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131.
132.
L. E. García-Ayuso J. Velasco M. C. Dobarganes M. D. Luque de Castro 《Chromatographia》2000,52(1-2):103-108
Sumamry Soybean, rape and sunflower lipids have been extracted with a focused microwave-assisted Saxhlet extractor. The main factors
affecting extraction efficiency, namely microwave irradiation power, number of cycles and microwave irradiation time were
optimised by means of a power, number of cycles and microwave irradiation time were optimised by means of a central composite
design based on a two-level-three-factor factorial design. A study of the influence of particle size on the extraction procedure
was also performed. The results obtained were compared with those obtained by use of an ISO method using a conventional Soxhlet
extractor. Quantitative results for lipid content based on gravimetric determinations and qualitative results based on analysis
of fatty acid methyl esters and polymeric compounds were similar to those obtained by Soxhlet extraction with hexane. Substantial
reduction of sample manipulation. analysis time and solvent wastage is achieved by use of the proposed method. 相似文献
133.
134.
Meng Li Beibei Zhang Mengnan Zeng Jingke Zhang Zhiguang Zhang Weisheng Feng Xiaoke Zheng 《Molecules (Basel, Switzerland)》2022,27(3)
Four new benzoylamide derivatives, lepidiumamide B–E (1–4), were isolated from the seeds of Lepidium apetalum Willd. The structures were determined by a combination of MS and NMR analyses. All compounds were evaluated for their protective effects against NRK-52e cell injury induced by lipopolysaccharide (LPS) in vitro. These compounds showed significantly protective activity and ameliorated LPS-induced NRK52e cells via the Nrf2/Keap1 pathway. The discovery of these active compounds is important for the prevention and treatment of renalinjury. 相似文献
135.
A. N. Karaseva V. V. Karlin A. I. Konovalov V. F. Mironov Yu. Ya. Efremov D. R. Sharafutdinova O. V. Tsepaeva E. R. Yunusov 《Chemistry of Natural Compounds》2000,36(3):269-271
The acid composition of seed oil ofAmaranthus cruentus and the synthesis of their glycidyl and pyridinecontaining esters are studied. It is demonstrated that 67% of the total acids are C18-polyunsaturated linoleic and linolenic. A new method for preparing glycidyl esters of C18-unsaturated carboxylic acids is developed by reacting their salts with ECG in an aprotic medium to produce the corresponding glycidyl esters. The reaction of the glycidyl esters and pyridine salts with carboxylic and phosphonic acids produces the propanolpyridine esters of the acids that combine the properties of the acids and pyridinium salts and are promising in the search for biologically active compounds.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 217–219, May–June, 2000. 相似文献
136.
The analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemi-carbazone (PPDOT) are described for the first time. The reagent gives colour reactions with copper(II) and nickel(II) in sodium acetate-acetic acid buffer medium. The copper complex shows maximum absorbance at 465 nm while the nickel complex at 395 nm. Therefore, these colour reactions have been advantageously used for the simultaneous spectrophotometric determination of copper(II) and nickel(II) in synthetic mixture and also in edible oils and seeds. 相似文献
137.
Liu X Abd El-Aty AM Cho SK Yang A Park JH Shim JH 《Biomedical chromatography : BMC》2012,26(10):1157-1162
The extraction and identification of bioactive compounds from herbs is of great interest. In this study, accelerated solvent extraction (ASE) technique was used to analyze the secondary volatile profiles in Nigella sativa seeds obtained from two different origins, Egypt and Bangladesh. The main extraction parameters, including extraction temperature, pressure and static extraction time, were investigated and optimized. Identification and quantification of the major constituents in nonpolar extracts (hexane) were achieved by means of GC‐FID/GC‐MS analysis with external standards. The two seeds showed a similar variety of chemical composition; however, the secondary volatiles profile of Bangladesh seed was higher than that of the Egyptian seed. A total of 25 compounds were identified from the ASE extract under the following optimum extraction conditions: 100°C, 1500 psi and 5 min, for extraction temperature, pressure and static time, respectively. The proposed technique can be used for the characterization of N. sativa varieties or cultivars. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
138.
Rapidly differentiating grape seeds from different sources based on characteristic fingerprints using direct analysis in real time coupled with time‐of‐flight mass spectrometry combined with chemometrics 下载免费PDF全文
The seeds of grapevine (Vitis vinifera) are a byproduct of wine production. To examine the potential value of grape seeds, grape seeds from seven sources were subjected to fingerprinting using direct analysis in real time coupled with time‐of‐flight mass spectrometry combined with chemometrics. Firstly, we listed all reported components (56 components) from grape seeds and calculated the precise m/z values of the deprotonated ions [M–H]–. Secondly, the experimental conditions were systematically optimized based on the peak areas of total ion chromatograms of the samples. Thirdly, the seven grape seed samples were examined using the optimized method. Information about 20 grape seed components was utilized to represent characteristic fingerprints. Finally, hierarchical clustering analysis and principal component analysis were performed to analyze the data. Grape seeds from seven different sources were classified into two clusters; hierarchical clustering analysis and principal component analysis yielded similar results. The results of this study lay the foundation for appropriate utilization and exploitation of grape seed samples. Due to the absence of complicated sample preparation methods and chromatographic separation, the method developed in this study represents one of the simplest and least time‐consuming methods for grape seed fingerprinting. 相似文献
139.
Naader Alizadeh Hamideh Kalhor Akram Karimi 《International journal of environmental analytical chemistry》2015,95(1):57-66
Thiram fungicide contamination in canola seeds, water and soil samples was monitored using headspace solid-phase microextraction (HS-SPME) combined with ion mobility spectrometer (IMS) to assess its environmental relevance. The influence of the various analytical parameters on microextraction procedure including pH, ionic strength, equilibrium time and temperature has been evaluated and optimised. HS-SPME-IMS allowed the determination of thiram in the concentration range of 10–300 ng mL?1 (R2 > 0.99). The detection limit and relative standard deviation were 6 ng mL?1 and 8% for five replicate analyses, respectively. The HS-SPME-IMS method with polypyrrole film doped with dodecylsulfate (PPy-DS) as solid phase provided an effective sample clean-up for the monitoring of thiram in canola and soil samples. The main advantages of this method are sensitive, good repeatability, organic solvent-free, less time-consuming and relatively inexpensive. 相似文献
140.
Two new glycosides,nor-rubrofusarin-6-O-β-D-(6′-O-acetyl)glucopyranoside(1) and 1-desmethylaurantio-obtusin-2-O-β-D-glucopyranoside (2) were isolated from the seeds of Cassia obtusifolia and their structures were established by chemical and spectral evidences. 相似文献