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1.
A sensitive and efficient method for trace analysis of some phenolic compounds using simultaneous derivatization and air‐assisted liquid–liquid microextraction from human urine and plasma samples followed by gas chromatography–nitrogen phosphorous detection
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Mir Ali Farajzadeh Mohammad Reza Afshar Mogaddam Ali Akbar Alizadeh Nabil 《Biomedical chromatography : BMC》2015,29(12):1921-1931
In present study, a simultaneous derivatization and air‐assisted liquid–liquid microextraction method combined with gas chromatography–nitrogen phosphorous detection has been developed for the determination of some phenolic compounds in biological samples. The analytes are derivatized and extracted simultaneously by a fast reaction with 1‐flouro‐2,4‐dinitrobenzene under mild conditions. Under optimal conditions low limits of detection in the range of 0.05–0.34 ng mL?1 are achievable. The obtained extraction recoveries are between 84 and 97% and the relative standard deviations are less than 7.2% for intraday (n = 6) and interday (n = 4) precisions. The proposed method was demonstrated to be a simple and efficient method for the analysis of phenols in biological samples. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
2.
The present study was designed to evaluate the contents of different antioxidants compounds and their antioxidant activities in Jalopeno peppers (Capsicum annuum) cultivars (El Dorido, Grande, Tula, Sayula and El Rey) extracts. Free radical scavenging activity of Grande was recorded as high as 87% followed by El Dorido (83%). Results of reducing power (Fe3+ to Fe2+) showed that Grande (0.85%) and El Dorido (0.81%) fruit extract absorbance value were close to synthetic antioxidant BHT (0. 97%) obtained at100 μg/mL. The results showed that total phenolic content of El Dorido and Grande were significantly higher compared to other Jalapeno pepper. Results indicated strong and positive correlation between antioxidant activity and carotenoids content (r = 0.75), vitamin C (r = 0.78) and total capsaicinoids (r = 0.84), respectively. The results of the antioxidant activity assays showed that the El Dorido and Grande had strongest antioxidant activity compared to other peppers cultivars in this study. 相似文献
3.
脂松香、石炭酸松香树脂和马林酸松香树脂的红外光谱剖析及鉴别 总被引:5,自引:0,他引:5
本文对脂松香、石炭酸松香树脂和马林酸松香树脂的红外光谱剖析及鉴别,方法快速,简便,准确。 相似文献
4.
Danny E. Akin W. Herbert Morrison III Luanne L. Rigsby Franklin E. Barton II David S. Himmelsbach Kevin B. Hicks 《Applied biochemistry and biotechnology》2006,129(1-3):104-116
Information is presented on structure, composition, and response to enzymes of corn stover related to barriers for bioconversion
to ethanol. Aromatic compounds occurred in most tissue cell walls. Ferulic acid esterase treatment before cellulase treatment
significantly improved dry weight loss and release of phenolic acids and sugars in most fractions over cellulase alone. Leaf
fractions were considerably higher in dry weight loss and released sugars with esterase treatment, but stem pith cells gave
up the most phenolic acids. Results help identify plant fractions more appropriate for coproducts and bioconversion and those
more suitable as residues for soil erosion control. 相似文献
5.
A New Bibenzyl Glycoside from Dendrobium moniliforme 总被引:1,自引:0,他引:1
Chun Sheng ZHAO Wei Min 《中国化学快报》2003,14(3):276-277
A new bibenzyl glycoside has been isolated from the stems of Dendrobium moniliforme (L.) Sw.(Orchidaceas).Its structure has been identified on the basis of spectroscopic and chemical methods. 相似文献
6.
L. Pistelli C. Noccioli M. Martera L. Giamperi A. Bucchini D. Fraternale D. Ricci 《Chemistry of Natural Compounds》2006,42(3):281-284
Seven flavonol glycosides were isolated and identified from the aerial parts of Dorycnium hirsutum, together with catechin, D-pinitol, β-sitosterol, and stearic acid. The extracts and the isolated flavonol glycosides were
evaluated for their antioxidant activity, using the DPPH test (radical scavenging) and the lipoxygenase assay (lipid peroxidation).
Dedicated to the memory of Prof. I. Morelli.
Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 233–235, May–June, 2006. 相似文献
7.
8.
A New Asterosaponin from the Starfish Culcita novaeguineae 总被引:1,自引:0,他引:1
HaiFengTANG YangHuaYI LingLI PengSUN DaZhengZHOU BaoShuLIU 《中国化学快报》2005,16(5):619-622
A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence. 相似文献
9.
Wu J Huang J Xiao Q Zhang S Xiao Z Li Q Long L Huang L 《Magnetic resonance in chemistry : MRC》2004,42(7):659-662
Ten phenylethanoid glycosides, including two new ones, isolated from the aerial parts of the mangrove plant Acanthus ilicifolius were identified. The first complete assignments of the 1H and 13C NMR chemical shifts for these glycosides were achieved by means of 2D NMR techniques, including 1H-1H COSY, TOCSY, HSQC and HMBC spectra. 相似文献
10.
Ranjana Yadav 《European Polymer Journal》2007,43(8):3531-3537
Models capable of predicting the maximum extent of conversion (p) of cardanol-based novolac-type phenolic resin, have been developed using response surface methodology to determine the optimum reaction conditions. Three-dimensional response surface and their contour plot were drawn. The maximum extent of conversion (98.93%) was predicted when the cardanol was condensed with formaldehyde (molar ratio 1:0.652) at 119.84 °C for a time period of 3 h with the catalyst (e.g., citric acid) concentration of 1.988% of total volume of cardanol and formaldehyde. The pH of the reaction mixture was maintained at 3.0. These predicted values for optimum process conditions were in good agreement with experimental data. 相似文献