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   7篇
  免费   3篇
化学   10篇
  2018年   1篇
  2017年   1篇
  2015年   2篇
  2014年   3篇
  2013年   1篇
  2011年   1篇
  2005年   1篇
排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
Valeriana jatamansi Jones is an important medicinal plant and its quality is closely related to its region of origin. In the current study, we utilized a flexible and powerful strategy for comprehensive evaluation of the quality diversity for 15 regions in China. The method was based on a hybrid linear ion trap‐Orbitrap mass spectrometry platform. For structure characterization, fragmentation patterns were detected by analyzing a series of standard compounds using data dependent multistage mass spectrometry acquisition. A fragment ion database for valepotriates was established, and the acquired data were high throughput filtered by fragment ion search for compound identification. For quantitative purposes, we normalized the mass spectrometry data of 15 samples using SIEVE 2.0 and the differences in composition were analyzed using principal component analysis combined with hierarchical clustering analysis. The results identified a total of 92 compounds from Valeriana jatamansi Jones. Samples from Dali, Kunming, and Baoshan have better qualities and concentrations of the main active constituents. To verify our strategy, we compared the valtrate, acevaltrate, and baldrinal contents using high‐performance liquid chromatography with diode array detector. We developed and validated a comprehensive qualitative and quantitative analytical method to achieve quality control of Valeriana jatamansi Jones.  相似文献   
2.
Nardostachys jatamansi DC. is a highly reputed Medhya and Nootropic (Learning and Memory) Ayurvedic medicinal plant. Its use as herbal medicine singly and as an ingredient of multi‐herbal formulations is fast increasing. In order to authenticate and evaluate it quantitatively, its standardization is highly warranted with respect to a reliable marker. In this connection a rapid and highly sensitive UPLC‐QTOF MS method has been developed. The analysis was carried out on an Acquity BEH C18 column with gradient elution of methanol–water and 3 mm ammonium acetate using QTOF mass detector in negative ionization mode. The method was validated over a concentration range of 9.76–156.25 ng/mL nardin. The calibration curve is linear with the correlation coefficient (r) and coefficient of determination (R2) were 0.9997 and 0.9995 respectively. The LOD and LOQ were 3.050 and 9.277 ng/mL respectively. The recovery of nardin in the range 96.36–111.13% achieved from spiked samples was consistent and reproducible. The inter‐day and intra‐day assay precision of the analytes over the entire concentration range was less than 5%. The developed method required only 4 min for chromatography to authenticate and quantify the marker, viz. nardin in N. jatamansi samples, in addition to the sample preparation time. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
3.
Valeriana jatamansi Jones (V. jatamansi) has been widely used for treating anxiety and its mechanism involves many aspects including GABA level. This study aimed to evaluate the anxiolytic potency of an iridoid fraction extracted from the radix and rhizomes of V. jatamansi. The iridoid fraction was extracted by using D101 resin; its major components were analysed preliminarily by thin layer chromatography, ultraviolet spectrophotometry and high-performance liquid chromatography; and its anxiolytic effects at 6 mg/kg (low-dose), 9 mg/kg (medium-dose) and 12 mg/kg (high-dose) were evaluated using the elevated plus maze test, the light–dark box test, the Vogel’s drinking conflict test, and the open field drink test. Its action mechanism was investigated using the ELISA. This study provided evidence on the anxiolytic potency of the iridoid fraction from V. jatamansi and revealed its action mechanism of regulating the GABA level.  相似文献   
4.
毛细管电泳-电化学检测法测定蜘蛛香中多元酚类化合物   总被引:12,自引:0,他引:12  
采用毛细管电泳 电化学检测法(CE ED)同时测定了蜘蛛香根中香叶木素、山奈酚、芹菜素、绿原酸 和咖啡酸等5种主要生物活性成分的含量,考察了运行缓冲液酸度、浓度、分离电压、氧化电位和进样时间等 实验参数对分离、检测的影响。在最佳实验条件下,以直径300μm的碳圆盘电极为工作电极,检测电位为+ 950mV(vs.SCE),在50mmol/L的硼砂缓冲溶液(pH9.23)中,上述各组分在23min内能完全分离。5种组 分在两个数量级的范围内呈良好线性关系,检测下限(S/N=3)达1.7×10-4~1.8×10-5g/mL。该法已成功 地应用于蜘蛛香根中活性成分的分离检测,结果令人满意。  相似文献   
5.
Two new iridoid esters, named valerjatadoids A and B ( 1 and 2 , resp.), together with three known iridoid esters, jatamanin O ( 3 ), jatamanvaltrate P ( 4 ), and jatamanvaltrate Q ( 5 ), have been isolated from the root and rhizome of Valeriana jatamansi Jones . The structures of the two new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.  相似文献   
6.
Five new sesquiterpenoids Nardosinanone A–E (15), were isolated from the extract of Nardostachys chinensis, and their structures were determined by extensive spectroscopic analysis. Compound 1 featured a nardosinane sesquiterpenoid with an unusual tricyclic skeleton. Compounds 24 were new nardosinane sesquiterpenoids bearing a rare 10,11-epoxy group. The absolute configurations were determined by single-crystal X-ray diffraction analysis, ECD calculation method, the CD analysis of the in situ formed [Rh2(OCOCF3)4] complex, and the CD data analysis based on the octane rule of cyclohexanone.  相似文献   
7.
采用DPPH、ABTS、羟自由基、超氧阴离子和还原力五种体外抗氧化测定方法对甘松95%乙醇提取物以及石油醚萃取物,乙酸乙酯萃取物,正丁醇萃取物和水萃取物等4个不同极性部位的抗氧化活性进行评价,同时分析抗氧化活性与其总多酚和总黄酮含量的相关性。研究结果表明,除水和石油醚萃取物外,甘松其他3个萃取物均表现出一定的抗氧化活性,且与总多酚和总黄酮含量呈显著相关。其中,乙酸乙酯萃取物中总黄酮和总多酚含量最高,分别为(157.22±1.89)mg·g-1和(99.43±1.23)mg·g-1,其清除DPPH、ABTS、超氧阴离子和羟自由基的IC50分别为(0.20±0.02)mg·mL-1、(0.15±0.01)mg·mL-1、(0.29±0.02)mg·mL-1和(0.35±0.02)mg·mL-1。甘松的乙酸乙酯萃取物具有显著的抗氧化活性,可以成为天然抗氧化活性化合物的良好来源。  相似文献   
8.
Two new iridoids, jatamanvaltrates P and Q ( 1 and 2 , resp.), together with three known iridoids, rupesin B ( 3 ), chlorovaltrate ( 4 ), and valtrate ( 5 ), were isolated from the root and rhizome of Valeriana jatamansi Jones . The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.  相似文献   
9.
Valepotriates, plant secondary metabolites of the family Valerianaceae, contain various acyloxy group linkages to the valepotriate nucleus and exhibit significant biological activities. Identification of valepotriates is important to uncover potential lead compounds for the development of new sedative and antitumor drugs. However, making their structure elucidation by nuclear magnetic resonance (NMR) experiments is too difficult to be realized because of the overlapped carbonyl carbon signals of acyloxy groups substituted at different positions. Thus, the mass spectrometric profiling of these compounds in positive ion mode was developed to unveil the exact linkage of acyloxy group and the core of valepotriate. In this study, electrospray ionization tandem multistage mass spectrometry (ESI‐MS/MSn) in ion trap and collision‐induced dissociation tandem MS were used to investigate the fragmentation pathways of four types of valepotriates in Valeriana jatamansi, including 5‐hydroxy‐5,6‐dihydrovaltrate hydrin (5‐hydroxy‐5,6‐dihydrovaltrate chlorohydrin), 5,6‐dihydrovaltrate hydrin (5,6‐dihydrovaltrate chlorohydrin), 5‐hydroxy‐5,6‐dihydrovaltrate and valtrate hydrin (valtrate chlorohydrin). The high‐resolution mass spectrum (HRMS) data of all the investigated valepotriates from quadrupole time‐of‐flight MS/MS were used as a supportive of the fragmentation rules we hypothesized from ion‐trap stepwise MSn. As a result, the loss sequence of acyloxy groups and the abundance of key product ions, in combination with the characteristic product ions corresponding to the valepotriate nucleus, could readily differentiate the four different types of valepotriates. The summarized fragmentation rules were also successfully exploited for the structural characterization of three new trace valepotriates from V. jatamansi. The results indicated that the developed analytical method could be employed as a rapid, effective technique for structural characterization of valepotriates, especially for the trace compounds that could not be identified by NMR techniques. This study may also arouse interest for further structural analysis of other valepotriate‐containing type herbal medicines. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
10.
Three new iridoids, jatamanins N–P ( 1 – 3 ), along with the seven known iridiods 4 – 10 , were isolated from the roots of Valeriana jatamansi. Compound 1 is an unusual iridoid bearing two epoxy bridges between C(3) and C(6) and between C(1) and C(10), forming a unique cage‐like rigid skeleton. The structures of the new compounds were assigned on the basis of spectroscopic methods.  相似文献   
1
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