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   11篇
  免费   1篇
  国内免费   3篇
林业   4篇
  2篇
综合类   6篇
畜牧兽医   2篇
园艺   1篇
  2017年   2篇
  2014年   1篇
  2013年   1篇
  2011年   1篇
  2009年   2篇
  2008年   2篇
  2007年   1篇
  2006年   1篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1997年   1篇
排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
A new iridoid diglucoside, 10-O-(E)-p-coumaroylmelittoside (1) and a new flavone glucoside, O-(6'-O-Acetyl-)-beta-glucopyranosylchrysoeriol (2), together with four known flavone glycosides, were isolated from the aerial parts of Sideritis lanata. The structures of the new compounds were elucidated by spectroscopic methods, 2D NMR and MS.  相似文献   
2.
试验旨在建立测定杜仲增免液中松脂醇二葡萄糖苷含量的RP-HPLC法。以Inersustain® C18(250 mm×4.6 mm,5 μm)为色谱柱,乙腈-0.2%磷酸(15:85)为流动相,流速1.0 mL/min,柱温35℃,紫外检测波长277 nm。以乙酸乙酯作为提取溶剂,在所建立的色谱条件下测定供试品溶液,以理论塔板数和分离度作为系统适用性指标。对对照品松脂醇二葡萄糖苷溶液进行线性回归,确定线性范围,考察分析方法的精密度、稳定性、重现性,并进行加样回收试验。结果显示,用所建立的方法测定供试品溶液中松酯醇二葡萄糖苷理论塔板数为8 588,分离度为3.046。松脂醇二葡萄糖苷对照品溶液在6~192 μg/mL浓度范围内线性关系良好,相关系数为0.9996;精密度试验结果显示松脂醇二葡萄糖苷对照品溶液峰面积相对标准偏差(relative standard deviation,RSD)为0.74%;重现性和稳定性试验结果显示供试品溶液中松酯醇二葡萄糖苷峰面积RSD分别为4.50%和2.69%;平均加样回收率为98.74%,RSD为0.65%(n=9);在所建立的色谱条件下,供试品中松脂醇二葡萄糖苷的平均含量为0.124~0.127 mg/mL。结果表明,应用该方法测定杜仲增免液中松脂醇二葡萄糖苷的含量,系统适用性好,精密度高,重现性和稳定性好,回收率高,快速简便、准确可靠,可作为杜仲增免液中松脂醇二葡萄糖苷含量测定方法。  相似文献   
3.
    采用高效液相色谱-二极管阵列检测-电喷雾质谱(HPLC-PAD-ESI-MS)法对开环异落叶松树脂酚二葡萄糖苷(SDG)进行定性和定量检测,研究方法的精密度、稳定性、定量检测限及加样回收率,并考察样品制备方法对定量检测结果的影响.采用Sephadex LH-20柱色谱分离制备SDG对照品,并用1H-NMR与13C-NMR对其进行表征.HPLC-PAD-ESI-MS检测所得紫外及电喷雾质谱信息与SDG结构相符.以自制的SDG(纯度96.6%)为对照,采用HPLC绘制定量标准曲线,方法精密度较高(RSD为1.36%),稳定性好(1周后RSD为1.21%),定量检测限较低(LOQ为3.4 mg·L-1),加样回收率达(99.7±3.2)%.此外,制样时采用碱法水解与混合溶剂提取,不仅节省时间,还更充分地提取了SDG.说明用HPLC-PAD-ESI-MS法栓测亚麻籽中的SDG方便省时,准确可靠.  相似文献   
4.
采用微波辅助提取法从亚麻籽饼粕中提取开环异落叶松树脂酚二葡萄糖苷(Secoisolariciresinol Diglucoside,SDG),确定了微波辅助最佳提取条件为70%乙醇,固液比为1∶8(g/mL),预浸搅拌30 min,辐照时间5 min,微波功率700 W。并建立了直接定性分析亚麻籽饼粕中SDG的TLC方法。经HPLC检测,亚麻籽饼粕中SDG含量为1.64%,微波辅助提取SDG粗提物产率为6.89%,纯化后SDG含量可达20.23%。结果表明:微波辅助提取制备SDG的方法与传统分离方法相比,得率高、工艺操作简单且安全无毒。  相似文献   
5.
Four lignans — pinoresinol, lariciresinol, secoisolariciresinol, matairesinol — were isolated from each ofDaphne odora andDaphne genkwa (Thymelaeaceae). Matairesinol isolated from both plants was optically pure (>99% e.e.) and dextrorotatory. Pinoresinol and lariciresinol isolated from the plants were not optically pure, and their enantiomeric compositions ranged from 88% to 95% e.e. in favor of (–)-enantiomers. As for secoisolariciresinol, the one fromD. odora was optically pure [(+)-enantiomer, >99% e.e.], and that fromD. genkwa was 97% e.e. in favor of the (+)-enantiomer. Lignan-synthesizing enzyme activity was detected from a Thymelaeaceae plant for the first time; cell-free extracts fromD. genkwa catalyzed the formation of (–)-lariciresinol (23% e.e.) from racemic (±)-pinoresinols. The stereochemistry of the enzymatic reaction is discussed in relation to the stereochemical features of the isolated lignans.Parts of this report were presented at the 42nd Lignin Symposium, Sapporo, October 1997; 48th Annual Meeting of the Japan Wood Research Society, Shizuoka, April 1998; and 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999  相似文献   
6.
The furano-lignan pinoresinol was toxic to fourth-instar larvae of the milkweed bug Oncopeltus fasciatus and of the haematophagous insect Rhodnius prolixus, a vector of Chagas disease. At lower doses, it also exerted antifeedant activity and dose-dependent antimoulting activity on both insects.  相似文献   
7.
【目的】对杜仲茎点霉SP-16F发酵生产松脂醇二葡萄糖苷(PDG)的营养条件进行优化,以提高发酵液中的PDG产量。【方法】在单因素实验的基础上,通过三元二次中心组合设计和响应面分析法优化杜仲茎点霉SP-16F发酵产生PDG的最佳营养条件。【结果】在液体培养条件下,茎点霉SP-16F产PDG的最佳培养基组成为:蔗糖47.5 g/L,NaNO33.0 g/L,K2HPO42.83 g/L。在最佳培养条件下,PDG产量预测值较优化前的最大值提高了3倍以上。【结论】获得了茎点霉SP-16F的最佳产PDG培养基,有效地提高了其发酵产PDG的能力。  相似文献   
8.
Genotype selection is an essential step in breeding programs determining nutrient content and composition and, thereby, the quality indices of grapevines and their products. The grapevine bioactive compounds, particularly flavonoids, are determinants of grape quality and possess strong health-promoting effects in grapevine and humans. Grapevine nutrient content and composition depends on genotype–environmental interaction in which genotype selection and stress conditions, particularly severity, time, and combination of stresses play significant roles in determining grape and wine quality. This review article aims to provide information required for appropriate genotype selection of grapevines for production of high-quality fruits. The influence of interacting factors, including genotype selection, grapevine metabolites, and environmental conditions, and their interrelationships on the quality of grapevines (flavor, aroma, pigmentation, color stability, and stress tolerance of red and white grapes) and their products (organoleptic properties and storage life of wine/must and juice) are discussed.  相似文献   
9.
The assay was aimed to determine the content of pinoresinol diglucoside (PDG) in Eucommie ulmoides immunoenhancement liquids. The chromatographic conditions were as follows:Inersustain® C18 column (250 mm×4.6 mm,5 μm) was under column temperature of 35℃, the mobile phase consisted of acetonitrile-0.2% phosphoric acid(15:85)with a flow rate of 1.0 mL/min,and the UV detection wavelength was 277 nm. Ethyl acetate was used as extraction solvent. In order to determine PDG of the test solution under the chromatographic conditions, the number of theoretical plates and resolution were used as system suitability indicators. Linear regression on reference substance (PDG),linearity range and the precision, stability, and reproducibility of the analysis method, the recovery test of adding samples were all determined. The results showed that under the content determination method, the number of theoretical plates of PDG in the test solution was 8 588, and the resolution was 3.046. PDG performed good linear relation at the linear range between 6 and 192 μg/mL, and the related coefficient was 0.9996. The precision experiments showed that the relative standard deviation (RSD) of reference substance solution was 0.74%. The RSD of reproducibility and stability of PDG in the test solution was 4.50% and 2.69%, respectively. The average recovery was 98.74% with RSD 0.65% (n=9). Under the chromatographic conditions established above, the contents of PDG in the test sample were between 0.124 and 0.127 mg/mL. The conclusion was that the RP-HPLC method performed well system suitability, precision, reoroducibility, stability, and high recovery rate. Meanwhile this method was quick, simple and reliable. It could be used to determine the content of PDG in Eucommie ulmoides immunoenhancement liquids.  相似文献   
10.
从亚麻籽和亚麻纤维2个方面,阐述了亚麻的开发利用潜能。  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