扩散加权的核磁共振方法在高血脂症血清快速识别中的应用

研究了扩散加权的NMR在区分冠心病患者和正常人的血清中的可能应用,证明了扩散加权的NMR与主成分分析(PCA)相结合是将冠心病血清从正常血清中识别出来的有效方法。分子自扩散运动加权的NMR能够有效抑制小分子代谢物的共振信号强度,从而使血脂和血蛋白的NMR特征更为明显。最佳的扩散权重因子(b)约为0.85×107s/cm2,增加或降低扩散权重因子都会影响识别效率。研究结果表明,分子量极小的代谢物(乳酸等)及相对较大的脂蛋白(VLDL)对区分两类血清的贡献较小。在最佳的b值条件下,高密度脂蛋白(HDL)和低密度脂蛋白(LDL)对区分两类血清的贡献得以提高,从而获得更好的区分效果。     

药物配体与生物大分子受体相互作用核磁共振的研究进展

药物与生物体内目标大分子之间的相互作用,是决定药物药理活性和代谢稳定性的主要因素。如何快速高效地识别出能与靶分子相互作用且能抑制其体外活性的药物分子,是制药工业普遍关注的问题。核磁共振已经成为研究小分子配体和生物大分子相互作用的一种非常重要的手段。检测小分子配体信号在作用过程中的变化以识别药物分子,是核磁共振进行药物筛选的主要方法之一。本文介绍了近年来这方面的研究进展。     

稀土对大鼠尿液成分影响的核磁共振研究

目前,稀土生物效应的研究已进入了分子和细胞水平,但在活体动物内研究稀土的作用情况还不多见。稀土化合物随食物进入动物体内后,会对动物体内的器官、组织、细胞产生一定影响,将导致其体液容量、分布、电解质浓度等方面的变化。现代NMR技术是目前药理毒理学研究的有效手段之一,它具有简便、全面、快捷、非破坏性等优点,可用于对体液样品的检测和研究。本文采用现代核磁共振技术研究了稀土化合物硝酸镧灌胃给药后对Wistar大鼠尿液中代谢产物的影响,为阐明稀土化合物的毒理学机制和稀土的进一步开发利用提供理论依据。     

Using Nuclear Magnetic Resonance and MS/MS Spectroscopy for the Identification of Brodimoprim Metabolites in Rat Urine

Brodimoprim,a trimethoprim analogue diaminopyrimidine, 2,4-diamino-5-(4'-bromo-3',5'-dimethoxybenzyl) pyrimidine, is a new inhibitor of bacterial dihydro folate reductases (OHFRs), it shows activity against a broad spectrum of Gram-positive and negative-bacteria. Recently we reported the results of the study on the metabolites of brodimoprim in vivo with SPE-NMR method (solid phase extraction coupled with nuclear magnetic resonance), five metabolites were detected in rat urine1. They were …     

高场核磁共振波谱在多糖结构研究中的应用

随着高场核磁共振波谱（ＮＭＲ）技术飞速发展,它在多糖的结构研究中发挥着日益重要的作用,不仅对共 结构,而且对于多糖在溶液中或固体状态下的构象以及动力学特性,ＮＭＲ分析也是最有力的工具。本文综述了高场ＮＭＲ技术在分析多糖结构方面的应用。     

红外光谱与核磁共振波谱在甲壳素结构研究中的应用

本文综述了红外光谱和核磁共振波谱在甲壳素和壳聚糖的乙酰度、衍生物的取代位置和取代度、晶体结构和结晶度以及构型和构象、与离子和其他分子间的相互作用等研究领域的应用状况，引用文献61篇。     

利用选择性激发核磁共振对混合物中的两种化合物进行结构解析

利用现代NMR的1D、2D技术对一个混合物进行了分析。结果表明：混合物由两种化合物组成。为了同时准确确定两种化合物的结构，本工作应用了1D-TOCSY技术，利用该技术选择性强的特点来补充常规的1D、2DHMR实验所提供的分子结构的信息。在没有进行预分离的条件下，顺利地完成了样品中两种化合物的核磁信号归属，并最终确定了它们的结构。     

Prediction of Low-Dose Aspirin-Induced Gastric Toxicity Using Nuclear Magnetic Resonance Spectroscopy-Based Pharmacometabolomics in Rats

Background: Low-dose aspirin (LDA) is the backbone for secondary prevention of coronary artery disease, although limited by gastric toxicity. This study aimed to identify novel metabolites that could predict LDA-induced gastric toxicity using pharmacometabolomics. Methods: Pre-dosed urine samples were collected from male Sprague-Dawley rats. The rats were treated with either LDA (10 mg/kg) or 1% methylcellulose (10 mL/kg) per oral for 28 days. The rats’ stomachs were examined for gastric toxicity using a stereomicroscope. The urine samples were analyzed using a proton nuclear magnetic resonance spectroscopy. Metabolites were systematically identified by exploring established databases and multivariate analyses to determine the spectral pattern of metabolites related to LDA-induced gastric toxicity. Results: Treatment with LDA resulted in gastric toxicity in 20/32 rats (62.5%). The orthogonal projections to latent structures discriminant analysis (OPLS-DA) model displayed a goodness-of-fit (R²Y) value of 0.947, suggesting near-perfect reproducibility and a goodness-of-prediction (Q²Y) of −0.185 with perfect sensitivity, specificity and accuracy (100%). Furthermore, the area under the receiver operating characteristic (AUROC) displayed was 1. The final OPLS-DA model had an R²Y value of 0.726 and Q²Y of 0.142 with sensitivity (100%), specificity (95.0%) and accuracy (96.9%). Citrate, hippurate, methylamine, trimethylamine N-oxide and alpha-keto-glutarate were identified as the possible metabolites implicated in the LDA-induced gastric toxicity. Conclusion: The study identified metabolic signatures that correlated with the development of a low-dose Aspirin-induced gastric toxicity in rats. This pharmacometabolomic approach could further be validated to predict LDA-induced gastric toxicity in patients with coronary artery disease.     

模糊自适应PID算法在核磁共振谱仪样品旋转控制系统中的应用

在核磁共振(NMR)实验中,样品旋转能够有效消除 XY 方向磁场的部分不均匀性,从而提高信号分辨率.在商用NMR谱仪中,一般采用PID算法进行待测样品的旋转控制.由于被控对象具有一定的非线性,存在着调节时间较长,稳定后存在误差等缺点.针对该现象,在Varian 500 MHz波谱仪气路系统的基础上,设计一套新的控制电路...     

采用核磁共振/液相色谱-质谱异相关谱方法开展药用植物草棉活性提取物中多组分的同步结构分析研究

基于不完全分离分析策略,建立了NMR/LC-MS异相关谱(NMR/LC-MS HCS)方法对系列混合物样品的LC-MS和NMR谱数据的整合分析,发掘混合物图谱中来自同一组分的LC-MS和NMR谱数据间的内在相关性.以新疆维吾尔民族药用植物草棉(Gossypium herbaceam L.)花瓣的乙醇提取物(AB-8-2...