甲磺酸多沙唑嗪的合成

甲磺酸多沙唑嗪(doxazosin mesylate,Ⅰ)的化学名为1-(4-氨基-6,7-二甲氧基-2-喹唑啉基)-4-(1,4-苯骈二恶烷-2-甲酰基)哌嗪甲磺酸盐,是一种新型的高选择性α1受体阻滞剂[1],半衰期长,且有明显的降压和降脂作用,同时对单纯性前列腺增生引起的排尿困难具有良好的作用.目前已成为国内外治疗轻中度高血压的一线药物[2,3,4].     

Effects of AC‐Electrolysis on the Enzymatic Activity of Glucose Oxidase

The change in the activity of glucose oxidase subjected to an asymmetrical alternating current (AC) electric field is investigated via horseradish peroxidase (HRP)‐coupled bioassay. The effect of the amplitude, frequency and enzyme concentration have been shown to affect the enzyme activity towards glucose oxidation. The decrease in the enzyme activity is directly related to the change in pH and temperature of the GOx solution during AC electrolysis. The enzyme activity reduces with increasing amplitude, enzyme concentration and decreasing frequency. Results from UV‐vis, FT‐IR and UV CD spectroscopy showed that the AC treated GOx samples undergo structural modifications.     

Glucose Biosensor Using Glucose Oxidase and Electrospun Mn2O3‐Ag Nanofibers

The highly porous Mn₂O₃‐Ag nanofibers were fabricated by a facile two‐step procedure (electrospinning and calcination). The structure and composition of the Mn₂O₃‐Ag nanofibers were characterized by SEM, TEM, XRD, EDX and SAED. The as‐prepared Mn₂O₃‐Ag nanofibers were then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. The biosensor shows fast response to glucose, high sensitivity (40.60 µA mM^?1 cm^?2), low detection limit (1.73 µM at S/N=3), low K_m,app value and excellent selectivity. These results indicate that the novel Mn₂O₃‐Ag nanfibers‐GOD composite has great potential application in oxygen‐reduction based glucose biosensing.     

Development of a Carbon Paste Electrode for Lactate Detection Based on Meldola’s Blue Adsorbed on Silica Gel Modified with Niobium Oxide and Lactate Oxidase

A reagentless amperometric biosensor sensitive to lactate was developed. The sensor employs a carbon paste electrode modified with lactate oxidase (LOx) and Meldola’s Blue (MB) adsorbed on silica gel coated with niobium oxide. The dependence on the biosensor response was investigated in terms of pH, supporting electrolyte, ionic strength, lactate oxidase (LOx) amounts and applied potential. The biosensor showed an excellent operational stability (96 % of the activity was maintained after 150 determinations) and storage stability (allowing measurements for more than 1.5 months, when stored in a refrigerator). The proposed biosensor also presented good sensitivity allowing lactate quantification at levels down to 6.5×10^?7 mol L^?1. Moreover, the biosensor showed a good linear response range (from 0.1 to 5.0 mmol L^?1 for lactate). Lactate analysis in biological samples such as blood was also performed. The precision of the data obtained by the proposed biosensor showed reliable results for real complex matrices.     

Synthesis,characterization of naphthalene‐based polyimides,and their use as immobilized enzyme membrane

A new monomer, 1,5‐bis(p‐dimethylaminophenylimino)naphthalene, was prepared through Schiff‐base condensation reaction of 1,5‐diaminonaphthalene and 4‐(dimethylamino)benzaldehyde in the presence of ethanol. A series of aromatic polyimides bearing naphthalene and ? CH?N? groups were synthesized from the diamine with five kinds of commercial dianhydrides via a conventional one‐stage process. The resulting naphthalene based polyimides (NBPs) showed good solubilities in N‐methyl‐2‐pyrrolidone and m‐cresol. NBPs had glass‐transition temperatures at 139–174°C and 10% weightloss temperatures above 430 °C in nitrogen atmospheres. Excellent properties of NBPs are attributed to the incorporation of the naphthalene and ? CH?N? group in 1,5‐bis(p‐dimethylaminophenylimino)naphthalene. Moreover, chemically prepared polyimides were used for immobilization of glucose oxidase (GOx). The amperometric responses of the NBPs‐GOx‐Pt electrodes toward glucose were examined at a potential of 0.7 V in PBS solution by means of time‐base (TB) technique. Results show that NBPs bearing ? O? group membrane (PI‐3) has many advantages in the immobilization of glucose oxidase because of its strong adherence to electrode surface and chemical stability and selectivity. Copyright © 2010 John Wiley & Sons, Ltd.     

黄嘌呤氧化酶－乙醛－吖啶酯化学发光分析新体系

乙醛在黄嘌呤氧化酶催化作用下，被空气氧化生成乙酸和过氧化氢，酶反应生成的过氧化氢氧化新吖啶酯试剂［１０－甲基－９－（对甲酰苯基）吖啶羧酸酯氟磺酸盐］产生化学发光，化学发光强度与己醛浓度在一定范围内成线性关系．由此建立了一种化学发光分析新体系，用于测定乙醇含量．线性范围２．０×１０－７～１．２×１０－３ｍｏｌ／Ｌ，测定５．０×１０－７ｍｏｌ／Ｌ乙醛，相对标准偏差为６．８％，检测限为１．２×１０－７ｍｏｌ／Ｌ，测定环境水样中乙醇含量，取得满意结果，回收率为９５～１０６％．     

O2 binding to cytochrome c oxidase-inspired nanomaterials

We investigate O₂ binding to cytochrome c oxidase (CcO)-inspired nanomaterials using ab initio density functional calculations. We consider iron-porphyrin (FeP) and copper-(imidazole)₃ [Cu(Im)₃] as a representative of the active binuclear center, and explore the effect of the Cu(Im)₃ on the FeP-O₂ adduct in relation to the geometric, vibrational, electronic and energetic properties. We find that the Cu(Im)₃ induces the weak O-O and Fe-O bonds mainly because of the electron transfer to the O₂ and the spin polarization of the Fe and O₂ by bridging the O₂ between the Fe and Cu, possibly resulting in the facile O₂ dissociation.     

A Novel Cholesterol Oxidase Biosensor Based on Pt-nanoparticle /Carbon Nanotube Modified Electrode

A variety of electrochemical biosensors for cholesterol detection have been proposed because of its importance in clinic and food analysis 1-2. Classical devices for the detection were based on monitoring either the consumption of oxygen or the production of H2O2. The amperometric determination of H2O2 oxidation is sensitive and stable, but it requires a high anodic potential (over 0.6 V vs Ag/AgCl) and is affected by co-oxidable substances such as ascorbic acid and uric acid usually presen…     

Glucose Measurement Using an Enzymatic Oscillatory Reaction

In biological systems, oscillatory reactions are often found. These reactions, so‐called biological oscillators, have a characteristic oscillation period ranging from seconds to years [1]. For the oscillation in which an enzyme is involved, the reaction has been studied both experimentally [2–5] and theoretically [6–10]. In many cases, temperature control, stirring, or continuous flow of the reactant is necessary to observe continuous oscillation. No trial has been made yet to control the oscillation period or waveform. Here, we report an enzymatic oscillation reaction using catalase and glucose oxidase in which the oscillation period and waveform can be changed by the addition of glucose. We achieved good reproducibility with an oscillation period and waveform change that was sufficient to be applied to the glucose quantification. The effect of coexisting chemicals such as ascorbic acid, urea, or acetamidophenol on the oscillation is examined.     

Enzymatic reactions in supercritical gases

The enzyme polyphenol oxidase has been found to be catalytically active in supercritical carbon dioxide and fluoroform: it readily oxidizesp-cresol andp-chlorophenol to their correspondingo-benzoquinones.