纳升级电喷雾离子源-四极杆-飞行时间质谱中磷酸化肽的离子抑制作用

目前磷酸化蛋白质组学研究中的主要技术是蛋白质酶解产生的磷酸化肽的质谱检测。但是实际样品中的磷酸化肽(特别是多磷酸化肽)很难被检测到。其原因普遍认为是由于质谱检测时,非磷酸化肽抑制磷酸化肽。但也有认为非磷酸化肽对磷酸化肽没有抑制作用。另外磷酸化肽之间是否存在离子抑制作用还没有报道。本文采用相同氨基酸序列的标准磷酸化肽和非磷酸化肽,将其单独和混合进行质谱检测,通过对比混合前后磷酸化肽的信号强度,证明了非磷酸化肽对磷酸化肽有离子抑制作用;单磷酸化肽对二磷酸化肽有一定的抑制作用,但不太显著;单磷酸化肽对三磷酸化肽、二磷酸化肽对三磷酸化肽均有显著的离子抑制作用。该研究为今后单磷酸化肽和多磷酸化肽的分段富集和检测提供了有力的证明。     

混合模式色谱材料Click TE-GSH高效富集多磷酸化肽

多磷酸蛋白对于生物体适应内外环境具有重要意义,而明确多磷酸蛋白的磷酸位点功能及其信号转导机制尤为关键. 复杂生物样品中多磷酸化肽的低丰度、低电离的特性,以及非磷酸化肽的抑制作用,决定了质谱分析前进行多磷酸化肽富集是非常必要的步骤. 本工作采用基于巯基-烯烃点击化学法合成的混合模式材料Click TE-GSH进行单磷酸化肽和多磷酸化肽的选择性富集. 我们建立了单磷酸化肽、双磷酸化肽和多磷酸化肽的顺序分段富集方法. 该优化方法能抗干扰,应用于脱脂牛奶时富集到11条多磷酸化肽. 与商品化固化金属亲和色谱(IMAC)材料相比,Click TE-GSH富集多磷酸化肽的选择性更好. 本工作所建立的富集方法为高效富集多磷酸化肽提供新方法和新技术.     

亲水/反相二维色谱法制备桔梗中的三萜皂苷

建立了亲水/反相二维色谱用于制备桔梗中三萜皂苷单体的方法。桔梗经水煮醇沉、反相和亲水两种模式的固相萃取后得到三萜皂苷类组分。选定XAmide色谱柱（150 mm×20 mm,5 μm）,以乙腈和水为流动相,在亲水色谱模式下进行组分制备。选择时间触发模式,以1 min为单位进行馏分收集,得到6~25 min之间的20个三萜皂苷精细组分。以第18个馏分（JG23）为例,在反相色谱模式下采用Atlantis Prep T3色谱柱（100 mm×30 mm,5 μm）制备,得到两个单体化合物。通过质谱和核磁共振对其进行定性,确定分别为deapi-platycoside E和platycoside E。实验结果表明,该制备方法具有好的正交选择性,对于复杂样品中三萜皂苷类化合物的分离纯化有一定的借鉴意义。     

亲水作用色谱固定相的发展及应用

亲水作用色谱作为一种高效液相色谱技术,在强极性和离子型化合物如氨基酸、碳水化合物和多肽等的分离分析中发挥着重要作用。作为色谱技术的核心,亲水作用色谱材料的发展直接影响着色谱分离的选择性和分离效率,制约着亲水作用色谱的应用和推广。目前商品化和学术报道的亲水作用色谱材料种类繁多,键合相结构丰富。本文从色谱材料结构出发,综述了近5年内基于硅胶基质的亲水作用色谱固定相,包括纯硅胶、氨基、氰基、二醇基、酰胺型、聚（琥珀酰亚胺）型、糖型和两性离子型键合相的发展及其在极性药物、蛋白质组学、代谢组学等方面的典型应用。同时简要介绍了近年来亲水作用色谱的色谱评价研究。     

Investigation of brush-type chiral stationary phases based on O,O'-diaroyl tartardiamide and O,O'-bis-(arylcarbamoyl) tartardiamide

Four chiral organosilanes based on O,O'-dibenzoyl tartardiamide, O,O'-bis-(3,5-dimethylbenzoyl) tartardiamide, O,O'-bis-(phenylcarbamoyl) tartardiamide and O,O'-bis-[(3,5-dimethylphenyl)carbamoyl] tartardiamide were synthesized and immobilized on silica to afford corresponding brush-type chiral stationary phases (CSPs) with well-defined structures. Using 54 compounds containing a wide variety of structures as analytes, the enantioselectivities of the four CSPs were evaluated under normal-phase modes. 3,5-Dimethyl substituent in the aryl group was found to significantly affect the enantioselectivity of CSPs containing aryl ester moieties. Aryl carbamate moieties in CSPs were observed more beneficial for enantioseparation than aryl ester moieties. The additional hydrogen-bond donors (NH) present in the carbamate groups contributed greatly to the enantioselectivity of CSPs, which is contrary to the results that have been found in network-polymeric CSPs.     

Establishment of a search library about benzylisoquinoline alkaloids based on selective separation on the binaphthyl column and standard analysis on C18 column

A search library about benzylisoquinoline alkaloids was established based on preparation of alkaloid fractions from Rhizoma coptidis, Cortex phellodendri, and Rhizoma corydalis. In this work, two alkaloid fractions from each herbal medicine were first prepared based on selective separation on the “click” binaphthyl column. And then these alkaloid fractions were analyzed on C18 column by liquid chromatography coupled with tandem mass spectrometry. Many structure‐related compounds were included in these alkaloids fractions, which led to easy separation and good MS response in further work. Therefore, a search library of 52 benzylisoquinoline alkaloids was established, which included eight aporphine, 19 tetrahydroprotoberberine, two protopine, two benzyltetrahydroisoquinoline, and 21 protoberberine alkaloids. The information of the search library contained compound names, structures, retention times, accurate masses, fragmentation pathways of benzylisoquionline alkaloids, and their sources from three herbal medicines. Using such a library, the alkaloids, especially those trace and unknown components in some herbal medicine could be accurately and quickly identified. In addition, the distribution of benzylisoquinoline alkaloids in the herbal medicines could be also summarized by searching the source samples in the library.     

The herbalome—an attempt to globalize Chinese herbal medicine

The herbalome is a project with the objective of globalizing Chinese herbal medicine (CHM) by clarification of its composition, structure, and function; by establishing a standard resource library; and by interpreting the synergistic and complementary mechanisms of multi-components on multi-targets. In phase I, it focuses on the development of systematic separation methodology for resolving and analyzing the complex components in CHM and establishment of a comprehensive resource library. This review summarizes recent advances in the herbalome project with regard to innovative separation techniques and demonstration of a resource library.     

Sequential elution of multiply and singly phosphorylated peptides with polar-copolymerized mixed-mode RP18/SCX material

Novel polar-copolymerized mixed-mode RP18/SCX material was developed for feasible phosphopeptide enrichment, in which multiply and singly phosphorylated peptides could be sequentially eluted and separated with high selectivity.     

Silica based click amino stationary phase for ion chromatography and hydrophilic interaction liquid chromatography

A silica based amino stationary phase was prepared by immobilization of propargylamine on azide-silica via click chemistry. This readily prepared click amino stationary phase demonstrated good selectivity in separation of common inorganic anions under ion chromatography (IC) mode, and the triazole ring in combination with free amino group was observed to play a major role for separation of the anions examined. On the other hand, the stationary phase also showed good hydrophilic interaction liquid chromatography (HILIC) properties in the separation of polar compounds including nucleosides, organic acids and bases. The retention mechanism was found to match well the typical HILIC retention.     

气相色谱法测定多溴联苯的蒸气压

采用气相色谱法,以二氯二苯三氯乙烷(DDT)为参考化合物,测定了6个多溴联苯(PBBs)在不同温度条件下的蒸气压, 然后使用Slide数理统计软件、以最小二乘法回归计算出Antoine方程的A,B,C参数,从而建立了6个PBBs的蒸气压与温度 的关联式。初步探讨了分子连接性指数与蒸气压的相关性,结果发现一阶拓扑指数与蒸气压表现出很好的线性关系,两者 的相关系数的平方大于0.99,标准偏差小于0.08。