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1.
Water-soluble constituents of dill 总被引:1,自引:0,他引:1
From the water-soluble portion of the methanol extract of dill (fruit of Anethum graveolens L.), which has been used as a spice and medicine, thirty-three compounds, including a new monoterpenoid, six new monoterpenoid glycosides, a new aromatic compound glucoside and a new alkyl glucoside were obtained. Their structures were clarified by spectral investigation. 相似文献
2.
Water-soluble constituents of ajowan. 总被引:4,自引:0,他引:4
From the water-soluble portion of the methanol extract of the fruit of Carum ajowan (ajowan), which has been used as a spice and medicine, 25 compounds, including five new monoterpenoid glucosides, a new monoterpenoid, two new aromatic compound glucosides, and two new glucides, were obtained. Their structures were clarified by spectral investigation. 相似文献
3.
From the water-soluble portion of the methanol extract of coriander (fruit of Coriandrum sativum L.), which has been used as a spice and medicine since antiquity, 33 compounds, including two new monoterpenoids, four new monoterpenoid glycosides, two new monoterpenoid glucoside sulfates and two new aromatic compound glycosides were obtained. Their structures, were clarified by spectral investigation. 相似文献
4.
Roberta Bernini Enrico Mincione Fernanda Crisante Maurizio Barontini Giancarlo Fabrizi 《Tetrahedron letters》2007,48(39):7000-7003
The efficiency of dimethyl carbonate (DMC) as chemoselective carbomethoxylating agent of the alcoholic chain of phenols has been investigated. In the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or sulfuric acid as catalysts, new carbomethoxylated phenolic compounds were obtained in quantitative yields. A new efficient derivatization of the aliphatic alcoholic chain of the precious natural hydroxytyrosol is described, which increases the lipophilicity of the hydroxytyrosol. The antioxidant activity of this new carboxymethylated hydroxytyrosol 8 has been investigated using DPPH radical scavenging test. The results showed that this new compound has an antioxidant activity similar to hydroxytyrosol. 相似文献
5.
Nanostructuration of soft hydrogels: synthesis and characterization of saccharidic methacrylate gels
Seila Rodriguez Vilches Childérick Séverac Christophe Thibaut Lo?c Laplatine Christophe Vieu Juliette Fitremann Anne-Fran?oise Mingotaud Philippe Martinoty Dominique Collin 《Colloid and polymer science》2011,289(13):1437-1449
With the tremendous development of biosensors, there is a strong need in new biocompatible materials avoiding possible denaturing
of biological species, which can be easily processed with already existing technologies. The scope of this study was to develop
new hydrogels which could be nanostructured by common lithographic methods. Therefore, new methacrylate hydrogels are described,
which include functionalized monomers bearing either neutral groups, such as saccharidic moieties, anionic, or cationic groups.
The gels have been synthesized by redox or photochemical-initiated radical polymerization. Their porosity has been characterized
by thermoporometry, AFM, and electronic microscopy. The kinetics of the photocross-linking has been analyzed by piezorheometry
on some of the materials and has been shown to be compatible with technological process time range. Although the obtained
hydrogels are soft, their nanostructuration into 500-nm patterns could be performed by nanoimprint photolithography process,
and these patterns were observed to be stable for several months. 相似文献
6.
7.
A new direct electrophilic diamination reaction of alpha,beta-unsaturated ketones and esters has been established without the use of any metal catalysts. Three types of nitriles (CH(3)CN, CH(3)CH(2)CN, and CH(3)CH(2)CH(2)CN) were employed as nucleophilic nitrogen sources. A new mechanism has also been proposed to explain the resulting regio- and stereoselectivity. 相似文献
8.
Zia Ul Haq Khan Amjad Khan Arif Ullah Khan Kamran Tahir Nawshad Muhammad 《Natural product research》2018,32(10):1161-1169
Some new pyrimidine derivatives have been synthesised by electrochemical oxidation of catechol (1a) in the existence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol (3) as a nucleophile in aqueous solution using Cyclic Voltammetric and Controlled Potential Coulometry. The catechol has been oxidised to o-quinone through electrochemical method and participative in Michael addition reaction, leading to the development of some new pyrimidine derivatives. The products were achieved in good yield with high pureness. The mechanism of the reaction has been conformed from the Cyclic Voltammetric data and Controlled Potential Coulometry. After purification, the compounds were characterised using modern techniques. The synthesised materials were screened for antimicrobial actions using Gram positive and Gram negative strain of bacteria. These new synthesised pyrimidine derivatives showed very good antimicrobial activity. 相似文献
9.
Sacha Legrand Harri Heikkinen Andrew Root C. Rikard Unelius 《Tetrahedron letters》2010,51(17):2258-2261
The preparation, characterization and application of a new stationary phase derived from 1,4-cyclohexanedione and diethyl (+)-tartrate are described. A suitable TADDOL for immobilization has been synthesized and grafted to a γ-mercaptopropylsilylated silica gel. The resulting modified stationary phase has been characterized and its ability to separate enantiomers has been studied. While the free TADDOL in solution was able to resolve a range of enantiomers, the resolving properties were lost on immobilization. Solid state 13C CPMAS NMR of the new stationary phase was used to explain the lack of stereoselective recognition. 相似文献
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11.
[reaction: see text] A new class of N-substituted radical has been studied. Obtained from the corresponding chlorides, beta-lactamido N-sulfonyl radicals were allylated and added onto electron-rich olefins. It has been shown that the radicals do not undergo desulfonylation and are electrophilic in nature. 相似文献
12.
Devkota KP Choudhary MI Nawaz SA Lannang AM Lenta BN Fokou PA Sewald N 《Chemical & pharmaceutical bulletin》2007,55(4):682-684
The microbial transformation of a steroidal alkaloid, dictyophlebine (1) with Rhizopus stolonifer (ATCC 10404) afforded three oxidized metabolites 2-4. Compound 2 was found to be a new product. These metabolites were structurally characterized on the basis of modern spectroscopic techniques. Their inhibitory activity towards acetyl- and butyrylcholinesterase has been evaluated and the new product 2 has been found to be more potent than the parent compound and other metabolites. 相似文献
13.
A new family of chiral alkoxy-N-heterocyclic carbene (NHC) ligands has been designed for the enantioselective copper-catalyzed conjugate addition of dialkylzincs to enones. These new bidentate NHC ligands were synthesized in high overall yields using a five-step procedure starting from commercially available β-aminoalcohols. Influence of the temperature, base, solvent and copper source were studied in order to optimize the stereoselectivity of the addition. High reactivity and excellent enantioselectivity were obtained at ambient temperature with a range of cyclic enones and dialkylzinc. Addition to acyclic enones has also been studied. 相似文献
14.
合成有机锗倍半硫化物的新方法 总被引:5,自引:0,他引:5
有机锗倍半硫化物的合成是有机锗抗癌药物研究中的热点之一。在路易斯碱(如吡啶或三乙胺)存在下,经有机锗三氯化物溶液中通干燥的硫化氢气体制得有机锗倍半硫化物的方法有许多缺点,如无法计算吸收的硫化氢的量、设备复杂、操作困难并产生硫化氢臭味和毒性。我们用无水硫化钠直接与有机锗三氯化物作用即可得到有机锗倍半硫化物。利用此法合成了8种有机锗倍半硫化物: 相似文献
15.
A new general equation of state recently reported for pure liquids has been developed to predict the volumetric and thermodynamic properties of six binary and two ternary liquid refrigerant mixtures (including HCs and HFCs mixtures) at different temperatures, pressures, and compositions. The results show this equation of state can be used to reproduce and predict different thermodynamic properties of liquid refrigerant mixtures within experimental errors. The composition dependence of the parameters of this equation of state has been assumed as quadratic functions of mole fraction. Using these mixing rules, the agreement between calculated and experimental densities is better than 0.6% for binary mixtures and 2.3% for ternary mixtures. To compare the performance of this new equation of state against other well-known methods such as the COSTALD method, the density of some refrigerant mixtures, for which the parameters of COSTALD were available, has been computed and compared with those of this new equation of state. 相似文献
16.
Atkinson IA Law MM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(4):873-885
A large experimental spectroscopic data set sensitive to the cubic anharmonic potential energy surface (PES) of methyl fluoride has been compiled from the literature for six symmetric and asymmetric top isotopomers of methyl fluoride: 12CH3F, 13CH3FF, 12CD3F, 13CD3F, 12CHD2F and 12CH2DF. This empirical data set has been used to critically assess the best available literature ab initio cubic force field and various 'improved' theoretical force fields. A perturbation-resonance approach to the calculation of the observables from the force constants has been utilized and existing PESs were found to reproduce the data poorly. The careful treatment required for the correct theoretical reproduction of empirical spectroscopic constants arising from highly correlated least-squares fits to the original data is discussed. A new fit to the data has been performed (optimising 19 of the 38 cubic force constants) resulting in a much improved PES. The latter has been used to predict currently unknown spectroscopic constants for the least well-characterised isotopomer 12CH2DF. The prospects for a future empirical determination of the complete cubic force field of methyl fluoride are discussed and new data most likely to yield new information on the PES identified. 相似文献
17.
I. Iovel L. Golomba S. Belyakov J. Popelis A. Gaukhman E. Lukevics 《Chemistry of Heterocyclic Compounds》2003,39(3):318-327
The reaction of furan, thiophene, pyridine, and also furylacryloyl aldehydes with 2-trifluoromethylanilines has been studied in the presence of molecular sieves and a series of new heterocyclic aldimines has been synthesized. The molecular and crystalline structure of some of them were determined by X-ray structural analysis. 相似文献
18.
Three new aryl sulphonylacetic acids have been prepared from 2-chlorotoluene, 1,2-dichlorobenzene and 1-bromonaphthalene.
The infrared spectra of these acids exhibited strong bands characteristic of carbonyl stretching frequencies of carboxylic
acids. Utilising these sulphonylacetic acids some new unsaturated sulphones were synthesised. An attempt has been made to
correlate the infrared and proton magnetic resonance spectral data to the configurations of unsaturated sulphones. 相似文献
19.
Matoga M Laborde-Kummer E Langlois MH Dallet P Bosc JJ Jarry C Dubost JP 《Journal of chromatography. A》2003,984(2):253-260
The dissociation constants of new 2-amino-2-oxazolines were determined by capillary electrophoresis (CE) as a new technique. A method based on a linear model has been used in the CE determination. A series of eight 2-amino-2-oxazolines are investigated to determine their ionization constant. Among them, three new oxazolines synthesized are presented. The Ka values were obtained from the plots of reciprocal effective mobility against inverse concentrations of protons. The potentiometric method (PM) was performed as a comparative method. No significant differences were observed between the determined dissociation constants using both methods. Thus, the pKa values have been found to vary between 8.55 and 8.68. 相似文献