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   19篇
  免费   1篇
  国内免费   1篇
化学   15篇
物理学   6篇
  2022年   1篇
  2021年   2篇
  2018年   1篇
  2015年   1篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2009年   1篇
  2008年   1篇
  2007年   3篇
  2006年   1篇
  2005年   1篇
  2003年   1篇
  2002年   1篇
  1996年   2篇
  1992年   1篇
排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
Isoquinoline alkaloids are the primary active ingredients of Corydalis, but an analytical method for quality assessment of the active ingredients in Corydalis impatiens (Pall). Fisch has not been reported. A new, simple, and multiple‐component quantification method was developed for the simultaneous quantification of 11 isoquinoline alkaloids including capnoidine, chelianthifoline, bicuculline, protopine, isoapocavidine, apocavidine, cavidine, tetrahydroepiberberine, ochotensimine, tetrahydrocoptisine, and tetrahydrocorysamine in C. impatiens. Separation of the isoquinoline alkaloids was performed on a RP C18 column (150 × 4.6 mm, 5 μm) with potassium dihydrogen phosphate buffer (pH 2.5, adjusted by phosphoric acid)/acetonitrile (53:47, v/v) containing 0.3% sodium dodecyl sulfonate. The flow rate and detection wavelength were set at 1 mL/min and 295 nm, respectively. Full validation of the assay was carried out including linearity, precision, accuracy, stability, LOD, and limit of quantitation. All calibration curves showed a good linear relationship (r > 0.999) in test range. The results demonstrated that the developed method was reliable, rapid, and specific. Six batches of C. impatiens samples from different sources were determined using the established method. The contents of alkaloids ranged from 11.68 to 351.83 μg/g. This method can be applied for quality evaluation and control of C. impatiens. Eleven isoquinoline alkaloids were first reported on simultaneous determination with HPLC.  相似文献   
2.
为了分析芍药对土壤矿质元素的吸收利用规律,采用ICP-AES法检测了不同产地芍药根和相应土壤中K,Ca,Na,Mg,Fe,Cu等主要矿质元素含量.结果表明:不同产地的芍药对土壤中矿质元素的吸收利用效率不同,反映在不同产地的芍药根中有些矿质元素含量有明显差异,从而使各地芍药药材质量在矿质元素方面也有差异,以黑龙江和内蒙古...  相似文献   
3.
Paeonia lactiflora Pall., one of the most famous classical herbal medicine, has been used to treat diseases for over 1200 years. In this research, the functional ingredients were purified by online-switch two-dimensional high-speed counter-current chromatography combined with inner-recycling and continuous injection mode. The antioxidant activity was evaluated by investigating the 2,2′-azobis (2-amidinopropane) dihydrochloride-induced oxidant damage in vitro and confirmed through molecular docking. n-Butanol/ethyl acetate/water (2:3:5, v/v) solvent system was used for the first-dimensional separation and optimized the sample loading. Two pure compounds and a polyphenol-enriched fraction were separated. The polyphenol-enriched fraction was separated with a solvent system n-hexane/ethyl acetate/methanol/water (2:8:4:6, v/v) with continuous injection mode. Five compounds were successfully separated, including gallic acid ( 1 ), methyl gallate ( 2 ), albiflorin ( 3 ), paeoniflorin ( 4 ), and ethyl gallate ( 5 ). Their structures were identified by mass spectrometry and NMR spectroscopy. The results from the antioxidant effect showed that albiflorin had stronger antioxidant activity. Molecular docking results indicated that the affinity energy of the identified compounds ranged from -3.79 to -8.22 kcal/mol and albiflorin showed the lowest affinity energy. Overall, all those findings suggested that the strong antioxidant capacity of albiflorin can be potentially used for the treatment of diseases caused by oxidation.  相似文献   
4.
Salsola collina Pall has a long history of being used as a traditional medicine to treat hypertension, headache, insomnia, constipation and vertigo. However, only a few biologically active substances have been identified from S. collina. Here, the shoots and roots of S. collina, namely L-Sc and R-Sc, were studied. The primary and secondary metabolites were investigated using ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). A total of 637 putative metabolites were identified and these metabolites were mainly classified into ten different categories. Correlation analysis, hierarchical clustering analysis, principal component analysis and orthogonal partial least squares discriminant analysis of metabolites showed that the L-Sc samples could be clearly separated from the R-Sc samples. Differential accumulated metabolite analysis revealed that most of differential primary metabolites were significantly lower in the L-Sc than in the R-Sc. Conversely, the major differential secondary metabolites had higher levels in the L-Sc than in the R-Sc. Further analysis indicated that the flavonoids were the major putative antioxidant components and most of putative antioxidant components exhibited higher relative concentrations in the L-Sc than the R-Sc. These results improve our understanding of metabolite accumulation and provide a reference for the study of medicinal value in S. collina.  相似文献   
5.
邵红梅  孙书芹  徐红娟 《色谱》1996,14(3):235-236
采用Shim-packCLC-ODSC_(18)色谱柱和AA03反相键合相柱,对盐地碱蓬(以下称碱蓬)汁中7种水溶性维生素和18种氨基酸进行了分离测定,结果令人满意。  相似文献   
6.
利用固相萃取-高效液相色谱-电喷雾串联质谱法(SPE-HPLC-DAD-ESI-MS2)分析了芍药(Paeonia lactiflora Pall.)及其炮制品酒芍药(Paeonia lactiflora Pall.preparated with wine)水煎液中化学成分的种类和结构,并对其主要有效成分芍药苷进行了定量测定.用此方法得到了芍药和酒芍药水煎液的紫外色谱(UV)图、总离子流色谱(TIC)图和萃取离子色谱(EIC)图,以及相应色谱峰的紫外光谱图和EIC/MS2的质谱图.对其进行解析,发现芍药和酒芍药水煎液中所含化学成分基本一致,但酒芍药水煎液中除主要活性成分芍药苷含量基本未变外,其它酚酸性化学成分含量相对于芍药水煎液均有不同程度的下降.同时鉴别出芍药和酒芍药水煎液中共同含有的16种成分,它们分别是:蔗糖、(+)-儿茶素、Mudanpioside E、芍药新苷、芍药内酯苷、氧化芍药苷、芍药苷、羟基芍药苷、没食子酰芍药苷*、牡丹皮苷Ⅰ、苯甲酰芍药苷、三没食子酰葡萄糖、四没食子酰葡萄糖、五没食子酰葡萄糖.以上分析说明,酒炙可保留芍药的药效,同时"缓和其酸寒伐肝之性".  相似文献   
7.
Nitraria sibirica is a traditional Uighur medicine. This study was undertaken to investigate the bioactivity of N. sibirica fruit extract and to evaluate their chemical compositions. The ethyl acetate extract from N. sibirica fruits exhibited the potential antioxidant activity (SC50 = 30.17 ± 0.06 μg/mL) and protein tyrosine phosphatase 1B inhibitory activity (IC50 = 7.15 ± 0.03 μg/mL) in vitro. In order to investigate the active constituents in this extract, a LC-QTOF-MS/MS method was developed and established. A total of 28 compounds including seven cinnamic acids, nine benzoic acids and 12 flavonoids were identified or partially characterised according to the accurate mass and the characteristic fragment ions at low and high collision energy. Most of them were reported for the first time in this plant. Phytochemical profiles of the active extract will help the development and utilisation of N. sibirica in food and medicine.  相似文献   
8.
The essential oils of the flower-buds, leaves and stems of Filipendula palmata( Pall. ) Maxim. were analyzed by GC and GC-MS. Thirty-three, forty-seven and forty-seven compounds in the flower-buds, leaves and stems were identified, respectively. Methyl salicylate exists in a great amount which is up to 70. 10% in the flower-buds. Its amount is also high in other two parts. The data obtained show that it may be one of the main natural mosquito-expelling and pain-alleviating components in the three parts. The flower-buds are the main active part with the mosquito-expelling function.  相似文献   
9.
FTIR应用于原产地中药材白芍的测定方法研究   总被引:6,自引:5,他引:1  
采用傅里叶变换红外光谱不同的测定方法进行了白芍的测试比较,并对白芍木质部及外表皮部、不同产地的药典白芍进行了质量分析,结果显示白芍木质部与外表皮部含有相同的化学成分,但所含的芍药苷及其衍生物的含量木质部比外表部要高,而在杭白芍、亳白芍及川白芍中,以杭白芍的质量为佳.  相似文献   
10.
沙打旺中两种新三萜化合物   总被引:1,自引:0,他引:1  
沙打旺(Astragalus Adsurgens Pall)是豆科黄芪属植物,我们对其化学成分和毒性成分进行了研究,从中分出2个新的四环三萜类化合物9和10.本文报道它们的分离鉴定工作。 1 新化合物的特征 化合物9:白色粉末,m.p.249~251℃,[a]_D~(20):—47.06°(C 0.34,CHCl_3),HRMS(M~+)m/z:486.3345,结合元素分析,分子式定为C_(30)H_(46)O_5.IR(cm~(-1))示有3367~3567(—OH),1724,1740(C—O,五元环);~1H NMR(δppm,CDCl_3,TMS),1.07~1.37处有7个—CH_3,0.44(1H,d,J=4.49 Hz),0.65(1H,d,J=4.48 Hz)AB型偶合系统和IR 3050cm~(-1),提示分  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