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1.
A further chemical investigation of the plant Rubus corchorifolius L. f., collected in Hunan Province, afforded two new ent‐kauranoids 6 and 7 . Their structures were elucidated by various spectroscopic methods.  相似文献   

2.
A further chemical investigation of the plant Rubus corchorifolius L. f., collected in Hunan Province, afforded three new ent‐kauranoids 3 – 5 . Their structures were elucidated by various spectroscopic methods.  相似文献   

3.
Leaves and stems of red raspberry (Rubus idaeus) are used in Lithuanian folk medicine. Healing properties of raspberry are related to the content of bioactive compounds, mainly polyphenols. Extracts of raspberry leaves contained higher total phenolic content (TPC) (1290 mg/L, expressed in gallic acid equivalent) compared to that in extracts of stems or peeled bark (up to 420 mg/L and 598 mg/L, respectively). To find out whether the collection time of herbal material was critical for the properties of the extracts, the stems were collected at different times of the year. TPC in the extracts depended more on extraction conditions rather than on the sampling time. Antioxidant activity of raspberry stem and bark extracts tested by spectrophotometric (DPPH scavenging) and electrochemical (cyclic and differential pulse voltammetry) assays correlated with TPC. DPPH radical scavenging activity values for stem, leaf, and bark extracts were as follows: ≤1.18 ± 0.07, 1.63 ± 0.10, and ≤1.90 ± 0.04 (mmol/L, TROLOX equivalent), respectively. Assessed electrochemically, hydrogen peroxide-scavenging activity of extracts was independent on TPC. The latter activity was related to the presence of some protein in the extract as revealed by gel electrophoresis. Prooxidant activity of raspberry stem extracts was dependent on solution pH and temperature.  相似文献   

4.
Summary.  Pyrrole α-aldehydes (2-formyl-4,5-dimethyl-1H-pyrrole and 2-formyl-N-methylpyrrole) condense readily at C(3) of indolin-2-ones to give dipyrrinone analogs, such as (3Z)-[(4,5-dimethylpyrrol-2-yl)-methylidenyl]-indolin-2-one and (3E)-[(1-methylpyrrol-2-yl)-methylidenyl]-indolin-2-one. 1H-NMR NOE analyses and X-ray crystallography confirm the syn-(Z) configuration for the former and the syn-(E) configuration for the latter. The former is stabilized by intramolecular hydrogen bonding. Molecular mechanics calculations of the latter indicate no energy difference between the syn and anti conformations. Corresponding author. E-mail: lightner@scs.unr.edu Received August 2, 2002; accepted August 30, 2002  相似文献   

5.
The aim of this work is to determine the biological activity of ellagitannins rich extracts from leaves of raspberry (Rubus idaeus L.) and wild strawberry (Fragaria vesca L.) in relation to cells and cell membranes. Detailed qualitative and quantitative analysis of phenolic compounds of the extract was made using chromatographic methods. Cytotoxic and antioxidant activities of tested extracts in relation to erythrocytes and human vascular endothelial cells (HMEC-1) were determined by using fluorimetric and spectrophotometric methods. In order to establish the influence of the extracts on the physical properties of the membrane, such as osmotic resistance and erythrocytes shapes, mobility and/or hydration of polar heads and fluidity of hydrocarbon chains of membrane lipids, microscopic and spectroscopic methods were used. The results showed that the extracts are non-toxic for erythrocytes and HMEC-1 cells (up to concentration of 50 µg/mL), but they effectively protect cells and their membranes against oxidative damage. The increase in osmotic resistance of erythrocytes, formation of echinocytes and changes only in the polar part of the membrane caused by the extracts demonstrate their location mainly in the hydrophilic part of the membrane. The results indicate that tested extracts have high biological activities and may be potentially used in delaying the ageing process of organisms and prevention of many diseases, especially those associated with oxidative stress.  相似文献   

6.
Two new steroidal glucosides from Ophiopogon.japonicus (L.f.) Ker-Gawl   总被引:1,自引:0,他引:1  
Two new steroidal glucosides, 26-O-β-D-glucopyranosyl (25S)-furost-5-ene-1β,3β,22α,26-tetraol l-O-β-D-xylopyranosyl- (1 → 3)-[α-h-rhamnopyranosyl-(1 → 2)]-[β-D-fueopyranoside and (25R) spirost-5-ene-3β,14α-diol-3-β-O-β-L-rhanmopyranosyl- (1 → 2)-[β-D-xylopyranosyl(1 → 4)]-[-β-D-glucopyranoside, were isolated from the Ophiopogon japonicus (L.f.) Ker-Gaw. Their structures were elucidated by spectroscopic methods.  相似文献   

7.
1 INTRODUCTION In the last decade, there has been great interest in the crystal engineering of supramolecular architectures organized by coordinate covalent bonds, hydrogen bonds and their combination owing to their fascinating structural diversity and potential applications as functional materials[1~3]. The self-assembly of coordinate polymers and supramolecules is highly influenced by factors such as ligands, metal ions, the counter ions, solvent, template, reaction temperature, pH va…  相似文献   

8.
The diquinoline derivative 12 was found to yield the diquinolinium dibromide 13 trihydrate on crystallisation from 2-bromoethanol. X-Ray crystallography revealed that the diquinolinium dications pack as parallel (and anti-parallel) stacks, with the bromide ions and water molecules occupying inter-stack channels. The interplay of aromatic offset face-face, N+-H ⋅s O, bromide ⋅s H-O, C-H ⋅s bromide and bromine ⋅s bromide interactions determines this solid-state structure.  相似文献   

9.
Isolation and Identification of Capillarin from Artemisia Ordosica Kraschen   总被引:1,自引:0,他引:1  
1 INTRODUCTION The whole body of herb of Artemisia Ordosica Kraschen (Artemisia genus of Compositae) has been long used to treat rheummarthritis, parotitis, intestinal obstruction as well as to stop bleeding in traditional Chinese medicine[1]. In our systematic studies of active metabolites, we have isolated seve- ral compounds from ethanol extracts of this plant[2], including flavones, flavanones, an isocoumarine, and capillarin. Coumarines commonly occur in na- tural plants as metabo…  相似文献   

10.
在单因素试验的基础上选择提取次数、提取试剂、料液比、超声时间4个因素为自变量,以树莓花色苷的提取率为响应值,进行Box-Behnken中心组合试验设计,采用响应面法(RSM)评估了这些因素对花色苷提取率的影响.并分别采用1,1-二苯基苦基苯肼(DPPH)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)法对花色苷的抗氧化活性进行研究.结果表明,超声辅助提取树莓中花色苷的最佳工艺条件为:超声提取3次,料液比1∶46g/m L,超声时间44 min,在此条件下预测花色苷的得率为6.79%.花色苷对于DPPH的清除率达到13.68μmol/g,对于ABTS的清除率达到8.37μmol/g.  相似文献   

11.
黄伟  佘能芳 《结构化学》2013,(9):1357-1361
The crystal structure of the new title compound 2,2-dimethyl-4-oxochroman-3-ylmorpholine-4-carbodithioate(C16H19NO3S2,Mr = 337.44) has been prepared and determined by single-crystal X-ray diffraction.The crystal is of triclinic,space group P1 with a = 9.5518(7),b = 9.7172(7),c = 11.0220(8),α = 67.08(1),β = 74.66(1),= 61.31(1)°,V = 822.72(10)3,Z = 2,Dc = 1.362 g/cm3,F(000) = 356,μ = 0.092 mm-1,MoKa radiation(λ = 0.71073),R = 0.0515 and wR = 0.1389 for 2623 observed reflections with I > 2(I).X-ray diffraction analysis reveals that the chroman ring adopts a half-chair conformation while the morpholine ring shows a chair conformation.Intramolecular and intermolecular C-H···S and C-H···O hydrogen bonds together with π-π interations are found in the structure.The result of MTT assay shows the title compound displays good antiproliferative activity against two human cancer cell lines.  相似文献   

12.
Ionic liquid was used as microwave absorption medium and applied to the extraction of essential oils from dried fruits of the Illicium verum Hook. f. and Cuminum cyminum L. by microwave‐assisted extraction. The extraction time is less than 15 min at the microwave power of 440 W. The constituents of essential oils obtained by the proposed method were compared with those obtained by hydrodistillation. There is no obvious difference in the constituents of essential oils obtained by the two methods.  相似文献   

13.
魏勇  曹成桥  金蕾  黄年玉  邹坤 《结构化学》2013,32(8):1199-1203
Compound 1, N-methyl-N-((2-(p-tolyl)quinolin-4-yl)methyl)aniline (C24H22N2), as a potential drug for the treatment of acid-related diseases has been synthesized via palladium-catalyzed intramolecular hydroarylation. The compound was characterized by MS and NMR spectra. Meanwhile, the crystal of 1 was obtained and determined by X-ray single-crystal diffraction. Crystal data: triclinic system, space group Pī, a = 5.548(5), b = 11.545(10), c = 14.546(12), α = 90.427(15), β = 90.727(14), γ = 101.099(16)°, V = 914.1(13)3, Z = 2, F(000) = 360, Dc = 1.230 g/cm3, μ = 0.072 mm-1, R = 0.0564 and wR = 0.1616 for 9768 independent reflections (Rint = 0.0447) and 3003 observed ones (I > 2σ(I)).  相似文献   

14.
The chemical constituents of the carboxylic acid derivatives from the ear of Schizonepeta were investigated. 1H and 13C NMR chemical shifts of the carboxylic acid derivatives were accurately assigned. Two carboxylic acid derivative constituents were separated by a silica gel column. The structures were elucidated by the physical and chemical properties, IR, 1H NMR, 13C NMR, MALDI‐TDF‐MS and X‐ray single crystal diffractometry. They were identified as 3‐imino‐N‐(α‐imidoethylamino)butyrolactam and neononane tetracid, respectively. The antitumoral activity on liver tumor cells SMMC‐7721 was determined in vitro. The experimental results showed that the former was better than the latter, and with increasing the concentration of the former the inhibitory activity was increased.  相似文献   

15.
1INTRODUCTIONThepolynucleard10metalcomplexesarepotentialluminescentsensormaterialsduetotheirattractivephotochemicalandphotophysicalpro-perties[1,2].Lowdimensionalmetal-organichalidecomplexeshavereceivedever-interestingattentioninrecentyearsfortheirpotentialapplicationsaselectronicandcatalyticmaterials[3,4].RecentlyHomo-metaloligomersandthechainsofcopperhavebeenreportedbyZubietaandthecoworkersviahydrothermalsyntheses[5,6].Theexistingexamplesofcopperwithmercuryareextremelyrare[7].Intherece…  相似文献   

16.
Diisopropyl genistein-7-yl phosphate (C21H23O8P, Mr = 434.11) has been synthesized by a facile phosphorylated reaction with genistein and diisopropyl phosphite, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n, with a = 9.0690(18), b = 9.0412(18), c = 26.544(5), β = 99.44(3)°, V = 2147.0(7) 3, Z = 4, Dc = 1.344 Mg/m3, μ = 0.172 mm-1, F(000) = 912, the final R = 0.0545 and wR = 0.1352. In the crystal structure, the title compound is constructed by both intramolecular (O–H···O=C) and intermolecular (O–H···O=P) hydrogen bonding as well as π-π stacking interaction.  相似文献   

17.
Isolation and Crystal Structure of Xanthones from Swertia Chirayita   总被引:1,自引:0,他引:1  
1 INTRODUCTION Swertia chirayita (Buch.-Ham.) grows abundantly in the temperate regions of Himalayas. It is used in Tibetan folk medicine as the traditional remedy for chronic fever, anaemia, asthma, liver disorders, hepatitis and stomachic. Recently, th…  相似文献   

18.
环境修复植物黑藻的化学成分   总被引:1,自引:0,他引:1  
环境修复植物黑藻的化学成分;黑藻;羟基豆甾烯酮;十八酸  相似文献   

19.
1 INTRODUCTION Coordination-driven supramolecular assembly hasattracted great interest in constructing beautiful mo-tifs and developing new materials[1~5]. It is crucial toselect or synthesize suitable bridging organic li-gands[6~10]. The reduced Schiff base N-(2-hydro-xybenzyl)-D,L-amino acid is an excellent ligand forself-assembly with metal ions, not only due to itsprolific coordination sites but also its strong abilityto afford hydrogen bonding from secondary aminegroup and carbox…  相似文献   

20.
Introduction Recently cyano bridged 3d-4f heterometallic compounds have attracted much attention because of their interesting structures and magnetic characteristics.1 The most successful and often the sole strategy for preparing these materials consists in assembling two building blocks that are transition and lanthanide metal complexes, one with terminal ligands that are able to act as bridging ligands and the other with available co-ordination sites. The [M(CN)4]2- (M=Ni, Pd, Pt),1f,2 [M…  相似文献   

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