靛红键合固定相分离黄酮类化合物

Preparation of isatin-bonded silica gel stationary phase separation of flavonoids by HPLC

以γ-[(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)为偶联剂,采用固液相表面连续反应法,制备了靛红键合硅胶固定相(ISSP)。采用红外光谱法、元素分析和热重分析表征配体的结构,根据碳含量数据计算得到硅胶上的靛红配体键合量为0.294mmol·g-1。将新固定相用于中草药有效成分黄酮类化合物的分离,分别考察了流动相pH值和甲醇含量对黄酮类化合物分离选择性的影响,探讨了相关色谱保留机理。结果表明,采用甲醇-0.01mol·L-1磷酸二氢钠(4060,pH=4.0)二元流动相,橙皮苷、芦丁、7-甲基黄烷酮、7-羟基黄烷酮、紫花牡荆素和染料木素在靛红键合相上达到了基线分离。该固定相不仅具有反相色谱特征,除疏水作用外,靛红配体还能为黄酮类化合物提供氢键、偶极作用等位点,因而显示较强的分离能力。

The isatin-bonded silica gel stationary phase （ISSP）was prepared by the solid-liquid successive re- action method, using 7-glyeidoxy-propyltrimethoxysilane （KH - 560） as coupling reagent. Its chemical structure was characterized by Fourier transform infrared spectrometry, elemental analysis and thermal a- nalysis. The bonded amount of ISSP was calculated to be about 0. 294 mmol ~ g-1 ,according to the carbon content of elemental analysis. In this paper,we used the new stationary phase to separate six common fla- vonoids. The effects of pH values and methanol content in mobiles on the selectivity of flavonoids were studied. The related separation mechanism was discussed in detail as well. The results showed that a better baseline separation of hesperidin, rutin, 7-methylflavanone, 7-hydroxyflavanoneon, vitexicarp genistein on ISSP could be easily achieved when using methanol--0.01 mol ~ L-I phosphate buffer （ v/v）as binary mobile. The new ISSP exhibited better separation ability for flavonoids because it was provide various action sites besides hydroprophobicity,such as hydrogen bonding,dipole-diploe and in and 40：60, able to so on, which played a significant role in the separation of flavonoids.