凤尾草抑菌活性成分提取及其抑菌作用的初步研究

发布时间：2018-03-26 10:00

  本文选题：凤尾草　切入点：抑菌活性　出处：《江西农业大学》2015年硕士论文

【摘要】：中草药是我国传统医学的瑰宝,千百年来,受到了国内外医药界广泛的关注。中草药凤尾草作为传统药用植物,具有广谱抗菌的作用。随着集约化养殖的发展,大肠杆菌耐药性日益严重,给畜牧养殖业带来了巨大的损失。本文对凤尾草中抑菌活性成分的提取工艺及其抑菌作用做了初步研究,以期为凤尾草抑菌活性单体提取、纯化及鉴定的研究提供理论参考。1.凤尾草提取物助溶剂的筛选。试管二倍稀释法测定二甲基亚砜(DMSO)、二甲基甲酰胺(DMF)、乙腈、乙醇、丙酮五种有机溶剂对大肠杆菌的最低抑菌浓度(MIC)及最低杀菌浓度(MBC),其中DMSO对大肠杆菌的MIC为12.5%,MBC为50%,确定为凤尾草提取物的有效助溶剂。2.凤尾草抑菌活性成分提取工艺的优化。以凤尾草提取物对大肠杆菌的抑制效果为评价指标,使用溶剂回流提取法,在单因素试验的基础上,对影响凤尾草抑菌活性成分提取的因素:乙醇浓度、提取温度、料液比、提取次数、提取时间进行L18(35)正交试验。确定最佳提取工艺为:70%乙醇溶液、料液比1:30、提取温度50℃,提取次数3次,提取时间0.5 h,经过验证,总黄酮含量平均为69.33 mg/g生药,抑菌圈直径平均为18.67±0.03 mm,得膏率平均为19.78%。3.凤尾草抑菌活性成分的初步分离。采用液-液萃取法追踪凤尾草抑菌活性成分的极性,选取正丁醇部分为研究对象。运用系统预试法对正丁醇部分的化学成分进行定性分析,正丁醇部分中可能含有机酸、生物碱、黄酮类、蒽醌类、强心苷等化学成分,可能不含植物甾醇、萜类、香豆素、内酯等成分。4.凤尾草提取物正丁醇部分抑菌作用及对细胞膜的影响。凤尾草提取物正丁醇部分对大肠杆菌ATCC25922、大肠杆菌K99、鸡沙门氏菌、金黄色葡萄球菌的MIC分别为12.5 mg/m L、25 mg/mL、12.5 mg/mL、12.5 mg/mL,MBC分别为50 mg/mL、50 mg/mL、50 mg/m L、25 mg/m L。抑菌曲线表明,正丁醇部分0.5MIC下,大肠杆菌的生长出现了一段时间的抑制,随后正常生长;1MIC下,大肠杆菌的生长一直处于抑制状态;2MIC下,大肠杆菌的生长快速进入衰亡期,并在4 h时被杀死。电导率曲线表明,经1MIC正丁醇部分处理的菌液的电导率不断上升,直至8 h时,而后呈稳定发展,由此说明,正丁醇部分可使大肠杆菌菌体的细胞膜受损,细胞内电解质外渗。
[Abstract]:Chinese herbal medicine is the treasure of Chinese traditional medicine, which has attracted extensive attention from domestic and foreign medical circles for thousands of years. As a traditional medicinal plant, Chinese herbal Herbal Herbal Echinacea has the function of broad-spectrum antimicrobial activity. With the development of intensive culture, The drug resistance of Escherichia coli is becoming more and more serious, which has brought great losses to the livestock industry. This paper has made a preliminary study on the extraction process and the bacteriostatic effect of the antibacterial active components from Euphorbia mandshurica, in order to extract the antimicrobial active monomer. The study of purification and identification provides theoretical reference. 1. Screening of the cosolvent for the extraction of Acetonitrile. Determination of dimethyl sulfoxide dimethyl sulfoxide DMSOF, dimethyl formamide, acetonitrile, ethanol by double dilution method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of five organic solvents of acetone against Escherichia coli were as follows: the MIC of DMSO to E. coli was 12.5MBC = 50, which was determined to be the effective cosolvent of the extracts of Euphorbia officinalis. 2. Optimization of the technology. The inhibitory effect of the extract of Euphorbia mongolicum on Escherichia coli was used as the evaluation index. On the basis of the single factor experiment, the factors influencing the extraction of the antibacterial active components of Euphorbia chinensis, such as ethanol concentration, extraction temperature, the ratio of material to liquid, the times of extraction, were studied by solvent reflux extraction method. The optimum extraction technology was determined as follows: 1: 70% ethanol solution, ratio of material to liquid 1: 30, extraction temperature 50 鈩，

本文编号：1667416