【作者】 郑振佳；

【导师】 王晓； 王明林；

【作者基本信息】 山东农业大学 ， 农产品加工及贮藏工程， 2011， 硕士

【摘要】 莲为多年生水生宿根草本植物,在全世界有着广泛的分布。同时,莲也是我国最具特色、栽培面积最大、品系资源最丰富的水生经济植物。荷叶是睡莲科莲属植物的叶,营养丰富且含有生物碱和黄酮等多种活性物质,是非常具有开发价值的天然植物资源。本研究通过对荷叶生物碱的分析以及分离纯化研究,为荷叶资源的进一步开发利用提供科学依据。主要研究结果如下:1.本研究利用阳离子固相萃取柱的定向吸附特性对样品进行净化,利用快速分离液相-飞行时间质谱提供的精确分子质量数,快速鉴定荷叶生物碱。样品采用1%盐酸超声提取,经固相萃取柱净化,再用氨水-甲醇进行洗脱,洗脱液浓缩后用甲醇定容。选用Welch Materials C18柱,以乙腈-水为流动相进行梯度洗脱,在正离子模式下,经飞行时间质谱分析,分离并检测了9种生物碱。实验建立的快速分离液相-四级杆飞行时间串联质谱结合阳离子交换固相萃取柱前处理技术,可以快速准确鉴定荷叶生物碱成分。2.本研究建立了荷叶中生物碱类化合物的快速分离纯化技术。通过实验优化得到了三个荷叶生物碱分离体系,分别为:四氯化碳/氯仿/甲醇/0.1 M盐酸(1/3/3/2,V/V)常规高速逆流分离体系和石油醚/乙酸乙酯/甲醇/水(5/5/2/8,V/V)、叔丁基甲醚/甲醇/水(4/1/5,V/V)两个pH区带逆流色谱分离体系。分离得到的4个生物碱单体纯度均大于98%,且经过质谱和核磁共振对化合物进行了结构的鉴定。结果表明pH区带逆流色谱法是一种高效的分离制备荷叶生物碱的技术。3.采用超声提取-高效液相联用分析荷叶中的O-去甲荷叶碱、N-去甲荷叶碱、荷叶碱和莲碱四种主要的生物碱,为荷叶及相关产品的质量控制参考。选用Welch Materials C18色谱柱,以乙腈-水(含0.1%三乙胺)为流动相进行梯度洗脱,实现了O-去甲荷叶碱、N-去甲荷叶碱、荷叶碱和莲碱四种生物碱的同时基线分离。在0.1-50μg/mL浓度范围内,O-去甲荷叶碱(r = 0.9998)、N-去甲荷叶碱(r = 0.9999)、荷叶碱(r = 0.9998)和莲碱(r = 0.9998)具有良好的线性关系,它们的检出限分别为1.87 ng、2.22 ng、2.34 ng和1.88 ng (S/N = 3)。该方法具有良好的精密度和回收率,可用于荷叶中的生物碱的快速测定。更多还原

【Abstract】 Nelumbo nucifera GAERTN (commonly known as lotus), one of the most well known ornamental and economic perennial aquatic plants and now widely cultivated and consumed all over the world. Nelumbo nucifera leaves is a kind of naturals plant material used both in food and medicine field, involving nutrients and many biological activities. In order to further the study of biological activities of these aporphine alkaloids and to control the quality of this traditional Chinese cash crops and their products, better analysis and purification methods are urgently needed.The main results are indicated as follows:1. A novel method for the analysis of alkaloids in Nelumbo nucifera leaves was established by SPE-RRLC-Q-TOF. The crude sample was extracted by 1% HCl with ultrasound-assisted extraction, then purified by SPE column, and eluted with ammonia–methanol (5:95, V/V). After concentration, the residue was dissolved by methanol solution. The real sample was analyzed by RRLC-Q-TOF. A Welch Materials C18 column was applied in the RRLC separation using acetonitrile and water as mobile phase. The elutens were detected by Q-TOF to obtain the MS spectra with extract molecular weights under positive ion mode. Nine alkaloids were identified. This method can be used to rapidly determine the alkaloids of Nelumbo nucifera leaves.2. Three methods of high-speed counter-current chromatography(HSCCC) were successfully applied to the separation of alkaloids from crude extract of Nelumbo nucifera leaves. The conventional HSCCC separations were performed with a two-phase solvent system composed of tetrachloromethane–CHCl3–methanol–0.1MHCl at a volume ratio of (1/3/3/2, V/V). Two pH-Zone-refining CCC were performed with a two-phase solvent system composed of petroleumether–ethyl acetate–methanol–water (5/5/2/8, V/V) and MtBE-methanol-water (4/1/5, V/V), where triethylamine (10mM) was added to the upper organic stationary phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluent, respectively. The targets were obtained in a single run each with a purity of over 98% as determined by HPLC. The structures of the isolated compounds were identified by ESI-MS, 1H-NMR and 13C-NMR. pH-Zone-refining CCC was the best method in sample-loading capacity, high purity, and high concentration of the collected fractions. The present method may be applied to purification of various other alkaloids from natural products.3. Using ultrasonic extraction, O-nornuciferin, N-nornuciferin, nuciferine and roemerine in Nelumbo nucifera leaves were extracted and determined by the established HPLC method. This work provided a new method for the rapid quality control of Nelumbo nucifera leaves and its products. Four alkaloids were separated on a reversed-phase Welch Materials C18 column with a gradient elution using acetonitrile-1% triethylamine solution as mobile phase. Linear regression of O-nornuciferin, N-nornuciferin, nuciferine and roemerin in the concentration range of 0.1~50μg/mL(R > 0.999) was satisfied and the detection limit were 1.87 ng, 2.22 ng, 2.34 ng and 1.88 ng (S/N = 3), respectively. The method had good precision, recovery and can be used for the determination of alkaloids from Nelumbo nucifera leaves.更多还原