苦荬菜属植物化学成份和药理活性研究进展

综述了苦荬菜属植物化学成分及药理活性的研究成果,为本属植物的深入研究提供了有用的资料。     

反相高效液相色谱测定中华苦荬菜中的木犀草素

目的：建立中华苦荬菜中木犀草素含量的测定方法。方法盐析法消除植物多酚的干扰；反相高效液相色谱法测定：C18为固定相；甲醇-水-醋酸(52：47．6：0．4v／v；pH=4．0)为流动相；检测波长254nm；柱温25℃。结果：木犀草素与其它物质得到了基线分离。结论：该方法为天然植物中木犀草素的开发提供了简便、灵敏、准确的测定方法。     

星宿菜总黄酮提取工艺及抗氧化性活性

为了最大限度获取星宿菜中的总黄酮,以星宿菜为原料,通过单因素实验和正交试验优化出提取星宿菜总黄酮含量的最佳工艺条件:35倍星宿菜的45%乙醇浓度溶解,45℃时超声提取55 min,此条件下总黄酮含量平均值为120.31 mg/g。同时测得星宿菜中黄酮的总抗氧化活性为2.266 mmol/L(FeSO_4当量值)。当星宿菜中总黄酮浓度为2.75 mg/mL时,DPPH自由基清除率为85.0%。方法操作简单、快捷、灵敏度高、成本低,仪器价格及日常维护费用不高。     

荷叶总三萜提取工艺研究及含量测定

目的研究荷叶总三萜的最佳提取工艺并测定总三萜的含量。方法最佳提取工艺采用正交实验法优选,以熊果酸为对照品通过比色法测定总三萜的含量。结果最佳提取条件为:20倍量50%乙醇回流提取2次,每次1小时。显色后的样品稳定,测定方法准确、重现性好,可用于该植物总三萜的含量测定。结论该提取工艺操作简单、经济省时、方便可行。     

正交试验法优化提取橘皮总黄酮工艺

为了确定橘皮中总黄酮类物质的提取工艺,文章以吸光度为考察指标,根据不同影响因素对橘皮中总黄酮物质的提取效果,并采用正交试验,研究了乙醇浓度、液料比、提取时间和提取次数对橘皮总黄酮类化合物提取的影响。确定了最佳提取工艺条件为:最佳提取乙醇浓度为60%,料液比为1∶15,提取时间2.5 h,提取次数2次。     

正交实验设计优化穿心莲总黄酮提取工艺

探讨了用乙醇回流提取穿心莲黄酮类化合物,找出最佳提取条件。通过正交实验探索乙醇回流法提取穿心莲黄酮类化合物的最佳工艺条件,采用紫外分光光度法测定总黄酮含量。影响实验因素的主次顺序是：固液比〉浸提时间〉乙醇浓度〉浸提温度,其中固液比对实验指标有显著性的影响。最佳提取工艺为固液比1：20、浸提时间4h、乙醇浓度60％、浸提温度50℃。     

辣木叶超微粉总黄酮提取工艺的优化研究

为了探究辣木叶超微粉中的总黄酮提取工艺,在单因素试验的基础上,通过建立四因素三水平的正交试验,分别考察乙醇浓度、提取温度、料液比、提取时间对辣木叶超微粉中总黄酮提取的影响,得出辣木叶超微粉总黄酮的最佳提取工艺条件。结果表明为:辣木叶超微粉总黄酮最佳提取条件为70%浓度的乙醇溶液作为提取剂,提取温度为80℃,料液比为1∶25,提取时间为1.5 h,测得总黄酮的含量为7.61%,比普通采用辣木叶为原料提取所得的总黄酮含量要高得多。     

车前子总三萜提取工艺研究及含量测定

本文研究车前子总三萜的最佳提取工艺并测定总三萜的含量。最佳提取工艺采用正交实验法优选,以熊果酸为对照品,通过比色法测定总三萜的含量;最佳提取条件为:10倍量70%乙醇回流提取3次,每次1小时;显色后的样品稳定,测定方法准确、重现性好,可用于车前子总三萜的含量测定。该提取工艺操作简单、经济省时、方便可行。     

超声波提取鸡矢藤总黄酮优化工艺研究

用正交试验法对鸡矢藤中的总黄酮提取工艺进行优化。以鸡矢藤中的总黄酮含量为考察指标,采用正交试验L9(34)表进行实验,对提取过程中的乙醇浓度、提取时间、提取次数及料液比四个影响因素进行研究。最佳提取工艺是:提取次数3,乙醇浓度80%,料液比1:20,提取时间15min.。优选得到的工艺稳定可行。     

超声波辅助法提取朱砂七鞣质的工艺

通过单因素实验及正交实验对超声波辅助法提取朱砂七鞣质的工艺条件进行优化.确定最佳提取条件为:乙醇体积分数60%、料液比1∶15(g∶mL)、提取温度70℃、提取时间50 min,在此条件下提取2次,提取率为2.00%.超声波辅助法提取朱砂七鞣质工艺简单、省时、节能、提取率高.     

菟丝子中总黄酮的闪式提取工艺及近红外透射光谱含量分析方法

利用闪式提取器对菟丝子中的总黄酮进行组织破碎提取,确定菟丝子中总黄酮闪式提取的最佳提取工艺为:料液比1∶8(mg∶mL),以50%的乙醇为溶剂提取8min。采用主成分分析(PCA)和偏最小二乘法(PLS)回归分析法建立了菟丝子提取液中总黄酮含量近红外透射光谱定量分析模型,该模型校正集的相关系数为0.99985,校正集标准偏差(RMSEC)为0.0685,预测集标准偏差(RMSEP)为0.160,交叉验证结果的相关系数为0.99966,交叉验证标准差(RMSECV)为0.102。利用该模型预测和紫外分光光度法测量的总黄酮含量相差很小,且模型具有良好的稳定性。     

漆姑草中总黄酮提取工艺研究与含量测定

采用正交实验进行提取工艺优选,研究了漆姑草中总黄酮的提取工艺并测定总黄酮的含量。用芦丁作对照品,硝酸铝做显色剂,测定波长508 nm,紫外分光光度法测定漆姑草中总黄酮的含量。最佳提取工艺条件是：80%甲醇,料液比为1∶20,浸提时间为4 h,提取温度为50℃。最佳工艺条件下,测定漆姑草中总黄酮的含量为11.768%。本提取工艺方法简单、合理,是漆姑草中黄酮类化合物的最佳提取工艺。     

微波萃取广山楂叶中黄酮类化合物的工艺研究

采用正交试验法,优选广山楂叶中黄酮类化合物的最佳微波萃取工艺。用分光光度法进行测定,以总黄酮的得率作为考查指标,对影响黄酮类化合物提取工艺的因素进行了研究。实验设计的3因素中对结果影响最显著的因素为微波辐射时间。广山楂叶的最佳提取工艺为:1 g 广山楂叶粉末,50% 的乙醇 40 mL,功率 240 W 的微波辐射 4 min(辐射前浸泡 10 min,采用间歇式辐射方式),最佳条件下总黄酮得率为 12.04%。     

正交试验设计法研究二安替比林-7(2-羟基)- 苯基甲烷试剂与铬(Ⅵ)的显色反应

以正交试验设计法研究并得到了二安替比林-(2-羟基)-苯基甲烷试剂吸光光度法测定微量铬的最佳显色条件,其最大吸收波长为480 nm.Cr(Ⅵ)在0.10～10 μg·25 mL-1范围内呈良好线性关系,线性回归方程为A=0.0583C+0.0478,线性相关系数为0.9971,摩尔吸光系数ε=1.37×105(L·moL-1·cm-1).灵敏度比文献报道有较大提高.方法应用于水样中铬(Ⅵ)的测定,结果满意.     

Supercritical Carbon Dioxide Extraction of Flavonoids from Pomelo (Citrus grandis (L.) Osbeck) Peel and Their Antioxidant Activity

Supercritical carbon dioxide (SC-CO₂) extraction of flavonoids from pomelo (Citrus grandis (L.) Osbeck) peel and their antioxidant activity were investigated. Box-Behnken design combined with response surface methodology was employed to maximize the extraction yield of flavonoids. Correlation analysis of the mathematical-regression model indicated that a quadratic polynomial model could be used to optimize the SC-CO₂ extraction of flavonoids. The optimal conditions for obtaining the highest extraction yield of flavonoids from pomelo peel were a temperature of 80 °C, a pressure of 39 MPa and a static extraction time of 49 min in the presence of 85% ethanol as modifier. Under these conditions, the experimental yield was 2.37%, which matched positively with the value predicted by the model. Furthermore, flavonoids obtained by SC-CO₂ extraction showed a higher scavenging activity on hydroxyl, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals than those obtained by conventional solvent extraction (CSE). Therefore, SC-CO₂ extraction can be considered as a suitable technique for the obtainment of flavonoids from pomelo peel.     

Bi_(1/2)Na_(1/2)TiO_3-BaTiO_3系无铅压电陶瓷制备工艺的优化及其结构分析

借助正交试验设计,通过对无铅压电陶瓷压电、介电性能的测试,研究了BaTiO3含量、预烧温度、烧结温度及保温时间对(1-x)(B i1/2Na1/2)TiO3xBaTiO3(简写为BNBT 100x)陶瓷性能的影响。研究结果表明制备BNBT系陶瓷的最优化工艺条件为:BaTiO3摩尔分数x=0.06、预烧温度850℃、烧结温度1 130℃、保温时间2 h。通过XRD分析了BNBT系压电陶瓷的晶体结构类型、晶胞参数及晶格畸变随着BaTiO3摩尔分数的变化,确定了该体系的三方四方的准同型相界在x=0.06~0.08之间。     

Gradient doping of Cu(I) and Cu(II) in ZnO nanorod photoanode by electrochemical deposition for enhanced photocurrent generation

This study describes the synthesis and characterization of Cu-doped ZnO nanorods (NRs) by an electrochemical method in the presence of two different Cu precursor (Cu⁺² and Cu⁺) in order to improve photocurrent generation. Analyses of the resulting materials by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis and electrochemical photocurrent (ECP) spectroscopy confirm the formation of well-aligned ZnO Würtzite nanostructures in the form of hexagonal rods. For both doping source with a concentration of up to 0.5%, the following changes were observed: a distortion of the ZnO morphology, an increase in transmittance to 96% for ZnO doped with Cu⁺², and a reduction of the energy gap from 3.36 eV to 3.06 and 3.02 eV for ZnO doped with Cu⁺² and Cu⁺, respectively. From photoelectrochemical tests, the photo-current density was improved up to 0.05 mA cm^-2 in the presence of Cu doping, which is twelve times superior to that of undoped ZnO nanorods, which means that the incorporation of Cu+2 or Cu + significantly improves the separation efficiency of photogenerated electron-hole pairs. These results can be considered promising for optoelectronic and photocatalysis applications.     

High surface area-activated carbon from Glycyrrhiza glabra residue by ZnCl2 activation for removal of Pb(II) and Ni(II) from water samples

A high-surface-area activated carbon was prepared by chemical activation of Glycyrrhiza glabra residue with ZnCl₂ as active agent. Then, the adsorption behavior of Pb(II) and Ni(II) ion onto produced activated carbon has been studied. The experimental data were fitted to various isotherm models. According to Langmuir model, the maximum adsorption capacity of Pb(II) and Ni(II) ions were found to be 200 and 166.7 mg g⁻¹, respectively, at room temperature. Kinetic studies showed the adsorption process followed pseudo second-order rate model. High values of intra-particle rate constants calculated shows the high tendency of activated carbon for removal of Pb(II) and Ni(II) ions.     

钢渣对水溶液中砷的吸附动力学和热力学特性试验

以炼钢厂固体废弃物钢渣为材料,通过批量平衡吸附法,并结合宏观热力学和动力模型应用,分析和研究了钢渣对水溶As(III)的吸附特征。结果表明钢渣在吸附As(III)过程中,初始阶段吸附量迅速增加,随着浓度的增加,吸附逐渐趋于饱和,最后达到平衡,具有"快速吸附、缓慢平衡"的特点。钢渣吸附材料具有极高的最大吸附容量,高达3.58×104mg/kg。钢渣对As(III)的吸附均符合Langmuir和Freundlich吸附等温线,其中钢渣对As(III)的吸附特征与Freundlich等温吸附方程吻合性最好,相关系数(R2)达到0.99以上。钢渣对As(III)的吸附动力学数据均符合一级动力学方程、Elovich方程和双常数方程,拟合优度用相关系数(R2)为0.92~0.98,相比较而言,钢渣对As(III)的吸附以Elovich方程为最佳模型。