【作者】 徐曌；

【导师】 靳素荣； 雷家珩；

【作者基本信息】 武汉理工大学 ， 应用化学， 2008， 硕士

【摘要】 植物黄酮类化合物具有抗氧化、抗衰老、治疗心血管疾病、降血脂等保健功能。本文以荷叶为原料,研究了荷叶中黄酮类物质的提取工艺、分离纯化方法及抗氧化作用,并通过颜色反应、紫外吸收光谱法等初步鉴定了荷叶黄酮类化合物。1.在提取荷叶中黄酮类化合物的工艺研究中,对微波辅助法的提取工艺条件进行筛选,通过正交实验得出微波辅助法提取荷叶中黄酮类化合物的最佳工艺条件为:微波时间为2min、料液比为1∶30、乙醇体积比为60%、微波功率为中火,在此条件下黄酮提取率为4.08%。2.采用超声法对荷叶中黄酮类化合物的提取工艺进行了研究,实验结果显示:料液比为1∶20,超声时间20分钟,乙醇浓度50%,提取3次为荷叶黄酮超声萃取法的最佳工艺条件。在此条件下黄酮化合物的提取率为4.85%。3.采用溶剂热提取法对荷叶中黄酮类化合物的提取工艺进行研究得到其最佳工艺条件为:料液比1∶30、乙醇体积比为60%、提取2h、提取温度90℃。在此条件下黄酮化合物的提取率为4.74%。三种提取方法相比,超声法提取荷叶黄酮类化合物的得率较高。4.在得到黄酮类化合物粗提液后,对粗提液中的黄酮类化合物的纯化方法进行了探索,结果表明D101型大孔吸附树脂对荷叶黄酮有较好的吸附分离性能,采用吸附流速为1BV/h,吸附液浓度为1.89mg/mL,洗脱剂为50%乙醇溶液,洗脱流速为1BV/h,洗脱剂用量为3BV为最佳纯化条件,经过D101型大孔吸附树脂精制后荷叶黄酮的纯度为78.43%。纯化后的样品通过薄层层析法、颜色反应法及紫外吸收光谱法初步鉴定,确定为黄酮类和黄酮醇类化合物。5.荷叶提取物对自由基的清除作用及抗氧化性质研究结果表明,荷叶黄酮具有良好清除·OH自由基能力及在油脂中抗氧化能力。更多还原

【Abstract】 Lotus leaf is a sort of crude plant material for medicine and food. Flavonoids have health functions, such as antioxidation, fighting against senium, curing cardiovascular diseases, reducing blood fat and so on. In this paper,the best extraction, purification technologys and the antioxidant were researched and the flavonoids were identified by the color reactivity ,TLC,UV and HPLC.1. Microwave extraction: the power of microwave medium(about 400W), the period of microwave treatment 2 minutes, 60% ethanol, liquid material ratio 1:30. The rate of extracting of flavonoids in lotus leaf was 4.08% under this condition.2. Ultrasonic extraction: The optimal process conditions were percent of ethanol volume 50%, ratio of solid to liquid 1 : 20(g/mL), three extraction times, and extraction period as 20 min. The rate of extracting of flavonoids in lotus leaf was 4.85% under this condition.3. This is the first time to take the solvent-thermal extraction as the method to extract.: the ratio of material to liquid 1:30, 60% ethanol, extraction time 2h, the extraction temperature 90℃, to extract two times. Under this condition the lotus leaf flavononids extraction rate is 4.74%The ultrasonic extraction is best for the low energy cost, short time and high extraction rate.4. The optimal adsorbent for flavonoids of D101 macroporous resins was selected and its dynamic absorbing behavior was studied. The results showed that the D101 resin possessed higher absorption and desorption capacity and the optimum conditions were the flow rate of absorption solution, solution concentration, elution solvent concentration, flow rate and dosage of elution were lBV/h,about 1.89mg/mL, 80%ethanol,1BV/h and 3BVrespectively.The product yield could be 78.43% by refinement of flavonoids from lotus leaf. And we identify the compounds are flavonoids and flavonol.5. The scavenging effect of flavonoids in lotus leaf on hydroxyl radical was etudied. The result showed that it was easy for flavonoids in lotus leaf to scavenge free radical (OH). The antioxygenation of flavonoids in lotus leaf was studied in the oil. The graph of POV showed that the flavonoids in lotus leaf is a good antioxidant.更多还原