Development of a chemiluminescent enzyme‐linked immunosorbent assay for five sulfonamide residues in chicken muscle and pig muscle

BACKGROUND: An enzyme‐linked immunosorbent assay (ELISA) based on polyclonal antibodies with enhanced chemiluminescent (ECL) detection of sulfonamides in food samples has been optimised and characterised. The specificity of the assay was assessed by determining cross‐reactivities with a set of 16 sulfonamides. The aim of this study was to develop a method for determining sulfonamides with high sensitivity. RESULTS: The sensitivity of the developed ECL‐ELISA was higher than that of colorimetric ELISA. The sensitivities of five of the sulfonamides (sulfisozole, sulfathiazole, sulfameter, sulfamethoxypyridazine and sulfapyridine) ranged from 0.73 to 2.92 µg L^?1, with limits of detection of 0.10–0.43 µg L^?1. The coefficients of variation of intra‐assay and inter‐assay studies carried out over 5 days were mostly less than 10%. Recovery studies of chicken muscle and pig muscle were performed with simple and rapid extraction. Good recoveries (62.1–110.3%) were achieved and the results correlated well with those obtained using high‐performance liquid chromatography analysis. CONCLUSION: This study has provided an effective analytical technique for the rapid and reliable determination of residues of sulfisozole, sulfathiazole, sulfameter, sulfamethoxypyridazine and sulfapyridine in food samples with high sensitivity. To the authors' knowledge, this is the first report on chemiluminescent ELISA for sulfonamide analysis. Copyright © 2008 Society of Chemical Industry     

A New Mechanism of the Selective Photodegradation of Antibiotics in the Catalytic System Containing TiO2 and the Inorganic Cations

The mechanism of sulfisoxazole (SFF) selective removal by photocatalysis in the presence of titanium (IV) oxide (TiO₂) and iron (III) chloride (FeCl₃) was explained and the kinetics and degradation pathways of SFF and other antibiotics were compared. The effects of selected inorganic ions, oxygen conditions, pH, sorption processes and formation of coordination compounds on the photocatalytic process in the presence of TiO₂ were also determined. The Fe³⁺ compounds added to the irradiated sulfonamide (SN) solution underwent surface sorption on TiO₂ particles and act as acceptors of excited electrons. Most likely, the SFF degradation is also intensified by organic radicals or cation organic radicals. These radicals can be initially generated by reaction with electron holes, hydroxyl radicals and as a result of electron transfer mediated by iron ions and then participate in propagation processes. The high sensitivity of SFF to decomposition caused by organic radicals is associated with the steric effect and the high bond polarity of the amide substituent.     

Betulin Sulfonamides as Carbonic Anhydrase Inhibitors and Anticancer Agents in Breast Cancer Cells

Hypoxia-regulated protein carbonic anhydrase IX (CA IX) is up-regulated in different tumor entities and correlated with poor prognosis in breast cancer patients. Due to the radio- and chemotherapy resistance of solid hypoxic tumors, derivatives of betulinic acid (BA), a natural compound with anticancer properties, seem to be promising to benefit these cancer patients. We synthesized new betulin sulfonamides and determined their cytotoxicity in different breast cancer cell lines. Additionally, we investigated their effects on clonogenic survival, cell death, extracellular pH, HIF-1α, CA IX and CA XII protein levels and radiosensitivity. Our study revealed that cytotoxicity increased after treatment with the betulin sulfonamides compared to BA or their precursors, especially in triple-negative breast cancer (TNBC) cells. CA IX activity as well as CA IX and CA XII protein levels were reduced by the betulin sulfonamides. We observed elevated inhibitory efficiency against protumorigenic processes such as proliferation and clonogenic survival and the promotion of cell death and radiosensitivity compared to the precursor derivatives. In particular, TNBC cells showed benefit from the addition of sulfonamides onto BA and revealed that betulin sulfonamides are promising compounds to treat more aggressive breast cancers, or are at the same level against less aggressive breast cancer cells.     

可生物降解润滑油添加剂哌嗪衍生物的合成及性能评定

选用六水合哌嗪为母体,二氯甲烷为溶剂,三乙胺为缚酸剂,正己胺、十二胺、氯乙酰氯为原料,合成新型可生物降解润滑油添加剂1,4-双（二硫代甲酸乙酰正己胺）哌嗪和1,4-双（二硫代甲酸乙酰十二胺）哌嗪;采用FT-IR,1HNMR,TG手段对合成产物进行结构表征及对产品热稳定性进行测试。以菜籽油为基础油,采用四球摩擦磨损试验机考察合成添加剂的抗磨性能,并对其进行可生物降解性测定。结果表明：合成产品与预测结构相同,热分解温度最低为305 ℃,与菜籽油的溶解度高达2.58%（质量分数）,1,4-双（二硫代甲酸乙酰十二胺）哌嗪具有较好的抗磨性能,1,4-双（二硫代甲酸乙酰正己胺）哌嗪具有较好的减摩性能,两者均具有优异的可生物降解性能（BDI大于80%）。     

TMC/TMPIP纳滤超薄复合膜的制备

基于哌嗪(PIP)与均苯三甲酰氯(TMC)界面聚合制备纳滤膜的原理,设计并合成了具有支化结构的三亚胺功能基团水相单体--均苯三甲酰哌嗪(TMPIP)盐酸盐,并与TMC界面聚合制得分子结构与TMC/PIP相同的TMC/TMPIP超薄纳滤复合膜。采用傅里叶红外光谱(FTIR)和扫描电镜(SEM)表征了复合膜皮层的化学结构和表面形貌,结果表明在聚砜底膜表面形成了膜厚为100 nm左右的TMC/TMPIP超薄皮层。通过与TMC/PIP复合膜对PEG 200水溶液的分离性能相比较发现,TMC/TMPIP复合膜因其高度的网络化结构和超薄皮层,因而具有更高的截留率和水通量。考察了TMC/TMPIP复合膜对水中不同盐的截留性能,其截留率顺序与TMC/PIP复合膜相同,而通量和截留率均优于后者。     

超声波强化Fenton试剂处理哌嗪废水的研究

采用超声与Fenton两种高级氧化技术联合处理哌嗪废水,取得了满意的效果。实验结果表明,超声波和Fenton试剂对哌嗪废水的催化降解存在协同效应。考察了初始pH、超声功率、Fenton试剂用量等因素对其CODCr去除效果的影响,并用正交试验优化降解条件。当超声波功率为70 W,初始pH为3.7,H2O2浓度为5.0 mmol/L,FeSO4浓度为0.15 mmol/L时,对哌嗪废水CODCr的去除率为99.9%。处理后出水CODCr<50 mg/L,达到了《污水综合排放标准》(GB 8978—1996)一级排放标准。     

填料塔中哌嗪二胺吸收低浓度SO_2的传质性能

为满足有机胺法脱硫设计开发的需要,采用动态吸收法测定了填料塔中哌嗪二胺(PA-A)水溶液吸收低浓度SO2的体积总传质系数KGa,考察了吸收工艺参数如吸收液中的PA-A浓度和初始pH值、液相流率、吸收温度、进气SO2浓度及流速等对KGa的影响。结果表明:KGa随着吸收液中的PA-A浓度和初始pH值、液相喷淋密度的增加而增大;随着吸收温度、气相流率及进气SO2浓度的增加而减小。通过实验结果分析得到体积总传质系数KGa与气液相流率比(qG/qL)之间符合指数关系式,该经验关系可用于工程设计计算。     

改性ZSM-5分子筛催化合成哌嗪

研究了不同金属离子改性得到的M-ZSM-5分子筛在以乙二胺(EDA)为原料合成哌嗪反应中的催化性能。通过NH3-TPD和BET法对催化剂进行表征,结果表明,经过离子交换后HZSM-5的骨架结构没有发生变化,仅仅是表面酸性发生了变化。重点考察了催化剂酸性对反应的影响,实验表明,提高弱酸和中强酸中心所占比例有利于哌嗪(PA)和三乙烯二胺(TEDA)生成。以Zn-ZSM-5和Zn/K-ZSM-5为催化剂,在常压,t=360℃,空速为0.25 g/(min.h),m(EDA)∶m(H2O)=4∶6的反应条件下,原料EDA的转化率分别为94.1%和82.6%;产物PA和TEDA的选择性分别为45.5%,42.1%和29.4%,50.1%。     

N-取代磺酰胺类化合物的合成研究进展

N-取代磺酰胺类化合物在制药行业是非常重要的一类化合物,因其表现出了广泛的生物活性,如抗癌、抗炎和抗病毒等生理功能,备受研究者们的关注。本文从不同的底物出发概述了N-取代磺酰胺类化合物的合成方法。     

哌嗪合成中催化剂的研究

采用浸渍法制备改性ZSM-5分子筛作为乙醇胺合成哌嗪的催化剂,改性后的催化剂具有较好的活性和选择性。考察了不同硅铝比的HZSM-5分子筛对反应的影响,对比了KCl、CaCl2和MgCl2作为改性剂的反应效果,确定KCl为改性较优的改性剂,2.5 mo1/L为较适宜的浸渍浓度。