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   0篇
化学   11篇
  2021年   1篇
  2018年   1篇
  2015年   2篇
  2014年   1篇
  2011年   1篇
  2009年   1篇
  2004年   2篇
  2002年   1篇
  1992年   1篇
排序方式: 共有11条查询结果,搜索用时 750 毫秒
1.
Information on flavones, flavanones, flavanonols, flavonols, chalcones, isoflavones, biflavonoids, lignoflavonoids, and lignane glycosides and stilbenes isolated from plants of the Scutellaria L. genus was systematized and reviewed. A list of 208 phenolic compounds was given according to flavonoid type with an indication of the plant sources, structures, and physicochemical properties and citations of the original articles.  相似文献   
2.
The genus Garcinia is reported to possess antimicrobial, anti‐inflammatory, anticancer, hepatoprotective and anti‐HIV activities. Garcinia hombroniana in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to isolate the chemical constituents from the bark of G. hombroniana and explore their possible pharmacological potential. Ethyl acetate extract afforded one new (1) and six (2–7) known 3 → 8 rotameric biflavonoids. Their structures were elucidated by UV, IR and NMR (1D and 2D) spectroscopy together with electron ionization/ESI mass spectrometric techniques and were identified as (2R, 3S) volkensiflavone‐7‐O‐rhamnopyranoside (1), volkensiflavone (2), 4″‐O‐methyl‐volkensiflavone (3), volkensiflavone‐7‐O‐glucopyranoside (4), morelloflavone (5), 3″‐O‐methyl‐morelloflavone (6) and morelloflavone‐7‐O‐glucopyranoside (7). The absolute configuration of compound 1 was assigned by circular dichroism spectroscopy as 2R, 3S. The coexistence of conformers of isolated biflavonoids in solution at 25 °C in different solvents was confirmed by variable temperature NMR studies. At room temperature (25 °C), compounds 1–7 exhibited duplicate NMR signals, while at elevated temperature (90 °C), a single set of signals was obtained. Compound 5 showed significant in vitro antioxidant activities against 1,1‐diphenyl‐2‐picrylhydrazyl and 2,2′‐azino‐bis‐3‐ethyl benzthiazoline‐6‐sulfonic acid radicals. The antibacterial studies showed that compounds 5 and 6 are the most active against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compounds 3 and 6 also showed moderate antituberculosis activity against H38Rv. Based on the research findings, G. hombroniana could be concluded as a rich source of flavanone–flavone (3 → 8) biflavonoids that exhibit rotameric behaviour at room temperature and display significant antioxidant and antibacterial activities. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
3.
A new prenylated biflavonoid, named dulcisbiflavonoid A, together with five biflavonoids were isolated from the leaves of Garcinia dulcis. Their structures were elucidated by analysing their spectroscopic data, especially 1D and 2D NMR.  相似文献   
4.
Baeckeins C (compound 1) and D (compound 2), a pair of new diastereomeric biflavonoids, were isolated from the roots of Baeckea frutescens. Their structures were elucidated on the basis of spectroscopic analysis, including HR-ESI-MS and one- and two-dimensional NMR spectra ((1)H and (13)C NMR, HSQC, HMBC, and ROESY). The absolute configurations of the 2,3-epoxide moiety for compounds 1 and 2 were determined by circular dichroism spectrometry combined with quantum chemical calculations.  相似文献   
5.
A biflavonoid glycoside with a new carbon skeleton, named carinoside A, was isolated from the n-BuOH crude extract of the whole plant of Lomatogonium carinthiacum (Wulf) Reichb. The structure of the new compound was elucidated by using spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.  相似文献   
6.
《Tetrahedron letters》2018,59(52):4545-4550
Two xanthones, 2-(3-hydroxy-3,3-dimethyldihydroallyl)-dihydro-6-deoxyisojacareubin (1) and dihydro-6-deoxyjacareubin (2), and two 3 ⟶ 8 rotameric biflavonoids, (2R,3S)-volkensiflavone-7-O-β-acetylglucopyranoside (3) and (2S,3S)-morelloflavone-7-O-β-acetylglucopyranoside (4), together with fifteen known compounds, were isolated from a dichloromethane/methanol (1:1, v/v) extract of the bark of the plant Allanblackia floribunda. The structures of the new compounds were elucidated by NMR spectroscopy and mass spectroscopic techniques and those of the known ones were deduced by comparison with data reported in the literature. The isolated biflavonoids were obtained as mixtures of conformers exhibiting duplicate NMR signals in solution at 25 °C and their respective absolute configurations were assigned using circular dichroism spectroscopy. Selected isolated compounds were assessed for their antibacterial and antioxidant properties.  相似文献   
7.
A New Biflavonoid from Stellera chamaejasme L.   总被引:4,自引:0,他引:4  
A new biflavonoid, stelleranol, was isolated from the roots of Stellera chamaejasme L..Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.  相似文献   
8.
Biflavonoids, composed of two monoflavonoid residues, occur naturally in angiosperms, bryophytes, ferns, and gymnosperms. More than 592 biflavonoids have been structurally elucidated, and they can be classified into two groups of C-C and C-linear fragments-C, based on whether the linker between the two residues contains an atom. As the linker can be established on two arbitrary rings from different residues, the C-C type contains various subtypes, as does the C-linear fragment-C type. Biflavonoids have a wide range of pharmacological activities, including anti-inflammatory, antioxidant, antibacterial, antiviral, antidiabetic, antitumor, and cytotoxic properties, and they can be applied in Alzheimer’s disease and Parkinson’s disease. This review mainly summarizes the distribution and chemistry of biflavonoids; additionally, their bioactivities, pharmacokinetics, and synthesis are discussed.  相似文献   
9.
Eight spiro‐biflavonoids named abiesinols A–H, along with three neolignans, quercetin, and protocatechuic acid were isolated from the MeOH extract of the bark of Abies sachalinensis. The structures of these phenolic compounds were characterized by spectroscopic methods including NMR and MS. The absolute configurations of the abiesinols were determined by Mosher's method, CD, and NOESY data.  相似文献   
10.
Summary The flavonoid content of olive leaves was studied by a method based on thin-layer chromatography and recording UV spectra directly on the layer. Three flavonoid glycosides, quercitrin, rutin and luteolin-7-glycoside, one flavonoid aglycone, luteolin, and chlorogenic acid were found in olive leaves. Three compounds with a biflavonoid-type sructure have been characterized. Ten cultivars were investigated in order to indicate qualitative and quantitative differences.  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