离子对高效液相色谱法对人工合成色素的分离和测定

本文介绍了用离子对反相液相色谱法对五种常用合成色素日落黄、苋菜红、胭脂红、亮蓝、柠檬黄的测定方法。5μm Zorbax-ODS 4.6mm×15cm柱;以含对离子试剂四丁基溴化铵0.005mol/L的甲醇:水=50:50(v/v)为流动相在10min内可全部出峰。回收率为92.2％～105.5％,相对标准偏差为3.1％。     

用毛细管电泳同时分析饮料中合成色素和防腐剂

建立了饮料中合成色素与防腐剂的毛细管电泳分离、紫外吸收检测分析方法；详细研究了缓冲体系组成与浓度对分离效果的影响。在优化条件下，１１ｍｉｎ完成５种色素和２种防腐剂的分析，检测限为１５～５８ｍｇ／Ｌ；保留时间精度为０３９％～１１％；峰高测量精度为１４％～２９％；该法成功地用于实际样品的分析。     

高效液相色谱法同时快速检测腌腊肉制品中20种非法添加合成色素

采用亚3μm色谱柱建立了同时快速检测腌腊肉制品中20种非法添加合成色素的高效液相色谱法。样品经石油醚脱脂、乙醇-氨水-水(7∶2∶1)提取、钨酸钠溶液沉淀蛋白,采用Agilent Poroshell 120 EC C18(50 mm×4.6 mm,2.7μm)色谱柱以甲醇-0.02 mol/L乙酸铵(p H 5.5)为流动相梯度洗脱,二极管阵列检测器检测,外标法定量。结果表明,待测物可在17 min内实现完全分离。20种成分的质量浓度在0.15~20.0 mg/L范围内与峰面积呈线性关系,相关系数(r)大于0.998,方法的回收率为70.3%~107.9%,相对标准偏差(RSD)为0.5%~3.1%,检出限为0.1~0.2 mg/kg。与传统5μm色谱柱ACE C18(250 mm×4.6 mm,5μm)相比,本方法节约了62%的分析时间,并能在常规HPLC系统内使用,具有广阔的应用前景。     

Qualitative and Quantitative Treatment of Thin-Layer Chromatograms of Incompletely Separated Synthetic Food Colors

A procedure for the qualitative and quantitative determination of dyes after thin-layer chromatographic separation is developed using an example of five synthetic food colors: Brilliant Blue, Tartrazine, Sunset Yellow, Ponceau 4R, and Azorubine. The chromatogram is scanned and saved in Windows 95/98 raster image format and processed by the Adobe Photoshop 5.0 program package. The procedure is applicable even when the dyes are incompletely separated on the chromatogram.     

Schinortriterpenoids: A Case Study in Synthetic Design

Since the pioneering days of total synthesis and retrosynthetic analysis, the community has embraced guiding principles for planning synthetic approaches towards complex natural products. These guideposts have enabled the community to synthesize ever more complex compounds by applying prior knowledge gained in new settings. The recently isolated schinortriterpenoid family of natural products has attracted considerable synthetic attention and provided a rich opportunity to evaluate the lessons learned in the construction of complex, polycyclic scaffolds. In this Minireview, a detailed discussion of the synthetic work within this family is provided, including the six reported total syntheses, as well as a comparative analysis of the approaches utilized in their construction.     

食品中46种禁限用合成色素的分级提取净化体系研究

建立了46种禁限用合成色素的分级提取净化体系,采用反相液相色谱多波长检测对该体系的效果进行了评价。提取净化体系的第一级采用正己烷振荡提取、凝胶渗透色谱净化,实现了对苏丹类染料的有效提取分离,回收率均大于80%;第二级采用水振荡提取,乙腈辅助提取的手段,实现了对大多数水溶性合成色素及工业染料的提取分离,回收率均大于60%;第三级采用甲醇-氨水振荡提取,可实现对少数极性较强染料的提取分离,回收率均大于55%。经过第二、三级提取后的样品,无需再净化,即可直接进行高效液相色谱分析,提高了分析效率。采用此体系对样品进行合成色素的测定分析,结果表明,本方法对含蛋白质、脂肪类食品基质具有较强的适用性。     

环肽合成方法的研究进展

介绍了纯环肽与杂环肽合成的方法、策略及其优缺点,列举了一些常用缩合试剂,探讨了反应溶液浓度、线型肽前体化合物的结构及构象等因素对环化反应的影响.     

含能富勒烯吡咯烷衍生物的合成及工艺研究

利用Prato反应合成分离出了新型含硝基富勒烯吡咯烷衍生物1, 并对其工艺条件进行了研究, 探讨了反应物计量比、温度及时间对产物1产率的影响, 得到了合成产物1的最佳工艺条件: C₆₀, 间硝基苯甲醛和N-甲基甘氨酸的物质的量比为1∶1∶2, 温度为100 ℃, 反应时间为16 h, 此时产物1产率达到94.8%(以消耗的C₆₀计). 同时用UV-Vis, FT-IR, ¹H NMR, ¹³C NMR and MS spectra等光谱手段确定了产物1的分子结构.     

UPLC-DAD法同时测定预调鸡尾酒中24种水溶性合成色素

建立了预调鸡尾酒中24种水溶性合成色素的超高效液相色谱-二极管阵列检测器(UPLC-DAD)分析方法,对流动相、色谱柱、洗脱梯度等色谱条件进行了优化,确定最佳分离条件为:Waters BEH C18色谱柱(2. 1 mm×50 mm,1. 7μm),流动相为10 mmol/L乙酸铵(pH 6. 25)和甲醇-乙腈(2∶8,体积比),采用梯度洗脱,在16 min内实现24种色素的快速分离。24种色素在0. 01～50. 0 mg/L范围内具有良好的线性关系(r~2 0. 998 0),方法检出限为0. 66～27. 78μg/L,定量下限为2. 19～92. 59μg/L;日内相对标准偏差(RSD)为0. 04%～5. 3%,日间RSD为0. 08%～6. 4%;回收率为53. 4%～114%。该方法具有所测色素种类多、分析时间短、检出限低等优势,已成功应用于市售预调鸡尾酒样品的检测。     

依匹哌唑的合成工艺研究

依匹哌唑是首个治疗精神分裂症的多巴胺、部分5-HT1A受体激动剂和5-HT2A受体拮抗剂类化合物,然而其目前的生产路线存在成本高及收率低等缺点。本文在文献方法的基础上,设计了一条合成依匹哌唑的新路线：以4-取代丁腈和7-羟基喹啉-2-(1H)酮为起始原料,经氧烃基化反应得醚化物1,将醚化物1氰基还原得到氨基物2,氨基物2与Boc-双氯乙基亚胺关环得环合物3,环合物3经脱保护得化合物4,化合物4与4-溴苯并噻吩反应得到目标产物依匹哌唑,采用核磁共振和质谱确证了中间体和目标产物的结构,目标产物纯度高达99.30%,且此合成路线具有操作简单、反应易控、原料易得、产物易分离以及环境友好等优点。     

阿斯巴甜合成工艺研究

探讨了以天冬氨酸和苯丙氨酸为原料制备甜味剂阿斯巴甜的合成工艺。首先对合成的各步反应进行了研究,然后考察了前三步反应每步之间连接的可能性,最后实现了中和之前各步反应的一锅化。一锅化的总收率达到63.6%左右,并且α－异构体与β－异构体的比率达到95.4：4.6。     

Synthetic Hydromagnesite as Flame Retardant. A Study of the Stearic Coating Process

A synthetic hydromagnesite obtained from an industrial by-product rich in magnesium oxide was employed and evaluated as a non-halogenated flame retardant for poly(ethylene-co-vinyl acetate). The filler was characterized with different techniques (such as specific surface area, TGA, particle morphology and size measurements, WAXS). Significant differences were found between the synthetic hydromagnesite and the natural one. Synthetic hydromagnesite was coated with stearic acid and the effectiveness of the coating process was studied by the dye adsorption method and sedimentation volume measurements. The amount of coating agent ranged from 1 to 4.5%. This factor was found to have a significant effect on the thermal decomposition behaviour of the filler. A poly(ethylene-co-vinyl acetate) (27% of VA) was filled with the coated synthetic grades of hydromagnesite as well as with two commercial flame retardants and different physicochemical properties were evaluated, including their flame retardant effect.     

含氟内酯化合物的合成方法研究进展

内酯化合物广泛存在于天然产物和具有生理活性的物质中, 因此, 内酯化合物的合成一直是人们非常关心的一个研究领域, 不仅作为天然产物的重要合成砌块, 也用来合成一些精细化工产品和医药中间体. 将氟原子或含氟基团引入到内酯化合物分子中, 可使其生理活性发生改变. 就含氟内酯化合物合成方法的研究进展进行了综述.     

Dynamic Interactions in Synthetic Receptors: A Guest Exchange Saturation Transfer Study

The accumulated knowledge regarding molecular architectures is based on established, reliable, and accessible analytical tools that provide robust structural and functional information on assemblies. However, both the dynamicity and low population of noncovalently interacting moieties within studied molecular systems limit the efficiency and accuracy of traditional methods. Herein, the use of a saturation transfer-based NMR approach to study the dynamic binding characteristics of an anion to a series of synthetic receptors derived from bambusuril macrocycles is demonstrated. The exchange rates of BF₄⁻ are mediated by the side chains on the receptor (100 s⁻¹<k_ex<5000 s⁻¹), which play a critical role in receptor-anion binding dynamics. The signal amplification obtained with this approach allows for the identification of different types of intermolecular interactions between the receptor and the anion, something that could not have been detected by techniques hitherto used to study molecular assemblies. These findings, which are supported by a computational molecular dynamic study, demonstrate the uniqueness and added value of this NMR method.     

合成龙脑与合成樟脑制备新工艺初探

报道了一种制备合成龙脑与合成樟脑的新工艺。常压下异龙脑在一种含锌催化剂作用下 ,可部分脱氢生成樟脑 ,部分异构化生成龙脑。将此产物分离提纯后可同时得到合成樟脑与合成龙脑     

Phainanoids的4,5-螺环骨架的合成探索

本工作报道了用铑(I)催化芳基化环化反应和芳香亲核取代反应为关键步骤,合成天然产物Phainanoids的4,5-螺环骨架的探索.从已知化合物1出发,经过结构修饰得到炔酮5,在铑(I)催化条件下,与苯硼酸发生芳基化环化反应,构建了多取代环丁烯6.随后经过羟基保护和臭氧解反应得到α-烷氧基环丁酮8,其与格氏试剂9发生加成反应得到环丁醇10.最后在碱性条件下发生芳香亲核取代反应,在酸性条件下脱除乙氧基甲基(ethoxymethyl, EOM)和缩酮保护基,得到了4,5-螺环骨架结构18.格氏试剂9与邻烷氧基环丁酮8未能按照Cram’schelation模型进行与天然产物Phainanoids中螺环手性中心一致的立体选择性加成.综合文献报道和相关实验,可能的原因是:邻烷氧基环丁酮8的相对刚性结构,增加了镁离子与羰基氧原子和邻位烷氧基螯合过渡态的能垒;以及格氏试剂9中的氟原子与镁离子发生分子内螯合,抑制了镁离子与羰基邻位的烷氧基的螯合作用.     

Synthetic Study Towards the Total Synthesis of Neocarzinostatin Chromophore

The chromophores of enediyne chromoprotein anticancer antibiotics have attracted a lot of efforts towards the total synthesis. Very recently, Myers group^[1] reported the first synthesis of neocarzinostatin chromophore 1. The key point of our approach for the total synthesis of this compound is to construct the highly strained and unstable bicyclic[7.3.0]epoxyenediyne core at the late stage of synthesis using an intramolecular acetylide aldehyde ring closure. The proposed approach is illustrated retrosynthetically as follows (Scheme).     

高分子微泡的研究——Ⅰ.二烯丙基二(十二烷基)季铵盐的合成与聚合

本文合成了二烯丙基二(十二烷基)溴化铵(DADD),用超声波分散其水溶液而形成微泡。用γ射线、偶氮二异丁睛(AIBN)、过硫酸铵(APS)引发使微泡发生聚合,井对所得的微泡进行表征。实验结果证明:用γ射线引发能使微泡双分子膜发生全部聚合、而用AIBN,APS引发则只能发生部分聚合,聚合后,微泡的形状(态),渗透性行为、相转变温度等都未发生变化,但其稳定性却提高了,用断裂电镜证实了本文所合成的微泡是单室的双分子膜微泡。