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The antioxidant activity of methanol extract/fractions of leaf, bark, and heartwood of Acacia catechu was evaluated by various antioxidant assays, including free radical, superoxide and hydroxyl radical, reducing power, metal ion chelation, as well as hydroxyl radical induced DNA strand scission. The leaf, bark, and heartwood powder was extracted in methanol and the lyophilized methanol extract was fractionated with different solvents in the order of increasing polarity. The results indicate that ethyl acetate fraction of heartwood has the highest antioxidant capacities, presenting lower EC(50) values particularly in free radical scavenging activity, including DPPH radicals (4.76 ± 0.14 μg/mL), superoxide anions (26.21 ± 0.79 μg/mL), and hydroxyl radicals (33.69 ± 1.42 μg/mL), in direct assay systems. Reducing power was also highest in ethyl acetate fraction of heartwood (EC(50) of 79.05 ± 1.02 μg/mL). As for the chelating power on ferrous ions, leaf extract was more effective than bark and heartwood extracts. Furthermore, the ethyl acetate and acetone fractions of heartwood significantly protected pBR322 supercoiled plasmid DNA against strand scission induced by hydroxyl radicals in a Fenton's reaction mixture. PRACTICAL APPLICATION: The present investigation suggests that the three organs of A. catechu differ significantly in their antioxidant potential as seen in the DPPH radical scavenging assay, reducing power assay, metal ion chelating assay, superoxide radical scavenging assay and hydroxyl radical scavenging assay. Further, our results showed that crude methanol extract and ethyl acetate fraction of heartwood of A. catechu might have a good potential as a source for natural health products due to its antioxidant and DNA protective activities. 相似文献
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目的评定气相色谱法测定食用槟榔中环己基氨基磺酸钠(又名甜蜜素)的不确定度评定方法。方法根据气相色谱法定量测定食用槟榔中甜蜜素含量的测定原理,较全面的考虑整个测定过程的不确定度来源,建立结果不确定度评定的数学模型,并探讨其测定结果不确定度。结果在95%的置信区间下,当槟榔中甜蜜素含量为6.19 g/kg时,其扩展不确定度为0.18 g/kg, k=2。结论槟榔中甜蜜素的检测不确定度主要来源为标准曲线的拟合。 相似文献
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采用传统植物染料红色染材茜草与黄色染材栀子黄,以明矾为媒染剂,在80℃温度条件下,同浴对棉织物进行混合染色,通过调整茜草与栀子黄的比例及改变染液浓度,染得橙系色彩色标形成完整色谱,进而分析了色标的CMYK值曲线变化,归纳了两者混合染色的显色规律.结果表明:茜草的显色效果比栀子黄更易受染液浓度影响;在该色谱中找到待复原的橙系目标色后,即可推得相应的染色条件与染液配比,从而实现传统棉纺织品的橙系色彩复原. 相似文献
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Our work tends to establish Green Energy from Waste concept. Refuses/wastes can be a secondary resource for variety of materials which may find applications in domestic, industrial, medical, electronic and energy devices. We have attempted to produce activated carbon powders from a cheap waste namely biomass of areca leaves. The material has been exploited as catalyst support materials in H2 production through water electrolysis. Catalyst powders of 10% Ni and 1% Pt by weight were supported on the carbon produced from the leaves using NaBH4 reduction of the respective salts. Physical features of the catalyst powders were evaluated through PXRD, FTIR, density, SEM, surface area. Catalytic activity of the biocarbon supported catalyst powders was assessed by LSV & CV. The carbon produced may attract technological importance because carbon source selected is cheap and green. Further the activated carbon may find applications such as electrode materials, adsorbent for color, odor and hazardous pollutants. 相似文献
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Antifungal Activity of Crude Extracts of Coffee and Spent Coffee Ground on Areca Palm Leaf Sheath (Areca catechu) Based Food Packaging 下载免费PDF全文
Athiya Nonthakaew Narumol Matan Tanong Aewsiri Nirundorn Matan 《Packaging Technology and Science》2015,28(7):633-645
This study observed the antifungal activity of crude coffee extract (CCE) and crude spent coffee ground extract (CSCGE) against Aspergillus sp., Aspergillus flavus, Aspergillus niger, Penicillum citrinum, Penicillum chrysogenum and Eurotium amstelodami on the surface of an areca palm leaf sheath (Areca catechu). The agar dilution method was employed to determine the minimal inhibitory concentration (MIC) of the CCE for the first, second and third extractions and CSCGE for the first and second extractions in malt extract agar at concentrations from 50 to 500 μg/ml. A mould test was then performed on durian paste product wrapped with the areca palm leaf sheath treated with the second CSCGE at its MIC. Gas chromatography‐mass spectrometry (GC‐MS) was performed to find the major components of the CCE and CSCGE and to measure the total phenolic content. For the second CSCGE treatment on the areca palm leaf sheath, the following qualities were studied: mould growth, wettability, measurements of hardness and thickness and a Fourier transform infrared spectroscopy scan. It was found that the CCE and CSCGE MICs from the first and second extractions ranged from 100 to 230 μg/ml and from 300 to 460 μg/ml, respectively. In addition, the MICs showed the capability of CCE and CSCGE to provide protection against mould growth on the leaf sheath for at least 21 days in comparison with the control (3 days) during storage at accelerated conditions (25 °C and 100% relative humidity). Shelf life of durian paste product wrapped with areca palm leaf sheath treated with the second CSCGE at 460 μg/ml was extended from 3 days to 21 days under storage condition of 30 °C. Caffeine was the main constituent of CCE (79.69%) and CSCGE (84.92%). Also, the total phenolic content of CCE and CSCGE measured were 0.640 and 0.981 mol ferulic acid 100 g?1, respectively. This study has demonstrated that the first and second CCE and CSCGE were capable of inhibiting mould growth under both in vitro and in vivo tests. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献