大黄素键合硅胶固定相的制备及其在核苷碱基药物分离中的研究

通过γ-(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)偶联剂将具有抗菌功能的植物有效成分大黄素键合到硅胶上,制备了大黄素液相色谱键合固定相(EDSP)。采用元素分析、红外光谱和热分析对该固定相的结构进行表征。以嘧啶、嘌呤和核苷为溶质探针,并用ODS柱做参比,对固定相的色谱性能及保留机理进行了研究。研究结果表明,该固定相具有类似ODS的反相色谱性能,除疏水作用外,由于大黄素的大π共轭体系,为溶质提供了n-π和π-π作用位点;且两个邻位羟基和两个羰基的存在,能够与溶质之间发生氢键作用和偶极-偶极作用。与ODS柱相比,该固定相在极性化合物分离中占优势,且分析速度较快。此外,实验还发现,该固定相能较好地分离二甲苯同分异构体,预示着该固定相有一定的立体选择性分离能力。

Study on the preparation of emodin-bonded silica stationary phase and its application in separation of nucleoside bases by HPLC

A new preparation method of emodin-bonded silica gel stationary phase (EDSP) for high performance liquid chromatography has been developed by using γ-glycidoxypropyltrimethoxysilane (KH-560) as a coupling reagent. Its structure was characterized by elemental analysis, Fourier transform infrared spectroscopy and thermal analysis. The chromatographic performance and the retention mechanism of the new packing material were evaluated by using purine, pyrimidine and nucleoside as solute probes. Meanwhile, the comparative study with ODS was carried out. The results showed that EDSP was a kind of excellent reversed-phase stationary phase with versatile chromatographic functions. The emodin ligand bonded on silica gel can provide n-π and π-π interaction sites for different analytes because of its integrated conjugated system. The polar hydroxy and carbonyl groups of emodin were responsible for dipole-dipole and hydrogen-bonding interactions between the ligand and analytes in the separation process. Comparing with ODS, EDSP had advantage in the fast separation of polar compounds because of weak hydrophobicity and various synergistic sites additionally, it was also observed that positional isomers of xylene were easily resolved, which indicated that EDSP had good stereo selectivity for isomeric compounds.