability of the analogues. To judge the effect of the synthesized analogues on central nervous system (CNS), toxicity and memory model studies were conducted on mice. Thus, overall results showcase analogues 11 and 14 as the most promising ones with the dual role of BACE1 inhibition and neuroprotection, along with memory retention.     

Fluorescent Dye Incorporated Magnetic/Silica and Fluorescent Silica Nanoparticles Based Myoglobin Detection from Whole Blood Samples

The anti myoglobin conjugated iron oxide/ru(bpy)₃²⁺/silica, anti myoglobin conjugated rhodamine 6G/silica particles were prepared, and used for myoglobin detections. The anti myoglobin conjugated iron oxide/ru(bpy)₃²⁺/silica particles were mixed with myoglobin in the micro centrifuge tube. After 10 min, the magnetic separators were introduced to catch the myoglobin‐captured anti myoglobin/iron oxide/ru(bpy)₃²⁺/silica particles from the homogenous solutions. For sandwich assays, the anti myoglobin conjugated rhodamine 6G/silica particles were incubated. The concentration of myoglobin was quantified based on anti myoglobin conjugated rhodamine 6G/silica particles. The calibration curve of the myoglobin showed the linear range to be between 1 × 10^?12 and 1 × 10^?10 (M) (R² = 0.9944). The minimum detectable concentration was 17.6 pg/mL. The fluorescence method offered the best way to determine myoglobin with a total analysis time of less than 30 min.