【作者】 李欣；

【导师】 仇汝臣；

【作者基本信息】 青岛科技大学 ， 化学工程与技术， 2021， 硕士

【摘要】 银杏叶提取物是世界上最珍贵的天然植物药提取物之一,具有促进血液循环、消除充血、降浊降脂、镇静、止痛、抗氧化等功能。目前,国内外关于银杏叶提取物以及其他制剂的研究主要集中在银杏叶中黄酮、黄花素、内酯和银杏酸等物质的含量,但对糖类化合物等银杏叶中其他成分的研究较少,其质量控制缺乏全面性和准确性。有研究表明,中草药的药理活性与其糖含量密切相关。由于糖类具有多种生物活性（抗癌、抗炎等）已成为近年的研究热点。因此,银杏叶中糖的分析对于探索这一珍贵植物资源的结构鉴定、构效关系及综合利用具有重要意义。本文分别采用液相色谱、离子色谱和高效毛细管电泳技术对银杏叶中游离的木糖、葡萄糖、甘露糖、岩藻糖、鼠李糖和半乳糖进行测定,为银杏叶中糖类化合物的测定提供了数据和方法支撑。本文首先采用高效液相色谱法示差折光检测器,在NH₂P-50色谱柱上优化了流速和流动相比例。在流动相为乙腈和水的条件下,流动相为乙腈-水（70:30）,柱温为30℃,流速为1.0 mL·min^-1条件下分离效果最好,可以分离鼠李糖、木糖、甘露糖和半乳糖。但仍然无法实现鼠李糖与岩藻糖、半乳糖与葡萄糖的基线分离,因此需要采用新的检测手段达到分离单糖的目的。然后应用离子色谱电化学安培检测器,在无需衍生化的条件下,在Carbo Pac PA20阴离子交换色谱柱上通过优化Na OH淋洗液浓度分离条件,最终确定在12.5mmol·L^-1的Na OH淋洗液梯度洗脱的条件下,实现了单糖的分析测定,银杏叶中单糖的回收率均在83.40%～116.30%之间。其次利用高效毛细管区带电泳技术和紫外检测器,通过单因素实验研究了分离六种单糖的衍生剂萃取次数、缓冲液浓度及pH值等因素对于分离实验的影响,得到了最优工艺条件为:萃取次数3、硼酸缓冲液浓度为30 mmol·L^-1、pH=9.5条六种单糖RSD均小于5%,应用于银杏叶中六种单糖的测定,回收率在80.64%～114.67%之间。另外采用一种新型胺类衍生剂——对甲氧基苯胺,利用毛细管区带电泳紫外检测同时分离了尿苷二磷酸半乳糖和尿苷二磷酸葡萄糖,并且通过单因素实验研究了最佳分离结果下的衍生化的加热时间和温度、缓冲液浓度及分离电压。该方法在缓冲液浓度为50 mmol·L^-1、pH 9.0、分离电压为20 kV的条件下分离效果最好。两种单糖异构体在15 min之内实现分离,RSD小于5%。更多还原

【Abstract】 Ginkgo biloba extract is one of the world’s most valuable natural botanical extracts,with functions such as promoting blood circulation,eliminating congestion,lowering turbidity and lipids,sedation,analgesia and antioxidant.At present,domestic and foreign research on Ginkgo biloba extract and other preparations mainly focuses on the content of flavonoids,flavonols,lactones and ginkgolic acid in Ginkgo biloba,but there is less research on other components in Ginkgo biloba such as sugar compounds,and their quality control lacks comprehensiveness and accuracy.Some studies have shown that the pharmacological activity of herbal medicines is closely related to their sugar content.As sugars have a variety of biological activities（anti-cancer,anti-inflammatory,etc.）have become a hot research topic in recent years.Therefore,the analysis of sugars in Ginkgo biloba is of great significance for exploring the structural identification,conformational relationships and comprehensive utilization of this valuable plant resource.In this paper,the free xylose,glucose,mannose,fucose,rhamnose and galactose in Ginkgo biloba were determined by liquid chromatography,ion chromatography and high performance capillary electrophoresis,respectively,to provide data and methodological support for the determination of glycans in Ginkgo biloba.In this paper,the flow rate and mobile phase ratio were firstly optimized on an NH2P-50 column using a high performance liquid chromatography with an oscillometric refractive index detector.The best separation was achieved with the mobile phase of acetonitrile-water（70:30）,column temperature of 30℃and flow rate of 1.0mL·min^-1,but the baseline separation of the above six monosaccharides was still not achieved.New assays are therefore needed for the purpose of separating monosaccharides.Then,the ion chromatography electrochemical amperometric detector was applied to the Carbo Pac PA20 anion-exchange column without derivatization,and the separation conditions were optimized for the concentration of the Na OH eluent,and the final determination of the monosaccharides was achieved under the gradient elution of12.5 mmol·L^-1Na OH eluent.The recoveries of monosaccharides in Ginkgo biloba were in the range of 83.40%to 116.30%.Secondly,the effects of the number of extractions,buffer concentration and pH of the derivatives on the separation of the six monosaccharides were investigated by single-factor experiments using high performance capillary zone electrophoresis and UV detector,and the optimal process conditions were obtained as follows:the number of extractions was 3,the concentration of borate buffer was 30 mmol·L^-1,pH=9.5 and the RSD of the six monosaccharides was less than 5%.The recoveries ranged from 80.64%to 114.67%for the determination of the six monosaccharides in Ginkgo biloba.In addition,a new amine derivatizer,p-anisidine,was used for the simultaneous separation of uridine diphosphate galactose and uridine diphosphate glucose using capillary zone electrophoresis with UV detection,and the heating time and temperature,buffer concentration and separation voltage of the derivatization were investigated by single-factor experiments for optimal separation results.The best separation was achieved at a buffer concentration of 50 mmol·L^-1,pH 9.0 and a separation voltage of 20 kV.The separation of the two monosaccharide isomers was achieved within 15 min with an RSD of less than 5%.更多还原