【作者】 李音；

【导师】 吕秀阳； Shuguang Deng；

【作者基本信息】 浙江大学 ， 化学工艺， 2013， 博士

【摘要】 生物碱是存在于生物界的一类含氮有机化合物,多数具有碱性和复杂的氮杂环结构,它是自然界中分布最广泛的天然产物之一,存在于包括隐花植物、显花植物、单子叶植物、双子叶植物在内的100余种植物体中。生物碱类化合物大多具有明显的生理活性,如抗肿瘤、抗菌、镇痛、降压等,为许多药用植物和多种我国传统中药的主要有效成分,已有多种生物碱在临床上被用于高血压、痛风、疟疾等疾病的治疗。现在,生物碱仍是具有开发潜力的重要天然药物之一,自然资源中生物碱的提取及分离纯化依然是天然药物研究开发领域的重要课题。然而,自然资源中的生物碱往往与大量其他化合物共存且含量极低,再加上生物碱自身的碱性和母环结构的多样性,使得从植物提取液中分离纯化生物碱类化合物成为一项极有挑战性的工作。吸附法是生物碱的分离纯化中最常用也最有效的方法之一,然而,现有的生物碱吸附分离工艺大多只针对植物提取液中一两种特定生物碱的分离或总生物碱的纯化,只适用于特定的原料体系,无法推广到其他体系中,且商业吸附剂虽通用性好,但吸附量不够大,选择性不够高。因此,探索生物碱类化合物的吸附分离规律,开发高吸附量、高选择性的新型吸附剂对生物碱类化合物的分离纯化具有重要意义。围绕生物碱的吸附分离规律研究,本文主要开展了以下工作。1野马追总生物碱的提取工艺通过单因素实验优化野马追总生物碱溶剂提取工艺,得到较优工艺条件为：0.5%乙酸、90%乙醇稀酸醇溶液,液固比8：1,沸腾浴提取时间1h,提取2次。在此条件下,野马追总生物碱提取率为0.52%。2超高交联树脂分离纯化水溶液中的盐酸小檗碱合成了一种超高交联树脂TEPA,以盐酸小檗碱作为生物碱模型物,考察TEPA树脂用于水溶液中盐酸小檗碱分离纯化的性能。选择分子大小不同的三种化合物(2-萘酚、盐酸小檗碱、刚果红)作为吸附质,考察了TEPA的分子筛效应。TEPA对2-萘酚吸附量最大,对盐酸小檗碱的吸附则大大弱于2-萘酚,而刚果红吸附量最小,表现出明显的分子筛效应。从动力学数据来看,2-萘酚的吸附速率最快,盐酸小檗碱次之,刚果红最慢。在此基础上,以动态吸附实验实现了水溶液盐酸小檗碱的分离纯化,将盐酸小檗碱的纯度从66.7%提高到99.4%。3大孔吸附树脂分离纯化生物碱类化合物的规律测定了5种生物碱模型物(奎宁、盐酸小檗碱、盐酸川芎嗪、秋水仙碱、苦参碱)在26种大孔吸附树脂上的静态吸附等温线、静态吸附动力学曲线及动态吸附穿透曲线。总体来看,生物碱模型物的平衡吸附量随着树脂极性的增加而降低,随着比表面积的增加而增加,但具体到不同生物碱,分子大小与树脂孔径之间的关系也会影响吸附效果。26种树脂中,非极性树脂中的HPD100B、HPD300,弱极性树脂中的AB-8、HPD722吸附效果较好。生物碱模型物混合溶液在HPD300上的吸附中表现出明显的竞争吸附现象。4有序介孔炭高效吸附水溶液中的生物碱合成了一种有序介孔炭,并首次将其用于水溶液中生物碱的分离纯化。以盐酸小檗碱、秋水仙碱、苦参碱作为生物碱模型物研究有序介孔炭材料对生物碱类化合物的吸附性能。有序介孔炭能有效吸附水溶液中的生物碱模型物,吸附量达到传统大孔吸附树脂HPD300、HPD100B的两倍甚至更高,且吸附能在很短的时间内达到平衡。极高的吸附量和极快的吸附速率显示了有序介孔炭有望成为植提液中生物碱类化合物分离纯化的高效吸附剂。更多还原

【Abstract】 Alkaloids are a group of natural organic compounds containing mostly basic nitrogen atoms in a heterocyclic ring and most of them are alkaline. Alkaloids represent one of the most widespread classes of natural products, which derive from more than100botanical families including cryptogams, phanerogams, mono-and dicotyledons. Alkaloids exhibit a range of biological and pharmacological activities such as anti-tumor, anti-bacterial, pain-relief and antihypertensive; many of them are the main bioactive ingredients of medicinal plants and traditional Chinese medicine, and some of them have been directly used as natural medicines in several clinical applications. Nowadays, alkaloids are still the potential natural products in drug discovery, and extraction, effective separation and purification of alkaloids from natural resources remain important topics in natural products research and development. However, alkaloids generally exist in multicomponent mixtures with a very low concentration in natural resources. Furthermore, the structural diversity and alkalinity of alkaloids make their separation and purification directly from plant extracts a very challenging task.Adsorption is one of the most widely used and the most effective methods for alkaloids separation and purification. However, the existing separation processes of alkaloids on commercial adsorbents were mostly used for one or two alkaloids isolation or total alkaloids purification from natural plant extracts; these processes are only applied to a few limited plant resources, and high adsorption capacity and selectivity are two main problems of commercial adsorbents. Therefore, study on adsorption of alkaloids on different commercial adsorbents and development of effective adsorbents for purification of alkaloids from aqueous solutions are very important. Focus on the adsorption separation and purification of alkaloids, the research works were summarized as follows:1Extraction of total alkaloids from Eupatorium lindleyanum DCThrough single-factor experiment, the extraction process of total alkaloids from Eupatorium lindleyanum DC was studied, and the optimal conditions of extraction were obtained as follows:the concentration of ethanol90%, the concentration of acetic acid0.5%, the ratio of solvent to material8and extraction times2with1h per time. The yield of total alkaloids from Eupatorium lindleyanum DC was0.52%at those conditions.2Hypercrosslinked poly(styrene-co-divinylbenzene) resin as a specific polymeric adsorbent for purification of berberine hydrochloride from aqueous solutionsA hypercrosslinked poly(styrene-co-divinylbenzene) resin (TEPA) was synthesized, characterized and to be used as a specific polymeric adsorbent for separation of berberine hydrochloride as an alkaloid model compound from aqueous solutions. Three organic compounds of different molecular sizes (2-naphthol, berberine hydrochloride and Congo red) were chosen as target molecules to elucidate the molecular sieving effect of the TEPA resin. The adsorption capacity of2-naphthol on TEPA was the largest, the adsorption capacity of berberine hydrochloride was much smaller while that of Congo red was the smallest among the three adsorbates, suggesting a potential molecular sieving effect of the TEPA resin. The adsorption kinetic data indicated that the adsorption of2-naphthol on the TEPA resin was the fastest, adsorption of berberine hydrochloride was much slower while that of Congo red was the slowest. The separation capability of the TEPA adsorbent for purification of berberine hydrochloride was well demonstrated in a dynamic adsorption experiment, and the purity of berberine hydrochloride increased from66.7%to99.4%.3Separation and purification of alkaloids on macroporous resinsThe adsorption properties (equilibrium, kinetics and column breakthrough) of five alkaloid model compounds (quinine, berberine hydrochloride, ligustrazine hydrochloride, colchicine and matrine) on26macroporous resins were studied. Generally, the resins with a low polarity and a high surface area offered high adsorption capacities for all alkaloids, while the pore size of the resins should also be considered during the selection of proper resins for certain alkaloids. Among all the resins, non-polar (HPD100B and HPD300) or weakly polar (AB-8and HPD722) resins were suitable for the adsorption of all the five alkaloid compounds. In dynamic adsorption experiment on HPD300, a competitive adsorption phenomenon happened between the five alkaloids in the mixture solution.4Ordered mesoporous carbon as a superior adsorbent for purification of alkaloids in aqueous solutionsAn ordered mesoporous carbon was synthesized, characterized, and used as an effective adsorbent for purification of alkaloid compounds from aqneous solutions for the first time. Berberine hydrochloride, colchicine and matrine were selected as the model compounds to evaluate the adsorption properties of the ordered mesoporous carbon for alkaloids. The ordered mesoporous carbon displayed a great adsorption capacity of the alkaloids (berberine hydrochloride, colchicine and matrine) which were more than double the adsorption capacities of these compounds on two commonly used commercial resins (HPD300and HPD100B) at a similar condition, and the adsorption equilibrium could be achieved in a very short time. Great adsorption capacity and high adsorption rate indicated the ordered mesoporous carbon to be a promising adsorbent for adsorption and purification of different alkaloids from plant extracts.更多还原