首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16篇
  免费   2篇
  国内免费   2篇
化学   10篇
物理学   10篇
  2022年   2篇
  2019年   1篇
  2016年   2篇
  2015年   2篇
  2013年   1篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   2篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  1988年   1篇
排序方式: 共有20条查询结果,搜索用时 15 毫秒
1.
宋青青  刘瑶  张玲玲  周利  屠鹏飞  宋月林 《色谱》2016,34(6):572-576
建立了在线加压溶剂微提取-湍流色谱-高效液相色谱(online PLME-TFC-HPLC)法,并将其应用于管花肉苁蓉中松果菊苷、毛蕊花糖苷和异毛蕊花糖苷3种苯乙醇苷类成分含量的同时测定。微量样品粉末(0.5 mg)置于空预柱芯中并用正相硅胶填充,得到提取池后装入预柱套(Security GuardTM)。将预柱套置于70℃柱温箱中,将一根长聚醚醚酮(PEEK)管线(1000 mm×0.13 mm)连于预柱套末端,采用0.1%(v/v)甲酸水为提取溶剂,以2.5 mL/min的速度流经PEEK管线,产生高压,实现管花肉苁蓉的在线加压溶剂微提取,通过TurboFlow cyclone色谱柱在线净化和富集。引入两个电子六通阀,将整个分析过程分为提取阶段和洗脱阶段,并在洗脱阶段将TurboFlow cyclone色谱柱中的分析物反冲至Capcell PAK C18 AQ分析柱上,以0.1%(v/v)甲酸水-乙腈为流动相进行梯度洗脱,以340 nm为检测波长同时定量分析松果菊苷、毛蕊花糖苷和异毛蕊花糖苷3种苯乙醇苷类成分。结果表明,3种苯乙醇苷类在1~200 mg/L范围内线性良好,相关系数r均大于0.999,定量限分别为0.50 mg/L(松果菊苷)、0.25 mg/L(毛蕊花糖苷)和0.38 mg/L(异毛蕊花糖苷),加标回收率为83.13%~114.00%,相对标准偏差为1.89%~13.34%。该方法简便、快速、可靠,不仅节约了药材和溶剂的使用量,而且极大地简化了前处理方法,省时省力,同时显著降低了化学成分在提取过程中降解的几率,适用于管花肉苁蓉中苯乙醇苷类化合物的含量测定。  相似文献   
2.
《Analytical letters》2012,45(17):2783-2794
Cistanche deserticola (Orobanchaceae) has been widely used in China for food and medicinal purposes. Chemical differentiation between the raw and steamed C. deserticola was performed by high-performance liquid chromatography coupled with diode array detection and mass spectrometry. Eight chemicals (echinacoside, cistanoside A, acteoside, cistanoside C, 2′-acetylacteoside, isoacteoside, isocistanoside C, and tubuloside B) were obtained from raw and steamed C. deserticola, and the kinetics in the steaming process were investigated in detail. When the steaming time increased, the concentrations of echinacoside, cistanoside A, acteoside, cistanoside C, and 2′-acetylacteoside decreased, while the levels of isoacteoside, isocistanoside C, and tubuloside B increased. Furthermore, two compounds, 5-hydroxymaltol and 5-hydroxymethylfurfural, were found only in the steamed form. In addition, hierarchical clustering analysis and principal component analysis were performed to evaluate the classify the chemical concentrations among steamed C. deserticola. The results showed that steaming had a significant influence on the chemical constitution. The study provide chemical analysis of raw and steamed C. deserticola, including possible transformation pathways, and should allow better understanding of the steaming process of this herb.  相似文献   
3.
肉苁蓉为稀有的名贵中药材 ,具有补肾、益精、润肠及抗衰老等功效 [1] .研究表明 ,肉苁蓉多糖具有延缓皮肤衰老、增强机体免疫功能、促进人体外成纤维细胞的生长及促进创伤愈合 [2 ] 等生理活性作用 .对于肉苁蓉多糖的深入研究尚未见报道 ,为探讨多糖的生物活性与结构的关系 ,本文对肉苁蓉茎水溶性多糖 SPA组分进行结构分析 .有关肉苁蓉茎水溶性多糖 SPA组分的分离纯化过程见文献 [3].1 实验部分1 .1 试剂与仪器  Sephadex G- 75 ( Pharmacia公司 ) ;二甲基亚砜 (江苏洪声化工厂 ) ;Shimadzu高压液相色谱 (日本岛津 ) ;Vavian 340 0…  相似文献   
4.
王国卫  赵芳 《光谱实验室》2011,28(3):1545-1548
研究了肉苁蓉多糖体外抗氧化活性。以抗坏血酸为对照,以类Fenton反应产生羟自由基,多巴胺自氧化反应产生超氧阴离子自由基,次氯酸钠与过氧化氢反应产生单线态氧、二苯代苦味肼基自由基为实验模型,采用紫外-可见分光光度法和化学发光分析法,首次测定新疆肉苁蓉多糖对超氧阴离子自由基、羟自由基、DPPH.自由基(二苯代苦味肼基自由基)、单线态氧的清除作用。结果表明:新疆肉苁蓉多糖对上述自由基均有明显清除作用,且清除作用与多糖浓度呈正相关性。  相似文献   
5.
应用红外光谱法鉴别肉苁蓉及其混淆品草苁蓉和锁阳   总被引:3,自引:0,他引:3  
采用傅里叶变换红外光谱法结合二维相关分析技术分别对药用植物肉苁蓉及其混淆品草苁蓉、锁阳进行了鉴别研究.结果表明,三者的红外光谱图表现出了一定的差异性:肉苁蓉在1 730和931 cm-1有吸收峰,草苁蓉在1 510,1 375,1 266 cm-1处存在吸收峰,锁阳的最高峰位于1 614cm-1处.在二阶导数谱图上三者差异更加明显:肉苁蓉在1 453,1 336,931,892 cm-1处都有较强的吸收峰.其中931 cm-1处的吸收峰较尖锐,强度也最强;草从蓉的最强峰位于1 509 cm-1,并且1 633和1 161 cm-1处的吸收峰明显变宽,强度也变大;锁阳在1 682cm-1处有较尖锐的吸收峰,1 605 cm-1附近的吸收峰强度也较大.二维红外谱图不但差别明显,而且直观.三者提取物的红外光谱同样存在显著差异.应用该方法能够实现肉苁蓉药材与混淆品的快速、准确鉴别.  相似文献   
6.
矿质元素含量是中药材质量评价的重要指标,且与中药材生长发育、功效物质形成及其疗效发挥密切相关。矿质元素含量及比例因产地、采收时期、采收部位等不同存在差异,但种质是影响中药材矿质元素含量及比例最为稳定和重要的因素。电感耦合等离子体原子发射光谱法(ICP-AES法)可快速同时测定多种矿质元素,目前已广泛应用于中药材矿质元素含量测定。肉苁蓉为著名补益类中药,其矿质元素含量及比例越来越受到人们关注。该研究以不同花色肉苁蓉种质为材料,经硝酸和高氯酸消解后,采用ICP-AES法测定了不同花色肉苁蓉种质中的矿质元素K,P,Ca,Mg,Na,Fe,Mn,Zn,Cu和Mo含量,并对结果进行统计分析与比较。结果表明:(1)种质影响肉苁蓉矿质元素含量,不同花色肉苁蓉种质中均具有丰富的矿质元素K,P,Ca,Mg,Na,Fe,Mn,Zn,Cu,Mo,但含量具有明显差异。(2)不同花色肉苁蓉种质的常量矿质元素均以K含量和累积量最高,P含量和累积量最低;白色花种质K含量和累积量最高,为15.91 mg·g-1和727.76 mg·株-1;淡紫色花种质P含量和累积量最低,为0.45 mg·g-1和21.80 mg·株-1。(3)不同花色肉苁蓉种质的微量矿质元素均以Fe的含量和累积量最高,Mo含量和累积量最低;黄色花种质的Fe含量和累积量最高,达到了722.33 μg·g-1和30 251.29 μg·株-1;淡紫色花种质的Mo含量和累积量最低,为0.11 μg·g-1和5.12 μg·株-1。(4)白色花种质的K,Ca,Mg,Mn,Zn含量和累积量较高,而淡紫色花种质的K,Ca,Mg,Na,Mn含量和累积量较低。(5)种质影响肉苁蓉矿质元素比例,不同花色肉苁蓉种质中的矿质元素比例存在差异,其中K∶P和Fe∶Mn差异较大,而Ca∶Mg和Zn∶Cu差异较小。结果表明:肉苁蓉具有丰富的矿质元素,种质影响肉苁蓉中矿质元素含量、累积量及矿质元素比例,且不同花色种质间存在较大差异,应引起关注和重视。矿质元素为中药材质量评价的重要指标且影响中药材生长发育,研究结果可为不同花色肉苁蓉种质质量评价、营养价值评价及科学合理施肥提供依据。  相似文献   
7.
Echinacoside (ECH) and acteoside (ACT), as the most and major active components of Cistanche tubulosa, were reported to possess cardioactive, neuroprotective and hepatocyte protective effects, as well as antibacterial, antioxidative effects. Recently, more studies have focused on their pharmacological activities. However, their metabolic profiles in vivo have not been sufficiently investigated. This study proposes an approach for rapidly identifying the complicated and unpredictable metabolites of ECH and ACT in rat plasma, bile, urine and feces, and systematically and comprehensively revealing their major metabolic pathways, based on powerful ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. Plasma, bile, urine and feces were collected from rats after a single 200 mg/kg oral dose. A total of 49 metabolites were detected in rat biological samples. Through analyzing metabolites in bile samples, it was found that ECH and ACT were subjected to a marked hepatic first‐pass effect in liver. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
8.
应用ICP-AES法测定不同产地管花肉苁蓉及其土壤中的矿质元素含量。结果表明:(1)不同产地的管花肉苁蓉均含有丰富的K,P,Ca,Mg,Na,Fe,Mn,Zn,B等多种矿质元素,且具有明显差异。(2)不同产地的管花肉苁蓉中常量矿质元素含量均较高,其中以K元素含量为最高;微量矿质元素中Fe元素含量高于其他元素含量,其中产自新疆于田的Fe元素含量高达433.56 μg·g-1。(3)各产地的管花肉苁蓉对矿质元素的吸收比例差异较大,其中对K,P,Na三种元素的吸收能力较强。(4)管花肉苁蓉矿质元素含量和吸收比例新疆于田高于其他产地。研究结果将为管花肉苁蓉的质量评价和引种栽培提供科学依据。  相似文献   
9.
An efficient ultrasound‐assisted aqueous two‐phase extraction and enrichment process for phenylethanoid glycosides from Cistanche deserticola Y. C. Ma stems was developed in this work. An ethanol/ammonium sulfate system was chosen for the aqueous two‐phase system due to its fine partitioning and recycling behaviors. Single‐factor experiments and response surface methodology were used to optimize the process parameters of the ultrasound‐assisted aqueous two‐phase extraction. The optimal conditions were as follows: a salt concentration of 23.5%, an ethanol concentration of 20%, an extraction time of 37 min, an extraction temperature of 30°C, a liquid/solid ratio of 30:1 w/w, and an ultrasound power of 300 W. Under the above conditions, the extraction yields of echinacoside and acteoside (the main components of phenylethanoid glycosides) reached 5.35 and 6.22 mg/g dry material weight, respectively. The contents of echinacoside and acteoside in the extracts reached 27.56 and 30.23 mg/g, respectively, which were 2.46‐ and 2.58‐fold higher than the amounts obtained in ultrasound‐assisted extraction. In conclusion, ultrasound‐assisted aqueous two‐phase extraction was an efficient, ecofriendly, and economical method, and it may be a promising technique for extracting and enriching bioactive components from plants.  相似文献   
10.
红外光谱法用于肉苁蓉属中药鉴别研究   总被引:8,自引:1,他引:8  
采用傅里叶变换红外光谱(FTIR)及其二阶导数谱和二维相关红外光谱对传统名贵中药材肉苁蓉、管花肉苁蓉和盐生肉苁蓉进行鉴别研究。结果表明,肉苁蓉与管花肉苁蓉的红外谱图有明显区别,相似系数仅0.623 3;而肉苁蓉与盐生肉苁蓉的峰形和峰位均极其相似,相似系数达0.904 8,仅从一维图上无法看出两者的成分差异,但通过二阶导数谱中1 730(1 738),816 cm-1处的峰形差异可发现二者的一些成分含量存在较明显差异。二维相关谱更直观地反映出三者的差异,它们的自动峰个数均不相同。可见,红外光谱法基本可以实现了对肉苁蓉属3种药材的鉴别,而且具有快速、有效和无损等优点。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号