槐花米中清除自由基活性成分的提取及其性能研究

用体积分数75%的乙醇提取了槐花米中具有清除自由基活性的粗提物,然后用碱提酸沉法从槐花米中提取了芦丁,并制备了芦丁的水解产物槲皮素.测定了不同质量浓度的粗提物、芦丁和槲皮素对DPPH自由基的清除能力,它们对DPPH自由基均有良好的清除作用,清除能力大小顺序为槲皮素＞粗提物＞芦丁＞BHT;0.5 mg/mL的槲皮素、芦丁、粗提物对DPPH自由基的最高清除率分别为83.75%、80.16%、80.89%;而1.0mg/mL的槲皮素最高清除率可高达88.95%.     

金线莲中六种黄酮成分的含量测定及其主成分、聚类分析

建立HPLC同时测定金线莲中6种黄酮类成分芦丁、异槲皮苷、水仙苷、槲皮素、山柰酚和异鼠李素含量的方法,并对不同栽培方式的金线莲中6种成分的含量进行主成分分析和聚类分析。30批金线莲样品主成分分析中,前3个主成分累积方差贡献率为86. 95%;系统聚类分析,当10阈值25时,可聚为2类。建立的方法操作简便,结果准确可靠,可用于金线莲中芦丁、异槲皮苷、水仙苷、槲皮素、山柰酚和异鼠李素含量的同时测定,可为不同种植方式金线莲药材的区分提供科学依据。     

芦丁水解制备槲皮素的实验条件比较研究

为了寻找芦丁水解制备槲皮素的最佳实验条件,为槲皮素的生产提供实验数据,采用在不同溶液中,使用不同的酸,不同浓度,加热不同的时间,观察芦丁水解的情况。实验发现：芦丁在水溶液中,使用盐酸或硫酸,酸的浓度在0．5％时,芦丁水解制备槲皮素的生产成本最低、收率高、综合效益最好。实验结果表明：在0．5％的盐酸或硫酸水溶液中,加热1h,芦丁水解制备槲皮素的收率为91．0％。     

HPLC法测定糯米藤中槲皮素和山柰酚的含量

建立测定糯米藤中槲皮素和山柰酚含量的方法.采用HPLC法测定糯米藤中槲皮素和山柰酚的含量.色谱柱为X-Peonyx C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.1％磷酸(55:45),检测波长为360 nm,流速1.0 mL·min-1,柱温30℃,进样量为10μL.槲皮素和山柰酚的进样量分别在0...     

超声波提取赶黄草中槲皮素方法的研究

研究了赶黄草中槲皮素的最佳提取条件。采用超声提取,用紫外分光光度法,以芦丁作为对照,在370 nm处测定槲皮素的含量。结果显示:赶黄草最佳提取条件为以浓度为60%乙醇,超声功率50 W,超声温度55℃,料液比1∶25,超声时间60 min,槲皮素浸出率最高。超声提取工艺稳定、简单可行。     

槐花米中芦丁的抗氧化性及抑菌性研究

目的:研究槐花米中芦丁的抗氧化性及抑菌性。方法:以中药槐花米为原料,采用碱溶酸沉法提取其中的芦丁并精制,对精制物进行红外光谱分析;采用清除羟基自由基能力测定来分析研究芦丁的抗氧化性;采用滤纸片法以大肠杆菌和金黄色葡萄球菌为抑菌对象,分析芦丁的抑菌性。结果:芦丁浓度越高抗氧化性越强,芦丁的抗氧化性优于抗坏血酸;芦丁对大肠杆菌和金黄色葡萄球菌均有抑菌作用。结论:芦丁有较好的抗氧化性和抑菌性。     

燕子掌总酚超声提取工艺条件的优化

研究燕子掌总酚的超声提取工艺,以总酚含量为指标,选择超声功率、料液比、提取时间、温度为考察因素,采用正交试验确定燕子掌总酚的最佳提取条件。以Folin-Ciocalteu法于760 nm处测定,结果表明在65%的乙醇中最佳提取条件为:料液比1∶40、提取温度60℃、提取时间20 min、超声功率120 W,提取液中总酚含量为13.71 mg/g。     

超声辅助提取鱼腥草中芦丁的工艺优化

以提取时间、提取温度和甲醇体积分数为考察因素,以提取液中芦丁含量为考核指标,通过单因素实验和正交实验优化鱼腥草中芦丁的超声辅助提取工艺。结果表明,各因素对芦丁含量的影响顺序为提取温度甲醇体积分数提取时间,最优提取工艺为:提取时间30min、提取温度60℃、甲醇体积分数60%。     

黔产八角莲超声提取工艺的优化

优化黔产八角莲超声提取工艺。以甲醇体积分数、料液比、提取时间为影响因素,4′-去甲基鬼臼毒素、槲皮素、山奈酚、鬼臼毒素总含量为评价指标,采用正交试验法优化提取方法。最佳条件为甲醇体积分数80%,料液比1:10,提取时间40 min, 4′-去甲基鬼臼毒素、槲皮素、山奈酚、鬼臼毒素总含量为13.15 mg/g。该方法简便快速,可用于超声提取八角莲。     

微波协同碱提酸沉法从槐花米中提取芦丁的工艺研究

采用微波协同碱提酸沉法从槐花米中提取芦丁,比较不同抗氧化剂的提取产率,并优化了提取工艺条件.通过单因素及正交实验,确定了提取芦丁的最佳工艺条件为:提取时间为20 min,抗氧化剂为硼砂和乙二胺四乙酸二钠组成的复合抗氧化剂,提取次数为1次,料液比为1∶18,此条件芦丁的产率为15.58％.     

Separation of Mixtures of Rutin and Quercetin: Evaluating the Productivity of Preparative Chromatography

The flavonoid rutin is present in significant amounts in the flower buds of Sophora japonica L. It offers numerous desired pharmacological effects. Under certain extraction conditions quercetin is found as a hydrolysis product which needs to be separated from rutin. This paper describes the application of liquid chromatography to solve this task. Based on the determination of adsorption equilibrium constants and column efficiencies, the productivity of the separation process is estimated, and scale-up considerations are presented. A comparison with alternatively directly crystallizing rutin from raw extracts is also reported.     

由芦丁制备槲皮素的工艺研究

本文以芦丁水解制备槲皮素,以料液比,酸度,反应时间为影响因素,利用均匀设计对工艺参数进行了优化,结果显示最佳工艺为：配料比12：1（v／w）硫酸用量2．5％（w／w）,反应时间5．0h。在此最佳工艺条件下,槲皮素得率为49．6％,含量达98．4％。     

Cottonseed flavonoids as lipid antioxidants

Methanolic extracts of cottonseeds were found to possess antioxidant activity. Separation of antioxidant components was achieved by paper, thin layer (TLC) and gas liquid chromatography (GLC) and spectral analysis. Chromatographic technique indicated that the flavonoids quercetin and rutin were the major flavonoids present. GLC analysis of the cottonseed extract eluted from TLC plates, developed in n-butanol/acetic acid/water (4:1:5, v/v/v) and ethyl acetate/methyl ethyl ketone/formic acid/water (5:3:1:1, v/v/v) solvents, corresponded in retention times to the rutin standard (10⁻⁴ M). TMS derivatives of the aglycone fraction, prepared by acid hydrolysis, correlated to the retention time of quercetin. Spectral analysis of the aglycone fraction also indicated quercetin derivatives to be present in cottonseed. The glycosyl substitution of the flavonoids were identified by the 3 chromatographic procedures to be glucose and rhamnose. Chromogenic spray reagents were used to further characterize the cottonseed flavonoids and flavonoid components on TLC and paper chromatography. The investigation, therefore, demonstrated that quercetin derivatives appear to be the main flavonoid species in cottonseed. Rutin was found to be one of the major quercetin glycosides. Quercetin and rutin are shown to possess potent antioxidant activity.     

预处理玻碳电极线性扫描伏安法测定槲皮素的研究

运用循环伏安法、线性扫描伏安法等测试技术研究了槲皮素在预处理玻碳电极上的电化学行为,建立了一种直接测定槲皮素的电化学分析方法。结果表明,与裸玻碳电极相比,预处理玻碳电极能显著提高槲皮素的氧化峰电流。在优化的实验条件下,氧化峰电流与槲皮素浓度在1.0×10-7～2.0×10-5mol/L范围内呈良好的线性关系,最低检测限为6.2×10-8mol/L。该方法简便、快捷、准确、灵敏度高。本法用于芦丁水解产物槲皮素的测定,效果良好。     

胶原纤维吸附剂分离芦丁和槲皮素

以戊二醛交联的胶原纤维为吸附剂,研究其对芦丁和槲皮素的吸附分离特性。结果表明,在乙醇中,胶原纤维吸附剂对芦丁和槲皮素的吸附以氢键作用为主;在水中,吸附作用以疏水键为主。采用90%乙醇水溶液和70%乙醇水溶液进行分步洗脱,芦丁和槲皮素能够得到分离,回收率分别为96.70%和101.47%。胶原纤维吸附剂具有良好的重复使用特性,在5次重复分离实验中,其分离性能无明显降低。因此,戊二醛交联胶原纤维吸附剂可以用于芦丁和槲皮素混合物的分离。     

胶原纤维吸附剂分离芦丁和槲皮素

以戊二醛交联的胶原纤维为吸附剂,研究其对芦丁和槲皮素的吸附分离特性。结果表明,在乙醇中,胶原纤维吸附剂对芦丁和槲皮素的吸附以氢键作用为主;在水中,吸附作用以疏水键为主。采用 90% 乙醇水溶液和 70% 乙醇水溶液进行分步洗脱,芦丁和槲皮素能够得到分离,回收率分别为 96.70% 和 101.47%。胶原纤维吸附剂具有良好的重复使用特性,在5次重复分离实验中,其分离性能无明显降低。因此,戊二醛交联胶原纤维吸附剂可以用于芦丁和槲皮素混合物的分离。     

Antioxidant activities of six natural phenolics against lipid oxidation induced by Fe2+ or ultraviolet light

The mechanisms and antioxidant activities of six natural phenolics against lipid oxidation induced by ultraviolet (UV) radiation or Fe²⁺ were studied. An oil emulsion was prepared with flax oil and the thiobarbituric acid-reactive substances (TBARS) method was used to determine lipid oxidation. The antioxidant activities of the six phenolics against UV-induced lipid oxidation were as follows: quercetin > rutin = caffeic acid = ferulic acid = sesamol > catechin. The inhibitory concentrations (IC₅₀) showed that the effectiveness of these antioxidants against Fe²⁺-induced lipid oxidation was in the order quercetin (1.7 μM) > rutin (10.3 μM) > catechin (14.9 μM) > sesamol (18.5 μM) > caffeic acid (19 μM) > ferulic acid (>250 μM), and quercetin was more efficient than butylated hydroxytoluene (BHT) (2.9 μM). Quercetin and rutin had absorption maxima at the UV-A (320–380 nm) region, while the other phenolics tested had absorption maxima near (catechin, 278 nm) or at the UV-B (280–320 nm) region. The stoichiometric ratios of quercetin, rutin, catechin, and caffeic acid to Fe²⁺ were 3:1, 2:1, 1:1, and 1:1, respectively. Although free-radical scavenging capability of antioxidants was the most critical, UV absorption and/or Fe²⁺-chelation properties of natural phenolics also contributed significantly to the control of lipid oxidation induced by UV or Fe²⁺ in oil systems.     

决明子中总黄酮的酶法提取工艺研究

采用果胶酶酶解预处理与乙醇浸提相结合提取工艺从决明子中提取总黄酮。以芦丁为对照品,采用紫外可见分光光度法,在波长510nm处测定决明子中总黄酮含量;在单因素实验基础上,通过正交试验得出决明子中总黄酮的最佳提取工艺条件为：酶解温度30℃,酶用量2mg,酶解pH3．0,酶解时间0．5h,乙醇用量35mL,乙醇浓度70％,最佳提取工艺条件下总黄酮提取率达2．03％。酶解-溶剂提取法是一种安全高效的提取方法,可用于决明子中总黄酮的提取。