金银花有效成分绿原酸的提取工艺研究

以广西产金银花为原料,对其有效成分绿原酸的提取工艺进行研究。采用酸醇回流提取法,探索不同条件下对金银花样品中绿原酸提取率的影响因素。结果表明,单因素实验最佳提取条件:提取溶剂为80%乙醇溶液,料液比为1:30,酸度为pH值=5,提取时间为150min;正交实验得出的最佳提取条件:提取溶剂为70%乙醇溶液,料液比1:30,pH值为3,提取时间为150min,按正交实验最佳提取条件提取金银花样品中绿原酸,绿原酸提取率为8.18%。     

微波预处理-溶剂回流提取马占相思叶多酚的工艺研究

研究微波预处理-溶剂回流提取马占相思叶多酚的工艺条件。以干马占相思叶粉为原料,用正交实验法对马占相思叶总多酚的微波预处理提取工艺进行优选,考察预处理乙醇浓度、固液比、微波处理时间对马占相思叶总多酚提取量的影响。结果表明,微波预处理溶剂回流提取马占相思树叶总多酚的最佳工艺参数为:润湿乙醇浓度为50%,用量为样品量的2倍,在微波功率800 W条件下处理30 s后,用体积分数70%乙醇在料液比1∶7,水浴温度70℃、自然pH值(pH=6.38)浸提条件下回流提取30 min。在此工艺条件下,可提取总多酚18.013 mg/g马占相思树叶,所得的多酚提取物以总多酚计的清除DPPH自由基的IC50值为39.126 g DPPH/g总多酚。     

金银花中提取绿原酸的研究

文章以绿原酸的粗提取率为指标,实验研究了乙醇作为提取剂,用索氏提取法,从乙醇体积浓度,提取溶剂的pH和虹吸次数这三个因素通过单因素和正交实验讨论提取绿原酸最佳条件。经过试验表明,乙醇的体积浓为70%,pH为4,虹吸次数为5,效果最佳;而利用超声波辅助提取绿原酸,超声波时间为0.5 h,绿原酸的粗产率较高。抑菌试验发现,绿原酸对金黄色葡萄球菌与黑曲霉具有一定的抑菌作用,对金黄色葡萄球菌的抑菌效果较好。     

金银花中提取绿原酸的研究

文章以绿原酸的粗提取率为指标,实验研究了乙醇作为提取剂,用索氏提取法,从乙醇体积浓度,提取溶剂的pH和虹吸次数这三个因素通过单因素和正交实验讨论提取绿原酸最佳条件。经过试验表明,乙醇的体积浓为70%,pH为4,虹吸次数为5,效果最佳;而利用超声波辅助提取绿原酸,超声波时间为0.5 h,绿原酸的粗产率较高。抑菌试验发现,绿原酸对金黄色葡萄球菌与黑曲霉具有一定的抑菌作用,对金黄色葡萄球菌的抑菌效果较好。     

牛蒡不同部位绿原酸的提取与含量比较

研究乙醇法提取牛蒡各部位绿原酸的最佳提取工艺和含量差异。采用超声提取法分别对牛蒡的根、茎、叶、果实进行绿原酸的含量比较,得出牛蒡绿原酸含量最高的部位在根部。在相同的条件下,分别用水煎法、乙醇热回流法和乙醇超声提取法对牛蒡根中的绿原酸进行提取,得出最佳的提取方法是乙醇热回流提取法。通过L9(34)正交试验,确定出牛蒡的最佳提取条件是温度70℃、时间100 min、乙醇浓度70%、料液比1∶100。在最佳条件下,对牛蒡各部位绿原酸含量进行比较,得出各部位绿原酸的提取率从高到低依次为根5.90%、叶3.42%、茎1.93%、果实0.79%。牛蒡各部位绿原酸的提取工艺和含量差异分析,可为后续研究和实际应用提供一定的理论基础。     

响应面法优化超声辅助提取金银花中绿原酸

采用超声辅助乙醇从金银花中提取绿原酸,通过单因素实验考察pH值、料液比、乙醇体积分数和提取时间对绿原酸提取率的影响,采用响应面法优化提取工艺条件。确定最佳工艺条件为:pH值5.2、提取时间21min、乙醇体积分数63%、料液比1∶13.5(g∶mL)。在该优化条件下,绿原酸的提取率达到10.862%。     

微波辅助提取向日葵籽壳中绿原酸工艺条件的研究

以向日葵籽壳为原料,研究微波法辅助提取向日葵籽壳中绿原酸的工艺。以绿原酸的提取率为考查指标,考查乙醇浓度、溶剂用量、微波时间、微波功率、微波温度、浸提温度、浸提时间、pH八个因素对向日葵籽壳中绿原酸提取率的影响。     

蛇足石杉中黄酮类化合物的提取工艺研究

以乙醇为溶剂,研究用乙醇热回流法从蛇足石杉中提取黄酮类化合物的工艺。以芦丁为标准品,用紫外分光光度法测定其中总黄酮的含量,建立了标准工作曲线回归方程为A=10.60C-0.003 39,相关系数：r=0.997 1。用正交实验研究了乙醇浓度、提取时间、加热温度、固液比等因素对提取效果的影响,在本实验范围内,总黄酮提取的最佳工艺条件为乙醇浓度60%,萃取时间90 min,加热温度90℃,固液比1∶20,在此条件下,提取率为0.447%。     

苎麻根中绿原酸的提取工艺研究

对苎麻根中绿原酸的提取工艺进行了研究。以绿原酸提取率为考察指标,通过单因素实验和正交实验对提取条件进行了优化。确定了苎麻根中绿原酸的最佳提取条件为:乙醇体积分数50%、料液比1∶13(g∶mL)、提取温度90℃、提取溶液pH值5、提取时间100min,在此条件下,绿原酸的提取率为0.2759%。     

从银杏叶中提取银杏黄酮的研究

采用水-乙醇作提取溶剂回流提取了银杏叶中的银杏黄酮.设计正交实验确定影响提取银杏黄酮的显著因素为料液比、乙醇浓度、提取温度.单因素实验确定提取工艺的最佳条件为料液比110,乙醇浓度70%,提取温度70℃,粒度40～80目,回流提取时间为2h.银杏黄酮的提取率达到86.5%.     

大孔树脂对金银花中绿原酸的纯化研究

考察不同型号的大孔吸附树脂对金银花中的绿原酸的提取纯化效果,为进一步开发金银花的相关产品提供参考。采用HPLC法测定绿原酸含量;选用5种不同型号的大孔树采用静态吸附法,筛选出吸附效果和解吸效果较好的大孔吸附树脂;采用动态吸附法,考察大孔树脂的吸附、解吸附性能和纯化效果。NKA-9大孔树脂综合性能最佳,提取液在酸性条件下吸附量最佳。NKA-9大孔树脂对绿原酸的提取纯化效果较好,可用于工业化生产。     

超临界CO2流体萃取金银花的工艺研究

采用超临界CO2流体萃取技术得到金银花提取物,通过用正交试验法进行了最佳工艺优化,对产物进行GC/MS定性分析。结果表明：萃取时间2.5 h、萃取温度55℃、CO2流量9 L/h、萃取压力25 MPa,得率为2.94%,共鉴定出18种香味成分。     

金银花水饮料澄清工艺研究

采用单一壳聚糖澄清处理金银花浸提液,通过正交试验研究确定最佳澄清工艺条件;在最佳工艺基础上,初步研究壳聚糖/海藻酸钠复合絮凝剂对金银花浸提液的澄清效果。研究结果表明,絮体加固剂海藻酸钠的加入有利于提高浸提液的有效成分,且可以获得较好的澄清效果。     

Extraction and HPLC Characterization of Chlorogenic Acid from Tobacco Residuals

Abstract

Chlorogenic acid is a highly valuable natural polyphenol compound used in medicine and industries. Its current commercial sources are from plant extracts of Lonicera japonica Thunb and Eucommia ulmoides Oliver. These sources are limited and expensive. On the other hand, tobacco residuals contain chlorogenic acid and other natural polyphenol compounds. Large quantities of tobacco residuals are produced each year as waste materials from tobacco manufacturing, potentially providing an alternative commercial source of chlorogenic acid and other valuable compounds. In this paper, microwave and ultrasound extractions of chlorogenic acid with mixed solvent were studied. Total polyphenol concentrations in extract solutions obtained with different extraction methods were analyzed with the method of ferrous tartrate and UV‐Vis spectrophotometry and compared. The extraction solutions were also characterized for polyphenol compositions with the method of HPLC. Experimental results indicated that high extract concentrations of chlorogenic acid were obtained with a mixed solvent of acetone and water (1:2 v/v). A total polyphenol concentration of up to 4.87 mg/ml and a chlorogenic acid concentration of up to 2.12 mg/ml were achieved. The application of microwave and ultrasound significantly increased the extract concentrations. The extraction time needed was also much reduced. HPLC analysis indicated that acetone water mixed solvent extraction achieved much higher relative concentrations of chlorogenic acid to other compounds in the extract solutions. These results indicted that fast and effective extraction of chlorogenic acid from tobacco residuals were achieved.     

雪莲果中绿原酸的提取及其抗氧化性测定

以雪莲果为原料,采用醇提法提取绿原酸,通过对不同乙醇质量分数、提取时间、提取温度、料液的提取效果进行比较分析,确定了最佳提取条件为：乙醇质量分数40%,提取时间2.5 h,提取温度80℃,料液比1∶20（g∶mL）,绿原酸提取量为1.63mg/g。邻二氮菲-Fe2＋法测定雪莲果提取物清除.OH（羟自由基）的能力,结果表明雪莲果中的绿原酸具有一定的抗氧化性。     

Simultaneous detoxification and preparative separation of chlorogenic acid from Eupatorium adenophorum by combined column chromatography

An efficient method for simultaneous detoxification and preparative separation of chlorogenic acid from Eupatorium adenophorum was developed. The entire procedure consisted of two separation steps. The first step was enrichment of chlorogenic acid from the crude extract by NKA-II macroporous resin. The purity of chlorogenic acid increased from 5.3% to 20.9% with a recovery of 88.7%. Subsequently, polyamide resin was used to achieve a higher purity. After the polyamide resin treatment, the main toxin 9-oxo-10,11-dehydroageraphorone was removed and the purity of chlorogenic acid reached 86.5% with a recovery of 84.8%. It provided a new way for the utilization of E. adenophorum.     

超声波提取绿原酸的工艺研究

以金银花为原料,采用乙醇为提取剂,提取了金银花中的绿原酸。通过正交试验优化了金银花中绿原酸的提取工艺,结果表明最佳工艺条件是:超声浸提温度为60℃,超声波功率为50%,乙醇浓度为40%,浸提时间为2 h,固液比为1∶90。在此条件下,绿原酸的提取率为8.03%。     

野菊花中绿原酸与木犀草苷同时超声提取条件优化

利用超声波辅助系统从野菊花中同时提取绿原酸和木犀草苷,通过正交试验设计考察料液比、提取时间、乙醇浓度、提取温度对绿原酸和木犀草苷含量的影响。试验结果显示野菊花中绿原酸和木犀草苷同时提取的最佳工艺条件为:75%乙醇水溶液、料液比1∶400、提取时间90 min、提取温度50℃。在最佳提取条件下野菊花中绿原酸和木犀草苷得率分别可达(8.94±0.03)mg/g和(2.97±0.04)mg/g。     

Phenolic composition and antioxidant activity of the aqueous extract of bark from residues from mate tree (Ilex paraguariensis St. Hil.) bark harvesting concentrated by nanofiltration

The goal of this study was to determine the best conditions to obtain the highest total polyphenol content from mate bark aqueous extract and investigate the phenolic composition and antioxidant activity of the concentrate obtained during nanofiltration. The Response Surface was employed to determine the optimum condition for extraction of polyphenolics from mate bark aqueous extract. The extract obtained using the best conditions (a temperature of 85 ± 5 °C and with extraction time of 1.5 min) contained approximately 1.6 mg/mL of chlorogenic acid equivalent, and was subjected to nanofiltration. The total polyphenol content values in the permeate and in the concentrate collected at different volume reduction factors (VRF of 1.5–6) were different from those detected in the optimized extract (unfiltered). The concentration of phenolic compounds and antioxidant activity increased when VRF was increased. The major compounds detected in optimized mate bark extract and its concentrates (VRF 4 and 6) were chlorogenic acid and epigallocatechin gallate, which can be related to the high antioxidant activity of mate bark aqueous extract.     

Autotoxic Compounds from Fresh Alfalfa Leaf Extracts: Identification and Biological Activity

Many investigators have attempted to identify the allelochemicals in alfalfa (Medicago sativa), that cause autotoxicity. The autotoxic compounds from fresh alfalfa leaves were separated and quantified, and their biological activity was determined. Chemical separation procedures involved an 80% methanol extract of fresh alfalfa leaves, treatment with activated charcoal, microcrystalline cellulose thin-layer chromatography (MCTLC), and finally separation by Sephadex LH-20 column chromatography. The various fractions were examined further by high-performance liquid chromatography (HPLC). Preliminary identification by HPLC analysis resulted in peaks with retention times close to those of chlorogenic (m/z = 354) and salicylic acid (m/z = 138) standards, and these compounds were confirmed with GC-MS. Several other peaks remain unidentified. Chlorogenic acid occurs in relatively large amounts (0.39 mg/g) in alfalfa aqueous extracts as compared to salicylic acid (0.03 mg/g), and bioassays suggest that chlorogenic acid is involved in alfalfa autotoxicity.