枸杞多糖的分离鉴定与体外肠道代谢初步分析

Separation and in vitro gut metabolism analysis of polysaccharides from the fruits of Lycium barbarum

对枸杞多糖的分离纯化工艺和结构鉴定、质量分析方法进行研究,并对其体外肠道代谢过程进行模拟分析,为其开发利用提供参考。枸杞子经乙醇提取除杂、水提、超滤浓缩、冷冻干燥获得枸杞多糖(LBP);LBP采用中压制备色谱系统在线检测,先经DEAE-650M阴离子交换色谱柱分离获得4个主要组分,再分别经超滤浓缩、Sephadex G25色谱纯化、冷冻干燥,获得纯化的4种主要枸杞多糖LBP-1~4。经HPSEC色谱分析,组分LBP-1~4相对分子量依次为65.58、63.83、62.67、65.58kD;采用HPAEC-PAD检测,表明LBP-1~4主要由岩藻糖、鼠李糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖等6种单糖组成,其中阿拉伯糖与半乳糖含量较高;采用紫外-可见分光光度法分析,测定LBP-1~4的中性糖、糖醛酸和总蛋白质含量分别为64.08%~73.05%、8.5%~18.0%、7.27%~18.67%;体外模拟肠道代谢分析结果表明,LBP在人工胃液中稳定,在人工肠液、大鼠肠道菌群液中会发生降解代谢。上述研究结果可为枸杞多糖的制备与质量控制、产品应用开发提供参考。

Polysaccharides of Lycium barbarum were separated followed by their structure characterization and in vitro gut metabolism analysis,which gave clues for their future utilities and standard quality evaluations in this study.Total polysaccharide of Lycium barbarum(LBP)were extracted at first,followed by DEAE-650M and Sephadex G25 column purifications using medium pressure liquor chromatography(MPLC)instrument.As results,four major fractions(LBP-1-4)were separated from LPS with success.They showed similar relative molecular weight to be 65.58,63.83,62.67 and 65.58 kD respectively as measured by HPSEC.They were all composed of 6 monosaccharides(Fuc,Ara,Rha,Man,Gal and Glc),of which arabinose and galactose were relative abundant as measured by HPEAC-PAD method.UV-Vib methods were used to measure the total amount of their sugar,glucuronic acid and protein contents,and the results of which indicated to be 64.08%-73.05%,8.5%-18.0%and 7.27%-18.67%respectively.LBP was stable in artificial gastric juice,while unstable in artificial intestinal juice or rat intestinal flora solution.These results could be beneficial for preparation and quality control of LBP as well as its potential utilizations.