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991.
The polyphenolic profiles and antioxidant effects of Agastache rugosa Kuntze (Banga) flower,leaf, stem and root
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Yun‐Hi Kim Won Sup Lee Soo Jung Lee Jong Sung Jin A. M. Abd El‐Aty Ho‐Chul Shin Jae‐Han Shim Sung Chul Shin 《Biomedical chromatography : BMC》2016,30(2):225-231
Agastache rugosa Kuntze (Korean mint) is used as a spice and in folk medicine in East Asia. The present study identified a total of 18 polyphenols from the flower, leaf, stem and roots of this plant using high‐performance liquid chromatography–tandem mass spectrometry. Fourteen of these compounds had not previously been identified in these plant tissues. Each polyphenol was validated in comparison with external calibration curves constructed using structurally related compounds, with determination coefficients >0.9993. The limits of detection and quantification were 0.092–0.650 and 0.307–2.167 mg/L, respectively. Recoveries of 61.92–116.44% were observed at two spiking levels, with 0.91–11% precision, expressed as relative standard deviation (except anthraquinone spiked at 10 mg/L). Hydroxycinnamic acid was the most abundant compound in the root, while the flowers showed the highest total flavonoid level. Antioxidant activities, determined in terms of reducing power, Fe2+ chelating activity and the radical scavenging activities using α,α‐diphenyl‐β‐picrylhydrazyl and 2‐2?‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, increased in a concentration‐dependent manner; the highest activity was identified in the stems, followed by leaves > flowers > roots. These findings indicate that A. rugosa is a good source of bioactive compounds and can be used as a functional food. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The temperature fields and the energy dissipations of shape memory alloys during the stress-induced martensitic transformations are studied theoretically and experimentally. The effect of the loading rate is analyzed. It was found that the temperature field inside a shape memory alloy sample varies strongly in space and time. The increase rate of the temperature is given by the difference between the rate of the latent heat release and the rate of the heat convection and conduction. The notion and the rate dependence of the energy dissipation are discussed in connection with the stress–strain hysteresis, the entropy production, and the Clausius–Duhem inequality. 相似文献
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A new and green method for the synthesis of α,β-unsaturated arylsulfones had been achieved through the condensation of aromatic aldehydes,chloroacetonitrile,benzenesulfinic acid sodium salt in the presence of l-butyl-3-methyl imidazolium hydroxide([bmim]OH) in EtOH under reflux.The ionic liquid was recovered and recycled for subsequent reactions.The advantages of this protocol were non-toxic,easy work-up and good yields. 相似文献
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For different dimensions, heights and irregular shapes, small and large particles cannot be viewed simultaneously as sharp images under the microscope due to optical defocusing effects. Bi-orthogonal wavelet transform is used in this paper to depress such defocusing effect by merging the wavelet coefficients of the image series. The algorithm is presented in detail, using SWE(13,7) and CDF(2,2), and a few particle images are provided to validate the proposed method. 相似文献
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J.Y. MeiH. Wang G.J. WangX.H. Sun T. LiC.M. Lei C.C. Wang 《Physica B: Condensed Matter》2012,407(7):1082-1085
A sample of Gd2CuO4 (GCO) has been prepared through the solid state reaction technique. Dielectric properties of this material have been measured in detail as functions of temperature (between 285 and 450 K) and frequency (20 Hz-10 MHz). A step-like increase below 330 K and a broad peak around 360 K were observed in the real part of the permittivity (ε′) which were found to be originated from the oxygen vacancy hopping motions that cause a dipolar relaxation, followed by a Maxwell-Wagner relaxation as the hopping carriers are blocked by the interfaces and surfaces of the sample. 相似文献
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