4,4'-二氨基三苯胺的合成与纯化

以苯胺和对硝基氯苯为原料, K₂CO₃作催化剂, 合成出了中间产物4,4'-二硝基三苯胺(DNTPA). 将中间产物用10%(质量分数)的Pd/C催化剂加氢催化还原, 得到纯度为96.6%的目标产物4,4'-二氨基三苯胺(DATPA), 合成总产率为38%. 与其它方法相比, 该方法原料便宜易得, 纯度很高, 产物可作为反应的单体原料.     

4,4'-二氨基三苯胺的合成与纯化

以苯胺和对硝基氯苯为原料,K2CO3作催化剂,合成出了中间产物4,4'-二硝基三苯胺(DNTPA).将中间产物用10%(质量分数)的Pd/C催化剂加氢催化还原,得到纯度为96.6%的目标产物4,4'-二氨基三苯胺(DATPA),合成总产率为38%.与其它方法相比,该方法原料便宜易得,纯度很高,产物可作为反应的单体原料.     

电堆集富集非水毛细管电泳同时测定水杨酸、肉桂酸、阿魏酸和香草酸

建立了同时分离测定水杨酸、肉桂酸、阿魏酸和香草酸的电堆集富集-非水毛细管电泳(NACE)的新方法。运行缓冲溶液为40mmol/L乙酸钠-2.5mmol/L氢氧化钠甲醇溶液,电压-25kV,在225nm波长下紫外检测。对电压、乙酸钠浓度、氢氧化钠浓度、进样时间、样品溶液等因素对电堆集及分离的影响做了系统的研究。水杨酸、肉桂酸、阿魏酸和香草酸分别在1.4~28mg/L、0.40~8.0mg/L、0.7~18mg/L和0.7~30mg/L范围内线性关系良好(r=0.9999、r=0.9997、r=0.9994、r=0.9997);回收率分别为95.8~99.6%、96.2~98·2%、95.7~105%和98.9~103%,基于3倍信噪比(S/N=3),4种有机酸的检出限分别为0.069、0.051、0.107和0.089mg/L。     

Surface Functionalization of Magnetite Nanoparticles with Sulfonic Acid and Heteropoly Acid: Efficient Magnetically Recoverable Solid Acid Catalysts

New magnetically recoverable solid acid catalysts for acid‐catalyzed reactions were designed via the surface chemical functionalization of silica‐coated magnetite nanoparticles (SCMNPs) with sulfonic acid groups. First, the SCMNPs were covalently functionalized with 3‐aminopropyl groups to achieve Amp‐SCMNPs. Then, reaction of the Amp‐SCMNPs with 1,4‐butane sultone followed by acidification with phosphotungstic acid (HPW) or diluted sulfuric acid produced magnetically recoverable solid acid catalysts, HPW‐ampsul‐SCMNPs and H‐ampsul‐SCMNPs, respectively. Both catalysts were characterized by various physicochemical analyses such as Fourier transform infrared (FT‐IR) and inductively coupled plasma‐optical emission (ICP‐OES) spectroscopies, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), and energy‐dispersive X‐ray (EDX) analyses. Finally, the catalytic activities of the prepared catalysts were examined in the esterification of acetic acid with butanol and acetalization of benzaldehyde with ethylene glycol. Excellent catalytic efficiencies were obtained in both cases. The catalysts were consecutively recovered and reused five times without significant loss of their activities.     

Experimental and theoretical IR and Raman spectra of picolinic, nicotinic and isonicotinic acids

The experimental and theoretical (B3PW91/6-311++G**) vibrational (IR and Raman) spectra of picolinic, nicotinic and isonicotinic acids (pyridine-2-, -3-, and -4-carboxylic acid, respectively) were studied. Three stable calculated structures were found for picolinic acid: the structure with intramolecular hydrogen COOH?N bond, and the two without hydrogen bond. For the nicotinic acid two stable theoretical structures differ in orientation of the COOH group with respect to the nitrogen atom, whereas for the isonicotinic acid only one form was stable. The theoretical vibrational spectra of the three acids were interpreted by means of potential energy distributions (PEDs) using VEDA 3 program. Next, selected experimental bands were assigned based on the scaled theoretical wavenumbers. Finally, the wavenumbers and intensities for the three isomeric acids were compared and discussed in terms of location of the carboxylic group.     

Determination of oleanolic acid and ursolic acid in cornel by cyclodextrin-modified micellar electrokinetic chromatography

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was established for the determination of oleanolic acid and ursolic acid in cornel. The two components were separated in the running buffer of 40 mmol/L sodium borate containing 5% methanol, 25 mmol/L SDS and 15 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The applied voltage was 24 kV. The wavelength of detection was 200 nm. The temperature was kept at 25 C. Cinnamic acid was used as the internal standard. The analytical performance of the method was tested with respect to linearity, precision and recovery. The calibration curves were linear in the range of 10.15-243.6 microg/mL, r=0.9993 (oleanolic acid) and 10.07-241.7 microg/mL, r=0.9994 (ursolic acid); the intra-day precision (RSD) was less than 3.7% (oleanolic acid) and 4.1% (ursolic acid); the inter-day precision (RSD) was less than 4.2% (oleanolic acid) and 4.9% (ursolic acid). The limits of detection were 1.6 microg/mL for both components. The method proved to be sensitive, rapid, accurate and suitable for the determination of oleanolic acid and ursolic acid in cornel.     

Toward the assembly of heparin and heparan sulfate oligosaccharide libraries: efficient synthesis of uronic acid and disaccharide building blocks

The monosaccharide moieties found in heparin (HP) and heparan sulfate (HS), glucosamine and two kinds of uronic acids, glucuronic and iduronic acids, were efficiently synthesized by use of glucosamine hydrochloride and glucurono-6,3-lactone as starting compounds. In the synthesis of the disaccharide building block, the key issues of preparation of uronic acids (glucuronic acid and iduronic acid moieties) were achieved in 12 steps and 15 steps, respectively, without cumbersome C-6 oxidation. The resulting monosaccharide moieties were utilized to the syntheses of HP/HS disaccharide building blocks possessing glucosamine-glucuronic acid (GlcN-GlcA) or iduronic acid (GlcN-IdoA) sequences. The disaccharide building blocks were also suitable for further modification such as glycosylation, selective deprotection, and sulfation.     

在线扫集-胶束毛细管电动色谱法测定扛板归中的阿魏酸、咖啡酸和原儿茶酸

采用在线扫集-胶束毛细管电动色谱法(sweeping-MEKC)分离测定扛板归中的阿魏酸、咖啡酸和原儿茶酸。采用未涂层熔融石英毛细管(50 cm×50μm,有效柱长36 cm);环境温度25℃;缓冲体系为20 mmol/L NaH2PO4-80mmol/L十二烷基磺酸钠(SDS)-12.5%乙腈(V/V)(pH 2.20),紫外检测波长为216 nm,运行分离电压-20 kV,进样时间100 s。在优化条件下,3种有机酸均在20 min内出峰,峰面积RSD均小于5%。检出限分别达到98.52,118.73和27.27μg/L。     

Efficient formation of novel and versatile building blocks from mucohalic acids: new substitute for tetronic acid and γ-alkylidenebutenolide

Novel and useful building blocks were synthesized efficiently by DABCO mediated highly selective dehalogenation of Knoevenagel aldol adducts of mucochloric acid and mucobromic acid. These new compounds were found to undergo palladium catalyzed C-C bond forming reactions (Suzuki and Sonogashira cross-coupling) in high yields.     

聚对氨基苯磺酸/碳纳米管复合膜修饰电极对尿酸与抗坏血酸的同时测定

通过在碳纳米管修饰玻碳电极表面电聚合的方法制备了聚对氨基苯磺酸/碳纳米管复合膜修饰电极(PABSA/CNT/GC),采用扫描电镜对电极形貌进行了表征。运用循环伏安法研究了尿酸(UA)和抗坏血酸(AA)在该修饰电极上的电化学行为,在pH7.0的PBS中,UA和AA分别在0.312、-0.025 V处产生灵敏氧化峰,与其在聚氨基苯磺酸和碳纳米管单层膜修饰电极上的电化学行为相比,两者的氧化峰电流显著增加,峰电位差(ΔEpa)达到337 mV,表明碳纳米管和聚合物产生协同增效作用,探讨了其作用机理。在优化实验条件下,建立了差分脉冲伏安法同时测定UA和AA的方法,UA、AA的线性范围分别为2.5×10-7~5.0×10-4、8.0×10-6~4.0×10-3mol/L,检出限分别为7.5×10-8、5.0×10-6mol/L。该方法用于尿样中UA和AA的测定,结果令人满意。     

Anthranilic acid derivatives from Inula japonica

Three new anthranilic acid derivatives, N-heneicosanoylanthranilic acid （1b）, N-tricosanoylanthranilic acid （1d）, N-tetracosanoylanthranilic acid （1e）, and two known N-arachidylanthranilic acid （1a） and N-docosanoylanthranilic acid （1c） were isolated from the aerial parts of lnula japonica Thunb. Their structures were established by spectroscopic and chemical methods.     

Investigation of phenolic acids in yacon (Smallanthus sonchifolius) leaves and tubers

Thin-layer chromatographic (TLC) screening of crude extracts of dried leaves and tubers of yacon (Smallanthus sonchifolius, Asteraceae) and products of acid hydrolysis of tubers on the silica gel HPTLC plates using the developing solvents ethyl acetate-formic acid-water (85:10:15, v/v/v) and n-hexane-ethyl acetate-formic acid (20:19:1, v/v/v) proved the presence of chlorogenic, caffeic and ferulic acid. These phenolic acids were isolated from the crude extract of yacon leaves by preparative TLC, and identified after elution by HPLC/MS, as well as by direct injection of the crude extract into the HPLC/MS system. Acid hydrolysis of tubers released the increased amount of phenolic acids (e.g. caffeic acid and ferulic acid), flavonoid quercetin and an unidentified flavonoid, which was detected by TLC analysis. Ferulic acid, isomers of dicaffeoylquinic acid and still an unidentified derivative of chlorogenic acid (Mr = 562) as constituents of yacon leaves and ferulic acid as constituent of yacon tubers are reported here for the first time. These acids gave significant contribution to the radical scavenging activity detected directly on the TLC plate sprayed with 1,1-diphenyl-2-picrylhydrazyl (DPPH).     

几种糖醛酸及其寡糖的薄层层析分析

以葡萄糖醛酸（GlcA）、半乳糖醛酸（GalA）、甘露糖醛酸（ManA）、古罗糖醛酸（GulA）、半乳糖醛酸寡糖（Oligo-GalA）、甘露糖醛酸寡糖（Oligo-ManA）、古罗糖醛酸寡糖（Oligo-GulA）和酶解褐藻胶寡糖（Oligo-u-Alg）为研究对象,探讨其薄层色谱（TLC）行为。结果表明,TLC对不同糖醛酸寡糖有良好的分离和分析效果,其中Oligo-GalA与褐藻胶来源的寡糖兄值不同,而同样来源于褐藻胶的Oligo-ManA与Oligo-GulAR,值相同;首次发现酸解与酶解褐藻胶寡糖聚合度相同时兄值不同。此外,4种糖醛酸对不同的显色剂的显色灵敏度也略有不同,其中硫酸铈显色剂的显色效果最灵敏。这些结果为快速有效分析酸性寡糖的纯度及其聚合度,提供了简便有效的方法。     

紫外辐射接枝法修饰聚乳酸表面及其细胞相容性

通过紫外辐射接枝在聚乳酸膜表面引入聚丙烯酸的方法使聚乳酸材料表面的亲水性和细胞相容性得到改善,研究了各种处理条件对材料表面的羧基密度、表面形态和表面接触角的影响,同时还考察了紫外辐射接枝聚丙烯酸的聚乳酸表面的成骨细胞相容性.红外光谱分析和羧基密度测定结果表明:通过紫外光引发接枝,聚丙烯酸被成功接枝到聚乳酸表面,而且接枝密度受接枝时间和聚丙烯酸质量分数的影响很大.接触角和原子力显微镜研究结果表明:接枝聚丙烯酸后的聚乳酸表面的亲水性和粗糙度明显增加,能够促进成骨细胞的生长.     

高效液相色谱法分离和测定酒石酸和马来酸

１引言 酒石酸（２,３一二羟基丁二酸）和马来酸（顺丁烯二酸）都是重要的有机化工原料,它们被广泛地应用于有机合成和其它化工生产领域［１］． 酒石酸的制备常用钨酸作为催化剂,由马来酸识水溶液与过氧化氢进行环氧化反应再经水解精制而成,其中常含有微量的没有反应的马来酸,因此,建立有效的分离和测定酒石酸和马来酸的方法,对于酒石酸生产条件的选择与控制,以及产品的质量检测等都有十分重要的意义． 目前尚未发现有关同时分离和测定酒石酸和马来酸的文献报道．我们首次采用反相高效液相色谱法,跟踪监测了酒石酸生产过程中的物…     

新型饱和脂肪酸胆酸缀合物的合成及抗胆结石活性研究

胆结石是常见多发病, 但临床缺乏有效的治疗药物. 饱和脂肪酸与胆酸的缀合物能有效预防胆固醇结晶、溶解体内胆固醇结石. 以胆酸或熊去氧胆酸24位羧基为连接位点, 以氨基酸为连接子, 通过酰胺键将载体与具有溶石活性的饱和脂肪酸偶联, 设计合成了一系列新型脂肪酸胆酸缀合物, 其结构经元素分析, IR, 1H NMR和MS光谱分析确证. 通过测定化合物对模型胆汁溶液胆固醇结晶及模型小鼠胆结石的溶解活性, 研究了其体内外溶石活性.     

离子排斥色谱法测定甘油催化氧化产物中的H2CO3和HCOOH

建立了测定甘油催化氧化产物中H2CO3和HCOOH的离子排斥色谱分析方法。采用离子排斥柱分离,分别用纯水和4 mmol/L HCl作流动相进行H2CO3和HCOOH的分析。检测方式为非抑制电导检测。实验结果显示,H2CO3和HCOOH工作曲线的线性范围为2～100 mg/L和6.23～124.6 mg/L,检出限分别为0.45 mg/L和2.49 mg/L(S/N=3)。H2CO3的保留时间和峰面积的相对标准偏差分别为0.07%和4.0%,HCOOH的保留时间和峰面积的相对标准偏差分别为0.09%和2.2%。方法已用于甘油催化氧化产物中H2CO3和HCOOH的分析。     

高效液相色谱-串联质谱法测定调味料中的痕量苯甲酸与山梨酸

建立了调味料中痕量苯甲酸、山梨酸的高效液相色谱-串联质谱检测方法.调味料样品经盐酸酸化后用乙醚多次提取,酸性氯化钠洗涤提取液,挥干后用1 mL90% 0.2 mmol/L NH4OAc(pH 5.0)的乙腈溶液溶解,过膜备用.采用电喷雾负离子电离(ESI-)模式和单反应监控(SRM)模式检测,外标法定量.该方法在0.5...     

胶束扫集毛细管电泳分离测定绿原酸和咖啡酸

采用胶束扫集毛细管电泳分离测定双黄连口服液中的绿原酸和咖啡酸.试验条件为:重力进样时间40 s;以20 mmol/L NaH_2PO_4,100 mmol/L 十二烷基磺酸钠(SDS)为电泳缓冲液(含体积分数15%甲醇,pH 2.20),分离电压-20 kV,检测波长214 nm,讨论了pH、SDS浓度、样品溶剂等对分离效果的影响.在优化条件下,绿原酸和咖啡酸的检出限分别达到1.02和0.168 μg/mL,线性范围分别为5.86～51.5 μg/mL和1.27～14.5 μg/mL.     

Determination of Monochloroacetic Acid and Dichloroacetic Acid for Quality Control of Acetic Acid Chlorination Industry by Ion Chromatography

An ion chromatographic method is described for the purpose of quality control in the process of monochloroacetic acid production. Using 2.5 mM NaOH–10% methanol as eluent, the simultaneous determination of acetic acid, monochloroacetic acid, dichloroacetic acid, and Cl⁻ was obtained in a single run. Monochloroacetic acid and dichloroacetic acid showed good linearity in the range 0.1–20 and 0.15–20 μg/ml and correlation coefficients were 0.9999 and 0.9998, respectively. The detection limits (signal-to-noise ratio 3:1) of monochloroacetic acid and dichloroacetic acid were 17 and 25 ng/ml. This simple, sensitive, and time-saving method can be applied for composition analysis in acetic acid chlorination production.