Li Yanzhe, Sheng Zhe, Zhu Chuanlei, Yin Wei, Chu Changhu
School of Pharmacy, Shanghai Key Laboratory of New Drug Design, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China.
School of Pharmacy, Shanghai Key Laboratory of New Drug Design, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China.
Talanta. 2018 Feb 1;178:195-201. doi: 10.1016/j.talanta.2017.07.037. Epub 2017 Jul 14.
Crown ether is a type of typical macrocyclic polyether compounds, which can produce strong interactions with cationic species, such as metal ions and protonated amines due to its cavity structure and the strong electronegative effect of heteroatoms on the crown ether ring. In this paper, a type of silica based crown ether stationary phase was prepared by covalently bonding dibenzo-18-crown 6-ether (DBCE) on silica gel via copper (I) catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC). The tetraazido DBCE was rapidly prepared by bromomethylation and subsequent azido substitution of DBCE. Finally, this key intermediate was covalently bonded to silica beads by click chemistry to get click-DBCE. Its structure was confirmed by FT-IR and elemental analysis, and the structures of all related intermediates were confirmed by NMR, IR and MS spectra. The crown ether based stationary phase showed good chromatography characteristics and column efficiency (up to 43,553 plates m theoretical plate number is obtained in the case of fluoranthene) under reverse phase liquid chromatographic (RPLC) model. The primary chromatographic evaluation showed that click-DBCE displayed better chromatography efficiency than commercial C18 stationary phase (THERMO BDS HYPERSIL), when they were applied in the separation of regio-isomers of benzene, polycyclic aromatic hydrocarbons (PAHs) and macrolide pharmaceuticals. Furthermore, this stationary phase could also be used to separate fullerenes under normal phase mode, and in this case, 1-chloronaphthalene was suitable additive for improving chromatographic separation ability.
冠醚是一类典型的大环聚醚化合物，由于其空腔结构以及冠醚环上杂原子的强电负性效应，它能与阳离子物种（如金属离子和质子化胺）产生强烈相互作用。本文通过铜（I）催化的叠氮化物-炔烃1,3-偶极环加成反应（CuAAC）将二苯并-18-冠-6-醚（DBCE）共价键合在硅胶上，制备了一种基于硅胶的冠醚固定相。通过DBCE的溴甲基化及随后的叠氮取代反应快速制备了四叠氮基DBCE。最后，通过点击化学将该关键中间体共价键合到硅胶珠上得到点击-DBCE。通过傅里叶变换红外光谱（FT-IR）和元素分析确认了其结构，所有相关中间体的结构通过核磁共振（NMR）、红外光谱（IR）和质谱（MS）进行了确认。在反相液相色谱（RPLC）模式下，基于冠醚的固定相表现出良好的色谱特性和柱效（在荧蒽的情况下理论塔板数高达43553块/米）。初步色谱评价表明，当用于分离苯的区域异构体、多环芳烃（PAHs）和大环内酯类药物时，点击-DBCE比市售的C18固定相（THERMO BDS HYPERSIL）表现出更好的色谱效率。此外，该固定相还可用于正相模式下富勒烯的分离，在这种情况下，1-氯萘是提高色谱分离能力的合适添加剂。
