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1.
采用实沸点蒸馏仪对白石湖煤液化油进行馏分切割,切取<170℃液化粗油进行加氢精制脱除其中硫、氮化合物,采用硫化学发光气相色谱仪(GC-SCD)、氮化学发光气相色谱仪(GC-NCD)对液化粗油和精制油中硫、氮化合物进行分析表征,研究加氢精制过程硫、氮化合物的转化规律。结果表明,液化粗油中含硫化合物主要是噻吩类化合物和硫醇,经过加氢精制后基本消失,苯并噻酚类化合物脱除比例要低于噻吩类化合物,属于较难脱除含硫化合物。液化粗油中含氮化合物主要是苯胺类化合物,其次是吲哚类化合物,经过加氢精制吲哚类化合物全被脱除,苯胺和喹啉类化合物属于碱性含氮化合物,是精制油中残留的主要含氮化合物,含量达1.61 mg/kg。  相似文献   

2.
Designing of molecules for drugs is important topic from many decades. The search of new drugs is very hard, and it is expensive process. Computer assisted framework can provide the fastest way to design and screen drug-like compounds. In present work, a multidimensional approach is introduced for the designing and screening of antioxidant compounds. Antioxidants play a crucial role in ensuring that the body's oxidizing and reducing species are kept in the proper balance, minimizing oxidative stress. Machine learning models are used to predict antioxidant activity. Three hydroxycinnamates are selected as standard antioxidants. Similar compounds are searched from ChEMBL database using chemical structural similarity method. The libraries of new compounds are generated using evolutionary method. New compounds are also designed using automatic decomposition and construction building blocks. The antioxidant activity of all designed and searched compounds is predicted using machine learning models. The chemical space of searched and generated compounds is envisioned using t-distributed stochastic neighbor embedding (t-SNE) method. Best compounds are shortlisted, and their synthetic accessibility is predicted to further facilitate the experimental chemists. The chemical similarity between standard and selected compounds is also studied using fingerprints and heatmap.  相似文献   

3.
A method is described for the simultaneous determination of nanogram amounts of mono-, di- and tri-butyltin compounds in water. The procedure is based on the conversion of tin compounds to volatile species by Grignard pentylation and analysis using GC with flame photometric detection (GC FPD). The ionic compounds are extracted from diluted acidified (HBr) aqueous solutions by using a pentane-tropolone solution. The extracted organotin compounds are pentylated by a Grignard reagent and purified on a Fluorisil column before analysis by GC FPD. The detection limits are 20 ng dm?3 for butyltin compounds and 50 ng dm?3 for phenyltin compounds. Recoveries from spiking experiments in tap-water and natural seawater matrices, in which no organotin compounds were detected, were greater than 90% for most of the alkyltin compounds.  相似文献   

4.
Synthesis of biologically active compounds, including natural products and pharmaceutical agents, is an important and interesting research area since the large structural diversity and complexity of bioactive compounds make them an important source of leads and scaffolds in drug discovery and development. Many structurally and also biologically interesting compounds, including marine natural products, have been isolated from nature and have also been prepared on the basis of a computational design for the purpose of developing medicinal chemistry. In order to obtain a wide variety of derivatives of biologically active compounds from the viewpoint of medicinal chemistry, it is essential to establish efficient synthetic procedures for desired targets. Newly developed reactions should also be used for efficient synthesis of desired compounds. Thus, recent progress in the synthesis of biologically active compounds by focusing on the development of new reactions is summarized in this review article.  相似文献   

5.
Trifluoroethanol (TFE) is strongly hydrogen bonded to aromatic compounds containing a pyridinic nitrogen. For many aza-aromatic compounds this causes an increase in the fluorescence emission yield of up to two orders of magnitude and a change in the nature of the emission with respect to that observed in most common aliphatic alcohols. The emission from these aza-aromatic compounds in TFE is, in fact, a cation-like fluorescence. This allows the easy identification of the single components of a mixture of aromatic and aza-aromatic compounds.  相似文献   

6.
韦丹  丁文军  周桔  彭端  李明 《化学进展》2009,21(5):896-902
在糖尿病的治疗研究中,体内和体外的研究表明,钒化合物可以降低I型和II型糖尿病血糖,促进葡萄糖转运和糖原合成,具有“类胰岛素作用”。本文综述了近年来钒化合物在降低和改善糖尿病症状的生物效应及其通过胰岛素信号通路在降糖作用的分子机制的研究进展。  相似文献   

7.
As a result of the recent developments of high-throughput screening in drug discovery, the number of available screening compounds has been growing rapidly. Chemical vendors provide millions of compounds; however, these compounds are highly redundant. Clustering analysis, a technique that groups similar compounds into families, can be used to analyze such redundancy. Many available clustering methods focus on accurate classification of compounds; they are slow and are not suitable for very large compound libraries. Here is described a fast clustering method based on an incremental clustering algorithm and the 2D fingerprints of compounds. This method can cluster a very large data set with millions of compounds in hours on a single computer. A program implemented with this method, called cd-hit-fp, is available from http://chemspace.org.  相似文献   

8.
High content screening is a method for identifying small molecule modulators of mammalian cell biology. The nature of the experiment generates an enormous amount of data in the form of photographic images of cells after treatment with compounds of interest. The interpretation of data from these experiments is challenging both in terms of automatically perceiving the images, extracting, and understanding differences between screened compounds and visualizing the results. This paper discusses the application of statistical and visual methods that have been used to interpret data from a simplified DNA stain (DAPI) screen to quickly identify compounds of interest. An understanding of the mechanism of action of the screened compounds can be obtained by comparing them to control compounds of known mechanism of action. Statistical and visual methods will be shown that facilitate easy comparison of screened compounds against these control compounds. As an example, a subset of the internal repository at ArQule was screened, together with control compounds that were known to induce characteristic mitotic arrest. Subsequent data processing described in this paper permitted the easy identification of compounds that were similar to (and very different from) the control compounds.  相似文献   

9.
A multibed on-line sorption trap is used to preconcentrate organic vapors from air samples and inject the analytes into a GC separation column. Injection plug widths depend on the boiling point for the lipophilic compounds and on the polarity and boiling point for the polar compounds. Injection plug widths are sufficiently small (0.7-0.8 s) as to allow the direct injection of the most volatile compounds into the GC column without the need for a second focusing device. The presence of water in the samples has an effect on the retention of polar compounds by the trap. However, this effect is reproducible for a fixed water content and so can be overcome by using calibration standards under the same conditions of humidity as the samples. The thermal decomposition of many volatile organic compounds in an on-line sorption trap during the GC analysis of air samples is examined. The results show that degradation of unstable compounds is governed by the amount of heat transferred to the compounds during desorption (i.e., applied temperature and pulse duration). The use of an on-line trap results in the immediate transfer of desorbed compounds to the analytical column, which can reduce the formation of artifacts.  相似文献   

10.
Abstract

Trace amounts (ppb or less) of phosphorus containing compounds present in aqueous samples are adsorbed on XAD-4 and subsequently eluted by means of ethyl acetate. The solvent and the eluted compounds are evaporated and swept over a Tenax-GC tube. This gas stripping method traps the phosphorus containing compounds together with only a small amount of the solvent whereas the water entrapped in the XAD step is removed simultaneously. The compounds are desorbed from the Tenax-GC tube and injected into the gas chromatograph using the combination of thermal desorption, cold trapping and flash heating. The subsequent analysis is carried out on a capillary column and the compounds are detected by means of a flame photometric detector. The various steps of the analytical procedure are discussed, including the recoveries of the different compounds studied and some instrumental aspects.  相似文献   

11.
The use of carbon nanostructures in different modalities is a topic of growing interest. This article provides a systematic comparison of surfactant-coated single-wall carbon nanotubes, multi-wall carbon nanotubes and C(60) fullerenes as pseudostationary phases (PSPs) in electrokinetic chromatography. The differences on the electrophoretic behaviour as a function of the pseudostationary phase for phenolic compounds, triazines and nitroimidazole derivatives have been explored. Phenolic compounds, triazines and nitroimidazole derivatives has been selected as model compounds of aromatic compounds, pi-exceeding heteroaromatic compounds and pi-deficient heteroaromatic compounds, respectively. Resolution was also evaluated on the basis of the differences in the electrophoretic behaviour and in this sense the best PSP for each group of compounds can be proposed.  相似文献   

12.
郭霖 《高分子通报》1997,(2):118-121
通过引入官能团的单官能团物质贡献率这一新参数,用统计的方法导出了可反映的单官能团物质的用量对体型缩聚凝胶点之影响,并可预测体系的凝胶点的新公式,同时给出了该公司的应用示例。  相似文献   

13.
Two-phase dehydrogenation, which is a new reaction of aryl substituted carbazide compounds, is described in this paper. Ten new azo compounds were synthesized by the reaction of aryl substituted carbazide compounds with a phenoxyl radical between two phases in good yields.  相似文献   

14.
Fruit aroma, a mixture of chemical compounds with odor, is a strong attractant derived from a complex mixture of different amounts and intensities (threshold) of chemical compounds found in fruits. The odor-producing compounds of fruit aroma are derived from carbohydrates, lipids, phenolic compounds, and mono- and sesquiterpenes, among others. The identification of compounds responsible for fruit aroma is usually conducted using gas chromatography coupled with olfactometry (GC-O). This technique separates the chemical compounds from the aroma of foods using a chromatographic column and divides the resultant outflow between the physical detector and a testing outlet (sniffing port). Trained judges describe the perceived odor in terms of the intensity of the odor zones perceived according to their training method. Moreover, the use of GC-O coupled with a mass detector (GC-MS-O) allows for the retrieval of chemical information such as identification and quantification of compounds, which can be correlated to sensory information. This review aimed to demonstrate the application of GC-MS-O in the identification of precursor compounds in fruit aroma, considering important factors for the application, main results, and most recent advances in this field.  相似文献   

15.
More than 60% commonly used pharmaceutical active ingredients are chiral compounds. Developing more effective and safe chiral compounds has become a focus in the pharmaceutical industry. Chiral compounds widely exist in traditional Chinese medicine and include alkaloids, flavonoids, volatile oils, and amino acids. The characterization of chiral compounds used in traditional Chinese medicine remains limited. Here, the characterization of chiral compounds commonly used in traditional Chinese medicine is reviewed focusing upon their separation and pharmacology.  相似文献   

16.
17.
利用两根极性不同的毛细柱,在全二维气相色谱上分析辽河油田遭受严重生物降解形成的稠油饱和烃组分,可以将传统色谱分析时形成的“基线鼓包”即不可分辨的复杂混合物(Unresolved Complex Mixtures)分开.根据饱和烃全二维气相色谱谱图的族分离特点和瓦片效应,结合飞行时间质谱提供的质谱信息初步解析不可分辨的复杂混合物主要成分.发现常规色谱分析时形成的所谓“基线鼓包”是由成千上万、含量相对较低的不同取代基的环状化合物组成,这些化合物在一维色谱上以分子量递增的顺序排列,在二维色谱上以极性的差异或者环的多少排列.C24之前的第一组不可分辨的复杂混合物主要由环己烷为基本单元的单环、双环和三环烷烃类化合物组成,信噪比在100以上的化合物数量约为饱和烃总数量的75%,质量分数是饱和烃总量的80%以上,是饱和烃的主要组成部分.C24之后出现的第二组不可分辨的复杂混合物主要由四个环或者五个环为基本单元的化合物组成,信噪比在100以上的化合物数量约为饱和烃总数量的17%,质量分数是饱和烃总量的0.5%.对稠油中这些不可分辨的复杂混合物的解析有助于对其成因机理的认识和高效开采方案的制定.  相似文献   

18.
含顺二酚的分子,如糖类、糖苷和糖蛋白等,在糖组学、代谢组学和蛋白质组学等不同领域都有着至关重要的作用。但是这类样品分子通常存在于非常低丰度的环境中且与许多干扰化合物共存,给临床和生物学上的分离检测带来了巨大的困难。因此,开发建立对顺二醇类化合物简单高效的分离方法具有重要意义。分子印迹技术,是基于模拟生物体内抗原与抗体相互作用原理而发展起来的一种新兴技术,近年来因其特定的分子识别能力以及材料的稳定性和重复性而引起了广泛关注,也在顺二醇类化合物的分离方面得到了许多应用。本综述总结了在顺二醇类化合物的分子印迹方面的最新进展,并对其未来发展的方向和前景进行了讨论。  相似文献   

19.
Twelve compounds each having a six membered Si-contained heterocycle, have been successfully synthesized. Of these eleven compounds have never been reported in the literature. The structures were confirmed by Spectral analysis and elementary analysis. The stability and properties of these compounds is also discussed.  相似文献   

20.
"A-B" type photosensitive compounds including two-photon chromophore and benzophenone moiety have been designed, synthesized and characterized. The UV-vis absorption and fluorescence emission of the compounds have been extensively studied in various solvents. The results show that the absorption of "A-B" type compounds displays obvious double absorption bands, one of which at short-wavelength is related to the benzophenone moiety, the other at long-wavelength is mainly contributed by chromophore. The emission of "A-B" type compounds at 500-700nm shows an "unexpected" blue-shift comparing with that of the sole chromophore. The photosensitive compounds with amino group display strong emission in apolar solvents and have a low fluorescence quantum yields in polar solvents. In contrast, the compounds without amino group exhibit strong fluorescence emission in polar solvents, and low fluorescence quantum yields in apolar solvents. The fluorescence quantum yields of "A-B" type compounds are higher than those of the sole chromophore. The discoveries suggest that charge redistribution induced by the introduction of benzophenone moiety plays a key role on the absorption and emission spectroscopy.  相似文献   

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