【作者】 孙红娜；

【导师】 廖丹葵；

【作者基本信息】 广西大学 ， 化学工艺， 2008， 硕士

【摘要】 高血压是一种以动脉收缩压或舒张压升高为特征的临床综合症,它常伴有心脏、血管、脑和肾脏等器管疾病。食品蛋白质中含有具有降血压作用的活性肽（降血压肽）,它可以通过抑制血管紧张素转换酶（ACE）的活性来达到降血压的作用,因此也称为血管紧张素转换酶抑制肽（ACEI）。以茶树菇为原料,采用溶剂提取法提取茶树菇中的降血压活性肽,以蛋白质提取率（D）和提取液对ACE活性抑制率（IP）为指标,考察了以水和50%乙醇为提取溶剂的提取效果。实验结果显示茶树菇水提液的提取率为85.78%,抑制率为48.43%,50%乙醇提取液的提取率为41.48%,抑制率为49.16%,综合考虑选择水作为提取溶剂,并优化了水提法的提取工艺,确定了提取的适宜工艺条件为:提取温度30℃,最适pH为8,提取时间9h,此时蛋白质提取率（D）可达到88.3%,对ACE的抑制率（IP）为49.3%。使用活性炭对提取液脱色,采用单因素实验法,考察了活性炭用量、脱色温度、溶液pH值、脱色时间对脱色率（D_c）和活性损失率（L_P）的影响,实验结果表明,在加入0.5%活性碳、脱色温度40℃、溶液pH3.5的条件下脱色40min,脱色效果较好,脱色率（D_c）可达到78.86%,活性损失率（L_P）为15.68%,对ACE的抑制率（IP）为41.57%。实验使用10kDa超滤膜对脱色液进行超滤富集活性成分,收集滤液,进行层析分离,考察了Sephadex G-25凝胶、Sephadex G-15凝胶的分离效果。选用Sephadex G-15凝胶为层析材料,以水为洗脱溶剂,洗脱速度为1.0mL·min^-1,上样量为3mL时,可收集到3种组分,活性肽回收率（R_P）可达91.1%,其中洗脱Ⅲ峰有较高的ACE抑制效果,抑制率（IP）为46.4%,Ⅲ峰活性肽回收率（R_P）为25.6%。选用Ⅲ洗脱峰为原料,采用RP-HPLC反相制备色谱分离,可以得到4种组分,经活性检测,ACE抑制活性最强组分位于Ⅲ-d（1）组分,纯度可达95%以上,其IC₅₀为0.0109 mg·mL^-1。更多还原

【Abstract】 Hypertension is one kind of the clinical syndrome taking that arterial systolic pressure or diastolic pressure rises as characteristic,it frequently accompanies heart,blood vessels, kidney and brain diseases.A number of peptides which can depress blood pressure have been isolated and characterized from foods.The peptide which also named ACE-inhibitory peptide （ACEI）by inhibiting the activity of Angiotensin-converting enzyme（ACE）to depress the blood pressure.Taking Agrocybe aegirit as the raw materals,the effect of solvent on extraction of ACEI and its inhibition for ACE was tasted.The water extracts showed the extraction rate（D）and the inhibitory activity（IP）at 85.78%and 48.43%;the ethanol（50%）extracts showed the D and IP at 41.48%and 49.16%.Therefore,distill water was selected as extraction solvent. Meanwhile,the optimal extraction conditions of ACEI from Agrocybe aegirit was investtigated. The result showed that the optimal extraction conditions as following:extraction time was 9 hour,extraction temperature 30℃,and then the D and IP were 88.3%and 49.3%.Activated carbon was adopted in decolour water extracts solution by single factor experiment. The factors including quantity of activated carbon,temperat- ure,pH,and adsorption time were investigated in terms of decolouring efficiency（D_c）and bioactivity loss（L_p）.The results showed that optimum decoloration effect was obtained from the following conditions: quantity of activated carbon 0.5%,temperature 40℃,pH value 3.5,and adsorption time 40 minutes.Then decolouring efficiency and bioactivity loss were 78.86%and 15.68%,and inhibitory activity（IP）was 41.57%.Water extracts solution which was decoloured with the activated carbon was separated with ultrafiltrate membrane which molecular weight is 10 kDa.Further purification of the active fraction was carried out by gel-filtration with Sephadex Gel-25 and Sephadex Gel-15. The filter solution was isolated three peaks with the Gel-15 when eluted with water at a flow rate of 1.0 mL·min^-1and initial volume at 3 mL,the peptide total yield（R_p）was 91.1%.The third peak has the strongest inhibitory to ACE,the inhibitory activity（IP）was 41.57%,and the peptide yield（R_p）was 25.6%.The third peak’s sample was purified by RP-HPLC,it can be separated into four components.The highest active component which namedⅢ-d（1）was identified by RP-HPLC, its purity can reach 95%,and IC₅₀was 0.0109 mg·mL^-1.更多还原