离子对反相薄层色谱法分离碱性染料

Lepri等首先用离子对技术研究了18种水溶性食品染料在氯化十二烷基吡啶浸渍的硅烷化硅胶薄层板上的色谱行为.随后Ruijten指出,离子对反相色谱技术对手芳香化合物和脂肪化合物中离解基团的鉴定是一种有效的手段,化合物中的R值与分子中各种基团(羧酸基、磺酸基、胺基等)数目和位置相关。在染料分子中多含有磺酸基、羧酸基或伯、仲、叔的胺基。因而,离子对反相色谱技术对它们的分离特别有用。我们曾用苯基键合板以溴化四丁基胺为反离子,成功地分离了四种酸性食品染料。本文用甲基苯乙基二氯硅烷与硅胶G预涂板反应,制备了一种新的键合板,用于分离碱性染料效果良好。     

官能化硅烷及其配位化合物的研究

硅原子具有空的3d轨道,可以作为电子接受体,这样就赋予了有机硅化合物独特的性质。在硅原子上引入官能化基团的小分子化合物称为官能化硅烷。近年来官能化硅烷及其配位化合物引起了化学工作者的重视,在光学、电学、催化等方面得到广泛的应用。按照官能化基团的不同,官能化硅烷可以分为含烯基、炔基、芳环等基团的π型官能化硅烷和含N、O、P、S等杂原子的官能化硅烷两类。本文概括了官能化硅烷合成方法,总结了其配合物的制备途径及研究进展,并对其研究和发展方向进行了展望。     

D-苯甘氨酸手性固定相的制备及对多种手性化合物的拆分

以D-3,5-二硝基苯甲酰苯甘氨酸和3-氨丙基硅烷化硅胶合成了D-苯甘氨酸衍生手性固定相,并自制了手性高效液相色谱分离柱,用正己烷-异丙醇作流动相,对非衍生化的氨基酸、胺、醇和羧酸类等10种手性化合物进行了高效液相色谱拆分。结果表明:所拆分的10种手性化合物,有7种手性化合物能得到基线分离,最好的分离度Rs=5.56。该文还用苯对柱性能进行了评价,理论塔板数达每米8万块。     

乙酸丁酸纤维素手性固定相的制备及对手性化合物的拆分

将乙酸丁酸纤维素涂敷在硅烷化的硅胶上制备了涂渍型高效液相色谱固定相,在40MPa压力下将所得固定相装入色谱柱.在正相的条件下,对20种手性化合物进行拆分,包括醇类,胺类,氨基酸类手性化合物以及外消旋体药物,有13种手性化合物得到了较好的分离.     

苯基乙烯基甲基聚硅氧烷涂敷的反相高效液相色谱固定相

用苯基乙烯基甲基聚硅氧烷涂敷于硅烷化的微粒硅胶上,制备出反相高效液相色谱固定相。制备出的固定相对极性、非极性化合物有良好的分离能力,峰对称性好。对其稳定性进行了考察,连续使用１２００ｈ后,固定相的含碳量及色谱性能保持不变,且用ｐＨ１１．０的流动相冲洗２６０ｈ,固定相的色谱性能仍很好,可见固定相的耐碱性能良好。     

一维NOESY技术在醇胺混合物分析中的应用

N-甲基二乙醇胺、三乙醇胺、2-二异丙基氨基乙醇分别属于化武相关化合物氮芥气HN2、氮芥气HN3、神经性毒剂Vx前体化合物。采用一维NOESY选择性激发核磁共振技术实现了高背景干扰下对痕量3种醇胺类化合物相关峰的指认和结构的鉴定。方法对三乙醇胺、N-甲基二乙醇胺、2-二异丙基氨基乙醇检测限(S/N3)分别为5,10,10μg/m L。该方法简单、快速、不需要复杂的样品前处理步骤,可以有效排除背景干扰,解决核磁共振氢谱中目标化合物部分峰被掩盖,无法对化合物实施充分鉴定的情况。以第32次禁化武组织的水平考试编号322的有机样品为基质,添加20μg/m L 3种醇胺化合物,使用该方法进行分析,取得了良好的效果。     

QuEChERS-气相色谱-三重四极杆质谱法测定白花蛇舌草中18种有机磷农药

建立了QuEChERS-气相色谱-三重四极杆质谱法(GC-MS/MS)测定白花蛇舌草中18种有机磷农药(OPPs)含量的方法.用乙腈提取样品中的目标化合物,用无水硫酸镁去除水分,用乙二胺-N-丙基硅烷、C18吸附剂、石墨化炭黑的混合物去除杂质,得到的溶液供GC-MS/MS分析.用Rxi-5 Sil MS毛细管气相色谱柱...     

具有抗肿瘤活性甾体氮芥类化合物的研究进展

本文按照甾体的甾核结构对甾体氮芥化合物进行分类,综述了近年来新合成的甾体氮芥类化合物及其衍生物的抗肿瘤活性及研究进展,并对此方面的发展趋势和应用前景作了展望。     

用L-脯氨酸衍生物作为手性流动相添加剂拆分对映异构体

用自制的N-十二酰基-L-脯氨酸和N-十二酰基-L-脯氨酸-3,5-二甲基苯胺两种L-脯氨酸衍生物作手性流动相添加剂,在氨丙基硅烷化硅胶柱上,用正己烷/异丙醇作流动相,对多种手性化合物进行了高效液相色谱拆分.实验结果表明用N-十二酰基-L-脯氨酸作添加剂拆分的12种手性化合物,有8种手性化合物能得到拆分,具有较好的手性选择性.虽然用N-十二酰基-L-脯氨酸-3,5-二甲基苯胺作添加剂,手性选择性也较好,但由于含有苯环,紫外吸收增强,基线波动严重.     

气相色谱-质谱法分析硫芥子气及相关化合物

用气相色谱－质谱法对含硫芥子气类化合物进行了分析。探讨了长链芥子气的电子轰击电离的质谱规律，并对待测化合物的色谱保留数据进行了研究，在给定条件下，各种待测含硫芥子气在气相色谱柱中能有效的分离和鉴定。     

茄呢基氮芥衍生物的合成及生理活性

茄呢基氮芥衍生物的合成及生理活性;氮芥;茄呢醇;合成;生理活性     

Synthesis and characterization of glycosylated nitrogen mustard derivatives and their interaction with bovine serum albumin

To improve the specificity of nitrogen mustards towards tumor cells, glucose-nitrogen mustard, fructose-nitrogen mustard, and lactose-nitrogen mustard were prepared as three novel glycosylated nitrogen mustard derivatives by esterification of bis(2-chloroethyl)carbamic chloride (BCC) with glucose, fructose, and lactose, respectively. BCC was synthesized from bis(2-chloroethyl)amine hydrochloride and triphosgene. The topic products were characterized by infrared (IR) and mass spectrometry (MS), and their interaction with bovine serum albumin was investigated by measuring fluorescence spectra in tris(hydroxymethyl)aminomethane hydrochloride (Tris–HCl) buffer solution at physiological conditions.     

Single-molecule detection of nitrogen mustards by covalent reaction within a protein nanopore

Mustards, including sulfur mustards and nitrogen mustards, form a class of cytotoxic, vesicant chemical warfare agents. Mustards have also been used to treat cancer and played a vital role in the development of chemotherapy. Additionally, because of their destructive properties, ease of synthesis, and the lack of effective antidotes, mustards are unquestionably terrorist threats. Therefore, quick and convenient detection of mustards is a critical issue. In the present study, we achieved detection of various mustards on the basis of their chemical reactivity by using engineered alpha-hemolysin (alphaHL) protein pores as sensor elements. We describe four classes of reactions for detecting mustards. These reactions occur between mustards and thiol groups contributed by cysteine side-chains within the lumen of the alphaHL pore or on an internal molecular adapter. The approach is quick and straightforward. It can confirm the existence of mustards in as little as 10 min at 50 microM or lower.     

Phosphoric amides. 7—Mass spectrometry of phosphoric amido esters: Fragmentation patterns and migratory aptitudes

Mass spectra of 38 organophosphorus compounds, containing both phosphate ester (P(O)OR) and phosphoramidate (P(O)NR′R″) functional groups, were recorded and discussed. Attention was focused on P? N bond cleavage, which can involve simple fission, fission accompanied by hydrogen migration from the ester group and fission accompanied by the migration of the ester R group to the departing nitrogen atom. Fragmentations characteristic for the N(β-chloroethyl) derivatives (phosphorylated nitrogen mustards) are also presented.     

Screening of nitrogen mustards and their degradation products in water and decontamination solution by liquid chromatography-mass spectrometry

Analysing nitrogen mustards and their degradation products in decontamination emulsions posed a significant challenge due to the different phases present in such matrices. Extensive sample preparation may be required to isolate target analytes. Furthermore, numerous reaction products are formed in the decontamination emulsion. A fast and effective qualitative screening procedure was developed for these compounds, using liquid chromatography-mass spectrometry (LC-MS). This eliminated the need for additional sample handling and derivatisation that are required for gas chromatographic-mass spectrometric (GC-MS) analysis. A liquid chromatograph with mixed mode column and isocratic elution gave good chromatography. The feasibility of applying this technique for detecting these compounds in spiked water and decontamination emulsion was demonstrated. Detailed characterisation of the degradation products in these two matrices was carried out. The results demonstrated that N-methyldiethanolamine (MDEA), N-ethyldiethanolamine (EDEA) and triethanolamine (TEA) are not the major degradation products of their respective nitrogen mustards. Degradation profiles of nitrogen mustards in water were also established. In verification analysis, it is important not only to develop methods for the identification of the actual chemical agents; the methods must also encompass degradation products of the chemical agents as well so as to exclude false negatives. This study demonstrated the increasingly pivotal role that LC-MS play in verification analysis.     

Pyridiniums as potential synthetic substitutes for nitrogen mustards

Dialkylamino-alkyl primary amines 1b and 2b are converted by pyrylium salts into the corresponding pyridinium derivatives. The pyridinium salts act as aminoalkylating agents for representative O-, S-, N-, and C-nucleophiles and are potentially safe substitutes for nitrogen mustards in the reactions.     

Synthesis of bis(2-chloroethyl)amino-1,8-naphthyridines for evaluation as anticancer agents

Some 1,8-naphthyridine nitrogen mustards have been synthesized for studies of their antitumor potentialities. All the tested intermediate and target compounds are devoid of antitumor properties.     

3D QSAR/CoMFA and CoMSIA studies on antileukemic steroidal esters coupled with conformationally flexible nitrogen mustards

Thirty-eight antileukemic steroidal esters possessing conformationally flexible nitrogen mustards were studied, and the 3D QSAR/CoMFA and CoMSIA methodologies were applied in order to derive the correlation between their structure and the in vivo antileukemic activity. These compounds show significantly reduced toxicity and possibly increased bioavailability compared to free nitrogen mustards and therefore constitute potent antileukemic drugs. Both the CoMFA and CoMSIA studies gave similar results indicating that the steric effect and the hydrophobic/hydrophilic balance especially in the steroidal part of the molecules probably determined their bioactivity. Of paramount interest is the observation that the orientation of the alkylating part of the SMEs toward the surface of ring B of the steroidal skeleton was related with increased activity. Concerning the steroidal part, the presence of hydrophobic groups in rings B and D was found to be important for enhanced activity. Enhancement of antileukemic potency is further observed if hydrophilic/H-bond acceptor groups are present at the positions 7 and 17 of the steroidal skeleton. Leapfrog simulations provided novel compounds which lead our future synthetic endeavor for obtaining SMEs with optimum bioactivity.     

Identification of nitriles in petroleum products : Complex formation as a method of isolation

Nitrogen compounds were completely removed from a hydrogenated furnace oil by shaking with a mixture of ferric chloride and zinc chloride. The resulting complexes were separated from the oil and thermally decomposed to liberate the nitrogen compounds. After removal of nitrogen bases with hydrochloric acid and indoles, carbazoles, and phenazines with perchloric acid, the nitrogen compounds remaining in the concentrate were separated by fractional clution from an aluminum oxide column and gas chromatography. The following compounds were identified or their presence was indicated in the resulting fractions by their ultraviolet and/or mass spectra: dicyanobenzene, dicyanocyclohexane, cyanoindene, cyano-2,3-dihydroindene, cyanonaphthalene, dicyanoindene, dicyano-2,3-dihydroindene, dicyanonaphthalene, cyanobiphenyl, dicyanooctahydronaphthalene, and/or several of their alkyl derivatives.     

光化疗抑瘤剂四苯基卟吩氮芥的合成

首次报道合成了6个四苯基卟吩氮芥化合物,其结构均经波谱及元素分析确证,活性实验表明所有受试化合物均具有对人肝癌细胞株SMMC-7721的化学杀伤和光动力效应双重活性,具有发展为高效低毒光化抗肿瘤药物的前景。