中药多糖成分前处理及检测方法研究进展

多糖是中药的重要活性成分之一,具有降血脂、降血糖、增强免疫、抗肿瘤、抗氧化、抗凝血、抗炎症、抗衰老等活性。该类物质具有极性强、分子量大、结构难确证等特点,成为中药多糖新药开发的瓶颈。该文综述了近10年关于中药多糖成分的前处理及检测方法,以期为中药多糖定性定量分析,质量控制的提高,多糖药物深度开发和中药物质基础的全面研究提供参考。     

Detailed Structural Analysis of the Immunoregulatory Polysaccharides from the Mycobacterium Bovis BCG

Bacillus Calmette-Guérin polysaccharide and nucleic acid (BCG-PSN), extracted from Mycobacterium bovis, is an immunoregulatory medicine commonly used in clinic. However, the structural characteristics and potential pharmacological efficacy of the polysaccharides from BCG-PSN remain unclear. Herein, two polysaccharides (BCG-1 and BCG-2) were purified and their structures were characterized. Monosaccharide composition analysis combined with methylation analysis and NMR data indicated that BCG-1 and BCG-2 were an α-D-(1→4)-mannan with (1→2)-linked branches, and an α-D-(1→4)-glucan with (1→6)-linked branches, respectively. Herein, the mannan from BCG-PSN was first reported. Bioactivity assays showed that BCG-1 and BCG-2 dose-dependently and potently increased the production of inflammatory mediators (NO, TNF-α, IL-6, IL-1β, and IL-10), as well as their mRNA expressions in RAW264.7 cells; both have similar or stronger effects compared with BCG-PSN injection. These data suggest that BCG-1 and BCG-2 are very likely the active ingredients of BCG-PSN.     

Preparation of HPLC chiral packing materials using cellulose tris(4-methylbenzoate) for the separation of chrysanthemate isomers

We investigated the separation of chrysanthemate isomers ( 1 ), particularly the (1R)-trans form, by high-performance liquid chromatography (HPLC) using polysaccharide derivatives, such as the phenylcarbamates and benzoates of cellulose and amylose, as the chiral stationary phases (CSPs). The chiral packing materials (CPMs) having a high chiral recognition for the chrysanthemic acid ethyl ester ( 1a ) were prepared by coating cellulose tris(4-methylbenzoate) ( 2a ) dissolved in solvents containing methyl benzoate or acetophenone as an additive on silica gel. The separation factor for 1a significantly depended on the preparation conditions of CPM 2a , such as the coating amount of 2a and the type and amount of additives. The chiral recognition ability created by imprinting the additives was lost when the CPM was heated at a high temperature, and was recovered by contacting it with the additive in a packed column. The structural change in 2a during these treatments was not clearly detected by spectroscopic methods. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5087–5097, 2006     

紫外可见分光光度法测定酶解桑葚酒中多糖含量

采用紫外可见分光光度法测定酶解桑葚酒中的多糖含量。向酶解桑葚酒中加入硫酸,使样品中的多糖水解成单糖,并迅速脱水生成糖醛衍生物,加入苯酚作为显色剂,检测波长为490 nm,标准工作曲线线性方程为y=0.056 8x–0.035,相关系数r=0.999 4。测定结果的相对标准偏差为0.03%(n=5),平均加标回收率为98.69%。该方法用于检测酶解桑葚酒中多糖含量,简便、快速。     

白芨多糖两亲性聚合物的合成及载药纳米体系

制备了硬脂酸改性白芨多糖两亲性聚合物(SA-BSPS)药物载体,采用红外光谱及核磁共振氢谱对SA-BSPS药物载体进行了表征,并以核磁共振氢谱峰面积计算取代度.以多西他赛(DTX)为模型药物,制备了多西他赛-硬脂酸改性白芨多糖聚合物(DTX-SA-BSPS)胶束,测定了DTX-SA-BSPS的粒径分布、Zeta电位、载药量及包封率.结果表明,硬脂酸已接枝到白芨多糖的羟基上,取代度为12.94%.DTX-SA-BSPS胶束的粒径为(97.01±3.17)nm,Zeta电位为(-19.56±0.22)m V,载药量为(9.13±0.17)%、包封率达(81.11±0.18)%.探讨了SA-BSPS胶束的细胞毒性及其被人肝癌细胞(Hep G2)株摄入的情况.细胞毒性实验表明,浓度为0.5μg/m L的SA-BSPS胶束孵育72 h时,肝癌细胞存活率为(78.82±3.25)%.荧光摄入实验表明,孵育4 h后细胞中包载罗丹明B的SA-BSPS胶束的荧光强度明显强于游离罗丹明B,且在孵育过程中,荧光强度随孵育时间的延长而增强.     

高山红景天多糖抗肺纤维化研究

将高山红景天多糖作用于转化生长因子β1(TGF-β1)诱导的A549细胞,观察细胞形态变化,MTT法测定其对细胞增殖的影响,WesternBlotting法及间接免疫荧光法测定细胞中间充质标志物Fibronectin-EDA(Fn-EDA)的表达变化.结果表明:高山红景天多糖可以抑制TGF-β1诱导的A549细胞凋亡;高山红景天多糖促进体外培养的TGF-β1诱导的A549细胞增殖;降低了TGF-β1诱导的A549细胞中Fn-EDA的表达;可以抑制TGF-β1诱导A549细胞向间充质细胞转化.研究结果显示高山红景天多糖可以明显改善体外诱导的肺组织细胞纤维化状态.     

Isolation and structural elucidation of a novel homogenous polysaccharide from Tricholoma matsutake

A crude polysaccharide possessing antitumour, radiation-resistant and anti-ageing attributes was extracted from Tricholoma matsutake by water extraction and alcohol precipitation. From this crude polysaccharide, a homogeneous polysaccharide, TMP-5II, was successfully purified by Sephacryl S-300 column chromatography. The average molecular weight (M_w) of TMP-5II was 15.76 kDa. Monosaccharide analysis indicated that the homogeneous polysaccharide contained four different residues: d-glucose, d-galactose, d-mannose and d-fucose. Attenuated total reflectance infrared spectroscopy revealed characteristics typical of carbohydrate polymers and a peak typical of a β-type glycosidic bond. TMP-5II was selected for structural characterisation by nuclear magnetic resonance (NMR) analysis. According to ¹H NMR, ¹³C NMR and two-dimensional-NMR analysis, TMP-5II contains two kinds of linkages, β and α, at a ratio of 4:1. Preliminary results indicated that the polysaccharide had (1-4)-beta-pyran glucose as the main chain, and a branched chain in the O-6 location with fucose (1-2) mannose (1-3)-alpha-pyran galactose.     

Yeast Synthetic Biology for the Production of Lycium barbarum Polysaccharides

The fruit of Lycium barbarum L. (goji berry) is used as traditional Chinese medicine, and has the functions of immune regulation, anti-tumor, neuroprotection, anti-diabetes, and anti-fatigue. One of the main bioactive components is L. barbarum polysaccharide (LBP). Nowadays, LBP is widely used in the health market, and it is extracted from the fruit of L. barbarum. The planting of L. barbarum needs large amounts of fields, and it takes one year to harvest the goji berry. The efficiency of natural LBP production is low, and the LBP quality is not the same at different places. Goji berry-derived LBP cannot satisfy the growing market demands. Engineered Saccharomyces cerevisiae has been used for the biosynthesis of some plant natural products. Recovery of LBP biosynthetic pathway in L. barbarum and expression of them in engineered S. cerevisiae might lead to the yeast LBP production. However, information on LBP biosynthetic pathways and the related key enzymes of L. barbarum is still limited. In this review, we summarized current studies about LBP biosynthetic pathway and proposed the strategies to recover key enzymes for LBP biosynthesis. Moreover, the potential application of synthetic biology strategies to produce LBP using engineered S. cerevisiae was discussed.