枸杞子糖缀合物的结构与生物活性研究

Study on Structure and Bioactivity of Glycoconjugate Compounds of Fructus Lycii

从宁夏枸杞中分离、纯化得到五个糖缀合物LbGp1～LbGp5。并对包括分子量、糖含量、单糖组成、氨基酸组成及元素分析等物理化学性质进行了研究。通过链霉蛋白酶E或β-消去反应等方法,将糖链从糖缀合物分子上解离下来,经凝胶柱层析或离子交换柱层析进行分离、纯化得到相应的糖链LbGp1-OL～LbGp5-OL。采用全水解和部分酸水解、甲基化分析、GC、GC/MS和~1H、^(13)C NMR等方法测定了这些糖链的重复单元结构。研究了这些糖级合物及其糖链的免疫活性和免疫调节机理;实验结果表明它们均能提高正常小鼠的免疫功能,但作用方式不尽相同。其中LbGp1、LbGp4、LbGp5及LbGp1-OL、LbGp4-OL、LbGp5-OL,其主要的作用靶细胞为B-淋巴细胞,而LbGp2、LbGp3及LbGP2-OL、LbGp3-OL不但能作用于B-淋巴细胞,也能作用于T-淋巴细胞。实验结果还表明,糖链是调节免疫功能的主要成分,如LbGp3-OL的免疫活性要比LbGp3强3倍。同时以LbGp4和LbGp4-OL为目标化合物,进行了免疫作用机理的进一步研究,通过对裸鼠脾细胞、纯化B-淋巴细胞增殖的影响及目标化合物与受体作用位点的结合,进一步证明了LbGp4及LbGp4-OL直接作用的靶细胞是B-淋巴细胞。它的免疫活性可能与核转录调节因子NF-κB和激活蛋白AP-1的表达有关。此外。

In the study five glycoconjugates (from Lb Gp1 to Lb Gp5) have been obtained via the separation and purification of Fuctus Lycii Ningxiaensis and their physical and chemical properties, such as molecular weight, saccharine content, the composition of monosaccharide, the composition of amino acid and the analysis of elements, have been explored. And a glycochain IbGpl-OL-LbGp5-OL has been found out by the way of Pronase E or β elimination reaction to dissociate the glycochain from the molecules of glycoconjugate and through the separation and purification of it by gel column chromatography, and ion exchange ohromatography and then its repetitive unit construction has been tested by the ways and means of full hybridization and partial acid hydrolisis, methylate analysis, Gc, Gc/Ms, iH and 1/3 CNMR. In addition, the immunoactivity and immune-regulating mechanisms of the said glycoconjugates and glycochains have been studied. The results show that all of them are able to improve the immune functions of normal mice, but their modes of action are quite different, of which Lb Gpl,Lb Gp4, Lb Gp5, Lb Gpl-OL, Lb Gp4-OL and Lb Gp5-OL have B-leukomonocyte as their functional target cell while Lb Gp2, Lb Gp3, Lb Gp2-01 and Lb Gp3-OL can exert their actions not only on B-leukomonocyte but also on T-Leukomonocyte, and that glycochains are main factors in the regulation of immune functions. For example, the immunoactivity of Lb Gp3-OL is as high as three times that of Lb Gp3. In the meantime, further studies on the mechanisms of immunization have been carried out by taking Lb Gp4 and LbGp4-OL as target compounds, and it has been proved via the impacts of the splenocyte and the proliferation of purified B-leukomonocyte of nude mice as well as the combination of target compounds with the sites on which acceptors imponse their actions, that B-leukomonocyte is the very target cell on which Lb Gp4 and Lb Gp4-OL have their actions, whose immunoactivity may be related to the expression of the regulating factors of nucleus transcription NF-KB and activated protein AP-1. Besides, Lb Gp2 is able to do away both the perocidating radicals occurring from the system of basic dimethyl sulphoxide and the hydrocarbon radicals coming from Fenton reaction, resuming a quantity-efficiency relationship. Lb Gp5 can retard the peroxidation of low-density lipoprotein.