高比表面季铵基树脂的结构调控及在三七叶总皂甙纯化中的应用研究

SYNTHESIS OF POLYMERIC ADSORBENT WITH QUATERNARY AMMONIUM GROUP AND HIGH SPECIFIC SURFACE AREA AND ITS APPLICATION IN PURIFICATION OF EXTRACT OF PANAX NOTOGINSENOSIDE LEAVES

利用Davankov后交联反应,合成了一类兼具高比表面积和高功能基含量的季铵基(—N+(CH)3)吸附树脂,考察了树脂比表面积和功能基含量的调控规律,并将其用于三七叶总皂甙的进一步纯化.结果表明,当树脂比表面积为692m2/g,交换量为2.1mmol/g时,树脂具有最佳的纯化效果,只通过吸附—解吸一步工艺,产品纯度即可从32.0%提高到90%以上,皂甙的回收率高于95%.最后,初步探讨了树脂对皂甙和色素的吸附机理,认为树脂对皂甙的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应.

Mechanism of adsorption for panax notoginsenoside （PNS） and pigment was studied by comparing with the static adsorption capacity and the influence of eluting agent on removal of PNS and pigment among three kinds of commercial resins, such as macroporous adsorbents AB-8, gel ion-change resins 201×2 and macroporous ion-change resins D280, respectively. The result of pilot study revealed that adsorption of PNS was based on the hydrophobic interactions, and that of pigment was based on the synergistic effect of ion exchange effect and hydrophobic interactions. Hereby a series novel polymeric adsorbents with high specific surface area and high content of quaternary ammonium groups （e. g .--N^＋ （CH）3） were synthesized using Davankov post-crosslinked reaction.Then adsorbents were used to purify the panax notoginsenoside （PNS） in the extract of leaves. Adsorption--desorption properties of the quaternary ammonium polymeric adsorbents were investigated . It was showed that the adsorbent with 692 m^2/g specific surface area and 2.1 mmol/g content of--N^＋ （CH）3 groups exhibited the best purification effect. The content of PNS increased from 36.2 % in crude extract of Sanqi leaves to 90.0% and E420 down to 0. 008. And the recovery of PNS was over 95 %. Since the mechanism for adsorption of PNS and pigment was different,PNS and pigments can be eluted from the adsorbent using different eluting agent, respectively. Thus, the adsorptive purification procedure of PNS in the extract of leaves by using this adsorbent is much simpler as compared with conventional purification methods, the purify processes are combined in one step. Moreover, the stability and the regeneration of the quaternary ammonium polymeric adsorbents are evaluated. The results showned that pigments on the adsorption can be removed by elution with 80 % aqueous ethanol solution containing 5 % of sodium hydroxide, and the adsorbent should be regenerated to remove the pigments after it had been used for five circles. The purifying performance of the adsorbent was very stable after regeneration, and it can be used repeatedly. So, the quaternary ammonium polymeric adsorbent with high specific surface area can be used to purifying PNS in the extraction of leaves with high quality.